Chapter 4: Igneous Rocks and Intrusive Activity, Chapter 5 Volcanoes and Volcanic Hazards, Chapter 6 Weathering and Soils, Chapter 7 Sedimentary Rocks, Chapter 8 Metamorphism and Metamorphic Rocks
Pressure, which also increases with _________, influences the melting temperature of rocks.
depth
Soils
nonrenewable resources
Most often, however, melting is _____ complete.
not.
Pyroclastic flows are also called ______________ _________________. These fiery flows are capable of racing down steep volcanic slopes at speeds that exceed 60 miles per hour.
nuee' ardentes (glowing avalanches)
In times, these quartz grains may become lithified to form the sedimentary rock______
sandstone
metamorphic aureole
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migmatite
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muscovite
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mylonite
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natural gas
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nitrogen cycle
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nonfoliated
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Stromboli is well known for eruptions that eject incandescent blobs of lava that it has been referred to as the __________ of the ______________.
"Lighthouse of the Mediterranean"
Because there are a variety of ways that the products of weathering are transported, deposited, and transformed into solid rock, ____ categories of sedimentary rocks are recognized.
3
Frost wedging
After water works its way into the cracks in rocks, the freezing water enlarges the cracks and angular fragments are eventually produced.
When the head of a superplume reaches the base of the lithosphere, _______________ melting progresses rapidly.
Decompression
This same process can also contribute to crumbling roadways where salt is spread to melt snow and ____in winter.
Ice
Other examples of how unloading occurs:
In deep mines, large rock slabs have been known to explode off the walls of newly cut tunnels.
and the copper ores of _______________
Michigan's Keweenaw Peninsula
Why does rock weather?
Response of Earth materials to a changing environment
Included in this group are gold deposits of the Homestake mine in _________________
South Dakota
secondary enrichment
The concentration of minor amounts of metals that are scattered through unweathered rock into economically valuable concentrations by weathering processes
The mechanisms that generate these mantle-derived magmas are essentially the same as those that create volcanic island arcs.
The most significant difference is that continental crust is much thicker and is composed of rocks having higher silica content than oceanic crust.
As the slab sinks deeper into the mantle, the increase in temperature and pressure drives water and carbon dioxide from the oceanic crust.
These mobile fluids migrate upward and reduce the melting point of hot mantle rock sufficiently to trigger some melting.
Foliated Textures
Various types of foliation exist, depending on the grade of metamorphism and the mineralogy of the parent rock.
basalt porphyritic
When it is porphyritic, basalt commonly contains small light-colored feldspar phenocrysts or green, glassy - appearing olivine grains embedded in a dark groundmass.
Composition
another factor influencing volcanic behavior is the composition
Most magma that erupts at Earth's surface is ___________ in composition and has a temperature of 1000 - 1250 C
basaltic
Near Earth's surface, rock behaves like a -_____ solid
brittle
Pegmatites contain some of the least abundant ______________________.
elements
The shape of sand grains can also help decipher the history of a sandstone. When streams, wind, or waves move sand and other larger sedimentary particles, the ______lose their sharp edges and corners become more rounded as they collide with other particles during transport.
grains
viscosity
magma's mobility
Eventually, all of the ___________ is transformed into a solid mass of interlocking ____________ ________________ that we call an ______________ ____________________.
melt silicate minerals igneous rock
While both of these mechanisms flatten mineral grains, the ____ remains the same
mineralogy 1. solid-state flow 2. pressure solution
Volcanic necks are also called ________________.
plugs
Coal fields are widespread and contain supplies that should last for hundreds of years.
Although coal is plentiful, its recovery and utilization present a number of challenges. Surface mining can turn the countryside into a scarred wasteland if careful and costly reclamation is not carried out to restore the land. Although underground mining does not scar the landscape to the same degree, it presents significant risks to health and safety.
This active zone consists in part of a chain of continental volcanoes that are distributed along the west coast of the _______________.
Americas, including the large cones of the Andes in South America and the Cascade Range of the western United States and Canada.
Rocky shorelines and _____ regions are common settings for this process.
Arid
Extraordinary amounts of lava have been extruded along fissures in a relatively short time. The voluminous accumulations are commonly referred to as __________ _______________ because most have a ________________ __________ and tend to be rather flat and broad.
Basalt plateaus Basaltic composition
Much of the world's copper is extracted from disseminated deposits, included those at Chuquicamata, Chile, and the huge ______________________ Canyon copper mine in Utah
Bingham
It begins when sea sprays from ___ ____ or _____ ______ penetrates crevices and pore spaces in rock.
Breaking waves Salty groundwater
whereas the ____________________________ Complex in South Africa, contains over 70 percent of the world's known reserves of platinum
Bushveld
Eventually the limestone may be exposed at Earth's surface, where chemical weathering will cause the carbon stored in the rock to be released to the atmosphere as ____.
CO2
Mechanical weathering breaks rocks into smaller pieces and this aids _____________ weathering
Chemical
The lead, zinc, and silver ores near __________ _________________________
Coeur d'Alene, Idaho
Earth's most picturesque yet dangerous volcanoes are _________________________ ____________________
Composite volcanoes, also known as stratovolcanoes
The first lava flow came from a fissure that opened just north of the ______________________________________.
Cone, but after a few months, flows began to emerge from the base of the cone.
As hot rock rises, it experiences a decrease in _______________ pressure and undergoes melting without the addition of heat. This process is called decompression melting.
Confining
Volcanism associated with convergent plate boundaries may also develop where slabs of oceanic lithosphere are subducted under continental lithosphere to produce___ __ ___ .
Continental volcanic arc
Although the depth at which mantle plumes originate is a topic of debate, some appear to form deep within Earth, at the ____ ___ boundary.
Core-mantle boundary
Italy's Etna and Stromboli
Display very persistent eruption activity, and molten lava has been observed in their summit craters for decades.
Gneissic texture or banding
During high grade metamorphism, ion migration can result in the segregation of minerals. The dark biotite and amphibole crystals and light silicate minerals (quartz and feldspar) have separated, giving the rock a banded appearance called gneissic texture or gnessic banding. Metamorphic rocks with this texture are called gneiss (pronouced "nice") Although they are foliated, gneisses do not usually split as easily as slates and some schists.
Figure 4.1
During the catastrophic eruption of Vesuvius in A.D. 79, the entire city of Pompeii was completely buried under several meters of pumice and volcanic ash
Because of the severity of the storms, the region came to be called the ___________ _________
Dust STorms , and the period was called the Dirty Thirties
Most of the recent activity on Kilauea has occurred along the flanks of the volcano, in a region called the _____ ____ _______,.
East Rift Zone
In other cases, their importance is related to the physical properties they exhibit.
Examples include minerals such as corundum and garnet, which are used as abrasives.
The process of transporting essentially unaltered magma though 93 miles of solid rock is _____________ and accounts for the scarcity of natural diamonds.
Exceptional
As the overburden is removed, the outer parts of the granitic mass expand more than the rock below and separate from the rock body. Continued weathering eventually causes the slabs to separate and spall off, creating an ____ _____
Exfoliation dome
Rather than build cones, ______________ ____________________ usually emit fluid basaltic lavas that blanket wide areas.
Fissure eruptions
Numerous fissures eruptions have buried the landscape, creating a lava plateau nearly 1 mile thick. Some of the lava remained molten long enough to flow 90 miles from its source. The term _____________ ____________ describe these extrusions. Lava Domes
Flood basalts
It has long been known that when moist soil freeze, they expand or ___ ____, due to the growth of ice lenses.
Frost heave
During the 1930's, large dust plagued the ___ ____.
Great Plains
clastic
Greek means broken rocks that display a clastic texture consists of discrete fragments and particles that are cemented and compacted together
Why do eruptions occur in the interiors of plates?
Hawaii's Kilauea, one of the world's most active volcanoes, is situated thousands of kilometers from the nearest plate boundary, in the middle of the vast Pacific plate.
fluid basaltic magmas tend to generate two types of lava flows known by ________________ names.
Hawaiian names
Thus, rounded grains likely have been airborne or waterborne. The degree of rounding indicates the distance or time involved in the transportation of sediments by currents of air or water.
Highly rounded grains indicate that a great deal of abrasion and hence a great deal of transport has occurred.
The gaseous portion of most magmas makes up ______%
1 to 6 %
Destruction of Pompeii
1. A.D. 79 eruption of Italian volcano we now called Mount Vesuvius 2. entire city of Pompeii near Naples and few thousand of its residents were entombed beneath a layer of volcanic ash and pumice that fell like rain
Example of several young volcanic island arcs border the western Pacific basin, including the 1. 2. 3.
1. Aleutians 2. Tongas 3. Marianas
Examples of shield volcanoes 1. 2. 3.
1. Canary Islands 2. Hawaiian Islands 3. Galapagos 4. Easter islands
Example: Flourite and limestone
1. are part of the steelmaking process, the 2. the abrasives required to make a piece of machinery 3. the fertilizers needed to grow a food crop
Granite
1. best known of all igneous rocks 2. used for tombstones and monuments and building stones 3. found in Barre, Vermont, Mount Airy, NC, St. Cloud, Minnesota 4. coarse-grained rock 5. 10% to 20 % quartz and roughly 50% potassium feldspar 6. quartz appears rounded in shape, glassy, and clear to gray in color. 7. feldspar crystals are generally white, gray, or salmon pink in color, and blocky or rectangular in shape
most gneiss contain lesser amounts of 1. 2. 3.
1. biotite 2. muscovite 3. amphibole
When clay minerals are buried to a depth where temperatures exceed 200 degrees C, they become the minerals 1. 2.
1. chlorite, mica-like mineral formed by the metamorphism of dark iron and magnesium - rich silicate minerals. 2. muscovite mica
To summarize: the weathering of potassium feldspar generates a 1. 2. 3.
1. clay mineral 2. soluble salt 3. silica
Because soil-forming processes operate from the surface downward, variations in 1. 2. 3. 4.
1. composition 2. texture 3. structure 4. color gradually evolve at varying depths
Basic metamorphic environments are: 1. 2. 3. 4.
1. contact or thermal metamorphism 2. hydrothermal metamorphism 3. burial and subduction zone metamorphism 4. regional metamorphism
Other important building materials include
1. cut stone 2. aggregate (sand, gravel, and crushed rock) 3. gypsum for plaster and wallboard 4. clay for tile and bricks 5. cement and aggregates go into the making of concrete, a material is essential to practically all construction
As magma cools and solidifies, these elements combine to form 2 major groups of silicate minerals 1. 2.
1. dark or ferromagnesian silicates = rich in iron and magnesium and comparatively low in silica (olivine, pyroxene, amphibole, and biotite mica are the common dark silicate minerals of Earth's crust 2. light or nonferromagnesian silicates = contain greater amounts of potasium, sodium and calcium rather than iron and magnesium. light silicate minerals including quartz, muscovite mica, and the most abundant mineral group, the feldspars, are richer in silica than the dark silicates
Magma can be generated three ways. 1. 2. 3.
1. decrease in pressure without an increase in temperature can result in decompression melting 2. the introduction of water can lower the melting temperature of hot mantle rock sufficiently to generate magma 3. heating of crustal rocks above their melting temperature produce magma
Describe how lava is emitted from the magma chamber.
1. escaping gases propel it from the magma chamber 2. explosively ejected, producing steam and ash eruptions 3. not all violent; many volcanoes emit quiet outpourings of fluid lava
What has accelerated the rate of erosion?
1. farming 2. logging 3. construction, which remove or disrupt the natural vegetation
why are nonmetallic mineral resources extracted and processed?
1. for the nonmetallic elements they contain 2. physical and chemical properties they contain although these resources have diverse origins, many are sediments or sedimentary rocks
mica schists often contain accessory minerals, some of which are unique to metamorphic rocks. Some common accessory minerals that occur as porphyroblasts include: 1. 2. 3.
1. garnet 2. staurolite 3. andalusite Now the rock is called garnet-mica schist, staurolite-mica schist, or andalusite-mica schist
Granitic (Felsic) igneous rocks
1. granite 2. rhyolite 3. obsidian 4. pumice
It should be pointed out that transported soils form in ___ on parent materials that have been carried from elsewhere and deposited by 1. 2. 3. 4.
1. gravity 2. water 3. wind 4. ice
The agents of metamorphism are 1. 2. 3. 4.
1. heat 2. pressure 3. directional stress 4. chemically active fluids
Why is Earth's interior extremely hot?
1. heat released from the repeated collision of asteroid-size bodies during the formation of our planet 2. energy being continually released by the decay of radioactive elements
Sedimentary rocks
1. information about Earth's history 2. economically important as well 3. associated with important mineral and energy resources
The precipitation of material occurs in two ways 1. 2.
1. inorganic (in = not, organicus = life) 2. organic (life)
Hydrothermal solutions circulating through the seafloor also remove large amounts of metals, such as 1. 2. 3 4. from the newly formed crust
1. iron 2. cobalt 3. nickel 4. silver 5. gold 6. copper
Other granitic laccoliths have since been identified in Utah
1. largest is part of the Pine Valley Mountains located north of St. George, Utah 2. Others are found in the LaSal Mountains near Arches National Park 3. found in Abajo Mountains directly to the north
Volcanoes extrude 1. 2. 3.
1. lava 2. large volumes of gas 3. pyroclastic material: broken rock, lava, bombs, fine ash, and dust
The results are 1. 2. 3. 4.
1. lower productivity 2. poorer crop quality 3. reduced agricultural income 4. ominous future
tropical rain forest
1. millions of acres are cleared for agriculture and logging 2. this results in soil degredation, loss of biodiversity, and climate change
Where does magma come from? 1. 2. 3.
1. most comes from Earth's uppermost mantle 2. greatest quantities are produced at divergent plate boundaries, in association with seafloor spreading, with lesser amounts forming at subduction zones, where oceanic lithosphere descends into the mantle 3. magma can be generated when crustal rocks are heated sufficiently to melt
What are the long term consequences of bauxite mining?
1. occur in environmentally sensitive areas of the tropics 2. mining is preceded by the removal of tropical vegetation 3.thin layer of organic matter is also disturbed 4. when the soil dries out in the hot sun, it becomes bricklike and loses its moisture-retaining qualitites 5. such soil cannot be productively farmed, nor can it support significant forest growth
There are two primary sources of heat within Earth. 1. 2.
1. one is the increasing temperature that occurs as we travel deeper into Earth's interior 2. heat released to the surrounding rocks as a magma body cool
Examples of foliation 1. 2. 3. 4.
1. parallel alignment of platy minerals 2. parallel alignment of flattened mineral grains or pebbles 3. compositional banding in which the separation of dark and light minerals generates a layered appearance 4. rock cleavage where rocks can be easily split into tabular slabs
Soil is the product of the complex interplay of several factors: 1. 2. 3. 4. 5.
1. parent material 2. time 3. climate 4. plants 5. animals 6. topography
Place these phenomena related to soil erosion in the proper sequence
1. rain drop impact 2. sheet erosion 3. rills 4. gullies 5. stream
What are some uses of shale? 1. 2. 3.
1. raw material for pottery, brick, tile, and china 2. shale is mixed with limestone to make Portland cement 3. in the future, one type of shale, called oil shale, may become a valuable energy source
Heat may be transported from the mantle into the shallowest layers of the crust. 1. 2. 3.
1. rising mantle plumes 2. upwelling at mid-ocean ridges 3. magma generated by partial melting of mantle rock at subduction zones
In order of increasing particle size, common detrital sedimentary rocks include: 1. 2. 3.
1. shale 2. sandstone 3. conglomerate or breccia
Characteristic of large caldera-forming eruptions
1. slow upheaval of the floor of the caldera that produce a central elevated region called a resurgent dome 2. Unlike calderas associated with shield volcanoes or composite cones, Yellowstone-type depressions are so large and poorly defined that many remained undetected until high -quality aerial and satellite images became available.
Although we are using greater quantities of energy from alternative sources such as 1. 2. 3. 4. the U.S. Department of Energy projects that fossil fuels will continue to be very important for decades to come, providing more than 75% of U.S. energy in the year 2035.
1. solar 2. wind 3. geothermal 4. hydroelectric
The preceding discussion has shown that the origin and history of sandstone can be deduced by examining the 1. 2, 3,
1. sorting 2. roundness 3. mineral composition of its constituent grains Knowing this information allows us to infer that a well-sorted, quartz - rich sandstone consisting of highly rounded grains must be the result of a great deal of transport.
What caused the Dust Bowl?
1. strongest winds 2. expansion of agriculture during an unusually wet period that set the stage for the disastrous period of soil erosion 3. mechanization allowed the rapid transformation of the grass-covered prairies of this semiarid region into farms
What two climate factors are crucial to rate of rock weathering? 1. 2.
1. temperature 2. moisture
Climate is considered to be the most influential control of soil formation. Name the elements that exert the strongest impact. 1. 2.
1. temperature 2. precipitation
Very angular grains, on the other hand, imply 2 things: 1. 2.
1. that the material were tranported only a short distance before they were deposited 2. some other medium may have transported them ex: when glaciers move sediment, the particles are usually made more irregular by the crushing and grinding action of the ice
Name the 3 factors that influence the textures of igneous rocks. 1. 2. 3. What is the dominant factor?____
1. the rate at which molten rock cools 2. the amount of silica present 3. the amount of dissolved gases in the magma rate of cooling tends to be the dominant factor
The nature of the parent material influences soils in two ways. 1. 2.
1. the type of parent material will affect the rate of weathering and thus the rate of soil formation Because unconsolidated deposits are already partly weathered, soil development on such material will likely progress more rapidly than when bedrock is the parent material 2. The chemical makeup of the parent material will affect the soil's fertility. This influences the character of the natural vegetation the soil can support.
Thus, as with other sedimentary rocks, conglomerates and breccias contain clues to their history. 1. 2.
1. their particle sizes reveal the strength of the currents that transported them 2. degree of rounding indicates how far the particles traveled 3. the fragments within a sample identify the source rocks that supplied them.
Mount Saint Helens
1. trees within a 400 km area lay intertwined and flattened 2. mudflows carried ash, trees, and water and saturated rocks debris 29 kilometers down the Toutle River 3. 59 dead 4. some suffocated from cloud of ash and gases 5.
Give examples of structures consisting of igneous rocks.
1. volcanoes ex: Mt. Rainier 2. Sierra Nevada 3. Black Hills 4. high peaks of Adirondacks 5. stones for monuments and household countertops
potassium feldspar
In addition to formation of clay minerals, some silica is removed from the feldspar structure and carried away by groundwater. This dissolved silica precipitates to produce nodules of chert or flint or it fills in the pore spaces between sediment grains, or it is carried to the ocean, where microscopic animals remove it from the water to build hard silica shells
Overview of these processes provides a useful perspective
1. weathering begins the process -physical and chemical disintegration of preexisting igneous, metamorphic, and sedimentary rocks -generates a variety of products, including various solid particles and ions in solution; these are the raw materials for sedimentary rock 2. soluble constituents are carried away by runoff and groundwater. -solid particles are frequently moved downslope by gravity, a process termed mass wasting before running water, groundwater, wind, and glacial ice remove them -transportation moves these materials from the sites where they originate to locations where they accumulate -the transport of sediments is usually intermittent. example: during a flood, a rapidly moving river moves large quantities of sand and gravel. as the floodwaters recede, particles are deposited, only to be moved again by a subsequent flood
In June 1944, a clinker aa flow ______________ meters thick moved over much of the village of ________________________________, leaving only the church steeple exposed.
10 meters or 30 feet thick San Juan Parangaricutiro
These flows destroyed nearly ____homes, covered a major roadway, and eventually reached the ______.
100 rural homes sea
Temperature increases from surface conditions to about _____C or 1800 F is displayed along the top, and pressure is shown along the vertical axis.
1000 C
Per capita consumption of nonfuel resources in the United States is nearly ___ metric tons, of which more than ___ percent are nonmetallics
11 94 %
How many orders?
12
In the first day, the cone grew to __________ feet and by the fifth day it was more than 330 feet high.
130
______% carbon dioxide
15%
The longest and largest rift eruption ever recorded on Kilauea began in ______ and continues to this day.
1983
Basaltic magma crystallizes over a range of at least ___________ of cooling about 1200 to 1000C
200
Minerals are composed of a mixture of minerals, and therefore, tend to melt over a temperature range of at least ________________ C
200
Mt. Etna in Italy has more than _____ secondary vents, some of which have built parasitic cones.
200
Paricutin is located about ______ miles west of Mexico City.
200 miles
As a result of this short life span, cinder cones are small, usually between 100 feet and 1000 feet. A few rare examples exceed ______________ feet in height.
2100.
Intermediate rocks contain at least _______ % dark silicate minerals, mainly 1. 2. 3. 4.
25% 1. amphibole 2. pyroxene 3. biotite mica 4. plagioclase feldspar
Nearly all of St. Pierre's __________________ inhabitants were killed. Only ___person on the outskirts of town --a prisoner protected in a dungeon and a few people on _______________ in the harbor were spared.
28,000 1 ships
1902 eruption of Mount Pelee' killed
28,000 people wiping out the entire population of nearby city of Saint Pierre
salt dome
In the gulf coastal plain region of the united states, important accumulations of oil occur in association with salt domes. Such areas have thick accumulations of sedimentary strata, including layers of rock salt. salt concurring at great depths have been forced to rise in columns by the pressure of overlying beds. these rising salt columns gradually deform the overlying strata. Because oil and gas migrate to the highest level possible, they accumulate in the upturned sandstone beds adjacent to the salt column
Shale, Mudstone, or Siltstone
It is common to apply the term shale to all fine-grained sedimentary rock, especially in a nontechnical context
In summary 1. Carbon moves among all ____ of Earth's major spheres 2. it is essential to every living thing in the biosphere. 3. In the atmosphere, carbon dioxide is an important greenhouse gas. 4. In the hydrosphere, carbon dioxide is dissolved in lakes, rivers, and the ocean. 5. In the geosphere, carbon is contained in carbonate sediments and sedimentary rocks and is stored as organic matter dispersed through sedimentary rocks and as deposits of coal and petroleum.
4
__________% nitrogen
5%
More than ______ eruptions have been witnessed here since 1823
50
Magmas that produce mafic rocks such as basalt contain _____ silica
50 %
Intermediate rock types, like andesite and diorite produce magma with ____ silica
60 %
The greatest volume of magma (____%) is produced along the oceanic ridge system in association with seafloor spreading.
60 %
Together, petroleum and natural gas provide more than __% of the energy consumed in the United States.
60%
Magmas that produce felsic: granite and its extrusive equivalent, rhyolite contains more than _____ silica
70 %
_______%water vapor
70%
After __________________ years of intermittent pyroclastic explosions and nearly continuous discharge of lava from its vents at its base, the activity ceased almost as quickly as it had begun.
9
500 million people from ___________ and ____________ to Italy and oregon live near active volcanoes. They face a number of volcanic hazards, such as pyroclastic flows, lahars, lava flows, falling volcanic ash, and volcanic gases.
Japan and Indonesia
bombs 6 meters and weighing 200 tons were blows 600 meters from the vent during an eruption of the ____ ___ ____
Japanese volcano Asama
Eruptions that involve very fluid basaltic lavas, such as the eruptions of _____________-- on Hawaii's Big Island, are often triggered by the arrival of a new batch of molten rock into a near - surface magma chamber.
Kilauea
Some magmas become enriched in iron or copper. At _________________, Sweden, magma composed of over 60 percent magnetite solidified to produce one of the largest iron deposits in the world.
Kirava, Sweden
Composite cones are ______________, nearly symmetrical structures consisting of alternating layers of explosively erupted ___________________ and ______________ interbedded with lava flows.
Large Cinders and ash
As the thick lava is squeezed out of a vent, it often produces a dome-shaped mass called a ___ __.
Lava dome
burial metamorphism
Low grade metamorphic conditions may be reached within the deepest layers. confining pressure and heat drive the recrystallization of the constituent minerals, changing the texture and/or mineralogy of the rock WITHOUT deformation.
It is thought that most intraplate volcanism occurs where a mass of hotter than normal mantle material called a ___________ _____
Mantle plume assends toward the surface.
After sufficient quantity of the rock has melted, blobs of buoyant magma slowly __________ __________.
Migrate upward.
layers of chromite, interbedded with other heavy minerals, are mined at ___________________ Stillwater Complex,
Montana's Sillwater Complex
Equivalent source of diamonds in US is located near
Murfreesboro, Arkansas is exhausted and serves as tourist attraction
Feldspar masses the sizes of houses have been quarried from a pegmatite in ___ Feldspar is used in the production of _____________
North Carolina ceramics
Some shield volcanoes form on continental crust 1. 2.
Nyamuragira, Africa most active volcano Newberry Volcano, Oregon
Over time, the cooler outer layer of the dome may start to crumble, producing relatively small pyroclastic flows consisting of dense blocks of lava.
Occasionally, the rapid removal of the outer layer causes a significant decrease in pressure on the hot gaseous magma in the interior of the dome.
Giganic hexagonal crystals of muscovite measuring a few meters across have been found in ____ Muscovite is used for _________________ insulation and _________________
Ontario, Canada electrical insulation and glitter
The Ring of fire, a belt of explosive volcanoes, surrounds the ___ basin.
Pacific
Most are located in a relatively narrow zone that rims the Pacific Ocean, called the ___ _____ ___.
Ring of Fire
These plumes of solid yet mobile rock _______toward the surface in a manner similar to the blobs that form within a lava lamp.
Rise
Although the main pyroclastic flow was largely confined to the valley of ___________________ Blanche, a low-density fiery __________________ spread south of the river and quickly engulfed the entire city.
Riviere Blanche surge
As this water evaporates, ___ crystals form. As these crystals gradually grow larger, they weaken the rock by pushing apart the surrounding grains or enlarging tiny cracks.
Salt
Another expansive force that can split rocks is created by the growth of ___ ____.
Salt crystals
When a rock undergoes mechanical weathering, it is broken into ____ and ____ pieces, each retaining the characteristics of the original material.
Smaller and smaller
The coarse particles in a conglomerate may reflect the action of energetic mountain streams or result from strong wave activity along a rapidly eroding coast.
Some glacial and landslide deposits also contain plentiful gravel
calderas
Some volcanoes have very large circular depressions called _____ that have diameters greater than .6 miles and in some cases exceed 30 miles
Poorly drained and waterlogged soils found in bottom-lands have a much different character.
Such soils are thick and dark. The dark color results from the large quantity of organic matter that accumulates because saturated conditions retard the decay of vegetation.
Breaking a rock into smaller pieces increases the ______________ __________available for chemical attack.
Surface area
By breaking rocks into smaller pieces, mechanical weathering increases the amount of ____ ____ available for chemical weathering.
Surface area
The capital city, Plymouth, was destroyed and ___________ of the population that evacuated.
Two-thirds
Plant roots in search of nutrients and water grow into fractures, and as the roots grow, they ____ apart the rock
Wedge
clearing of rain forest
accelerates soil erosion when vegetation si there, roots anchor the soil and leaves and branches provide a canopy that protects the ground by deflecting the full force of the frequent heavy rains when the protective vegetation is gone, soil erosion increases
Thin blanket of
air
bituminous coal is metamorphosed into
anthracite, a very hard, shiny black metamorphic rock anthracite is a clean burning fuel, only a relatively small amount is mined. anthracite is not widespread and is more difficult and expensive to extract than the flat-lying layers of bituminous coal
For two weeks prior to the first eruption, numerous Earth tremors caused ___________________ in the nearby village of _____________.
apprehension Paricutin
Cinder cones
are built from ejected fragments that begin to harden in flight to produce the vesicular rock scoria
The gas-laden magmas that migrate through pipes travel rapidly enough to undergo minimal alteration during their _______.
ascent
When magmas with intermediate (andesitic) or felsic (rhyolitic) compositions erupt explosively, they emit ______________ and the vesicular rock ________________.
ash pumice
The pyroclastic fragments range in size from fine ________ to _________________ that may exceed 3 meters in diameter.
ash to bombs
Andesitic magmas can also form when rising basaltic magmas ______________________ crustal rocks that tend to be ___________ rich.
assimilate silica
Eruption colums can rise 25 miles into the ________________.
atmosphere
Vast majority of lava of Earth is _________ in composition. 90%
basaltic
The hot __________________ magma may heat the overlying crustal rocks sufficiently to generate a secondary, silica - rich magma. If these low-density silica rich magmas reach the surface, they tend to produce ___________________ eruptions that we associate with convergent boundaries.
basaltic explosive
How can we detect this event?
because the summit of the volcano begins to inflate and rise months or even years before an eruption
Why are shales considered weak?
because they are poorly cemented and therefore not well lithified
Parent material can either be the overlying ___ or a layer of ____ deposits.
bedrock unconsolidated deposits
One product of this chemical weathering of solid rock is the soluble _____________ ion
bicarbonate ion, which is carried by groundwater and streams to the ocean.
Like coal, petroleum and natural gas are ___ ___ derived from the remains of organisms. However, the environments in which they form are different as are the organisms.
biological products
The parent rocks of most marbles contain impurities that color the stone Thus marble can be pink, gray, green or ___ and may contain accessory minerals such as chlorite, mica, garnet, and wollastonite
black
These hot, metal-rich fluids eventually rise along fractures and gush from the seafloor at temperatures of about 360 F, generating particle filled clouds called ___ ___.
black smokers
particles larger than 64 millimeters in diameter are called ______________ when they are made of hardened lava
blocks
Melting of these _______________ , a process called ______________________________, changes the overall composition of the magma body.
blocks assimilation
Each drop acts like a tiny __, blasting movable soil particles out of their positions in the soil mass. Then, water flowing across the surface carries away the dislodged soil particles. Because the soil is moved by thin sheets of water, this process is termed ___ ____.
bomb sheet erosion
Because large particles abrade and become rounded very rapidly during transport, the pebbles and cobbles in a _____indicate that they did not travel far from their source before they deposited.
breccia
As magma rises, the confining pressure is reduced, causing the dissolved gases to separate from the melt to form tiny __________.
bubbles
How are detrital sedimentary rocks distinguished?
by particle size
Most common cements are 1. 2. 3.
calcite = will effervesce with dilute HCl silica= hardest cement, produces hardest sedimentary rocks iron oxide= an orange or dark-red color indicates this
Further cooling generates _____________________ rich plagiochase feldspar as as well _________________.
calcium - rich pyroxene
Water - dewelling organisms extract this dissolved material to produce hard parts of ____________ __________.
calcium carbonate.
gypsum
calcium sulfate CaSO4 2H20 main ingredient in rock gypsum basic ingredient in plaster of Paris used in wallboard and interior plaster
Calderas
caldaria = cooking pot large steep-sided depressins with diameters that exceed .6 miles and have a circular form those less than 1 kilometer across are called collapse pits or craters
A _______________________ usually forms when the roof of solid rock above a magma chamber collapses.
caldera
Another feature to many active shield volcanoes is a large , steep - walled ________________________, that occupies the summit.
caldera
Soils
can be improved through fertilization and irrigation but can be destroyed through careless activities
Diamonds are thought to originate at depths of nearly 200 km, where the confining pressure is great enough to generate this high-pressure form of
carbon
As is the case with other fossil fuels are burned, the combusion of coal produces
carbon dioxide
The injection of a fresh supply of hot molten rock heats and remobilizes the semi-fluid magma ________________.
chamber
In the most extreme environments, even the highest-grade metamorphic rocks undergo ____.
change
during the crystallization process, the composition of the remaining liquid of the magma also continually ____________________.
changes
Natural rates of erosion vary greatly from one place to another and depend on soil ________ as well as factors such as ___, ____, and type of vegetation.
characteristics climate slope type of vegetation
The types of and abundance of organisms present have a strong influence on the physical and ____ properties of a soil.
chemical
Many rock outcrops have a rounded appearance. This occurs because ______ weathering works inward from exposed surfaces. Fig. 6.10 shows how angular masses of jointed rocks change through time. This process is called ____________ _____________
chemical spheroidal weathering
Lesser amounts of ______
chlorine, hydrogen and argon
An idealized transition in mineralogy that results from the regional metamorphism of shale is shown in figure 8.25 First new minerals to form as shale changes to slate is _____
chlorite
The mineral ____ begins to form when temperatures are relatively low, less than 400 F. Thus rocks that contain chlorite (usually slates) are ___ ___.
chlorite low-grade
This process begins when compressional stress begins to deform rock units, producing broad folds. With further deformation, the clay minerals in shale, which initially aligned roughly parallel to the bedding surfaces, begin to recrystallize into tiny flakes of _____ and _____.
chlorite and mica
This type of magmatic segregation serves to concentrate selected metals, producing major deposits of ________________ ore of chromium, magnetite and ________________.
chromite magnetite and platinum
Some chemical sedimentary rocks exhibit this __ texture also.
clastic ex: coquina, the limestone composed of shells and shell fragments, is clastic ex: oolitic limestone
Other important factors examined here include the roles of rock characteristics and _____.
climate
Some of these eruptions may have an impact on Earth's ________________.
climate
Dolostone
closely related to limestone is dolostone, a rock composed of the calcium - magnesium carbonate mineral
Air pollution in another significant problem associated with the burning of ___.
coal
In addition to oil and natural gas, ____ is commonly called a fossil fuel.
coal
The third category is organic sedimentary rock, which form from the carbon-rich remains of organisms. ex: _____ The black combustible rock consists of organic carbon from the remains of plants that died and accumulated on the floor of a swamp. The bits and pieces of undecayed plant material that constitute the "sediments" in coal are quite unlike the weathering products that up detrital and chemical sedimentary rocks
coal
In some cases, a very dense form of quartz called ________ and minute ________________ are found.
coesite diamonds
A conical shape with a steep summit area and gradually sloping flanks is typical of most large __________________________ cones.
composite
When a volcano becomes inactive, congealed magma often becomes preserved in the feeding _______________ of the volcano as a crudely cylindrical mass.
conduit
Most volcanic eruptions are fed lava through __________ that connect shallow magma chambers to vents located at the surface.
conduits
Silicate minerals make up most of Earth's ___ and that these minerals are composed of only ___ elements.
crust 8
Heat from the hot magma is often sufficient to partially melt the overlying _____________ rocks, generating a less dense, silica rich magma, which continues the journey toward's Earth's surface.
crustal
rain forest soils
develop under conditions of high temperatures and rainfall, they are severly leached leaching removes soluble calcium carbonate removes silica insoluble oxides of iron and aluminum become concentrated in the soil iron oxide gives soil its distinctive color bacterial action is high, so there is little humus leaching destroys fertility because most plant nutrients are removed by the large volume of downward-percolating water soil contains few available nutrients
Another economically important mineral with an igneous origin is ________________.
diamond
These ________________ are clearly related to variations in the degree of ___________________ experienced in each metamorphic zone.
differences metamorphism
Slope orientation
direction a slope is facing, is another consider the difference in the amount of solar radiation received causes differences in soil temperature and moisture, which in turn influence the nature of the vegetation and the character of the soil
Regional and subduction metamorphism involve ____ stress.
directional
Another important type of accumulation generated by hydrothermal activity is called a ______________________________ deposit.
disseminated deposit
carbon dioxide
dissolved in water forms carbonic acid, the same weak acid produced when soft drinks are carbonated
Marble headstone composed of calcite or calcium carbonate, readily ___________________ in a weakly ___________________ solution.
dissolves acidic
In some metamorphic environments, hot fluids transport mineral matter over considerable ___. This occurs, when hot, iron-rich fluids are expelled from a magma body as it cools and solidifies.
distances
Much of Earth's volcanic activity occurs along oceanic ridges or _______________- boundaries
divergent
This process is responsible for generating magma along -________plate boundaries (oceanic ridges) where plates are rifting apart.
divergent
Coal, petroleum, and natural gas are the primary fuels of our modern industrial _______
economy.
Eventually, some of the fuels are recovered and burned to generate ____ and ___ our transportation system
electricity fuel
petrified wood
example of chert is chert made when silica-rich material such as volcanic ash buries trees. groundwater rich in silica from the ash penetrates the wood as the dissolved silica precipitates, it gradually replaces the wood shape and structures such as growth rings are preserved
Composite cones are noted for generating _______________________ eruptions that eject huge pyroclastic material.
explosive
Gases also give magmas their ________________ character.
explosive
Different parts of each layer possess a distinctive set of characteristics that reflect the conditions in a particular environment. To describe such sets of sediments the term ____ is used.
facies
Steepness of slop is an important factor in soil erosion. The steeper the slope, the ____ the water runs off and the greater the erosion.
faster
When granite weathers, the ____ crystals dull and slowly turn to clay, releasing the once interlocked quartz grains, which still retain their fresh, glassy appearance.
feldspar
other common minerals in detrital rocks are 1. 2.
feldspars and micas Because chemical weathering rapidly transforms these minerals into new substances, their presence in sedimentary rocks indicates that erosion and deposition were fast enough to preserve some of the primary minerals from the source rock before they could be decomposed
partial melting of intermediate rocks yields __________________ or ____________ magmas
felsic or granitic
These materials are important because they are sources of specific chemical elements or compounds. Such minerals are used in the manufacture of chemicals and the productin of
fertilizers
Through the study of metamorphic rocks in their natural settings called ____ ____ and through the experimental studies, researchers have learned that certain minerals, such as those in figure 8.25 are good indicators of the metamorphic environment in which they formed.
field studies
Although most dislodged soil particles move only a short distance during each rainfall, substantial quantities eventually leave the ___ and make their way down slope to a ____.
fields stream
As large slabs of rock move in opposite directions, the minerals in the fault zone between them tend to form elongated grains that give the rock a _______ and/or lineated appearance. Rocks formed in these zones of intense ductile deformation are termed _______________________.
foliated mylonite mylo = a mill ite = a stone
A rock that exhibits a preferred orientation of its mineral constituents is said to possess ______.
foliation
Metamorphic rocks are classified by the type of ___ exhibited and, to a lesser extent, the chemical composition of the parent rock.
foliation
Uses of soils
food fiber other basic materials
Every time it rains, raindrops strike the land with surprising ___.
force
Volcanic activity frequently begins when a fissue (crack) develops in Earth's crust, as magma moves ____________ up through a fissue, its path is usually localized into a circular _______________ that terminates at a surface opening called a ________________.
forcefully conduit vent
Detrital rocks
form from the solid products of weathering
pillow lavas
form on the ocean floor and have elongated shapes, resembling toothpaste coming out of a tube
Kilauea's caldera
formed by gradual subsidence as magma slowly drained laterally from the underlying magma chamber, leaving the summit unsupported
Under the right conditions, some of these carbon - rich deposits are converted to _____ ______.
fossil fuels such as coal, petroleum, or natural gas
At the other extreme, highly viscous magmas expel particles of ____________________ lava and gases at supersonic speeds, creating buoyant plumes called _________________ _______________.
fragmented lava eruption columns
Many of these vents emit only gases and are called _______________.
fumaroles
________________ is the intrusive equivalent of basalt. Intrusive means coarse or large grained. Like basalt, it tends to be dark green to black in color and composed primarily of ___________________ and ______________- ______________ plagioclase feldspar. Gabbro is uncommon in the continental crust, it makes up a significant percentage of ________________ __________________
gabbro pyroxene calcium - rich oceanic crust
During recrystallization, certain metamorphic minerals, such as ____, tend to develop a small number of very large crystals.
garnet
Near the magma body, higher-temperature minerals such as _____may form, whereas farther away, low grade minerals such as chlorite are formed
garnet
Under more extreme conditions , metamorphic rocks may contain ______ and ____ crystals
garnet staurolite
Like schists, gnesses may also include larger crystals of accessory minerals such as _____ and _______.
garnet and staurolite
Then, on February 20, sulfurous _________ began billowing from a small depression that had been in the cornfield for as long as local residents could remember.
gases
When fluid basaltic magma erupt, the pressurized _____________ readily escape.
gases
Hawaii's Kilauea Volcano
generated relatively quiet outpourings of fluid lavas gentle eruptions are not without some fiery displays. fountains of incandescent lava sprays hundreds of meters in the air most recent active phase began in 1983 180 homes destroyed national park visitor center destroyed
Soil erosion by water also occurs on _____ slopes.
gentle
Soil forms where the 1. 2. 3. 4. meet
geosphere atmosphere hydrosphere biosphere
As shown in figure 4.17, when a typical geothermal gradient is compared to the melting point curve for the mantle rock peridotite, the temperature at which peridotite melts is higher than the _____________________ gradient. Thus, under normal conditions, the mantle is _____________________. However, tectonic processes trigger melting through various processes, including ________________ the melting point (temperature) of mantle rock.
geothermal solid reducing
Obsidian flows, typically few hundred feet thick, provide evidence that rapid cooling is not the only mechanism that produces a ____________________ texture. Magmas with a high ___________ content tend to form long, chain-like structures (polymers) before crystallization is complete. These structures, in turn, impede ionic transport and increase the magma's viscosity. _______________ is a measure of a fluid's resistance to flow.
glassy silica viscosity
Some volcanic structures that appear to be somewhat randomly distributed around the __.
globe
Gneiss represents the highest-grade metamorphic rock in the sequence of shale, slate, phylolite, schist, and ____
gneiss
Under more intense conditions, a _____ texture that exhibits layers of ______ and _____ minerals may develop.
gneistic texture dark and light
It varies from low grade to high ____.
grade
One conservation method in which crops are planted parallel to the contours of the slope. This pattern reduces soil loss by slowing runoff. Strips of ___________________ or cover crops such as hay slow runoff even more and act to promote water _______________________ and sediment.
grass infiltration
Pyroclastic flows are propelled by the force of _______________________- and tend to move in a manner similar to snow avalanches
gravity
Still deeper cuts in the soil, known as _____are created as rills enlarge.
gullies
aa
have surfaces of rough, jagged blocks with dangerously sharp edges and spiny projections aa lavas cannot change to pahoehoe
The most important factor driving metamorphism is ____ because it provides the energy needed to drive the chemical reactions that result in the recrystallization of existing minerals.
heat
Most gneisses are generated through ____ grade metamorphism of shale
high
high grade
high temperatures and pressures
formation of lignite and bituminous coal
higher temperatures bring about chemical reactions within the plant material and yield water and organic gases (volatiles) water and volatiles are pressed out and the proportion of fixed carbon increases the greater the carbon content, the greater the coal's energy ranking as a fuel lignite turns into bituminous coal
3. Yellowstone - Type Calderas
historic and destructive eruptions such as Mount St. Helens and Vesuvius pale in comparison what happened 630,000 years ago in the region now occupied by Yellowstone National Park 240 cubic miles of pyroclastic material erupted. catastrophic eruption sent showers of ash as far as the Gulf of Mexico and resulted in the formation of a caldera (43 miles across) vestiges of this event are the many hot springs and geysers in the Yellowstone region
In 1991, a hot ash cloud from Japan's Unzen Volcano engulfed and burned hundreds of ______________ and moved cars ___________________________ feet.
homes 250 feet
These vertical differences, which usually become more pronounced as time passes, divide the soil into zones or layers known as ______.
horizons
Sometimes sediments do not accumulate in horizontal beds. When a bed of sedimentary rock is examined, we see layers within it that are inclined to the _________________. This is called ____ ____, and it is most characteristic of sand dunes, river deltas, and certain stream channel deposits
horizontal cross-bedding
Along convergent plate boundaries, the greatest differential stress is directed ____ in the direction of plate motion. Consequently, in these settings, the crust is greatly shortened (horizontally) and thickened (vertically) resulting in ____ topography.
horizontally mountainous
over the next 3 years, the general eruptive patterns consisted of short periods __________ to ______________ when fountains of gas-rich lava sprayed skyward.
hours to days
These large volume eruptions account for the majority of _________________ _________________
human fatalities
When rock has been blasted in search of minerals or for road construction, the impact of ____is particularly noticeable.
humans
About one-half of the total volume of good quality surface soil is a mixture of disintegrated and decomposed rock (mineral matter) and _____ , the decayed remains of animal and plant life (organic matter).
humus
The end product is ___, a material that no longer resembles the plants and animals from which it is formed.
humus
Among the best known and most important ore deposits are those generated from hot, iron-rich fluids called _______________________ (hot-water) solutions.
hydrothermal
Many of the most productive deposits of gold, silver, and mercury occur as ________________________ vein deposits
hydrothermal
If complete melting occurs, the rock has entered the realm of _____________ activity.
igneous
Most pegmatites are located within large ______________________ masses or as dikes or veins that cut into the host rock that surrounds the magma chamber.
igneous
gold, silver, copper, mercury, lead, platinum, and nickel are produced by ___________________- processes.
igneous
What two types of parent rocks make up most of Earth's crust and mantle?
igneous and metamorphic rocks
magma is completely or partly molten rock, which when cooled solidifies to form ________________ ______________ composed of __________minerals.
igneous rock silicate minerals
Fig. 4.2
igneous rock composed of interlocking crystals (picture of a granite rock)
laccoliths
igneous rock forcibly injected between sedimentary strata, so as to arch the beds above while leaving the beds relatively flat.
most of the solid Earth consists of 1. 2.
igneous rocks metamorphic rocks
Sedimentary rocks
illustrate the portion of the rock cycle that occurs near Earth's surface--the part that pertains to sediments and sedimentary rocks
A horizon
image
Bowen Reaction series
image
C horizon
image
Crater Lake, Oregon
image
Dust Bowl
image
E horizon
image
Granite
image
Half dome in Yosemite National Park
image
Kilauea caldera
image
Mount Pelee'
image
Mt. Etna in Italy
image
O horizon
image
Plants and Animals in soil formation
image
Stone Mountain, Georgia
image
The Destruction of Pompeii
image
White Chalk Cliffs
image
Wizard Island
image
Yellowstone - type calderas
image
acid rain
image
andesite
image
biotite
image
bituminous coal
image
blocks volcano
image
bombs in volcano
image
coal
image
coesite
image
cross bedding
image
dark ferromagnesian silicates
image
detrital sedimentary rock
image
fissility
image
flint
image
foliation
image
fumaroles
image
garnet
image
geysers
image
glassy texture
image
gneiss
image
good drainage soil
image
gullies
image
hornfels
image
hot springs
image
humus
image
impact metamorphism
image
joints in rocks
image
leaching
image
quartz (SiO2) sandstone
image is the parent of quartzite
arkose
image when sandstone contains appreciable quantities of feldspar (25% or more) also contains quartz and bits of mica mineral composition of arkose indicates that the grains were derived from granitic source rocks particles are poorly sorted and angular, which means short distance transport, mineral chemical weathering in a relatively dry climate and rapid deposition and burial
coast of Wales
image 7.1
Taj Mahal
image of building made of marble
carbon organic compounds
image of glucose is the building block of life, as it readily combines with hydrocarbons and oxygen to form the fundamental organic compounds that compose living things.
rust
image of iron oxide
Lincoln Memorial
image of marble building
All magma contain some water vapor and other gases that are kept in solution by the ___________________________ pressure of the overlying rock.
immense
Many of the differences exist because the length and steepness of slopes have a significant _______________on the amount of erosion and the water content of soil.
impact
Consequently, the chemical makeup of an igneous rock can be ____________ directly from the _____________ content.
inferred silica
Accumulation of plant remains
initial stage in coal formation is the accumulation of large quantities of plant remains must have a swamp environment plants are attacked by bacteria and partly decompose the organic material and liberate the oxygen and hydrogen as these elements escape, carbon gradually increases bacteria cannot finish decomposing because their growth is impeded by acids liberated by plants
fig. 4.3
intrusive versus extrusive rocks smart figure (listen to it)
Some gneisses will split along the layers of platy minerals, but most break in
irregular fashion
diagenesis
is a collective term for all the chemical, physical, and biological changes that take place after sediments are deposits and during and after lithification dia = change genesis = origin
Soil
is a combination of mineral and organic matter, water, and air--the portion of the regolith that supports the growth of plants
weathering
is a key process in the formation of soil
quartz
is abundant because it is extremely durable and very resistant to chemical weathering when igneous rocks such as granite are attacked by weathering processes, individual quartz grains are freed
C horizon
is characterized by partially altered parent material whereas O, A, E, and B horizons bear little resemblance to the parent material, it is easily identifiable in the C horizon. Although this material is undergoing changes that will eventually transform it into soil, it has not yet crossed the threshold that separates regolith from soil
soil
is dynamic and sensitive to almost every aspect of its surroundings
Coastal batholith of Peru
is even thinner essentially a flat slab with an average thickness of only 2 to 3 kilometer
limestone
is made from calcite
Coal
is made of organic matter end product of large amounts of plant material, buried for millions of years
Soil
is material that develops in response to complex environmental interactions among different parts of the Earth system.
chert
is silica rich
Diorite
is the intrusive equivalent of andesite. coarse grained rock that looks like gray granite.
quartz
is the main mineral in most sandstones such rock is often called quartz sandstone
water
is the most important agent of chemical weathering
scoria
is the name applied to vesicular ejecta that is a product of basaltic magma These black to reddish brown fragments are generally found in the size range of lapilli and resemble cinders and clinkers produced by furnaces used to smelt iron.
metamorphism
is the transformation of one rock type into another rock type
Why is carbon dioxide important?
it is a greenhouse gas, which means it is an efficient absorber of energy emitted by Earth and thus influences the heating of the atmosphere.
The loss of fertile topsoil may not be obvious to the untrained eye,
it is a significant and growing problem as human activities expand and disturb more and more of Earth's surface
Soil erosion is a natural process; ___
it is part of the constant recycling of Earth materials that we call the rock cycle.
Sediment has two principle sources 1. 2.
it may be an accumulation of material that originates and is transported as solid particles derived from both mechanical and chemical weathering deposits of this type are termed detrital and the sedimentary rocks that they form are called detrital sedimentary rock
Fractures produced by these activities generally form a definite pattern and are called ____.
joints
Many physical features, such as ______ can be important because they influence the ability of water to penetrate rock
joints
In addition to violent eruptions, large composite cones may generate a type of fluid mudflow referred to by its Indonesian name, ________________.
lahar
As silt and clay accumulate, they tend to form thin layers, which are commonly referred to as ____.
laminae lamin = thin sheet
Why did erosion occur at slower rate in the past?
land surface was covered and protected by trees, shrubs, grasses, and other plants
In continental settings, the density of crustal rocks is ____________- than that of the ascending material, causing the __________ to pond at the crust-mantle boundary.
less magma
When the partially melted rock cools the ____ bands will be composed of _____ or ____-appearing components, while the dark bands will consist of unmelted ______ material.
light igneous or igneous -appearing metamorphic
Igneous rocks and the magmas from which they form can be divided into broad groups according to their proportions of ______ and -_________ minerals.
light and dark
Because marble and the common sedimentary rock limestone have the same mineralogy (calcite), it seems reasonable to conclude that ____ is the parent rock of marble.
limestone
crater
located at the summit of most volcanic cones is a somewhat funnel-shaped depression
most nutrients that support the rain forest are
locked up in the trees themselves as vegetaion dies and decomposes, the roots of the rain forest trees quickly absorb the nutrients before they are leached from the soil when trees are removed for farming or for timber, most of the nutrients are removed as well what remains is a soil that contains little to nourish planted crops
Cinder cones are composed mostly of ______ scoria fragments, some produce extensive lava fields.
loose
Because slate typically forms during the ___ - grade metamorphism of shale, evidence of the original sedimentary bedding planes is often preserved.
low
Basaltic magmas are _____in silica and are generally more ______________. Basaltic magmas also erupt at higher temperatures than granitic magmas --usually at temperatures between _______________ and _______________.
low fluid 1050 and 1250 Celsius or 1920F and 2280F
In addition to textural changes, we encounter corresponding changes in mineralogy as we shift from regions of ___-grade metamorphism to regions of ___grade metamorphism.
low high
Silica content ranges from a ___________ of about 40 percent in _____________ rocks to a high of more than _______________ percent in _____________ rocks.
low ultramafic 70% felsic
Carbonaceous shale is a sign of a ___ energy, organic-rich environment, such as a swamp or lagoon.
low - energy
Notice that hydrothermal metamorphism occurs in relatively ____ temperature and ____ pressure environments,
low temperatures low pressure
low grade
low temperatures and pressures
Burial and subduction metamorphism occur under relatively _____ temperature and _________pressure conditions.
low- temperature and high-pressure
Decompression meling occurs where hot, solid mantle rock ascends in zones of convective upwelling, thereby moving into regions of _____ pressure.
lower
As rock begins to melt, the minerals with the ______________ melting temperatures are the first to melt.
lowest
The gaseous components in magma, mainly dissolved water, also affect the mobility of ________________
magma
The majority of hydrothermal deposits originate from hot, metal-rich fluids that are remnants of late-stage magmatic processes. During solidification, liquids plus various metallic ions accumulate near the top of the ___________________ chamber.
magma
One way andesitic magma can form is when a rising mantle-derived basaltic magma undergoes ___________________ ________________ as it slowly makes its way through the continental crust.
magmatic differentiation
the formation of one or more secondary magmas from a parent magma is called
magmatic differentiation
Magmatic segregation is important in the late stages of the ______________________ process.
magmatic process
Along certain convergent plate boundaries, two plates move toward each other, and a slab of oceanic lithosphere descends into the ____, generating a _______________________.
mantle deep - ocean trench
And, limestone is metamorphosed to produce
marble
differential weathering
masses of rock do not weather uniformly
Although Pure water is nonreactive, a small amount of dissolved ______________ is generally all that is needed to activate it.
material
Although supplies are generally plentiful, most industrial minerals are not nearly as abundant as building ___
materials.
Chemical weathering contributes to __________________ weathering also. It does so by weakening the outer portions of some rocks, which in turn, makes them more susceptible to being broken by mechanical weathering processes.
mechanical
What are some factors that influence the rate of rock weathering? 1.
mechanical weathering, breaks rocks into smaller pieces, the amount of surface area exposed to chemical weathering increases.
metamorphic rocks are produced from preexisting sedimentary and igneous rocks, as well as from other
metamorphic rocks
Hot, chemically active fluids enhance _____________ by dissolving and transporting ions from one site in the crystal structure to another, thereby facilitating the process of __________________.
metamorphism recrystallization
Because calcite and quartz are simple chemical compounds compared to clay minerals, their mineralogy does not change during ___.
metamorphism calcite remains calcite quartz remains quartz These minerals recrystallize to produce larger fused grains that are the main constituents of marble and quartzite, respectively.
The _________________________ changes because the rock is subjected to new conditions, usually elevated temperatures and pressures, which are significantly different from those in which it initially formed. For example, clay minerals which are the most common minerals in sedimentary rocks, are stable only at Earth's surface.
mineralogy (mineral constituents)
In areas affected by metamorphism, there are systematic variations in _____ and _____ of the rocks that can be observed.
mineralogy and texture
dikes can also radiate from an eroded volcanic ____________, like spokes on a wheel. In these situations, the active ascent of magma generated fissures in the volcanic cone out of which lava flowed.
necks
Some chemical sedimentary rocks have a ___ or crystalline texture, in which the minerals form a pattern of interlocking crystals.
nonclastic ex: rock salt, ex: rock gympsum ex: limestone
metamorphic rocks that do not exhibit foliated textures are referred to as _______.
nonfoliated.
Basaltic rocks make up the _______________ floor as well as many of the volcanic islands located within the ocean basins. Basalt also forms extensive _______flows on the continents.
ocean lava
rain dissolves some carbon dioxide as it falls through the atmosphere, and additional amounts released by decaying ____ matter are acquired as the water percolates through the soil.
organic
Certain bog soils are composed almost enirely of ___ matter, whereas desert soil might contain as little as a small fraction of ___ %
organic 1%
Plants and animals furnish ___ matter to the soil.
organic matter
___ ___ also has a high water-holding ability and thus aids water retention in a soil.
organic matter
Because many of the processes that operate on Earth involve carbon dioxide, this gas is constantly moving into and ____ of the atmosphere.
out
_____________________ dissolved in water oxidizes some material example iron nail in moist soil will develop iron oxide : coating of rust
oxygen
Others are ___________________ cones that are found on the flanks or within the calderas of larger volcanic structures.
parasitic
These ion-rich fluids can also generate _____, very coarse -grained granitic (felsic) igneous rocks.
pegmatites
Joints are important rock structures that allow water to ____ depth and start the process of weathering long before the rock is exposed.
penetrate
Another important igneous rock, ________________ contains mostly olivine and pyroxene and thus falls on the opposite side of the compositional spectrum from granitic rocks.
peridotite
Further evidence for a mantle source are inclusions of the rock __________________, which basaltic magmas often carry up to the surface from the mantle
peridotite
Gradually, it undergoes ___ and ____ changes as the processes of soil formation progress.
physical and chemical
One rare type of conduit, called a ________, carries magma that originated in the mantle at depths that may exceed 93 miles.
pipe
Usually such enrichment occurs in deposits containing ____, the most common widespread sulfide mineral. Pyrite is important because when it chemically weathers, _____ _____ forms, which enables percolating waters to dissolve the ore metals.
pyrite sulfuric acid
Powerful hot blasts that carry small amounts of ash separate from the main body of a _____________________ flow.
pyroclastic
Pyroclastic flows may originate in a variety of volcanic settings. Some occur when a powerful eruption blasts _________________ material out of the side of a volcano.
pyroclastic
near one end of the continuum are rocks composed entirely of light colored silicates :_____ and ________ ______________. Igneous rocks in which these are the dominant minerals have a ______________ composition. Geologists also refer to granitic rocks as being ______________, a term derived from (fel)dspar and (si)lica (quartz).
quartz and potassium feldspar granitic composition felsic
2. recrystallization the produces new minerals
recrystallization is the creation of new mineral grains from preexing ones. when recrystallization occurs as rock is being subjected to differential stress, any elongated mineral (such as amphiboles) and platy minerals (such as micas) that form tend to recrystallize perpendicular to the direction of maximum stress. newly formed mineral grains
Earth's land surface is covered by ______, a layer of rock and mineral fragments.
regolith
After flowing as a thin, unconfined sheet for a relatively short distance, threads of current typically develop, and tiny channels called ____ begin to form.
rills
In addition, hot ion-rich solutions facilitate the movement of mineral matter into and out of ____ bodies, thereby changing their overall chemical composition.
rock
Oftentimes, pumice and obsidian can often be found in the same ________________ mass, where they exist in alternating forms.
rock
For example, in a near-surface environment where rocks are brittle, as the magma pushes upward, it causes numerous fractures in the overlying _________________. The force of the ________________ magma is often sufficient to dislodge and incorporate the surrounding host rock.
rock injected
This most commonly occurs on the ocean floor in association with _________________________ spreading.
seafloor
Most shield volcanoes begin on the ocean floor as _________________, a few of which grow large enough to form volcanic islands
seamounts
chert nodules are sometimes referred to as
secondary cherts or replacement cherts they most often occur with beds of limestone form when silica, originally deposited in one place, dissolves, migrates, and then chemically precipitates elsewhere, replacing older material
Other energy sources such as oil, natural gas and uranium are derived from s_________ rocks.
sedimentary
Some pegmatites contain ______________- gems such as beryl, topaz, and tourmaline
semiprecious gems
lava tubes
serve as insulated pathways that facilitate the advance of lava great distances from its source, therefore lava tubes are important features of fluid lava flows
Dikes
serve as tabular conduits that transport magma
Depending mainly on the composition of the parent rock, A variety of metamorphic rock can form in the same ____.
setting
Igneous rocks form in two basic _____________. 1. Molten rock may crystallize at _________ 2. It may solidify at Earth's ___________________.
settings 1. depth 2. Earth's surface
The particles range in size from very fine dust and sand-sized volcanic ash to pieces that weigh ____________ ________________.
several tons
A _____________________-volcano is produced by the accumulation of fluid basaltic lavas and exhibit the shape of a broad, slightly domed structure that resembles a warrior's shield.
shield
Shiprock is higher than most _______________________ and one of many such landforms that protrude conspicuously from the red desert landscapes of the _______ ________.
skyscrapers American SouthWest
Shale changes to fine grained ____
slate
Unlike shale, which splits along bedding planes, ___ often splits across bedding.
slate
example of low grade common sedimentary rock shale becomes the more compact metarmorphic rock ____. this transformation clay minerals in shale are transformed into tiny chlorite and muscovite flakes.
slate
Regional metamorphism produces some of the most common metamorphic rocks. In these settings shale is metamorphosed to produce the sequences of 1. 2. 3. 4.
slate phyllite schist gneiss
In low-grade metamorphic environments, ____ cleavage is known to develop where beds of shale and related sedimentary rocks are strongly folded and metamorphosed to form slate.
slaty
Cinder cones have simple, distinct shapes determined by the ________ that loose pyroclastic material maintains as it comes to rest.
slope
The movement of silica - rich rhyolitic lava may be too _______________ to perceive.
slow
Dikes weather more _____________________ than the surrounding rock. Dikes tend to have a wall like appearance.
slowly
highly insoluble clay minerals are very ____ removed by subsurface water
slowly
Other less-common types of metamorphism generate relatively _____ amounts of metamorphic rock that tends to be geographically ___________.
small localized
Once weathering and other processes create ____, plants carry the intermediary role of assimilating the necessary elements and making them available to animals, including humans.
soil
When Earth is viewed as a system, ____ is referred to as an interface--a common boundary where different parts of a system interact.
soil
Without the stabilizing effects of plants, the ____ is more easily swept away by the wind or carried downslope by sheet wash.
soil
If you were to dig a trench in soil, you would see that its walls are layered. Such a vertical section through all of the soil horizons constitutes the ________ ______
soil profile
Astronomers are so certain the Mauna Kea is over the hill that they built an elaborate observatory on its ______________, housing expensive teloscopes.
summit
Craters also form when the ______________ area of a volcano collapses following an eruption.
summit
vent in volcano
surface opening
Burial metamorphism
tends to occur where massive amounts of sedimentary or volcanic material accumulate in a subsiding basin such as Gulf of Mexico.
pyroclastic materials are also called _________
tephra
it is worth noting that certain rock names slate, schist, and gneiss are also used to describe rock ___.
texture
If the ripple marks were formed by air or water moving in essentially one direction,
their form will be asymmetrical
Because of accelerated erosion on steep slopes, the soils are ____ or in some cases nonexistent.
thin
Mount Etna, on the other hand has erupted once every ______________ years since 1979
2
migmatites serve to illustrate that some rocks are transitional and do not fit neatly into any of the ____ basic rock groups.
3
Most magmas have ______components. 1. 2. 3.
3 1. liquid component 2. solid component 3. gaseous component
How many ways can foliation occur?
3 ways
Today, __________________ is just one of the scores of cinder cones dotting the landscape in this region of ___________________.
Paricutin Mexico Like the others, it will not erupt again.
Rocks with compositions between granitic and basaltic rocks are said to have an ________________ composition or ___________________ composition, after the common volcanic rock ___________________.
andesitic composition or intermediate composition andesite
A few years earlier, a collapsed lave dome at the summit of Japan's Mount _____ produced a ________________________ __________ that claimed 42 lives
Unzen Pyroclastic flow Many of the victims were journalists and filmmakers who ventured too close to the volcano in order to obtain photographs and document the event.
Oil and natural gas are generated from the remains of marine plants and ______, mainly microscopic plankton, which died in ancient sea millions of years ago. This organic material was deposited in sedimentary basins together with mud, sand, and other sediments that protected it from oxidation. with increased temperature and burial, chemical reactions gradually transforms this organic matter into the liquid and gaseous hydrocarbons we call petroleum and natural gas.
animals
Gneisses made up of primarily dark minerals also occur. For example: an amphibole rich rock that exhibits a gneissic texture is called ___
amphibolite
The composition of volcanic gases is important because these gases contribute significantly to our planet's ______________.
atmosphere
This major greenhouse gas plays a significant role in the heating of our
atmosphere
certainly, one of the most active parts of the carbon cycle is the movement of CO2 from the atmosphere to the biosphere and back again. In the ___, carbon is found mainly as carbon dioxide.
atmosphere
Because silica-rich magmas are sticky (viscous) a significant portion of the gaseous material remains dissolved until the magma nears Earth's surface, at which time tiny _____________ begin to form and grow.
bubbles
This designation is correct because coal is ________, energy from the Sun that was stored by plants millions of years ago is being used, hence, the actual burning of "fossils"
burned
Environments where rocks may be carried to great depths and heated include ____ plate boundaries where slabs sediment - laden oceanic crust are being subducted.
convergent
Igneous rocks are exposed only at ___ of midocean ridges and at some volcanic areas.
crests
The general thickening of the ____ that occurs during mountain building results in buoyant lifting, in which deformed rocks are elevated high above sea level.
crust
Although the mineral portion of the soil is usually greater than the organic portion, humus is an essential component. In addition to being an important source of plant nutrients, humus enhances the soil's ability to retain ____.
water.
Evaporites
waters of the bay became saturated, and salt deposition began such deposits are called evaporites
If these iron - rich components are separated from the liquid by ______________ ________, the remaining melt will have an andesitic composition. These evolved (changed magmas) are termed _______________ ______________.
crystal settling
In this elevated level of activity, individual atoms migrate more freely between sites in the ______ structure.
crystalline
During the last stage of cooling, the magma body is like a __________________ _______________, resembling a bowl of thick oatmeal that contains only small amounts of melt.
crystalline mush
soil profile
image
solid-state flow
image
solum
image
spheroidal weathering
image
staurolite
image
steep slope in soils
image
steep slopes
image
travertine
image
limestone
image is composed of the mineral calcite, is the parent rock of marble
Kaolinite
image is one example of a clay mineral
shale
image is the most likely parent of most 1. slate 2. phyllite 3. schist 4. gneiss This sequence of metamorphic rocks reflects an increase in grain size, a change in rock texture, and a change in mineralogy.
granite porphyritic Some granites have a _________________ ______________________. These specimens contain elongated feldspar crystals a few centimeters in length that are scattered among smaller crystals of quartz and amphibole.
image porphyritic texture
Granite
image is the most abundant continental rock consists of quartz and potassium feldspar
Because of their iron content, __________ rocks are typically darker and _____________ than _________ rocks.
mafic denser granitic
Partial melting of ultramafic rocks yields ________________ or _____________ magmas.
mafic or basaltic
Rock characteristics encompass all of the chemical traits of rocks, including 1. 2.
mineral composition solubility
This air is the source of necessary ___ and ___ ___ for most microorganisms that live in the soil
oxygen carbon dioxide
Here, smooth-surfaced ________________ lava formed a lava lake.
pahoehoe
As a volcano matures, material also tends to be emitted from fissures that develop along the flanks or at the base of the volcano. Continued activity from a flank eruption may produce one or more small _____ cones.
parasitic cones
Every metamorphic rock has a _____ rock, the rock from which it was formed.
parent
formation of peat
partial decomposition of plant remains in an oxygen poor swamp creates a layer of peat, a soft brown material in which plant structures are still easily recognized. with shallow burial, peat changes to lignite, a soft brown coal burial increases the temperature of sediments as well as the pressure on them
Most magma is generated by _________________ ____________- of the the rock in the upper mantle and has a basaltic composition.
partial melting
The first mineral to crystallize is the ferromagnesian mineral _________________.
olivene
Soil fertility is in part related to the amount of __ matter present.
organic
The decay of plant and animal remains causes the formation of various _____ _____.
organic acids
obsidian is a dark colored glassy rock that usually forms when highly _______________ - rich lava cools quickly at Earth's surface. In contrast to the orderly arrangement of ions characteristic of minerals, the arrangement of _________________ in glass is unordered. Consequently, glassy rocks such as ________________ are not composed of __________________ in the same sense as most other rocks.
silica ions obsidian minerals
When chemically weathered, silicate minerals yield 1. 2. 3. 4.
sodium calcium potassium magnesium that form soluble products, which may be removed by groundwater.
Because of their mobility, these ion rich solutions can migrate great distances through the surrounding rock before they are eventually deposited, usually as _______________-- of various metals.
sulfides
The eruption of Kilauea that began in 1983 has been ongoing for more than ___ years
30
Prior to the appearance of humans sediment transported by rivers to oceans was over
9 billion metric tons per year
2. Hawaiian-Type Caldera
-unlike Crater Lake-type calderas, many calderas form gradually because of the loss of lava from a shallow magma chamber underlying the volcano's summit Hawaii's active shield volcano, Mauna Loa and Kilauea, both have calderas at their summits
Rhyolitic (felsic) flows make up ____%
1
In one study, half of all cinder cones examined were constructed in less than ___ month.
1 month and 95% were formed in less than 1 year..
3 and 4 continued
3. deposition of solid particles occurs when wind and water currents slow down and as glacial ice melts
One of the most destructive volcanic events, called the Laki eruptions began along a large fissure in southern Iceland in 1783.
3.4 cubic miles of fluid basaltic lavas 130 million tons of sulfur dioxide and other poisonous gases were released when sulfur dioxide is inhaled, it reacts with moisture in lungs to make sulfuric acid. this eruption's sulfur dioxide release cause the death of more than 50 percent of Iceland's livestock crop failure in parts of Western Europe thousands died from lung-related diseases a recent report estimates that a similar eruption today would cause more than 140,000 cardiopulmonary fatalities in Europe alone
What are the mobile agents that transport rock debris? 1. 2. 3. 4.
Wind Waves Glacial ice Running water
-the word sedimentary refers to this process; derived from latin sedimentum = to settle
a reference to solid material settling out of a fluid (water or air) examples: 1. floor on a lake 2. delta at the mouth of a river 3. gravel bar in a stream bed 4. particles in a desert sand dune 5. household dust
Schistosity
At higher temperatures and pressures, the minute mica and chlorite flakes in slate begin to recrystallize into larger muscovite and biotite crystals. When these platy minerals are large enough to be discernible with the unaided eye, they exhibt planar or layered structures called schistosity. Rocks that have this type of foliation are referred to as a schist. In addition to containing platy minerals, schist often contains deformed quartz and feldspar crystals that appear flattened or lens shaped and are embedded among the mica grains.
Hence, a mantle -derived magma changes chemically as it rises by assimilating silica - rich crustal rocks.
At the same time, extensive magmatic differentiation occurs, which means formation of secondary magma from parent magma.
Another group of volcanoes are the Seamounts that form along the crest of the mid-ocean ridges.
At these depths of 1 - 3 km below sea level, the pressures are so intense that the gases emitted quickly dissolve in the seawater and never reach the surface.
1783 eruption in Iceland, the atmospheric circulation around the globe appears to have been affected.
Drought in the Nile River valley and in India winter of 1784 brought the longest period of below zero temperatures in New England's history
Why is weathering important?
Many of life-sustaining minerals and elements found in soil, and ultimately in the food we eat, were freed from solid rock by weathering processes. Contributes to the formation of Earth's most spectacular scenery.
1902 pyroclastic flow and associated surge from Mount Pelee', a small volcano on the Caribean island of ____________________, destroyed the port town of St. Pierre.
Martinique
On exception is the cinder cone in _____________, which has erupted more than _____ times since it formed in 1850.
Nicaragua 20
The horizon from the surface downward are designated as 1. 2. 3. 4. 5.
O horizon A horizon E horizon B horizon C horizon
The Ring of Fire exists because oceanic lithosphere is being subducted beneath most of the landmasses that surround the ____ _____.
Pacific Ocean
One of the largest and most studied of all sills in the United States is the _____________ _____.
Palisade Sill. located along west bank of the Hudson River in southeastern New York and northeastern New Jersey
One of the very few volcanoes studied by geologists from its very beginning is the cinder cone called _____________.
Paricutin
These built an aesthetically pleasing cone, while fine ash fell over a much larger area, burning and eventually covering the village of ___________.
Paricutin
4. deposition of material dissolved in water is not related to the strength of water currents.
Rather, ions in solution are removed when chemical or temperature changes cause material to crystallize and precipitate or when organisms remove dissolved materials to build shells
Examples of exfoliation domes
Stone Mountain, Georgia Half Dome and Liberty Cap in Yosemite National Park
Large mantle plumes, dubbed __________________, are thought to be responsible for the vast outpourings of basaltic lava that created the large basalt provinces.
Superplumes
People often do not realize the importance of nonmetallic minerals because they see only the products that resulted from their use and not the minerals themselves.
That is, many nonmetallic minerals are used up in the process of creating other products.
Bowen and his coworkers demonstrated that as ____________________ magma cools, minerals tend to crystallize in a systematic fashion, based on their melting temperatures.
basaltic
If partial melting of mantle rocks generates most _______________ magmas, what is the source of the magma that crystallizes to form andesitic or ( intermediate) and granitic (felsic)rocks?
basaltic
Partial melting of mantle rock at spreading centers produces _______________ magma.
basaltic
Recall that the partial melting of mantle rock (peridotite) generates magma having a ___________ composition.
basaltic
Shield volcanoes owe their shape to fluid __________________ lavas.
basaltic
The pyroclastic material tends to have _______________ composition.
basaltic
Extensive study of the hawaiian islands revealed that they are constructed of a myriad of thin _______________ lava flows averaging a few meters thick, intermixed with relatively _______________ amounts of pyroclastic ejected material
basaltic minor
By contrast, ____________________ magma, which is low in silica forms very fluid lavas that, upon cooling, usually generate ______________ -grained crystalline rocks. However, when a basaltic lava flow enters the ocean, its surface is quenched rapidly enough to form a thin, _______________ skin.
basaltic fine-grained glassy
What color is obsidian? Obsidian has a chemical composition that is roughly equivalent to that of the light-colored ___________________ rock granite, not like dark rocks such as _____________________. Obsidian's dark color results from small amounts of _____________________ ions in an otherwise relatively clear, glassy substance.
black or reddish-brown igneous basalt metallic
Their upper surface consists largely of massive, detached blocks, hence the name _____________ ___________.
block lava Similar to aa flows, these lavas consist if blocks with slightly curved, smooth surfaces, rather than the rough, sharp, spiny surfaces typically of aa flows
volcanic breccia Particles in volcanic _____________ may consist of streamlined lava blobs that solidified in air, blocks broken from the walls of the vent, ash, and glass fragments.
breccia
Dikes and sills are typically shallow features, occurring where the country rocks are sufficiently ________________ to fracture. They can range in thickness from less than 1 millimeter to more than 1 kilometer
brittle
In low temperatures, rocks are ______.
brittle 1. tend to fracture 2. continued deformation grinds and pulverizes the mineral grains into small fragments
Diagenesis
burial promotes diagenesis because as sediments are buried, they are subjected to increasingly higher temperature and pressure occurs within the upper few km of Earth's crust as temperatures are generally less than 150 to 200 degrees C.
The mineralogy of an igneous rock depends on the _________________ makeup of its parent magma.
chemical
In addition, schists may be composed largely of minerals chlorite or talc, in which case they are called 1. 2.
chlorite schist talc schist Both chlorite and talc schists can form when rocks having basaltic compositions undergo metamorphism
These eruptions tend to steepen the slope of summit area, which often becomes capped with clusters of _____________ ______________.
cinder cones
Though a variety of minerals and rock fragments called ______may be found in detrital rocks 1. 2. are the constituents of most sedimentary rocks in this category.
clasts clay and quartz
Pyroclastic flows are generated by the ___________________ of tall eruption columns during an _________________________ event.
collapse explosive
Minerals containing the elements _______________, __________________, _________________________ and the rare earths are occasionally found
lithium cesium uranium and rare earths
A sandstone containing significant amounts of feldspar and angular grains of ferromagnesian minerals underwent ____ chemical weathering and transport and was probably deposited ____ to the source area of the particles.
little close
Basaltic rocks contain a high percentage of _______________________ minerals, so geologists also refer to them as ______________ (from __________ and _________________, the Latin name for iron.)
ferromagnesian mafic (ma)gnesium and (fe)rrum
Because peridotite is composed almost entirely of ___________________ minerals, its composition is referred to as ______________________. Ultramafic rocks are rare at Earth's surface, but ________________ is the main constituent of the upper mantle.
ferromagnesian minerals ultramafic peridotite
When magma intrudes rocks at shallow depths, the ____ cools and releases heat, which bakes the surrounding host rock.
magma
________________ is the parent material for igneous rocks, is formed by partial melting that occurs at various levels within Earth's crust and upper mantle to depths of about 250 kilometers (about 150 miles).
magma
Most pegmatites are ________________ in composition and consists of unusually large crystals of ____, _____, & ___________.
granitic quartz feldspar muscovite
Hot mineral-laden fluids, called hydrothermal solutions, contribute to metamorphism by enhancing the recrystallization of existing ___________________.
minerals
However, _______________melt at different temperature
minerals
Porphyroblastic textures develop In a wide range of rock types and metamorphic environments when minerals in the parent rock recrystallize to form new _____________.
minerals
By contrast, when shale is metamorphosed to slate, the clay minerals are recrystallized and become new _____, usually ___ and ____
minerals chlorite and muscovite
Rather than being concentrated in narrow veins and dikes, these ores are distributed as_______________________ masses throughout the entire rock mass.
minute
Most rhyolitic lavas seldom travel more than a few ____________ from their vents.
kilometers
When organic matter is decomposed, important ___ are supplied to plants, as well as to ____ and ____living in the soil.
nutrients plants animals
In high grade metamorphism, such features as bedding planes, fossils and vesicles that existed in the parent rock are ______.
obliterated
In diamond-bearing pipes, nearly the entire pipe contains diamond crystals that are disseminated throughout an ultramafic rock called
kimberlite
Sandstone
is the name given to rocks in which sand-size grains predominate after shale, sandstone is the next most abundant sedimentary rock, accounting for 20 % of the entire group
Gneiss
is the term applied to medium - to - coarse grained banded metamorphic rocks in which granular and elongated (as opposed to platy) minerals predominate most common minerals 1. quartz 2. potassium feldspar 3. plagioclase feldspar
The effect of cooling on rock textures is straightforward. 1. slow cooling promotes the growth of ___________ crystals. 2. Rapid cooling tends to generate _______ crystals.
large small
A horizon
largely mineral matter biologically active humus together A and O make up the topsoil
Differential stress
occurs at convergent plate boundaries where slabs of lithosphere collide. here the forces that deform rock are unequal in different directions and referred to as ___ ___.
Sorting
all the particles in sandstone are not neccessarily identical in size refers to the degree of similarity in particle size in a sedimentary rock
Metamorphism
also alters a rock's texture, producing larger crystals and sometimes distinct layering or banded appearance
Hydraulic fracturing
also called hydraulic fracturing often called fracking
removal of vegetation
also exposes the ground to strong direct sunlight when baked by the sun, these tropical soils can harden to a brick-like consistency and become practically impenetrable to water and crop roots.
Chemical weathering involves the complex processes that ____ the internal structures of minerals by removing and/or adding elements.
alter
Below the ridge axis where lithospheric plates are continually being pulled apart, the solid yet mobile mantle responds by _____________ to fill the rift.
ascending
Pyroclastic rocks composed mainly of particles larger than ______are called ______________ _____________.
ash volcanic breccia
Caldera-forming eruptions are of colossal proportions, ejecting huge volumes of pyroclastic materials, mainly in the form of
ash and pumice fragments These materials form pyroclastic flows that sweep across the landscape, destroying most living things in their paths. Upon coming to rest, the hot fragments of ash and pumice fuse together, formed a welded tuff and closely resembles a solidified lava flow. Despite the immense size of these calderas, the eruptions that cause them are brief, lasting hours to perhaps a few days.
Volcanic eruptions can eject dust-sized particles of volcanic ash and sulfur dioxide gas high into atmosphere
ash particles reflect solar energy back to space, producing temporary atmospheric cooling
Based on the extraordinary volume of erupted material, researchers have determined that the magma chambers
associated with Yellowstone-type calderas must be similarly monstrous As more and more magma accumulates, the pressure within the magma chamber begins to exceed the pressure exerted by the weight of the overlying rocks An eruption occurs when the gas-rich magma raises the overlying crust to create vertical fractures that extend to the surface. Magma surges upward along these cracks, forming a ring-shaped eruption. With a loss of support, the roof of the magma chamber collapses.
One result of fossil-fuel combustion is the release of huge quantities of CO2 into the ______.
atmosphere
The emplacement of small intrusions such as dikes and silles typically form aureoles only a few centimeters thick. By contrast, large molten bodies that cool to form batholiths can produce _______________ that extend outward for several kilometers.
aureoles
In the broadly folded Appalachians of central Pennsylvania, the rocks that once formed flat-lying beds are folded and display a preferred orientation of _____ mineral grains, as exhibited by well-developed slaty cleavage.
platy
These new ___minerals grains grow so they are aligned roughly perpendicular to the maximum directional stress.
platy
In ____ regions, chemical weathering is ____ because frigid temperatures keep the available moisture locked up as ice.
polar ineffective
2010, eruption of Iceland's Eyjafjallajokull Volcano, sent high ash into the atmosphere
the thick plume of ash drifted into Europe causing airlines to cancel thousands of flights, leaving hundreds of thousands of travelers stranded.
Contact metamorphism, also known as ___________ metamorphism occurs in Earth's upper crust (low pressure), when rocks immediately surrounding a molten igneous body are baked (high temperature)
thermal
conglomerate
these particles range in size from large boulders to particles as small as peas
Felsic (rhyolitic) lavas are very viscous and tend to form short, _______________ flows.
thick
Hot, wet climate may produce a ____ layer of chemically weathered soil in the same amount of time that a cold, dry climate produces a thin mantle of mechanically weathered debris.
thick
What kind of soils are found in the rain forest?
thick red - orange soils called oxisols are common to wet tropics and subtropics end product of extreme chemical weathering because lush tropical rain forests are associated with these soils, many people assume that they are fertile and have great potential for agriculture these are the poorest soils for farming
Crustal ____ also results in the deep burial of large quantities of rock as one crustal block is thrust beneath another.
thickening
Most igneous and sedimentary rocks consists of mineral grains or crystals that have a _____ orientation and thus appear uniform when viewed from any direction.
random
On the other hand, when cooling occurs __________ for example in a thin ____ flow--the ions quickly lose their mobility and readily combine to form __________________. This results in the development of _____________embryonic nuclei, all of which compete for the available ions. The result is a solid mass of ____________ intergrown cystals.
rapidly lava crystals numerous tiny
geothermal gradient
rate of increase in temperature with depth in the upper crust, this increase averages 25 degrees C per kilometer.
In increasingly hotter environments, these fluids become correspondingly more ________.
reactive
The formation of new mineral grains that tend to be larger than the original grains is called ____.
recrystallization
Some quartz remains in the soil, and is transported to the sea or to other sites of deposition, where it becomes the main constituent of such features as ____ ____ and ___ dunes
sandy beaches sand dune
As we move farther eastward, into the intensely deformed crystalline Appalachians, we find large outcrops of _____.
schists
Cinder cones are also called
scoria cones
Impact or _____ metamorphism occurs when high - speed projectiles called meteorites (fragments of comets or asteroids) strike Earth's surface.
shock
Sediment accumulations that exhibit poor sorting usually result when particles are transported for only a relatively ____ ____ ____ ___ ___. Example: when a turbulent stream reaches the gentler slopes at the base of a steep mountain, its velocity is quickly reduced, and poorly sorted sands and gravels are deposited.
short time and rapidly deposited.
In contrast to fluid basaltic magmas that can travel many kilometers, viscous andesitic and rhyolitic magmas tend to generate relatively ______________ prominent flows.
short.
A magma's viscosity is directly related to its _________________ content.
silica
An important aspect of chemical composition of igneous rocks is ____________(SiO2) content.
silica
Recall from our discussion of Bowen's reaction series that as basaltic magma solidifies, the _______________ poor ferromagnesian minerals crystallize first.
silica
Rocks that are relatively low in ___________ contain large amounts of iron, magnesium, and calcium
silica
So, granitic magma, which is rich in _______________________, may be extruded as an extremely viscous mass that eventually solidifies to form obsidian.
silica
The _______________ rich magmas typical of composite cones generate thick, viscous lavas that travel less than a few kilometers.
silica
The amount of ______________ present in magmas strongly influences its behavior.
silica
The more ______________ in magma, the greater is viscosity. Silica impedes the flow of magma because silicate structures start to link together into long chains early in the crystallization process.
silica
On the Big Island of Hawaii, these lavas have been clocked at 19 miles per hour down steep ______________. Flow rates of 30 to 1000 feet per hour are more common.
slopes
These current ripple marks will have steeper sides in the downcurrent direction and more gradual ____ on the upcurrent side.
slopes
For up to 24 hours before an eruption, swarms of ___________________________ warn of the impending activity
small earthquakes
In the final stage of growth, shield volcanoes erupt more ____________________________, and __________________________ ejections are more common.
sporadically pyroclastic
During this transformation, the original rock decomposes into substances that are ____ in the surface environment.
stable
As an industrial mineral, limestone is an ingredient in the manufacture of _____ and is used in agriculture to neutralize acid soils.
steel
Cinder cones have high angle of repose (the steepest angle at which material remains stable are are therefore ______-sided, with slopes between 30 and 40 degrees.
steep
This may explain why Mauna Kea, which is more mature volcano that has not erupted in historic times, has a _________________ summit than Mauna Loa, which erupted in 1984.
steeper
5 peaks of Henry Mountains are not laccoliths but _____________.
stocks
Hot basaltic lavas, which are usually very fluid, generally flow in thin, broad sheets or ________________ ribbons.
streamlike
Particles washed by waves are commonly better sorted than materials deposited by _______
streams
Upon mixing with the cold seawater, _____ and ________ minerals containing these heavy metals precipitate to form metallic deposits. Geologists credit this process with the formation of the ____ ores mined today on the Mediterranean island of Cyprus.
sulfides and carbonate copper
Coal contains ___. Despite efforts to remove sulfur before the coal is burned, some remains. When coal is burned, the sulfur is converted into noxious sulfur dioxide gas. Through a series of complex chemical reactions in the atmosphere, sulfur dioxide is converted to sulfuric acid, which eventually falls to Earth's surface in acid or snow. This acid precipitation can have adverse ecological effects over widespread areas.
sulfur
_____________compounds are easily recognized by their pungent odor.
sulfur
Volcanoes are natural sources of pollution; some emit ______________________, which combines with atmospheric gases to form sulfuric acid and other sulfate compounds
sulfur dioxide
Burrowing animals further break down rock by moving fresh material to the _____, where physical and chemical processes can more effectively attack it.
surface
The newly formed magma, which is less dense than surrounding rock, slowly rises toward the ____________________.
surface
Igneous rocks that form when molten rock solidifies at the __________________ are classified as _______________________ ____________________ _________________. They are also called ___________ rocks, after Vulcan, the Roman fire god.
surface extrusive igneous rocks volcanic rocks
Thus, while sediment and sedimentary rocks make up only a small percentage of Earth's crust, they are concentrated at or near the _______________
surface, the interface among the geosphere, hydrosphere, atmosphere, and biosphere
These low-density clouds called ____________ can be deadly but seldon have sufficient force to destroy buildings in their path.
surges
As magma continues to lose heat to its ___________, the ____________________ join with each other and with other ions to form ___________ crystal _______________. Slowly each nucleus grows as ions lose their mobility and join the crystalline network.
surroundings, tetrahedra embryonic crystal nuclei
Other ripple marks have a ____ form. These features, called _____ ____ ____, result from the back and forth movement of surface waves in a shallow near shore environment.
symmetrical oscillation ripple marks
Because of these differences, intrusive igneous bodies are classified according to their shape as either _________________________ or ________________________ and by their orientation with respect to the host rock.
tabular or massive
Some intrusions or plutons have a _________________ or _______________shape, whereas others are best described as ____________________________ (blob shaped).
tabular or tablet massive or blob shape
Although many fractures are created by expansion, others are produced by contraction during the crystallization or magma, and still others are produced by ______ forces during mountain building.
tectonic
Rocks and sediments can also be carried to great depths along convergent boundaries where oceanic lithosphere is being subducted. In this setting, cold, dense oceanic crust and sediments, which are poor conductors of heat, are subducting rapidly enough that pressure increases faster than ___. This phenomenon called ____ zone ____, differs from burial metamorphism in the differential stress plays a major role in DEFORMING rock as it is being metamorphosed.
temperature subduction zone metamorphism
As the _____________ of the liquid drops, ions pack more closely together as their rate of ______________ slows.
temperature movement
As ____________ rises, ions vibrate more rapidly and consequently collide with ever-increasing vigor with their ________________.
temperature neighbors
___ and ____ also exert a strong influence on rates of chemical weathering and on the kind and amount of vegetation present.
temperature and moisture
Sills
tend to accumulate magma and increase in thickness
A very large magma body located many kilometers beneath Earth's surface will cool over a period of _____________________________________. Initially, relatively few crystal ____________ form. Slow cooling permits ions to migrate freely until they eventually join one of the existing crystals. Consequently, slow cooling promotes the _____________ of fewer but ______________ crystals.
tens of thousands to millions of years nuclei growth larger
When such slopes are farmed, _____________can be constructed.
terraces
The ____________________ is used to describe the overall appearance of a rock based on the size, shape, and arrangement of its mineral grains --not how it feels to touch.
texture
How are igneous rocks classified?
texture mineral composition
Because igneous rocks are classified on the basis of both mineral composition and texture, some rocks having similar mineral constituents but exhibiting different ________________________ are given different names
textures
Geologists estimate
that these two categoriesof igneous and metamorphic rocks represent 90 to 95 % of the outer 10 miles of the crust
soil
the bridge between life and the inanimate world
volcanic cone
the cone-shaped structure we call a __ __ is often created by successive eruptions of lava, pyroclastic material, or combination of both
The magma generated in the mantle may change from a fluid basaltic magma to a silica rich andesitic or rhyolitic magma as it moves up through ____
the continental crust
recrystallization
the development of more stable minerals from less stable ones ex: aragonite recrystallizes to the more stable calcium carbonate
Glass results when ______________ ions are frozen in place before they are able to unite into an orderly crystalline structure. ___________________, a common type of natural glass is similar in appearance to dark chunks of manufactured glass.
unordered obsidian
Occasionally, the lake overflowed, but more often lava escaped through ____________ to feed flows that moved down the southeastern flank of the volcano toward the sea.
tunnels
Graded bed is most associated with a _____ current, a mass of sediment-choked water that is denser than clear water and that moves down slope along the bottom of a lake or an ocean,
turbidity
It is estimated that flowing water is responsible about
two-thirds of the soil erosion in the U.S.
In nature, over periods of thousands of years, large quantities of limestone are dissolved and carried away by __________________________ water.
underground ex: seen by the large number of subsurface caverns found in every one of the 48 states
It is best to leave steep slopes _________________.
undisturbed
It takes place due to the great reduction in pressure that occurs as the overlying rock is eroded away, a process called ______________.
unloading
When dry condition prevail, strong winds can remove large quantities of soil from ____ fields
unprotected
Because all intrusions form far below Earth's surface, they are studied primarily after __________________ and ___________________ have exposed them.
uplifting and erosion
Why are soils classified?
useful for agricultural and related land-use purposes, but it is not useful system for engineers who are preparing evaluations of potential construction sites
pillow lavas
useful in reconstruction of geologic history because their presence indicates that the lava flows formed below the surface of a water body
Some of these fluids move along openings such as fractures or bedding planes, where they cool and precipitate metallic ions to produce ___ ___
vein deposits
By the summer of 1986, a new _______ opened 2 miles downrift.
vent
During the night, hot, glowing rock fragments were ejected from the __________, producing a spectacular fireworks display.
vent
Once the event ceases, the magma in the plumbing connecting the _______ to the magma source solidifies, and volcano usually does not erupt again.
vent
Most of the volume of a cinder cone consists of pea to walnut sized fragments that are markedly __________________ and have a black to ________________________ color
vesicular reddish-brown
Lavas increase in ____________________, resulting in thicker, shorter flows
viscosity
In contrast to hot basaltic lavas, cool silica -rich rhyolitic lavas are so __________ that they hardly flow at all.
viscous
Plants and animals play a ____ role in soil formation
vital
Most metamorphic rocks have the same overall chemical composition as the parent rocks from which they formed except for the possible loss or acquisition of ____ such as water and carbon dioxide
volatiles
Water and other ____________________ act as salt does to melt ice.
volatiles
The gaseous components of magma, called ___________________, are materials that vaporize (form a gas) at surface pressures. Name 3 volatiles 1. 2. 3.
volatiles 1. water vapor 2. carbon dioxide (CO2) 3. sulfur dioxide (SO2)
magmas contain varying amounts of dissolved gases called __________________
volatiles, held in the molten rock by confining pressure, just as carbon dioxide is held in cans and bottles of soft drinks
Substantial weathering and long transport lead to the gradual destruction of ___ and less stable minerals, including the ____ and ____.
weaker feldspars and ferromagnesian
When hot ash falls, the glassy shards often fuse to form a rock called ____________ __________.
welded tuff Sheets of this material as well as ash deposits that later consolidate, cover vast portions of the western United States
If all the grains in a sample of sandstone are about the same size, the sand is ____ _____
well sorted
mature soil
well-developed soil profile indicates that environmental conditions have been relatively stable over an extended time span
Welded tuff deposits cover vast portions of previously volcanically active areas of ________________ U.S.
western
mineral calcite
which composes the common building stones marble and limestone is easily attacked by even a weakly acidic solution
metamorphism
which means change form is a process that leads to changes in the mineralogy, texture, and sometimes chemical composition of the parent rock
coal
which provides a significan portion of our electrical energy is classified as a sedimentary rock.
Much of the remainder is caused by the
wind
An example of metasomatism is the formation of the mineral _________________ from calcite CaCO2, the primary ingredient in limestone.
wollastonite CaSiO3
Suspended blocks of unmelted host rock called __________________- are often found in hardened igneous bodies.
xenoliths
70 volcanoes expected each
year
Movement along a fault _____ fractures and pulverizes rock. The result is a loosely coherent rock called _____ ____, that is composed of broken and crushed rock fragments.
zone fault breccia
These large aureoles often consist of distinct _____ of mtetamorphism.
zones
sandstone rock
image
sandy beaches
image
schist
image
shale
image
sheet erosion
image
sillimanite
image
slate
image
soapstone
image
subduction zone metamorphism
image
surges in volcanoes
image
underground caverns
image
waterlogged soils
image
weathering
image
wedging in plants
image
wind erosion
image
wollastonite
image
Limestone
image 10% of total volume of all sedimentary rocks most abundant chemical sedimentary rock composed of calcite CaCO3 and forms either by inorganic means or as a result of biochemical processes those forms having a marine biochemical origin are by far the most common
recrystallization
image During this process, the mineralogy of the rock may or may not change.
Breccia
image If the large particles are angular rather than rounded.
Marble
image Marble is a crystalline metamorphic rock whose parent is limestone or dolostone pure marble is white and composed mainly of calcite because of its softness 3 on Mohs scale, marble is easy to cut and shape stones and monuments are carved Lincoln Memorial in D.C and Taj Mahal in India very susceptible to chemical weathering, because marble is made out of calcium carbonate
graywacke
image along with quartz and feldspar, this dark-colored rock contains abundant rock fragments and matrix more than 15% of graywacke's volume is matrix
Grading beds
image are another special type of bedding. In this case, the particles within a single sedimentary layer gradually change from coarse at the bottom to fine at the top. Graded beds are most characteristic of rapid deposition from water containing sediment of varying sizes.
Coquina
image biochemical limestone a coarse rock composed of poorly cemented shells and shell fragments
Australia's Great Barrier Reef
image develop in shallow, warm waters of the tropics and subtropics equatorward of about 30 degrees latitude
jasper
image example of chert red variety gets it bright color from iron oxide
agate
image example of chert the banded form agate precipitates in concentric rings within voids in a rock its striped appearance occurs by variations in impurities that occur while precipitation is taking place.
columnar jointing
image example: Giant's Causeway in Northern Ireland is an excellent example
pumice
image extrusive rock containing voids left by gas bubbles that escape as lava solidifies. Pumice is a frothy volcanic glass that displays vesicular texture.
dolostone
image forms when magnesium-rich waters circulate through limestone and convert calcite to dolomite through the replacement of some calcium ions with magnesium ions (process called dolomitization)
rhyolite is fine grained and frequently contains glass _____________ and _____________, indicating that it cooled __________________ in a surface, or ___________________ surface, environment.
image fragments and voids rapidly near
mud cracks
image indicate that the sediment in which they were formed was alternately wet and dry. When exposed to air, wet mud dries out and shrinks, producing cracks. Mud cracks are associated with such environments as tidal flats, shallow lakes, and desert basins.
1 large eruption every ______________.
decade
Soil erosion is a
serious environmental problem
ripple marks the ridges form at right angles to the direction of motion.
image
rock cycle
image
sand dune
image
andesite
1. medium gray fine - grained rock 2. typically of volcanic origin. 3. name comes from South America Andes Mountain, where numerous volcanoes are composed of this rock type 4. Volcanoes of Cascade Range and many of the volcanic structures occupying the continental margins that surround the Pacific Ocean are of andesitic composition.
Other examples of large calderas located in the United States
1. California's Long Valley Caldera 2. LaGarita Caldera, located in San Juan Mountains of southern Colorada 3. Valles Caldera west of Los Alamos, New Mexico These and similar calderas elsewhere around the globe are among the largest volcanic structures on Earth, hence the name "supervolcanoes". Volcanologists have compared their destructive force with that of the impact of a small asteroid
4 physical processes lead to the fragmentation of rock. 1. 2. 3. 4.
1. Frost wedging 2. Salt crystal growth 3. Expansion resulting from unloading 4. Biological activity
The volcanic structures comprise most of the islands of the deep-ocean basins, including the
1. Hawaiian Islands 2. Galapagos islands 3. Easter Island
Hydraulic fracturing
1. In some shale deposits, there are significant reserves of natural gas that cannot naturally leave because of the rock's low permeability 2. The practice of hydraulic fracturing shatters the shale, opening cracks through which the natural gas can flow into wells and then be brought to Earth's surface 3. The fracturing of the shale is initiated by pumping fluids into the rock at very high pressures 4. The fluid is mostly water but also includes other chemicals that aid in the fracturing process. 5. Some of these chemicals may be toxic, and there are concerns about fracking fluids leaking into aquifers that supply communities with freshwater. 6. The injection fluid also includes sand, so when fractures open in the shale, the sand grains can keep the fractures propped open and permit the gas to continue to flow. Because of concerns about potential groundwater contamination and induced seismicity, hydraulic fracturing remains a controversial practice.
Large calderas tend to exhibit a complex eruptive history.
1. In the Yellowstone region, for example, three caldera-forming episodes are known to have occurred over the past 2.1 million years. 2. The most recent event 630,000 years ago, was followed by episodic outpourings of degassed rhyolitic and basaltic lavas. 3. Geologic evidence suggests that a magma reservoir still exists beneath Yellowstone; thus another caldera-forming eruption is likely but not necessarily imminent
The heart of the Dust Bowl was nearly 100 million acres in the panhandles of 1. 2. 3. 4. 5.
1. Texas 2. Oklahoma 3. Colorado 4. New mexico 5. Kansas
where are intrusive igneous rocks found? 1. 2. 3 4.
1. WhiteMountains, New Hampshire 2. Stone Mountain, Georgia 3. Mount Rushmore in the Black Hills of South Dakota 4. Yosemite National Park, California
Stages in the formation of coal
1. accumulation of plant remains 2. formation of peat 3. formation of lignite and bituminous coal 4. formation of anthracite coal
ANDESITIC (INTERMEDIATE ROCKS) BEGINS HERE:
1. andesite 2. diorite
There are several common oil and natural gas traps 1. 2. 3. 4.
1. anticline 2. fault trap 3. salt dome 4. stratigraphic pinchout trap
chert deposits are found in one of two situations 1. 2.
1. as layered deposits referred to as bedded cherts and 2. as nodules, somewhat spherical masses varying in diameter from a few millimeters to a few centimeters
Basaltic (mafic) igneous rocks starts here:
1. basalt 2. gabbro
Dust storms were called
1. black blizzards 2. black rollers
Nonmetallic mineral resources are commonly divided into two broad groups: 1. 2. Because some substances have many different uses, they are found in both categories.
1. building material 2. industrial material
Bauxite forms in rainy tropical climates. When aluminum - rich source rocks are subjected to the intense and prolonged chemical weathering of the tropics, most of the common elements, including 1. 2. 3. are removed by leaching.
1. calcium 2. sodium 3. potassium
AT depth, hot water is released into the surrounding rocks when a magma body cools and solidifies. In addition, many minerals, including ___, ____, and ___, are hydrated --which means that contain water in their crystalline structures.
1. clays 2. micas 3. amphiboles
Most calderas are formed by one of the following processes 1. 2. 3.
1. collapse of the summit of a large composite volcano following an explosive eruption of silica rich pumice and ash fragments (Crater Lake - type calderas) 2. collapse of the top of a shield volcano caused by subterranean drainage from a central magma chamber (Hawaiian-type calderas) 3. collapse of a large area, caused by the discharge of colossal volumes of silica rich pumice and ash along ring fractures (Yellowstone - type calderas
Pyroclastic flows are composed of two parts: 1. 2.
1. low density cloud of hot expanding gases containing fine ash particles 2. ground-hugging portion that is often composed of pumice and other vesicular pyroclastic material
other metamorphic rocks that are produced by contact metamorphism are 1. 2.
1. marble = limestone is the parent of marble 2. quartzite = quartz sandstone is the parent of quartzite
Other eruptions that have produced significant effects on climate worldwide include: 1. Indonesia Mount Tambora in 1815 2. eruption of El Chichon in Mexico in 1982
1. produced the year without a summer (1816) 2. The eruption for El Chichon, although small, emitted an unusually large quantity of sulfur dioxide that reacted with water vapor in the atmosphere to produce a dense cloud of tiny sulfuric acid droplets. These particles, called aerosols, take several years to settle out of the atmosphere. Like fine ash, these aerosols lower the mean temperature of the atmosphere by reflecting solar radiation back to space
Purpose of slate:
1. roof and floor tiles 2. billiard table surface
Most metamorphic rocks that we observe at Earth's surface were derived from the three most common sedimentary rocks 1. 2. 3.
1. shale 2. limestone 3. quartz
The primary factors that affect the behavior of magma and lava are 1. 2. 3. These factors determine a magma's mobility or viscosity.
1. temperature and composition 2. amount of dissolved gases
Other sites of intraplate volcanisms meaning Within the plate include large outpourings of fluid basaltic lavas like those that compose : 1. 2. 3. 4.
1. the Columbia River basalts, 2. the Siberian Traps in Russia 3. India's Deccan Plateau 4. Several large oceanic plateaus including the Ontong Java Plateau located in the western Pacific (These massive structures are estimated to be 6 - 25 miles thick.
Where are extrusive igneous rocks found? 1. 2. 3.
1. western portions of Americas, where they make up the volcanic peaks of the Cascade Range and the Andes Mountains. 2. Many oceanic islands, including Hawaiian chain and Alaska's Aleutian islands
There are ___ main textures in sedimentary rock classification.
2 1. clastic 2. nonclastic
The amount of material currently transported to the sea by rivers is about
24 billion metric tons per year, or more than two and a half times the earlier rate
____% of the energy consumed in the U.S. comes from these basic fossil fuels.
82 %
Rocks that contain at least ____% dark silicate minerals and calcium rich ____________ feldspar (but no ______________) are said to have a ______________ composition.
45 % calcium - rich plagioclase feldspar (but no Quartz) basaltic
________%sulfur dioxide
5%
Kilauea's measures 2 by 3 miles and is ___________________deep. The walls of this caldera are almost vertical and as a result, it looks like a vast, nearly flat-bottomed pit.
500 feet
There are _____ igneous textures: anphantitic (fine grained) phaneritic (coarse grained) vesicular porphyritic glassy pyroclastic or fragmental
6
Displacement along California's San Andreas Fault have created a zone of fault breccia and related rock types more than _____ miles long and ____ miles wide.
600 miles long 2 miles wide
Across the ocean floor, which represents about ____% of Earth's solid surface, virtually everything is covered by sediment.
70 %
The temperature averages about _______________ per kilometer in the upper crust. This increase in temperature with ____________ is known as the ________________________ gradient.
75 F depth geothermal gradient
Granite continued
8. Other minor constituents include small amounts of dark silicates, particularly biotite and amphibole and sometimes muscovite 9. dark components make up less than 10% of most granites, dark minerals appear to be more prominent than their percentages indicates
Lava domes are usually only a few tens of meters high, and they come in a variety of shapes that range from pancake-like flows to a steep-sided plugs that were pushed upward like pistons. Most lava domes grow over a period of several years, following an explosive eruption of silica-rich magma.
A recent event is the dome that began to grow in the crater of Mount St. Helens immediately following the 1980 eruption.
Volcanic arcs can be constructed on oceanic as well as continental lithosphere. Those that develop within the ocean and grow large enough for their tops to rise above the surface are labeled ______ in most atlases.
Archipelagos
The volcanoes of the Cascade Range in the northwestern United States, included 1. 2. 3.
Are examples of volcanoes generated along a convergent plate boundary 1. Mount Hood 2. Mount Rainier 3. Mount Shasta
Time
As a rule, the longer a soil has been forming, the thicker it becomes and the less it resembles the parent material
All volcanoes succumb to forces of _______________ and ________________. Weathering and erosion.
As erosion progresses, the rock occupying the volcanic conduit, which is often highly resistant to weathering, may remain standing above the surrounding terrain long after the cone has been worn away.
Temperature
As lava cools and begins to congeal, its viscosity increases and eventually the flow halts
Other reefs
Bahamas Hawaii Florida Keys
How can you distinguish granite from diorite?
Because diorite contains little or no visible quartz crystals and has a higher percentage of dark silicate minerals. The mineral makeup of diorite is primarily plagioclase feldspar and amphibole. Because the light colored feldspar grains and dark amphibole crystals appear to be roughly equal in abundance, diorite has a salt and pepper appearance.
If a rock is _____, it may signify a dry climate, where little chemical alteration of feldspar is possible.
arkose
The ________________ Plateau located in northwestern United States, which consists of the Columbia River basalts, is the product of this type of activity.
Columbia Plateau
the silver deposits of the ________________ in Nevada
Comstock Lode
Sedimentary environments are placed into one of three categories 1. 2. 3
continental marine transitional (shoreline)
1. Crater Lake- Type Calderas
Crater Lake, Oregon, is situated in a caldera 6 miles wide and 3800 feet deep. formed 7,000 years ago composite cone, named Mount Mazama, extruded 12 to 17 cubic miles of pyroclastic material 1500 meters of the summit of this prominent cone collpased, producing a caldera that filled with rainwater Later, volcanic activity produced a small cinder cone called Wizard Island, provides a mute reminder of past activity
The rocks filling these pipes originated at great _______, where pressure is sufficiently high to generate ________________ and other high pressure minerals.
Depth Diamonds
In 1943, its eruptive phase began, in a cornfield owned by _______________ who witnessed the event as he prepared the field for planting.
Dionisio Pulido
Volcanic ash and aviation
During the 15 year, 80 jets have been damaged in flying into clouds of volcanic ash 1989 Boeing 747 carrying more than 300 people encountered an ash cloud from Alaska's Redoubt Volcano, engines stalled but were able to restart and land in Anchorage
Geologists consider pipes to be windows into ____________________ that allow us to view rocks that normally form only at great depths.
Earth
nonmetallic mineral resources
Earth materials that are not used as fuels or processed for the metals they contain are referred to as __ __ __.
Although most spreading centers are located along the axis of an oceanic ridge, some are not. In particular, the __________ _____ ____ is a site where continental lithosphere is being pulled apart.
East African Rift Vast outpourings of fluid basaltic lavas as well as several active composite volcanoes are found in this region of the globe.
The volcanic activity on Kilauea began along a series of fissures in the ____________ __ ___.
East Rift Zone
Along some ridge segments, outpourings of pillow lavas build numerous volcanic structures, the largest of which is _________
Iceland
mudstone
If the rock breaks into chunks or blocks
discordant intrusion
Igneous bodies are said to be ____________ if they cut across existing structures
concordant intrusion
Igneous bodies are said to be _____________ if they inject parallel to features such as sedimentary strata.
Bowen's reaction series
In a cooling magma, minerals crystallize in a specific order. 1. Ferromagnesian silicates such as olivine crystallize first, at the highest temperatures, 1250C 2. nonferromagnesian silicates such as quartz crystallize last, at the lowest temperature 650C 3. Bowen found that in between these temperatures, chemical reactions take place between the crystallized silicates and the melt, resulting in compositional changes in each and the formation of new minerals.
Chemical weathering
Involves a chemical transformation of rock into one or more new compounds
Weathering
Involves the physical breakdown (disintegration) And chemical alteration (decomposition) of rock at or near Earth's surface
Mechanical weathering
Is accomplished by physical forces that break rock into smaller and smaller pieces without changing the rock's mineral composition
Several months before each eruptive phase, _______________________inflates as magma gradually migrates upward and accumulates in a central reservoir located a few kilometers below the summit.
Kilauea
__________________ the most active and intensively studied shield volcano in the world, is located on the island of ___________________ in the shadow of Mauna Loa.
Kilauea Hawaii
The best known volcanic pipes are the diamond bearing -__________pipes of South Africa.
Kimberlite
From its base on the Pacific Ocean to its summit, ______________ Loa is over 6 miles high, exceeding the elevation of Mt. Everest
Mauna
Two basic categories of weathering 1. 2.
Mechanical weathering Chemical weathering
3. Flattening Spherically shaped grains
Mechanisms that flatten existing mineral grains are important in the metamorphism of rocks that contain minerals such as quartz, calcite, and olivine. these minerals develop spherical crystals and have a rather simple chemical composition a change in grain shape can occur as distinct units of a mineral's crystalline structure slide relative to one another along discrete planes, thereby distorting the grain. this type of gradual solid-state flow involves slippage that disrupts the crystal lattice as atoms shift positions by breaking existing chemical bonds and forming new ones
fig. 4.4
Mount Rushmore Memorial, Black Hillls of South Dakota is carved from intrusive igneous rocks 4 presidents
Figure 5.2 Douglas fir trees snapped off or uprooted by the lateral blast of
Mount St. Helens
When the activity became localized, a cinder and spatter cone, given the Hawaiian name ____ __, was built.
Puu Oo
Explosive degassing of the interior magma triggers a fiery _____________ flow that races down the flanks of the volcano.
Pyroclastic
When large masses of igneous rock, particularly granite are exposed by erosion, concentric slabs begin to break loose. The process that generates these onion-like layers is called ________.
Sheeting
____________, New Mexico, is a widely recognized and spectacular example of these structures geologists call ______ ____ or plugs.
Shiprock Volcanic necks or plugs
Soil scientists have devised a system for classifying soils known as the
Soil Taxonomy it emphasizes the physical and chemical properties of the soil profile and is organized on the basis of observable soil characteristics 6 hierarchical categories of classification, ranging from order, the broadest category, to series, the most specific category.
At one time the parent material was thought to be the primary factor causing differences among soils.
Soil scientists have come to understand that other factors, especially the climate are more important.
Since 1995, pyroclastic flows generated by the collapse of several lava domes on ___ ______________ _________.
Soufriere Hills Volcano have rendered more than half of the Caribbean island of Montserrat uninhabitable
Prior to the development of the theory of plate tectonics, geologists did not have an acceptable explanation for the distribution of Earth's___
Volcanoes
Example, when a fine grained limestone (made of calcite) is metamorphosed by the intrusion of a hot magma body, the small calcite grains recrystallize to form larger interlocking crystals.
The resulting rock, marble, exhibits large, intergrown calcite crystals.
The collapse of lava domes, particularly those that form on the summit or along the steep flanks of composite cones, may produce powerful pyroclastic flows.
These flows result from highly viscous magma slowly entering the dome, causing it to expand and steepen its flanks.
Because this newly formed magma is less dense than the mantle rock from which it was derived, it rises and collects in reservoirs located just below the ridge crest.
This activity continuously adds new basaltic rock to plate margins, temporarily welding them together, only to have them break again as spreading continues.
Why are the andesitic or intermediate so important?
This category of igneous rocks is associated with volcanic activity that is typically confined to the seaward margins of the continents and on volcanic island arcs such as the Aleutian chain.
Shape of a mineral may also be altered by a process in which individual atoms move from a location along the margin of the grain that is highly stressed to a low stressed position on the same grain.
This mechanism, called pressure solution, is significantly aided by hot iron-rich water. mineral matter (ions) dissolves where grains are in contact with each other (areas of high stress) and is deposited in pore spaces (areas of low stress) as a result, the mineral grains tend to become shortened in the direction of maximum stress and elongated in the direction of minimum stress.
Describe the different grades of metamorphism that might be encountered moving west to east from Ohio to the crystalline core
This systematic transition in metamorphic textures can be observed as we approach to Appalachian Mountains from the west. Beds of shale, which once extended over large areas of eastern U.S., still occur as nearly flat-lying strata in Ohio.
These volcanic chains develop roughly parallel to the associated ___________.
Trench at distances 200 to 300 km (100 to 200 miles)
Consequently, the products of chemical weathering remain essentially _____ as long as they remain in an environment similar to the one in which they formed.
Unchanged
Migmatite
Under high-grade metamorphism, light-colored (felsic) minerals in a gneiss may begin to melt, while the dark-colored (mafic) minerals remain solid. If this melt solidifies in place, the rock--called a migmatite--will contain light-colored igneous rock intermixed with metamorphic rock composed of dark-colored (mafic) minerals
Some of the most intense zones of metamorphism are found in ____ and___ ____, where gneissic rocks outcrop.
Vermont and New Hampshire
Section 5.2 The Nature of Volcanic Eruptions
Volcanic activity is commonly perceived as a process that produces a picturesque, cone-shaped structures that periodically erupts in a violent manner Many eruptions are not explosive
Volcanism at a convergent plate margin results in the development of a slightly curved chain of volcanoes called a ____________ ________.
Volcanic arc.
Geologists prefer the more descriptive term ________________ _______ _____or simply _______ _____
Volcanic island arcs Or island arcs
This causes the burst the burst of __________ that emits voluminous outpourings of lave to form a huge basalt province in a matter of million or so years.
Volcanism
The transformation of rock is what we call ________________
Weathering
potassium feldspar
When potassium feldspar is weathered, the hydrogen ion attach and replace potassium ions in the feldspar structure. Once removed, the potassium is available as a nutrient for plants or becomes the soluble salt potassium bicarbonate, which may be incorporated into other minerals or carried to the ocean in dissolved form by streams
Diamonds are used as
abrasives
quartz sandstone
after shale, sandstone is the next most abundant sedimentary rock
Name our 3 most indispensable resources 1. 2. 3.
air water soil
Because plants require ____ and ____ to live and grow, the portion of the soil consisting of pore spaces that allow for the circulation of these fluids is as vital as the solid soil constituents.
air water
The pore spaces that are not filled with water contain ___.
air.
soil orders
alfisol - vertisol
In metamorphic environments, foliation is driven by compressional stress that shortens rock units, causing mineral grains in preexisting rocks to develop parallel, or nearly parallel _______.
alignments
Gentle slopes
although shale is far more common than other sedimentary rocks, it does not usually attract as much notice as other, less abundant members of this group shale does not form prominent outcrops, as sandstone and limestone often do. Rather, shale crumbles easily and usually forms a cover of soil that hides the unweathered rock below.
Because ____ is extremely insoluble, it becomes concentrated in the soil as _____________________, a hydrated aluminum oxide. thus, the formation of bauxite depends on climatic conditions in which chemical weathering and leaching are pronounced plus, of course, the presence of aluminum-rich source rock.
aluminum bauxite
Whereas, the mafic silicates, such as ____ and ______ remain solid.
amphibole and biotite
the orientation of slate's cleavage usually develops at an _____ to the sedimentary beds.
angle
Each bedding plane marks the end of one episode of sedimentation and the beginning of ___________.
another
siltstone
another fine-grained sedimentary rock that, like mudstone, is often grouped with shale but lacks fissility is composed largely of silt-size particles and contains less clay-size material than shale and mudstone
lava
another image
obsidian If you examine a thin edge, obsidian will appear nearly _______________.
another image transparent
stratigraphic pinchout trap
another important geologic circumstance that may lead to significant accumulations of oil and gas These oil-bearing structures result from the original pattern of sedimentation rather than structural deformation. This stratigraphic trap exists because a sloping bed of sandstone thins to the point of disappearance
magma mixing
another means by which the composition of the magma can be altered. may occur during the ascent of two chemically distinct magma bodies as the more buoyant mass overtakes the more slowly rising body. Once they are joined, convective flow stirs the two magmas, generating a single mass that has an intermediate composition
oolitic limestone
another variety of inorganic limestone is composed of small spherical grains called ooids
corals
are capable of creating massive structures called reefs reefs consists of coral colonies made up of great numbers of individuals that live side by side on a calcite structure sectred by the animals calcium carbonate secreting algae live with the corals and help cement the entire structure into a solid mass
Sills
are nearly horizontal, concordant bodies that form when magma exploits weaknesses between sedimentary beds or other structures.
ash and dust
are produced when gas-rich viscous magma erupts explosively
clay minerals
are the most abundant product of chemical weathering of silicate minerals, especially the feldspars
In ___ regions where there is insufficient ___ to promote rapid chemical weathering is seen as well.
arid moisture
_________________ is the most common extrusive igneous rock. Many volcanic islands, such as the __________________________ Islands and _________________ are composed mainly of basalt.
basalt Hawaiian Iceland
Any such changes produces a gradual alteration of soil characteristics until a new _____ is reached.
balance
When marble forms from limestone interbedded with shale, it appears _____ and exhibits visible foliation. When deformed, these banded marbles may develop highly contorted mica-rich folds that enhance the rocks' artistic appearance. These decorative marbles have been used as building stones since prehistoric times.
banded
The inability of water to penetrate its microscopic pore spaces explains why shale often forms ___ to the subsurface movement of water and petroleum.
barriers
Due to the extreme nature of the eruption required to produce the large ______ provinces, some researchers believe the eruptions were responsible for the extinction of many of Earth's life-forms.
basalt
_____________________ is a very dark green to black, fine-grained rock composed primarily of pyroxene and calcium-rich plagioclase feldspar, with lesser amounts of olivine and amphibole.
basalt
Although granitic magmas can arise through magmatic differentiation of adesitic magmas, most granitic magmas probably form when hot ___________________ magma ponds below continental crust.
basaltic
most water-dwelling organisms that produce hard parts make them of
calcium-carbonate
Ash and pyroclastic material
can collapse roofs of buildings drawn into lungs of humans/animals get into aircraft engines emit gases, sulfur dioxide which affects air quality and when mixed with rainwater, may destroy vegetation and reduce the quality of ground water
In fact, the crust is by far Earth's largest depository of ___, where it is constituent of a variety of rocks, the most abundant being limestone.
carbon
When a silica- rich hydrothermal solution invades limestone, calcite reacts with silica to generate wollastonite, and the gas _______ is driven off.
carbon dioxide
Most carbon is bonded chemically to other elements to form compounds such as
carbon dioxide calcium carbonate hydrocarbons found in coal and petroleum
regions with lush vegetation have a thick mantle of soil rich in decayed organic matter from which chemically active fluids such as ___________ _________ and humic acids are derived.
carbonic acid
Confining pressure
causes the spaces between mineral grains to close, producing more compact rocks that have greater densities. does not fold or fracture rocks
The amount of pore space is reduced during _____.
compaction
Basic lithification processes include 1. 2.
compaction cementation
Batholiths
composed of felsic and intermediate rock types and referred to as "granite batholiths"
Although the mineralogy changes in the transition from shale to slate, the overall chemical ______________ remains essentially unchanged
composition
In addition to affecting the degree of rounding and the amount of sorting that particles undergo, the length of transport by turbulent air and water currents also influences the mineral _____ of sedimentary deposits.
composition
Once a magma forms, its __________________ can also change through the incorporation of foreign material.
composition
Soil components
composition by volume of a soil in good condition for plant growth; mineral and organic matter, water and air
Differential stress that squeezes a rock mass as it is were placed in a vise is termed _____ ____. Rocks subjected to compressional stress are shortened in the direction of greatest stress and elongated, or lengthened in the direction perpendicular to that stress.
compressional stress
these resources result from processes that ___________________ desirable materials to the extent that they can be profitably extracted.
concentrate
Weathering creates many important mineral deposits by ______ minor amounts of metals that are scattered through unweathered rock into economically valuable concentrations.
concentrating
Because of its excellent ________________ fracture and ability to hold a sharp, hard edge, _______________ was a prized material from which Native Americans chipped arrowheads and cutting tools.
conchoidal obsidian
The most widely recognized volcanic structures are the
cone-shaped edifices of composite volcanoes that dot Earth's surface
Buried rocks are subjected to ___ ____, which is analogous to water pressure, in which the forces are applied equally in all direction.
confining pressure
Unlike most building materials, which need a minimum of processing before they are ready to use, many industrial minerals require ___
considerable processing to extract the desired substance at the proper degree of purity for its ultimate use.
O, A, E, and B horizons together
constitute the solum or true soil solum that the soil forming processes are active and that living roots and other plant and animal life are largely confined
Crustal rocks can also melt during _____________________ collisions that result in the formation of a large mountain belt. During these events, the crust is greatly thickened, and some crustal rocks are buried to depths where the temperatures are elevated sufficiently to cause partial melting.
continental
When they are ______________ sufficiently, the forces of the chemical bonds again confine the ____________- to an _____________________ crystalline arrangement.
cooled ions orderly
The textures result from different _______________ histories.
cooling histories
It is estimated that topsoil is eroding faster than it forms on more than one-third of the world's ________________
coplands
Carbonate reefs
corals are one important example of organisms that are capable of creating large quantities of marine limestone. these simple invertebrates animals secrete a calcareous (calcium carbonate) external skeleton
Consequently, the __________ of many mountain belts consist of folded and faulted metamorphic rocks, often intertwined with _____________ bodies.
cores igneous
Moreover, deposits are far from more restricted in distribution and extent. As a result, many of these nonmetallic resources must be transported considerable distances, which of course adds to their ____.
cost.
Explosive discharges continued, throwing hot fragments and ash occasionally as high as 20,000 feet into the air. Larger fragments fell near the ____________, some remaining incandescent as they rolled down the slope.
crater
In addition, a cinder cone has a quite large, deep ______________ in relation to the overall size of the structure.
crater
Other craters form during explosive eruptions as the rapidly ejected particles erode the _____________ walls.
crater
Volcanoes built primarily of pyroclastic materials typically have _____________that form by gradual accumulation of volcanic debris on the surrounding rim.
craters
to explore this idea, N.L. Bowen carried out a pioneering investigation into the ________________________ of magma early in the 20th century.
crystallization
In the process of _________________, cooling reverses the event of ___________.
crystallization melting
The solid components (if any) in magma are _________________ of _________________ minerals.
crystals of silicate minerals As the magma body cools, the size and number of crystals increase.
Ripple marks produced by a stream flowing across a sandy channel and by wind blowing over a sand dune are two common example of _____ ____.
current ripples.
The first discharge began along a 4 mile fissure where 100 meter high ____________ of ______________ formed as red-hot lava was ejected skyward.
curtain of fire
____weathering and subsequent erosion are responsible for creating many unusual and sometimes ____________ rock formations and landforms.
differential spectacular
In 1980, May 18, 1980, the largest volcanic eruption to occur in North America in historic times transformed a picturesque volcanoe into a _________________ remnant
decapitated
When plants die and ____ or are _____, this biomass is oxided, and carbon dioxide is returned to the atmosphere.
decay burned
_________________- melting also occurs when ascending mantle plumes reach the uppermost mantle.
decompression
When confining pressure drops sufficiently, __________________ _____________ is triggered.
decompression melting
By understanding the conditions under which sedimentary rocks form, geologists can ____ the history of the rock, including information about the origin of is component particles, the method of sediment transport, and the nature of the place where the grains eventually came to rest --the environment of deposition
deduce
compressional forces of unimaginable magnitude and temperature hundreds of degrees above surface conditions prevailed for thousands or millions of years and produced th
deformation displayed by these rocks
Foliation is a fundamental characteristic of metamorphosed rocks that have been strongly ___, mainly by folding.
deformed
Elevated temperatures and pressures cause these minerals to ____, expelling hot, mineral - laden water
dehydrate
By studying the degree of sorting, we can learn much about the ____ ___.
depositing current
The size of the component grains also provide useful information about environments of __________.
deposition
Pressure, like temperature, increases with ____ because the thickness of the overlying rock increases.
depth
Chemical sediments
derive from ions that are carried in solution to lakes and seas. this material does not remain dissolved in the water indefinitely, however. some of it precipitates to form chemical sediments. these become rocks such as limestone, chert, and rock salt
In environments, where temperatures and pressures are more extreme, metamorphism causes a transformation so complete that the identity of the parent rock cannot be easily ________.
determined
All ___ rocks have clastic texture.
detrital
How do earthworms help?
earthworms and other burrowing animals act to mix the mineral and organic portions of the soil. Earthworm feed on organic matter and thoroughly mix soils in which they live, often moving and enriching tons per acre each year. Burrows and holes aid the passage of water and air through the soil.
While dikes and sills can occur as solitary bodies, Dikes tend to form in roughly parallel groups called _______________ ________. The multiple structures reflect the tendency for fractures to form in sets when tensional forces stretch brittle country rock.
dike swarms
hydrothermal and contact metamorphism do not involve ________________ stress
directional
Igneous bodies are said to be _____________________ if they cut across existing structures.
discordant
Dikes
discordant bodies that cut across bedding surfaces or other structures in the country rock.
Although relatively symmetrical, some cinder cones are elongated and higher on the side that was ______________ during the final eruptive phase.
downwind
When drilling punctures the lid created by the cap rock, the oil and natural gas, which are under pressure, migrate from the pore spaces of the reservoir rock to the ___ ___.
drill pipe
In high temperatures, high-pressure environments rocks are___.
ductile 1. mineral grains are flattened 2. ability to flow rather than fracture 3. creates folds
Because quartz is very ___, it is usually the mineral that survives a long trip in a turbulent environment.
durable
The _____________ formed minerals have space to __________________ and tend to have better-developed crystal faces than do the ones that form later and occupy the remaining spaces.
earliest grow
1. Rotation of platy mineral grains
easiest of the foliation mechanisms to envision new alignment is roughly perpendicular to the direction of maximum stress physical rotation of platy minerals contributes to the development of foliation in low-grade metamorphism, other mechanisms dominate in more extreme environments
When gravity overcomes the initial upward thrust provided by the escaping gases, the _____________ materials begin to fall, sending massive amounts of incandescent blocks, ash, and ________________ cascading downslope.
ejected pumice
The percentage of silica in igneous rocks varies in a systematic manner that parallels the abundance of other ________________.
elements
Continental collision, which result in mountain building cause some rocks to be uplifted while others are thrust downward, where _____ ____ and pressure trigger metamorphism
elevated temperatures
When a current experiences a rapid ___ loss, the largest particles settle first, followed by successively smaller grains.
energy
Animals that consume these plants or that consume other animals that eat plants use these organic compounds as a source of ____, and through the process of _____ , return carbon dioxide to the atmosphere.
energy respiration
The quantities of nonmetallic minerals used each year are
enormous
Instead, the existing atoms are rearranged into new crystalline structures that are more stable in the new _________________.
environment
The characteristic and extent of development of horizons vary in different _______________.
environments
Nonfoliated metamorphic rocks develop in environments where deformation is minimal and the parent rocks are composed of minerals that exhibit ______________ crystals, such as quartz or calcite.
equidimensional crystals
Southwestern Washington State, Mount Saint Helens ________________ with tremendous force.
erupted
lava
erupted magma
The cap rock halts the upwardly mobile oil and gas and keeps the oil and gas from ______________ at the surface.
escaping
Carbon also moves from the geosphere and hydrosphere to the atmosphere and back again.
ex: volcanic activity early in Earth's history is thought to be the source of much of the carbon dioxide found in the atmosphere.
Limestone is the most versatile and widely used rock of all is the best ____. As a building material is used not only as crushed rock and building stone but also in making ___.
example cement
flint
example of chert dark color results from the organic matter it contains
This is true of _____________magma in which the residual melt can become enriched in rare elements and some heavy metals
granitic
rhyolite is the _____________-grained equivalent of granite and, like granite, is composed essentially of the light-colored silicates. This fact accounts for its color, which is usually buff to ______________ or occasionally light gray.
fine pink
____________________(fine grained) texture: Igneous rocks that form at the surface or as small intrusive masses within the upper crust where cooling is relatively rapid exhibit a __________________ - ____________ texture termed ____________________
fine-grained texture aphanitic a = not phaner = not visible
Shale must exhibit the ability to split into thin layers along well-developed, closely spaced planes. This property is called __________.
fissility
The greatest volume of volcanic material is extruded from fractures in Earth's crust called ___________.
fissures
The optimum terrain for soil development is a _____to undulating upland surface. Good drainage minimum erosion sufficient infiltration of water into soil
flat
Mafic (basaltic) laves, which contain less silica are relatively ____________________and travel 90 miles before solidifying.
fluid
However, many composite cones also emit various amounts of __________ basaltic lava and occasionally, ___________________ material having felsic (rhyolitic) compositon.
fluid pyroclastic
The flanks of Mauna Loa have gentle slopes of only a few degrees. This low angle results cause very hot, ____________ lava traveled fast an far from the _____________.
fluid vent
Water dissolved in magma tends to increase _________________- because it reduces formation of long silicate chains by breaking silicon-oxygen bonds
fluidity
When rocks deep in the crust are subjected to compressional stress, like being placed in a giant vise, the entire mass may be deformed usually by ____.
folding
Because contact metamorphism does not involve directional stress, rocks found within a metamorphic aureole are not ___.
foliated
_______ rocks may be heated sufficiently to trigger _________.
gneissic rocks melting
By mapping the occurrences of index minerals, geologists can identify zones of varying metamorphic _________________.
grades
Start with clay-rich sedimentary rock such as shale or mudstone , there is a ________ increase in metamorphic intensity that is accompanied by a general __________________ of grain size.
gradual coarsening
Soil
gradually evolves to a state of equilibrium or balance with the environment.
In addition to quartz and feldspar, most ___________ rocks contain about ____% dark silicate minerals, usually biotite ________and __________. Granitic rocks are rich in silica (about ______%) and are the major constituent of the continental ______.
granitic 10% biotite mica and amphibole silica (70%) continental crust
Not all late-stage magmas produce pegmatites, nor do all have ___________________- compositions. Rather, some magmas become enriched in iron or copper.
granitic composition
The water for hydrothermal metamorphism can be _____ that has percolated down from the surface where it is heated and circulates upward. This type of metamorphism tends to occur at ____ pressure (shallow depth) and relatively low to moderate ________.
groundwater low temperature
Creating grassed waterways is another common practice. Natural drainage ways are shaped to form smooth, shallow channels and then planted with grass. The grass prevents the formation of __________ and traps soil washed from cropland.
gullies
These fountains are usually __________ and not associated with major explosive events that cause great loss of life and property.
harmless
These complex acids ___ the weathering process.
hasten
Thus, ________________ causes the ions to occupy more space, which in turn causes the _________ to expand. When the ions are vibrating rapidly enough to overcome the force of their chemical bonds, _______________ occurs. At this stage, the ions are able to slide past one another, and the orderly crystalline structure _______________.
heating solid melting disintegrates
Because water and other volatiles do not crystallize along with the bulk of the magma body, these fluids make up a ______ percentage of the melt during the final phase of solidification.
high
Much of the deformation associated with fault zones occurs at great depth and thus at _____ temperatures. In this environment, preexisting minerals deform by _______ flow.
high ductile
In some settings, _____________ temperature basaltic magmas reach Earth's surface, where they produce highly _____________ lavas.
high fluid
If melting continues, minerals with ________________ melting points begin to melt, and the composition of the melt steadily approaches the overall composition of the rock from which it was derived.
highest
During contact metamorphism of mudstones and shales, the clay minerals are baked, much like clay is baked in a kiln to make pottery. The result if a very hard, fine-grained metamorphic rock called ___.
hornfels Hornfels can form from a variety of other materials, including volcanic ash and basaltic rocks.
If the rocks that surround the pluton differ markedly in chemical composition from the invading fluids, there may be an exchange of ions between the fluids and the ___- rock.
host
When magma rises through the crust, it forcefully displaces preexisting crustal rocks referred to as _______________ _______________ or _______________ __________________.
host rock or country rock
When deeply buried magma bodies crystallize, the remaining volatiles collect as ___, ________-rich fluids that migrate through the surrounding rocks.
hot, water-rich These hot fluids play an important role in metamorphism and will be considered in chapter 8.
When hot, ion - rich water circulates through pore spaces or fractures in rock, a chemical alteration called _________________ ___________ may occur.
hydrothermal metamorphism
Water that drives hydrothermal metamorphism may also arise from _____ activity. As large magma bodies cool and solidify, ion-rich waters are driven into the surrounding host rocks. When the host rock is porous or highly fractured, mineral matter contained in these fluids may precipitate to form important deposits of __, __, and ___.
igneous copper, silver, and gold
Over time, these deformed rock masses are uplifted, and erosion removes the overlying material to expose the ______ and _____ core of the mountain range.
igneous and metamorphic
calcite mineral
image
chemical sedimentary rocks
image
chert
image
chlorite
image
earthworms in soils
image
facies of sediments
image
fault breccia
image
light nonferromagnesian silicates
image
lignite
image
limestone
image
marble
image
mechanical weathering
image
oil fossil fuels
image
olivine
image
oscillation ripple marks
image
photosynthesis
image
phyllite
image
potassium feldspar
image
pumice
image
pyroclastic
image
pyroclastic flow
image
pyroclastic flows
image
Workers in underground mines know that temperatures ______________ as one descends deeper below Earth's surface
increase
quartz
image
quartz sandstone
image
quartzite
image
residual soil
image
rills
image
Quartzite
image is a very hard metamorphic rock formed from quartz sandstone under moderate to high- grade metamorphism, the quartz grains in sandstone fuse together. The recrystallization is often so complete that, when broken, quartz splits across the original quartz grains rather than along their boundaries. In some instances, sedimentary features such as cross-bedding are preserved and give the rock a banded appearance. Pure quartzite is white, but iron oxide may produce reddish or pinkish stains, while dark mineral grains may impart shades of green or gray.
schist
image medium to coarse grained metamorphic rocks in which platy minerals are dominant these flat components include muscovite and biotite that display parallel alignments that give the rock its foliated texture quartz and feldspars some have amphiboles (dark minerals) parent rock is shale that has undergone medium-to high grade metamorphism
A large mass of magma may require thousands or even millions of years to solidify. Because different minerals crystallize under different environmental conditions (temperature and pressure), it is possible for crystals of mineral to become quite ______________ before others even begin to form. If molten rock containing some large crystals moves to a different environment --for example, by erupting at the surface --the remaining liquid portion of the lava cools more quickly. The resulting rock, which has large crystals embedded in a matrix of smaller crystals is said to have a _________________ texture.
image porphyritic texture
phyllite
image represents a degree of metamorphism between slate and schist constituent platy minerals are larger than those in slate but not large enough to be identifiable with unaided eye can be distinguished from slate by its glossy sheen and wavy surface exhibits rock cleavage and is composed mainly of very fine crystals of muscovite, chlorite , or both
rock or slaty cleavage
image rocks that split into thin slabs when hit with a hammer exhibit rock cleavage best displayed in slates that exhibit an excellent splitting property call slaty cleavage
Fossils
image the remains or traces of prehistoric life, are important inclusions in sediment and sedimentary rocks. important tools for interpreting the geologic past Knowing the nature of the life-forms that existed at a particular time helps researchers understand past environmental conditions. Fossils are important time indicators and play a key role in correlating rocks of similar ages that are from different places.
Pumice is a glassy volcanic rock with a _____________________ texture that forms when large amounts of _____________ escape through silica-rich lava to generate a gray, frothy mass. In some samples, the _____________ are quite noticeable, whereas in others the pumice resembles fine shards of ____________________ glass.
image vesicular gas voids intertwined
vesicular Common features of many extrusive rocks are the ______________ left by ______ bubbles that escape as lava solidifies. These nearly spherical openings are called ________________, and the rocks that contain them are said to have a ___________________ texture.
image voids gas vesicles vesicular
granite continued
image 10. granites appear gray in color from a distance 11. when composed of dark pink feldspar grains, granite can exhibit a reddish color.
halite
image chief component of rock salt used in cooking and seasoning of food melts ice on roads making hydrochloric acid sought, traded, and fought over in human history
conglomerate
image consists largely of gravels
Anphanitic is ______________grained.
image fine composed of crystals that are too small for the individual minerals to be identified without a microscope
when magma crystallizes at depth, it forms __________ ______________ __________ or _______________ rocks. These rocks are observed at the surface in locations where uplifting and erosion have stripped away the overlying rocks.
image intrusive igneous rocks or plutonic rocks, after Pluto, the god of the lower world in classical mythology.
chert
image is the name used for a number of very compact and hard rocks made of microcrystalline quartz
regolith
image layer of rock and mineral fragments produced by weathering. Some woudl call this soil, but soil is more than an accumulation of weathered debris.
Slate
image very -fined grained foliated rock composed of minute chlorite and mica flakes too small to be visible may contain quartz and feldspar crystals slate appears dull and resembles shale excellent rock cleavage or tendency to break into flat slabs generated by low-grade metamorphism of shale, mudstone, or siltstone also produced when volcanic ash is metamorphosed
texture of rock
image example
Giant's Causeway in Northern Ireland
image fig. 4.29
pegmatites
image of pegmatites
obsidian
image of rock
serpentinite
image of rock
iron oxide
image of rust
scoria
image of scoria
soil
image of soil
Yellowstone National park
image of the park
The existence of these high pressure chemical minerals provides convincing evidence that pressures and temperatures involved in ______ __________________ can be as great as those found in the upper mantle.
impact metamorphism
The products of these impacts, called _____________, include mixtures of fused fragmented rock plus glass-rich ejecta that resemble volcanic bombs.
impactiles
Where do gravels accumulate?
in a variety of environments indicate the existence of steep slopes or very turbulent currents.
Each event was followed by nearly a month of ____________________________.
inactivity
Graywacke
is associated with submarine deposits made by dense sediment-choked torrents called turbidity currents
using these _____ _____, geologists distinguish among different zones of regional metamorphism.
index minerals
Unlike most igneous rock names, such as granite and basalt, the terms tuff and volcanic breccia do not imply ________________ _____________. Instead, they are frequently identified with a modifier: for example, rhyolite tuff =
indicates a rock composed of ash - size particles having a felsic composition
A wide variety of resources are classified as ___ ___.
industrial minerals
The second major source of sediment is soluble material produced largely by chemical weathering. When these ions in solution are precipitated by either ____ or _____ processes, the material is known as chemical sediment, and the rocks formed from it are called ___ ____ rocks
inorganic or biological processes chemical sedimentary rocks
Across areas where regional metamorphism has occurred, rock textures vary based on the _________________ of metamorphism.
intensity
partial melting of mafic rocks yields ____________________ or ________________________ magmas.
intermediate or andesitic
The bands in the migmatites often form ___ ____ and may contain tabular ____ of the dark components.
intricate folds inclusions
19th century study by G.K. Gilbert of the U.S. Geological Survey in the Henry Mountains of Utah produced the first clear evidence that igneous _______________ can lift the sedimentary strata they penetrate
intrusions
The structures that result from the emplacement of magma into preexisting rocks are called ______________________ or __________________.
intrusions or plutons
Carbonic acid ionizes to form the reactive hydrogen ion and the bicarbonate ____.
ion
back carbonaceous slate contains organic material red slate get color from ____ green slate gets color from mineral ____
iron oxide chlorite
The element iron combines with oxygen to produce ___ ___
iron oxide, which give soil a reddish-brown or yellowing color.
So are major sources of ___, ___, _____, and ____ fertilizer, plus numerous materials essential to the construction industry, such as cement and aggregate.
iron, aluminum, manganese, phosphate
Regional metamorphism
is a common widespread type of metamorphism typically associated with mountain building, where large segments of Earth's crust are intensely deformed by the collision of two continental blocks. Sediments and crustal rocks that form the margins of the colliding continents are folded and faulted, and as a result, they shorten and thicken like a rumpled carpet. Continental collisions may also cause crystalline basement rocks, as well as slices of oceanic crust that once floored the intervening ocean basin, to be uplifted and deformed.
Sierra Nevada batholith
is a continuous granitic structure that forms much of Sierra Nevada in California
Hornfels
is a fine - grained nonfoliated metamorphic rock, and unlike marble and quartzite, it has a variable mineral composition.
black shale
is black because it contains abundant organic matter called carbon
pumice
is lighter in color and less dense than scoria, and many pumice fragments have so many vesicles that they are light enough to float
dolostone versus limestone
limestone with fizz with dilute HCl dolostone unless it is powdered will not visibly react to the acid
O horizon
largely organic material upper portion: plant litter, such as loose leaves and other organic debris lower portionL partly decomposed organic matter (humus) in which plant structures can no long be identified microscopic life: bacteria, fungi, algae and insects all organisms contribute oxygen, carbon dioxide and organic acids to the developing soil
Coast Mountains of western Canada into southern Alaska
larger batholith
lapilli
larger pyroclasts that range in size from small beads to walnuts; they are also called cinders
batholiths
largest intrusive igneous body occur as mammoth linear structures several hundred kilometers long and up to 60 miles wide ex: Sierra Nevada batholith
When molten rock reaches Earth's surface, it is called ________________.
lava
and bombs, when they are ejected as incandescent _____________
lava
Because cinder cones are composed of loose fragments rather than solid rock, the ___________ usually flows out from the uncosolidated base of the _______ rather than from the crater.
lava cone
Extrusive igneous rocks form when ____________ solidifies or when volcanic debris falls to ___________________ Surface.
lava Earth's
Rocks that exhibit a vesicular texture often form in the upper zone of a ___________ flow, where cooling occurs _______________ enough to preserve the _______________________ produced by the expanding gas bubbles.
lava rapidly openings
pahoehoe flows often dvelop cave-like tunnels called ________ _________, that were previously conduits for carrying lava from an active vent to the flow's leading edge
lava tubes
Recall that during high grade metamorphism, the light and dark components separate, given gneisses their characteristic banded or ____appearance.
layered thus most gneisses consists of alternating bands of white or reddish feldspar-rich zones and layers of dark ferromagnesian minerals These banded gneisses often exhibit evidence of deformation, including folds and sometimes faults
According to Bowen's reaction series, olivine crystallizes first and is _____ resistant to chemical weathering.
least
E horizon
light-colored layer that contains little organic material As water percolates downward through this zone, finer particles are carried away. washing of fine soil components is termed eluviation water percolating downward also dissolves soluble inorganic soil components and carries them to deeper zone. this depletion of soluble materials from the upper soil is termed leaching
formation of anthracite coal
lignite and bituminous coals are sedimentary rocks when sedimentary layers are subjected to the folding and deformation associated with mountain building, the heat and pressure cause a further loss of volatiles and water, thus increasing the concentration of fixed carbon
chert
like glass, it has conchoidal fracture its hardness, ease of chipping, and ability to hold a sharp edge made chert a favorite of Native Americans for fashioning points for spears and arrows
When the remaining melt solidifies --either in place or another location, if it migrates into fractures in the surrounding rocks--it will form a rock with a ___________________ much different from the _________________ __________________.
mineralogy parent magma
The most widespread occurrence of hydrothermal metamorphism is along the axis of the mid-ocean ridge system. As plates move apart, upwelling _____________ from the mantle generates new seafloor. As seawater percolates through the young, hot oceanic crust, it is heated and chemically reacts with the newly formed _____________ rocks. The result is the conversion of basaltic rocks of the oceanic crust and uppermost mantle into the hydrated rocks ___ and ___
magma basaltic serpentinite and soapstone
In some settings, deeply buried rocks become heating beyond their melting points, producing _____. When these magma bodies grow large enough to buoyantly, they __________________ the overlying metamorphic and sedimentary rocks.
magma intrude
Data of this type led them to examine the possibility that _____________ might change (evolve), and thus one magma body could become the _____________________ to a variety of igneous rocks.
magma parent
As a Large basaltic magma body cools, the heavy minerals that crystallize early tend to settle to the lower portion of the ________________ ___________________________
magma chamber
clay minerals
make up a high percentage of inorganic material in soils most abundant sedimentary rock, shale, contains a high proportion of clay minerals in picture is shale
When a rock undergoes partial melting, it forms a ____________ that is enriched in ions from minerals with the lowest melting temperatures, while the ________________ portion is composed of minerals with _________________ _____________ ______________.
melt unmelted highest melting temperatures.
These gases tend to separate from the _____________ as it moves toward the surface (from a high-to a low-pressure environment.
melt As the gases build up, they may eventually propel magma from the vent.
Liquid portion is called _____________, is composed mainly of mobile ions of the eight most common elements found in Earth's crust. 1. 2. 3. 4. 5. 6. 7. 8.
melt 1. silicon 2. oxygen 3. aluminum 4. potassium 5. calcium 6. sodium 7. iron 8. magnesium
Partial ________________ of basaltic rocks is yet another way in which at least some ____________________ magmas are produced.
melting andesitic
Thus, ______________ converts a ___________ consisting of tight, uniformly packed ions into a ________________ composed of unordered ions moving ___________ about.
melting solid liquid randomly
Many copper and silver deposits result when weathering processes concentrate _______________ that are dispersed through a low-grade primary ore.
metals
In Black Hills, _____________________ crystals as thick as telophone poles _____ feet have been
spodumene 40 feet
The altered rocks occur in a zone called a ___________ ____.
metamorphic aureole
The degree to which a parent rock changes during metamorphism is called its ___ ___.
metamorphic grade
There are many different environments in which ______ occurs. Most of these environments occur in the vicinity of plate margins, and several are associated with igneous activity.
metamorphism
In other words, these fluids bring in new atoms or take out atoms rather than simply reorganize what is already present. When this occurs, the overall chemical composition of the surrounding rock changes in a process called _______________.
metasomatism
Occasionally, these expanding gases propel incadescent lava hundreds of ____________ into the air, producing lava fountains.
meters
example: schists composed primarily of muscovite and biotite are called ____
mica schist
____, including ____, _____, and single-celled ___, play an active role in the decay of plant and animal remains.
microorgananisms fungi bacteria protozoa
Rocks of this type are called ______.
migmatites migma - mixture ite - stone
Crystallization in a fluid-rich environment, where ion ______________________ is enhanced, results in the formation of crystals several centimeters, or even a few meters, in length.
migration
Unlike the organic matter from which they formed, the newly created petroleum and natural gas are ____. These fluids gradually squeezed from the compacting mud-rich layers where they originate, called the _____ ____, into adjacent permeable beds such as __, where openings between sediment grains are larger.
mobile source rock sandstone
Soil water not only provides the necessary ______________ for the chemical reactions that sustain life, it also supplies plants with nutrients in a form they can use.
moisture
In addition, swelling of the magma chamber fractures the rock above, allowing the fluid magma to move upward along the newly formed openings often generating outpourings of lava for weeks, _____________ or years
months
Loss of gases renders magma (lava) ____________ viscous.
more
How many series?
more than 19,000
Quartz, which crystallizes last, is ______ resistant.
most
compaction of sediments
most common physical diagenetic change a reduction in pore space by packing grains more tightly together
Mt. Rainier, Washington
most dangerous volcano because like Nevado del Ruiz, it has thick, year-round mantle of snow and glacial ice 10,000 people live in the valleys around Rainer future rain could produce lahars that could be similarly destructive
Deep in the roots of _____, elevated temperatures caused by deep burial are responsible for the most intense metamorphic activity with a mountain belt.
mountains
At higher temperatures, flakes of _____ and ______ begin to dominate
muscovite and biotite
Certain microorganisms aid soil fertility because they have the ability to convert atmospheric nitrogen into soil___.
nitrogen
Inorganic limestones
occurs when chemical changes or high water temperatures increase the concentration of calcium carbonate to the point that it precipitates example: travertine ==type of limestone see in caves groundwater is the source of calcium carbonate
columnar jointing
occurs when igneous rocks cool and develop shrinkage fractures that produce elongated, pillar-like columns that move often have six sides
Lava has been intermittently pouring into the ______________________ever since, added new land to the island of _________________.
ocean Hawaii
Most active volcanoes on land are located along the margins of the _____ _____--notably within the _______ ________________ _____________known as the ___ ___ ____
ocean basins Circum-Pacific Belt "Ring of Fire"
The upper layers of the __________________--crust consist of basalt. In the United States, large portions of ________________ Oregon and ________________________ were the sites of extensive basaltic outpourings. These once -fluid basaltic flows have accumulated to thicknesses approaching ______ km or ____ miles
oceanic central Washington 3 km or 2 miles
Because this occurs in a marine environment, the rock layers containing the ___ and ___ are saturated with __.
oil and gas salt water
A geologic environment that allows for economically significant amounts of oil and gas to accumulate underground is termed an____ ___
oil trap
1500 of Earth's known volcanoes have erupted at least _______________, and some several times, in the past 10,000 years.
once
Once soil forms, erosional forces, especially water and wind, move soil components from ___ place to another
one
Unlike confining pressure, which squeezes rock equally in all directions, differential stresses are greater in ____ direction than in others.
one
frost wedging
one important example from mechanical weathering is that the frequency of freeze-thaw cycles greatly affects the amount of _ ____.
anticline as oil trap
one of the simplest traps, is an uparched series of sedimentary strata rising oil and gas collect at the top of the fold
B horizon
or subsoil is where much of the material removed from the E horizon by eluviation is deposited zone of accumulation accumulation of the fine clay particles enhances water retention in the subsoil in extreme cases clay accumulation forms a very compact and impermeable layer called hardpan
In some environments, ions may actually migrate into or out of a rock, thereby changing its ______ chemical composition.
overall
biosphere
owes its existence to a dozen or so elements that must ultimately come from Earth's crust
The abundant element in earth's crust is _____________. It makes up 47 % of Earth's crust by weight and _____% by volume.
oxygen 94% Oxygen atoms are so much bigger than most other atoms in common minerals that Earth's crust is mainly atoms packed closely together with smaller atoms , such as silicon, aluminum, potassium, tucked in between.
fig. 4.19 Water lowers the melting temperature of hot mantle rock to trigger _______________ melting. As an oceanic plate descends into the mantle, water and other volatiles are driven from the subducting crustal rocks into the mantle above.
partial melting
Experiments show that under the high pressure conditions calculated for the upper mantle, ______________ ______________ of the ultramafic peridotite yields a magma of _______________ composition.
partial melting basaltic
Because of this unique position, sediments and the rock layers that they eventually form contain evidence of ____ conditions and events at the surface.
past Furthermore, sedimentary rocks contain fossils, which are vital tools in the study of the geologic past.
The resulting rocks, called ______________ are composed of these unusually large crystals.
pegmatites
Partial melting of the mantle rock _____________ generates hot basaltic magma whose temperatures may exceed 1250 C or 2300F
peridotite
____________________is coarse grained texture. When large masses of magma slowly crystallize at great depth, they form igneous rocks that exhibit a coarse-grained texture described as phaneritic. Coarse grained rocks consists of a mass of _______________ crystals that are roughly equal in size and ______________ enough so the the individual minerals can be _____________________- with the aid of a _____________________. Geologists often use a small magnifying _________ to aid in identifying minerals in a phaneritic rock.
phaneritic phaner = visible intergrown large identified microscope lens
The large crystals in porphyritic rocks are referred to as __________________________, whereas the matrix of smaller crystals is called ___________________________.
phenocrysts (pheno = sho) (cryst = crystals) groundmass
Through the process of ____, plants absorb carbon dioxide from the atmosphere to produce the essential organic compounds needed for growth.
photosynthesis
Slate forms _______
phyllite, through continued recrystallization, generates a medium-grained schist.
As long as precipitation was adequate, the soil remained in ___.
place
Andesite commonly exhibits a porphyritic texture. The phenocrysts are often light, rectangular crystals of _____________________- feldspar or black, elongated __________________ crystals. Andesite may resemble _________________, so its identification usually requires microscopic examination to verify mineral makeup.
plagioclase amphibole rhyolite
Coal is formed mostly from ___material that accumulated in swampy environments on land
plant
Climatic conditions are an important control on the type of ___ and ____ life present.
plant and animal
The primary source of organic matter in soil is ___, although ____ and an infinite number of ____ also contribute.
plants animals microorganisms
The basic connection between plate tectonics and volcanism is that ___
plate motions provide the mechanisms by which mantle rocks undergo partial melting to generate magma
The crystals that make up aphanitic rocks are so small that individual minerals can be distinguished only with the aid of a ____________________ microscope or other techniques. Therefore, we commonly characterize fine -grained rocks as being _______________, ___________________, or _____________- in color. Light -colored aphanitic rocks are those containing primarily light-colored _________________________ silicate minerals
polarizing light, intermediate dark nonferromagnesian
Humans can influence the rate of weathering by producing _______ that alter the composition of the atmosphere. ex: acid rain
pollutants
graywacke continued
poor sorting and angular grains characteristic of graywacke suggests that particles were transported only relatively short distance from their source area and were then rapidly deposited. Before the sediment could be reworked and sorted further, it was buried by additional layers of material.
On steep slopes, soils are ___ developed. Moisture content of the soil may not be sufficient for vigorous plant growth.
poorly
If the rock contains mixed large and small particles, the sand is said to be ___________ ____________.
poorly sorted
The remaining half consists of ____ spaces among the solid particles where air and water circulate.
pore
The addition of cement into a sedimentary deposit reduces the _____ as well.
porosity
Several geologic structures may act as oil traps, all have two basic features: 1. _______________________________ _______________ 2. ___ ____
porous permeable reservoir rock that will yield petroleum and natural gas in sufficient quantities to make drilling worthwhile 2. cap rock, such as shale, that is virtually impermeable to oil and gas
Metamorphic rocks may also contain some unusually large grains, called _________________, that are surrounded by a fine-grained matrix of other minerals.
porphyroblasts
A rock with a porphyritic texture is termed a ____________________.
porphyry
Amount of ______ influences the degree to which various materials are removed from the soil by percolating waters (a process called ____) and thereby affecting soil fertility.
precipitation leaching
Variations in temperature and precipitation determine whether chemical or mechanical weathering will _____ and also greatly influence the rate and depth of weathering.
predominate
By contrast, metamorphic rocks that contain platy minerals (such as micas) and or elongated minerals (such as amphiboles) typically display some kind of _____ orientation in which the mineral grains exhibit a parallel to subparallel alignment
preferred
Although the proportion of the major components in soil vary, the same four components are always _______to some extent
present
Partial melting that produces mantle-derived magmas may be triggered by a reduction in confining ________________________ during the process of __________________________ melting. this can occur, for example, where hot mantle rock ascends as part of slow-moving convective flow at mid-ocean ridges.
pressure decompression
Each type of metamorphism occurs over a range of temperatures and ____
pressures.
Basaltic (mafic ) magmas that originate from partial melting of mantle rocks are called ___________________ or ___________________ magmas because they have not yet evolved.
primary or primitive
organic
processes of water-dwelling organisms also form other chemical sediments are said to be biochemical ex: many water - dwelling animals and plants extract dissolved mineral matter to form shells and other hard parts after the organisms die, their skeletons collect by the millions on the floor of a lake or an ocean as biochemical sediment
inorganic
processes such as evaporation and chemical activity can produce chemical sediments example: dripstone that decorates many caves ex: salt left behind as a body of seawater evaporates
diatoms and radiolarians
produce glasslike silica skeletons tiny organisms are able to extract silica even though seawater contains only tiny quantities it is from their remains that most bedded cherts are believed to originate some bedded cherts occur in association with lava flows and layers of volcanic ash the silica came from the decomposition of the volcanic ash and not from biochemical sources
Acids such as carbonic acid readily decompose many rocks and produce certain ______ that are soluble in water.
products
Upon impact, the energy of the once rapidly meteorite ( fragments of comets or asteroids) is transformed into heat energy and shock waves that pass through the surrounding rocks. The result is _____, _____ and sometimes melted rock.
pulverized, shattered
Because of large percentage of voids, many samples of _________________ float when placed in water. Oftentimes, flow lines are visible in pumice, indicating that some movement occurred before solidification was ___________________.
pumice complete
Another common vesicular rock, called __________________-, forms when ________-rich lava is ejected during an explosive eruption.
pumice silica
________________________ (fragmental) texture is another group of igneous rocks is formed from the consolidation of individual rock fragments ejected during explosive volcanic eruptions. The ejected particles might be very fine ash, molten blobs, or large angular blocks torn from the wall of a vent during an _____________________. Igneous rocks composed of these rock fragments are said to have a ________________________ or ___________________ texture.
pyroclastic eruption pyroclastic texture or fragmental
Some of the most destructive forces of nature are ____________ _____________, which consist of hot gases infused with incandescent ash and large lava fragments.
pyroclastic flows
When volcanoes erupt energetically, they eject pulverized rock, lava, and glass fragments from the vent. The particles produced are called ________________ ______________.
pyroclastic materials
The light colored silicates, usually ______ and ____ ____ have the lowest melting temperature and begin to melt first.
quartz potassium feldspar
For example, when quartz sandstone is metamorphosed to form _______, the mineralogy does not change; the quartz remain quartz.
quartzite
In addition, quartz sandstone is metamorphosed to produce
quartzite
During some volcanic eruptions, molten rock is ejected into the atmosphere, where it is _________________ and _____________ quickly to become a solid. Rapid cooling of this type may generate rocks having a _____________________ texture.
quenched cools glassy
One hazard associated with volcanoes is their ability to produce ________________
tsunamis
When the parent material is bedrock, the soils are termed
residual soil
Headstones of granite, which is composed of silicate minerals, are relatively _____ to chemical weathering.
resistant
Quartz, the other main component of granite is very ______ to chemical weathering; it remains substantially unaltered when attacked by weak acidic solution
resistant
Soil conservation programs can substantially reduce the loss of this basic _____.
resource
Andesites and other lavas of intermediate composition account for most of the ________.
rest
Gneisses having a felsic composition may be derived from granite or its fine grained equivalent, ____.
rhyolite
In contrast to granite, which is widely distributed as large intrusive masses, _______________ deposits are ________________ common and generally less voluminous. The thick rhyolite lava flows and extensive ash deposits in and around _____________________ _____________ _______________ are well known exceptions to this generalization.
rhyolite less Yellowstone National Park
When normal farm cultivation cannot eliminate the channels, we know the _______ have grown large enough to be called _____
rills gullies
Other features found in some sedimentary rocks also give clues to the past. ____ ______ are small waves of sand that develop on the surface of a sediment layer through the action of moving water or air.
ripple marks
Water causes _______ to melt at _________________ temperatures, just as putting rock salt on an icy sidewalk induces melting.
rock lower
Many factors influence the rate of rock weathering. Among the most important are variations in the composition of the ____. More resistant rock protrudes as ____ or as steeper _____ on an irregular hillside.
rock ridges cliffs
What can geologists infer from the texture?
rock's origin based on careful observations of grain size and other characteristics of the rock
The incomplete melting of ___________ is known as ________________________ ______________ a process that produces most magma.
rocks partial melting
Oil and gas, being less dense than water, migrate upward through the water-filled pore spaces of the enclosing ___.
rocks.
These nearly flat, step-like surfaces slow ______ and thus decrease soil loss while allowing more water to soak into the ground.
runoff
conduit in volcano
tube where magma comes up through
Such a transformation is often termed ____________ _________ and takes place in one or two ways. 1. 2.
secondary enrichment 1. chemical weathering coupled with down-ward percolating water removes undesired materials from decomposing rock, leaving the desired element in the upper zones of the soil. 2. basically the reverse of the first; the desirable elements that are found in low concentrations near the surface are removed and carried to lower zones, where they are redeposited and become more concentrated.
Once in the stream channel, these soil particles, which can now be called _____, are transported downstream and eventually deposited.
sediment
nevertheless, most of the Earth's solid surface consists of either _____ or ___________________!
sediment sedimentary rocks
Over a broad area, erosion caused by surface runoff may be estimated by determining the ___ __ of the streams that drain the region.
sediment loads
Not all dead plant material decays immediately back to carbon dioxide. A small percentage is deposited as sediment. Over long spans of geologic time, considerable biomass is buried with ____.
sediment.
___rocks are important in the interpretation of Earth history
sedimentary
Other types of pyroclastic rocks are composed of fragments that solidified before impact and became cemented together at some later time. Because pyroclastic rocks are made of individual particles or fragments rather than interlocking crystals, their textures often resemble those exhibited by _________________ rocks rather than those associated with ________________ rocks
sedimentary igneous
A thin veneer of _______________ rock and a small iron-________core plus igneous and metamorphic rocks make up the Earth.
sedimentary rich
Some of these bodies cut across existing structures, such as _____________________ strata, wheras others form when magma is injected between ______________________________ layers.
sedimentary sedimentary
An environment of deposition or ____________________________ ___________ is a geographic setting where sediment is accumulating.
sedimentary environment
5. As deposition continues, older sediments are buried beneath younger layers and gradually converted to ___ ___
sedimentary rock (lithified) by compaction and cementation -this and other changes are referred to as diagenesis, a collective term for all the changes (short of metamorphosis) that take place in texture, composition, and other physical properties after sediments are deposited
Shale
sedimentary rock consisting of silt and clay size particles account for over half of all sedimentary rocks particles in these rocks are so small that they cannot be readily identified without great magnification and this makes shale more difficult to study and analyze than other sedimentary rocks
When the organisms die, these skeletal remains settle to the ocean floor as biochemical sediment and become ____ ___.
sedimentary rock.
bedding planes
separate the strata or beds these are relatively flat surfaces along which rocks tend to separate or break changes in the grain size or in the composition of the sediment being deposited can create bedding planes pauses in deposition can also lead to layering because chances are slight that newly deposited material will be exactly the same as previously deposited sediment
In the Grand Canyon, where the gentler slopes of weathered ____ are quite inconspicuous and overgrown with vegetation, in contrast with the bold cliffs produced by more durable rocks.
shale
the parent rock of most hornfels is_____ or another clay-rich rock, which has been "baked" by a hot intruding magma body.
shale Hornfels tend to be gray to black in color and quite hard, and it may display conchoidal fracture.
With the exception of the volcanic islands that form above subduction zones, most other small oceanic islands are either a single _________________ volcano or the coalescence of two or more shields built on massive amounts of pillow lavas
shield
Recall that heat from the hot basaltic magma can partially melt the overlying crustal rocks, which are ______________ rich and have a much lower melting temperature, thereby producing large quantities of granitic magmas.
silica This process is thought to have been responsible for the volcanic activity in and around Yellowstone National Park in the distant past
By contrast, rocks high in _________ contain very little iron, magnesium or calcium, but are enriched with _____________ and __________.
silica enriched with sodium and potassium
Separation of these two fractions yields a melt with a chemical composition that is richer in ____________________ and nearer the _____________ granitic end of the spectrum than the rock from which it formed.
silica felsic (granitic)
Granitic magma, which as a high _______________ content, is quite ______________ "thick" and may erupt at temperatures as low as _____________________.
silica viscous 650 C or 1200F
_______________ - rich magmas erupt mainly along the continental margins.
silica - rich. This is strong evidence that continental crust, which is thicker and has a lower density that oceanic crust, must play a role in generating these more highly evolved magmas.
Composiste cones reflect the viscous nature of the material from which they are made. In general, composite cones are the product of _____________ - ___________ magna having an __________________________composition.
silica -rich andesitic
Although aluminum is the third most abundant element in Earth's crust, economically valuable concentrations of this important metal are not common because most aluminum is tied up in _____ minerals, from which is extremely difficult to extract.
silicate
Igneous rocks are composed mainly of _________________ minerals.
silicate
When magma cools, generally the _____________ and __________ atoms link together first to form_____________________________, the basic building blocks of the silicate minerals.
silicon and oxygen silicon-oxygen tetrahedra
What are the two most abundant constituents of igneous rocks? Name the other elements that when combined with Si and O comprise 98% by weight of most magmas. Magmas contain small amounts of many other elements like________________ and _______________ plus trace amounts of much rarer elements like ____________ , _________ and ____________.
silicon and oxygen 1. aluminum 2. calcium 3. sodium 4. potassium 5. magnesium 6. iron titanium and manganese gold, silver, and uranium
At temperatures approaching the melting point of rock, ____ forms. Sillimanite is a high-temperature metamorphic mineral used to make porcelains used in extreme environments, such as for spark plugs.
sillimanite
By contrast, the mineral ___ forms only in extreme environments, where temperatures exceed ______F and rocks containing it _____ - grade.
sillimanite 1100 F high - grade
Most cinder cones are produced by a ___________, short-lived eruptive event.
single
texture is used to describe the ____, ____, and arrangement of the mineral grains within a rock.
size shape and mineral grains
In addition, most of the lava (80%) flowed through a well-developed system of lava _____
tubes
By contrast, minerals such as muscovite and biotite typically form a large number of ________ grains. As a result, metamorphic rocks that contain large crystals (porphyroblast) for example, garnet embedded in a finer-grained matrix of biotite and muscovite are common.
smaller
stocks
smaller plutons are termed stocks
Gradually, sharp edges and corners become ________ and ___________.
smooth and rounded
pahoehoe
smooth surfaces that sometimes resemble twisted braids hotter and more fluid pahoehoe can change into aa lavas
chalk
soft, porous rock made up almost entirely of the hard parts of microscopic marine organisms found along the southeast coast of England
Although thinly distributed over the land surface, the _____ functions as a fundamental interface, providing and excellent example of the integration among many parts of the Earth system
soil
thinnest veneer of _____ combine to support a web of life of wondrous diversity in continous change
soil
Inf fact, for well-developed soils in many regions, the significance of natural vegetation in influencing ___ type is frequently implied in the description used by soil scientists. 1. 2. 3.
soil 1. prairie soil 2. forest soil 3. tundra soil
When the environmental changes occur, such as climate, vegetative cover, and animal (including human) activity, the
soil responds
during metamorphism, the rock remains essentially ____.
solid
The Earth's crust and mantle are composed primarily of _______________ not, molten, rock. Although the outer core is ____________, this iron-rich material is very ___________ and remains deep within Earth.
solid fluid dense
To better understand how magma crystallizes, let us consider how a simple crystalline ________melts. Recall that, in any crystalline solid, the ____________ are arranged in a closely packed regular pattern. However, they are not without some motion: they exhibit a restricted vibration about fixed points.
solid ions
Most magma originates in rocks from Earth's upper mantle that is essentially
solid, not molten
igneous rock forms as molten rock cools and __________________.
solidifies.
The felsic (granitic) magmas produced in this manner usually __________________ before reaching the surface, so volcanism is not typically associated with these collision - type mountain belts.
solidify
Soil water is far from pure water, instead, it is a complex solution that contains many ____ _____.
soluble nutrients
immature
some soils lack horizons altogether soil building has been going on for only a short time characteristic of steep slopes, where erosion continually strips away the soil, preventing full development
Deposits of wind-blown sand are usually better ____ than deposits sorted by wave activity.
sorted
mineral silvite
source of potassium "potash" fertilizer
parent material
source of the weathered mineral matter from which soils develop and is a major factor influencing newly forming soil
The most productive kimberlite pipes are those in
south Africa
Eventually, an angular block may evolve into a nearly ____ boulder.
spherical
Once this occurs, the boulder's shape does not change, but the ____ mass continues to get smaller.
spherical
what does texture reveal?
the environment in which the rock formed
The more viscous the material
the greater its resistance to flow ex: syrup is more viscous than water
potassium feldspar
the most abundant products of the chemical breakdown of feldspar are residual clay minerals
cementation
the most important process by which sediments are converted to sedimentary rock it is a change that involves the crystallization of minerals among the individual sediment grains gradually, the crystallization of new minerals from these ions takes place in the pore spaces, cementing the clasts together
The names of the classificaiton units are combinations of syllables, most of which are derived from Latin or Greek
the names are descriptive ex: aridosol Latin aridus - dry solum - soil are characteristically dry soils in arid regions inceptisol inceptum = beginning solum = soil are soils with only the beginning or inception, of profile development
conglomerates
the particles are large enough to be identified as distinctive rock types; thus, they can be valuable in identifying the source areas of sediments poorly sorted because the opening between the large gravel particles is sand or mud
Bauxite
the principle ore of aluminum is one important example of an ore created as a result of enrichment by weathering processes
Lithification
the processes by which unconsolidated sediments are transformed into solid sedimentary rocks. lithos = stone fic = making
strata or beds
the single most common and characteristic of sedimentary rocks each straum is unique it may be sandstone, a fossil-rich limestone, a black shale, the variations in texture, composition, and thickness reflect the different conditions under which each layer was deposited. thickness of beds ranges from microscopically thin to tens of meters thick.
magma
the source material for volcanic eruptions is _______, molten rock that usually contains some crystals and varying amounts of dissolved gas
crystal settling
this process occurs when the earlier formed minerals and denser (heavier) than the liquid portion and sink toward the bottom of the magma chamber
fault trap
this type of trap forms when strata are displaced in such a manner as to bring a dipping reservoir rock into position opposite an impermeable bed
There are ____ foliated textures
three 1. rock or slaty cleavage 2. schistosity 3. gneissic texture or banding
By applying a thorough knowledge of present-day conditions, geologists attempt to reconstruct the ancient environments and geographic relationships of an area at the ___ a particular set of sedimentary layers were deposited.
time
schist describes the texture of rocks and as such it is used to name rocks that have a wide variety of chemical compositions
to indicate composition, mineral names are added.
No single factor is responsible for a soil's character; rather it is the combined influence of parent material, time, climate, plants and animals, and ____ that determines this character.
topography
The lay of the land can vary greatly over short distances. Variations in ____ can lead to the development of a variety of localized soil types.
topography
By contrast, those developed on unconsolidated sediment are called ____ soils.
transported
Frequently, crop residues are left on fields. This debris protects the surface from both water and wind erosion. To protect fields from excessive wind erosion, rows of _____ and shrubs are planted as windbreaks that slow the wind and deflect it upward.
trees
Pyroclastic Rocks are composed of fragments ejected during a ________________ eruption. One of the most common pyroclastic rocks called _______________, is composed of many tiny, ash-sized fragments that were later cemented together. In situations where the ash particles remained hot enough to fuse, the rock is called _______________ _________________. Welded tuff consists of tiny glass shards, it may contain walnut size pieces of ___________________ and other rock fragments
volcanic tuff welded tuff pumice
Cinder cones number in the thousands around the globe. Some occur in groups such as the ____________________ field near _________________, Arizona
volcanic field Flagstaff, Arizona
Geologists have observed that, over time, a ______________ may extrude lavas that vary in ________________________.
volcano composition
The lava flows generally form in the final stages of the ___________________ life span, when the magma body has lost most of its gas content.
volcano's
these destructive sea waves sometimes result from powerful volcanic explosions or the sudden collapse of flanks of _________________ into the ocean.
volcanoes 1883, volcanic eruption on the Indonesian island krakatoa tore the island apart and generated a tsunami that killed 36,000
At temps that exceed 2000 F, these gases can quickly expand to occupy hundreds of times their original ______________________.
volumes
When a prolonged drought struck in the 1930's, the unprotected soils were _____ to the wind. Severe soil loss, crop failure, and economic hardship resulted.
vulnerable
The optimal environment for chemical weathing is a combinations of ____ temperatures and abundant __.
warm moisture
eluviation
washing out of fine soil components
Another factor affecting the melting temperature of rock is its ____ content.
water
Basaltic magmas are also generated at subduction zones, where __________ driven from the descending slab of oceanic crust promotes partial melting of the mantle rocks that lie above.
water
One way that carbon dioxide makes its way back to the hydrosphere and then to the solid Earth is by first combining with ____ to form carbonic acid (H2CO3), which then attacks the rocks that compose Earth's crust.
water
The 3 remaining elements aluminum silicon oxygen join with ________________ to produce residual clay minerals.
water
The salt dissolves in water and seeps into cracks that quite likely originated from frost action. When the _______ evaporates, the growth of salt crystals further breaks the pavement
water
Water is abundant in Earth's crust. In the upper crust ____ occurs as groundwater.
water
thinner film of
water
The introduction of ___________ to generate magma occurs mainly at ____________________ plate boundaries, where cool slabs of oceanic lithosphere descend into the mantle.
water convergent
lahars occur when volcanic ash and debris becomes saturated with ____________ and rapidly moves down steep volcanic slopes, generally following stream valleys.
water 1. Mt. St. Helens 2. 1985, deadly lahars during eruption of Nevado del Ruiz in the Andes mountains of columbia claimed 25,000 lives
When present in solid rock, they may be used to determine the direction of movement of ancient wind or ___ ____.
water currents