Earth Science 3/28/17

Oceanic Hot Spots and mid-oceanic ridges are generally associated with this type of magma that originates in the Upper Mantle.

Basaltic Magma

This magma type is very high in iron and magnesium, as much as 50%. As a result it can be described as very MAFIC.

Basaltic Magma

Peléean eruptions

Gases trapped in sticky magma build up tremendous pressure, as pressure is released, rocks and ash are thrown around

regional metamorphism

Metamorphism associated with large scale mountain building

Where do mid-ocean ridges form?

Mid-ocean ridges form long, underwater mountain ranges that sometimes have a rift valley down their center.

Intermediate igneous rocks

Midway betwen the felsic and mafic ends of the scale. These rocks are neither as rich in silica as the felsic rocks nor as poor in it as the mafic rocks. We find the intermediate intrusive igneous rocks to the right of granite.

Dike

Pluton that cuts across preexisting rocks and often forms when magma invades cracks in surrounding rock bodies

dike

Pluton that cuts across preexisting rocks and often forms when magma invades cracks in surrounding rock bodies.

Sill

Pluton that forms when magma intrudes parallel rock layers

sill

Pluton that forms when magma intrudes parallel rock layers.

Felsic Rocks

Poor in Iron and magnesium and rich in felsic minerals that are high in silica. Minerals include quartz, orthoclase feldspar, and plagioclase feldspar.

Ion

Positively and negatively charged atoms

Subduction

Process by which one tectonic plate slips beneath another tectonic plate

Decompression Melting

Produces the greatest volume of magma anywhere on Earth. It is a the process by which most basalts form on the seafloor.

Ex. Mount Vesuvius & Pompeii

Pyroclastic flow

Silicate minerals

Quartz, feldspars, muscovite, and biotite micas, amphiboles and pyroxenes, and olivine - form a systmeatic series. Felsic minerals are the highest in silica: mafic minerals are the lowest in silica. Mafic minerals crystallize at highter temperatures - that is, earlier in the cooling of a magma - than felsic minerals.

Laccolith

Relatively small, mushroom - shaped pluton that forms when magma intrudes into parallel rock layers close to earths surface

laccolith

Relatively small, mushroom-shaped pluton that forms when magma intrudes into parallel rock layers close to Earth's surface.

Magma chamber

Reservoirs for magma from where they erupt

>60% silica, high viscosity, high explosivity. Hot spots under continents. Very low temperature

Rhyolitic Magma

The most powerful explosions, such as the Yellowstone eruption 630,000 years ago have been linked to this type of magma.

Rhyolitic Magma

This magma type has the highest silica content of all magma types.

Rhyolitic Magma

Where does volcanoes also occur?

Volcanoes also occur where an oceanic plate is subducted beneath a continental plate.

Where is another place that volcanoes can occur?

Volcanoes can also occur where two plates push together,or converge.

Where can volcanoes occur?

Volcanoes can occur where two plates pull apart,or diverge.

What does volcano form?

Volcanoes form a regular pattern on Earth.

Where do volcanoes form?

Volcanoes form along the mid-ocean ridges,where two plates move apart.

What decreases the melting temperature beneath spreading ridges?

Water

What does the water in the sinking plate eventually leaves?

Water in the sinking plate eventually leaves the crust and rises into the wedges of the mantle above it.

What helps form magma?

Water that is brought down with the sinking plate eventually helps to form magma,which rises to the surface.

Continental drift

Wegener's hypothesis that earths continents were joined as a single landmass called Pangaea, that broke apart about 200 Mya and slowly moved to their present positions

Magnetic reversal

When earths magnetic field changed polarity between normal and reversed

What is a skylight?

When part of the roof of a lava tube collapses and people can look in and observe or access can be gained t an inactive lava tube.

What determines the rate of cooling and what the rocks will look like?

Where magma crystalizes determines their rate of cooling and the rate of cooling determines what the igneous rock will look like.

Laccolith

a lens-shaped pluton with a round top and flat bottom. Compared to batholiths and stocks, they are relatively small

Rift Valley

a long, narrow trough bounded by normal faults. It represents a region where divergence is taking place.

Subduction Zone

a long, narrow zone where one lithosphere plate and transported into the mantle

Ring of Fire

a major belt of volcanoes that rims the Pacific Ocean

Mantle Plume

a mass of hotter-than-typical material that ascends toward the surface, where it may lead to igneous activity. These plumes of solid yet mobile material may orginate as deep as the core-mantle boundry.

Laccolith

a massive igneous body intruded between preexisting strata

sheeting

a mechanical weathering process that is characterized by the splitting off of slablike sheets of rock.

Slab Pull

a mechanism that contributes to plate motion in which cool, dense oceanic crust sinks into the mantle and "pulls" the trailing lithosphere along.

shield volcano

a mountain with a broad, gently sloping sides, and a nearly circular base. form when layers of lava accumulate during nonexplosive eruptions. the largest types of volcanoes

Shield Volcano

a mountain with broad, gently sloping sides and a nearly circular base, stays active as long as the hot spot is still active, located at hot spots, if oceanic contains basaltic lava, if continental contains rhyloitic magma. Ex: Mauna Loa, Yellowstone

Natural Disaster

a natural event that causes great damage and/or loss of life

bedding plane

a nearly flat surface that seperate two beds of sedimentary rock. Each bedding plane marks the end of one deposit and the beginning of another having different characteristics

Dike

a pluton that cuts across preexisting rocks, form when magma invades cracks in surrounding rock bodies, range in size from a few centimeters to several meters wide and can be tens of kilometers long

An igneous rock with a mixed texture of coarse grains (phenocrysts) surrounded by fine crystals (groundmass) is termed a. porphyritic b. phaneritic c. aphanitic d. necrotic

a porphyritic

facies

a portion of rock unit that possesses a distinctive set of characteristics that distinguishes it from other parts of the same unit

magmatic differentiation

a process by which rocks of varying composition can arise from a uniform parent magma--occurs because different minerals crystallize at different temperatures

Carbonization

happens when an organism is buried, followed by compression, that squeezes out gases and liquids leaving a thin film of carbon; Impressions remain in the rock when the carbon film is lost; effective at preserving leaves and delicate animals.

rhyolite

extrusive equivalent of granite--has a fells composition and light color, but it much more fine grained

andesite

extrusive series--the volcanic equivalent of diorite

evaluate the following statements. volcanoes are only found along coastlines.

false,most found along plate boundaries and hotspots.

What are ultramafic rocks composed of?

ferromagnesian silicates.

differentiation

forces that are unequal in different directions

flood basalts

form when lava flows out of long cracks in Earth's surface

seismic waves

formed during earthquakes; stored up energy is released and the waves radiate in all directions from the focus

Laccolith

forms when magma intrudes into parallel rock layers

Sill

forms when magma intrudes parallel to layers of rocks. Can range from only a few centimeters to hundreds of meters in thickness

dike

forms when magma invades cracks in surrounding rock bodies

types of weathering

forst wedging, salt crystal growth, sheeting and unloading, biological activity

principle of fossil succession

fossils are arranged according to their age

passive margin

found along most coastal areas that surround the Atlantic Ocean; not associated with plate boundaries; experience little volcanism and few earthquakes; include: continental shelf, continental slope, continental rise

fault

fractures in the rocks where rocks on one side of the fault are displaced relative to the rocks on the other side of the fault

Volatile

gaseous components of magma dissolved in the melt. Volatiles will readily vaporize at surface pressures.

deformation

general term that refers to all changes in shape or position of a rock body in response to stress

Composite volcano

generally cone-shaped with concave slopes

composite volcano

generally cone-shaped with concave slopes; built by violent eruptions of volcanic fragments and lava that accumulate in alternating layers

composite volcano

generally cone-shaped with concave slopes; built by violent eruptions of volcanic fragments and lava that accumulate in alternating layers. much larger than cinder cones.

earthquake

ground shaking caused by sudden rapid movement of one block of rock sliding past another

shear

motion similar to slippage that occurs between playing cards when the top of the stack is moved relative to the bottom

Rifting

moving apart forming cracks, breaks, or fissures

Geologic Hazard

natural processes that become hazards only when people try to live where these processes occur

rifting

new ocean basin begins with a continental rift— an elongated depression where the lithosphere is stretched and thinned; when lithosphere is thick and cold, rifts are narrow; when lithosphere is thin and hot, the rift can be very wide

Dip slip fault*

occurs when movement is parallel to the inclination

what tectonic setting created mt. vesuvius?

oceanic continental convergent boundaries

thickness of crust

oceanic: averages 7 kilometers thick. continental: thickest- 70 kilometers, thinnest- 20 kilometers

There are three different forms

of volcanoes.

The form of a volcano depends

on the composition of its magma and the amount of water vapor and other trapped gases.

ductile

once the elastic limit of a rock is surpassed it bends

brittle

once the elastic limit of a rock is surpassed it breaks

granite

one of the most abundant and intrusive igneous rocks, contains about 70% silica.

pumice

one volcanic rock type, that is a frothy mass of volcanic glass in which a great number of spaced remain after trapped gas has escaped from the solidifying melt

cementation

one way in which sedimentary rocks are lithified. As material precipitates from water that percolates through the sediment, open spaces are filled and particles are joined into a solid mass.

environments of metamorphism

ontact or thermal, hydrothermal, burial, subduction zone, regional

vent

opening in Earth's crust through which lava erupts and flows out onto the surface

Vent

opening in Earth's crust through which lava flows out onto the surface

vent

opening in earth's crust through which lava erupts and flows and flows out onto the surface

humus

organic matter in soil that is produced by the decomposition of plants and animals

age of earth

our understanding of radioactivity helps us accurately determine numerical dates for rocks that represent important events in Earth's distant past. The earth is about 4.6 billion years old.

Mantle

over 82% of the earths volume is in the mantle; solid rocky layer.

Volcanoes are powerful displays of earth in action

scientists have determined that three forces within earth can create a volcano

What is the primary constituent of magma?

Silica.

Flood basalt

Huge amounts of lava that erupt from fissures

Caldera

Huge holes left by the collapse of a volcanic mountain (empty magma chamber)

What is the definition of Lava?

It is magma that reaches the Earth's surface.

What are the three types of plutons?

1) tabular,

Outer core

A liquid layer of Earth's core that surrounds the solid inner core, composed of iron & nickel

<50% silica, low viscosity, non-explosive, rifts and ocean hot spots, Very Very hot, hottest of the three magma types

Basaltic Magma

Tectonic plate

Huge pieces of earths crust that cover its surface and fit together at their edges

Transform Boundries

(transform fault boundary) a boundary in which two plates slide past one another without creating or destroying lithosphere

Lithosphere

"sphere of rock" the entire crust plus the uppermost portion of the mantle; forms the cool, rigid outer shell, 100-250 km thick

asthenosphere

"weak sphere" 400km deep, small amount of melting; mechanically detached from lithosphere, which can move independently

Thrust fault*

(convergent plate boundaries) have angles less than 45 degrees so the overlaying plate moves almost horizontally (most pronounced along convergent plate boundaries)

reverse fault*

(convergent plate boundary) hanging wall moving up relative to the footwall (compressional stress as the crust shortens)

Trench

(deep-ocean trench) a narrow, elongated depression of the seafloor

Normal fault*

(divergent plate boundaries) the wall movie down relative to the footwall (tensional stress)

Strike slipt fault

(transform plate boundaries) placement that is horizontal and parallel to the strike of the fault; Right lateral: as you face the fault, the opposite side of the fault moves to the right. Left-lateral: as you face the fault, the opposite side of the fault moves to the left

Volcanic Arc

(volcanic island arc) a chain of volcanic islands generally located in a few hundred kilometers from a trench where there is active subduction of one oceanic plate beneath another

What are the two types of lava flows?

1) Pahoehoe (pah-hoy-hoy): ropy surface like taffy

What are the two ways magmas can crystalize?

1) Rapid Cooling 1100-1200 degrees celcius (aphanatic fine grained texture)

Four ways in which Sill differs from lava flows and pyroclastic deposits

1) They lack the ropy, blocky, and vesicle-filled structures that characterize many volcanic rocks

What are the two branches that Bowen's reaction series consists of?

1) a discontinuous branch

What are the three main parts of magmas?

1) high temperature mix of crystalizing solids (minerals),

What are the two separate processes that account for how igneous rocks form?

1) magma or lava cools and crystalizes to form aggregates of minerals.

reasons for the variation in the composition of magmas

1. rocks in the upper mantle undergo partial melting to produce basaltic magmas

ways sill differs

1. they lack the ropy, blocky, and vesicle filled structures that characterize many volcanic rocks

divergent boundary

2 plates pull apart from each other

Volcanic island arc

A long, curved chain of volcanic islands, common in the pacific ocean where they border deep ocean trenches, part of the ring of fire, formed by 2 oceanic plates colliding

Lava Flow

90% is basaltic lava, <10% of lava is andesitic lava and 1% is rhyolitic lava

Ring of fire

A belt of volcanoes around the rim of the pacific ocean, encircles the pacific basin

Divergent Boundries

A boundry in which two plates move apart, resulting in the upwelling of material from the mantle to create new seafloor

Covergent Boundries

A boundry in which two plates move together, resulting in oceanic lithosphere being thrust beneath a continent. Example: andes and the cascades

Strike-slip fault

A break in rocks due to shearing force where rocks on either side of the fault line move past each other without upward or downward movement.

Shield volcano

A broad volcano with gently sloping sides, built by quiet eruptions of fluid basaltic lava which spreads out in flat layers

Shield volcano

A broad, gentle slopping volcano made of layers of lava rock, in the middle of dangerous

Magnetic Reversal

A change in the earths magnetic field from normal to reverse or vice versa

What is the mid-ocean ridge?

A long, underwater valley that winds through the oceans, along the ridge, lava pours out of cracks in the ocean floor

Gabbro

A coarse-grained, dark gray intrusive igneous rock. It has an abudance of mafic minerals, especially pyroxenes. It contains no quartz and only moderate amounts of calcium-rich plagioclase feldspar.

Reverse fault

A compression fracture in rocks. Rocks above the fault surface are forced up over rocks below the fault surface.

Rock cycle

A cycle where rocks are continuously changed from one type to another in a never ending cycle

Fumarole

A fountain of hot gases or steam

Geyser

A fountain of hot water and steam that shoots into the air at intervals

Continental drift

A hypothesis by Alfred Wegener, which states that continents have moved around the globe, over time, to their present locations

Caldera

A large opening formed at the top of a volcano when a crater collapses into the vent following an eruption.

Granodiorite

A light-colored rock that looks something like granite. It is similar to granite having abundant quartz,but is predominant feldspar is plagioclase, not orthosclase.

What does lahar mean?

A mudflow composed of pyroclastic materials such as ash.

Magmatic differentiation

A process by which rocks of varying composition can arise from a uniform parent magma.

Normal fault

A pull apart (tension) fracture in rocks. Rocks above the fault surface drop downward in relation to rocks below the fault surface

Hot spot

A region of volcanic activity in the middle of a tectonic plate, here, material from the mantle rises, forming magma that erupts, is subduction and is caused by magma melting into the core of earth

Sill

A sheetlike body formed by the injection of magma between parallel layers of bedded country rock.

When magmas spread out parallel on a plain of weakness what is that called?

A sill

What can cause laccoliths?

A sill inflating can cause laccoliths.

A cinder-cone volcano

A steep sided, cone-shaped volcano made of small rock particles and cinder, explosive, most dangerous

Hot spring

A stream of hot, bubbling water that flows out of the ground continually, occurs when magma heats water in the ground

Viscosity

A substance's internal resistance to flow

viscosity

A substance's internal resistance to flow.

Composite volcano

A symmetrical cone with steep inward-curving sides made of layers of ash, lava, cinders, and rock, least dangerous

Conduit

A tubelike structure that allows lava to reach the surface

Composite volcano

A type of volcano built of silica-rich lava and tephra layers accumulated from alternating cycles of tephra & lava eruptions

Pegmatites

A vein of extremely coarse-grained granite, crystallized from a water-rich magma in the late stages of solidification, that cuts across much finer grained country rock and may contain rich concentrations of rare minerals.

Volcano

A vent in the Earth's surface that often forms a mountain built of lava & volcanic ash, which erupts and builds up

Side vent

A vent in the side

Volcano

A vent/weak spot in earth's surface through which materials are forced out

Pumice

A volcanic rock type that has a frothy mass of volcanic glass in which a great number of spaces remain after trapped gas has escaped from the solidifying melt.

Where do a volcano forms?

A volcano forms above a hot spot when magma erupts through the crust and reaches the surface.

Obsidian

A wholly glassy volcanic rock type; unlike pumice; it contains only tiny vesicles and so is solid and dense. Chipped or fragmented obsidian produces very sharp edges, and the Native Americans and many other hunting groups used it for arrowheads and a variety of cutting tools.

cool, slow moving lava on land forms blocky in appearance

AA https://o.quizlet.com/.qmtpK1uUKeeJ2Edokt3Jw_m.jpg

How are magma types classified?

According to their silica content (50%-Basaltic, 60%-Andesitic, 70%-Rhyolitic)

Four stages of volcanoes

Active, dormant, extinct, and intermittent

What forms after the magma and lava cools?

After magma and lava cool,they form solid rock.

Where do most volcanoes occur?

Along diverging plate boundaries, mid-ocean rivers, or in subduction zones around the edges of oceans

What happens along the rift valley?

Along the rift valley,lava pours out of cracks in the ocean floor.This process gradually builds new mountains.

What is a volcanic neck?

An erosional remnant of the material that solidified in a volcanic pipe.

Basalt

An igneous rock that forms from lava

Porphyry

An igneous rock that has a mixed texture in which large crystals "float" in a predominately fine-grained matrix. Large crystals are called phenocrysts, which form in magma while it is still below Earth's surface. They before other crystals can grow, a volcanic eruption bring the magma to the surface, where it cools quickly to a finely crystalline mass.

Seismograph

An instrument used by seismologists to record primary, secondary, & surface waves from earthquakes

Tsunami

An ocean wave (seismic sea wave) that begins over an earthquake focus. (can reach 30 m high)

Types of Magma

Basaltic (50%), Andesitic(60%), Rhyloitic(70%)

Pangaea

Ancient landmass made up of all the continents that began to break apart about 200 mya

Granite

And igneous rock that forms below earth's surface

What rock do Composite Volcanoes form after cooling?

Andesite

50-60% silica, medium viscosity, medium explosivity. Subduction boundaries

Andesitic Magma

This type of magma generally results from the melting of the combination of oceanic and continental lithosphere.

Andesitic Magma

What is country rock?

Any preexisting rock that has been intruded by a pluton or altered by metamorphism.

Veins

Are deposits of minerals found within a rock fracture that are foreign to the country rock.

Fissure

Are long cracks in earth

Dikes

Are the major route of magma transport in the crust. Much like sills which are sheetlike igneous bodies, but dikes cut across the layers in bedded country rock and so are discordant intrusions.

Hot spot

Areas in Earth's mantle that are hotter than neighboring areas, forming melted rock that rises toward the crust

What happens as the discontinuous branch of Bowen's Reaction Series continues to cool?

As it continues to cool, reactions take where the minerals continuously change into another form moving it fro one type of magma to another.

What happens as the plates push together?

As the plates push together,one plate can sink beneath the other plate.

Smallest form of tephra

Ash

What can erupt from volcanoes that can fall to Earth forming pyroclastic igneous rocks?

Ash and ejecta.

Three types of lava

Ash, cinders, and bombs

Ophiolite Suites

Assemblages consist of deep-sea sediments, submarine basaltic lavas, and mafic igneous intrusions

How and where do magmas form?

At places in the lower crust and mantle where temperatures are high enough for partial melting of rock. Because minerals within a rock melt at different temperatures, the composition of magmas varies with temperatures, the composition of magmas varies with temperature. Pressure raises the melting temperate of rock, and the presence of water lowers it. Because melted rock is less dense than solid rock, magma rises through the surrounding rock, and drops of magma come together to form magma chambers.

Splish Splash! It is the largest of all igneous intrusions measure over 100 km2.

Batholith

irregularly shaped mass of coarse-grained igneous rocks that cover at least 100km2 and take millions of years to form. Common in interior of mountain chains.

Batholith https://o.quizlet.com/qQTaXlE-tcsmFxjKjdsFYQ_m.jpg

Vulcanian eruptions

Begin with huge, loud explosions followed by smaller ones, ash, dust, and other volcanic materials are blown into the air

Largest tephra

Blocks and bombs

Who published Bowen's findings?

Bowen had died at a young age and his coworkers published his findings crediting him.

Crater

Bowl - shaped depression that forms around the central vent at the summit of a volcano

crater

Bowl-shaped depression, usually less than 1 km in diameter, that forms around the central vent at the summit of a volcano.

Craters

Bowl-shaped depressions

Shield volcano

Broad volcano with gently sloping sides built by non explosive eruptions of basaltic lava that accumulates in layers

shield volcano

Broad volcano with gently sloping sides built by nonexplosive eruptions of basaltic lava that accumulates in layers.

What is pillow lava?

Bulbous masses of basalt resembling pillows formed when lava is rapidly chilled under water.

How are volcanoes created?

By powerful forces within earth, when two tectonic plates move together and one goes under the other. The rock in the mantle melts and becomes the magma. Melting rock produces gases that mix with magma. Rising magma soaks in a weak part of rock, and creates a magma chamber

In the continuous Branch of Bowen's Reaction Series, what crystalizes first?

Calcium-rich Plagioclase crystalizes first.

Also called scoria cones, these explosive volcanoes are noted for their small size and steep sides.

Cinder Cone Volcanoes

This type of small volcano is linked with eruptions of mostly pyroclastic material (i.e, not so much of other ejecta) that piles up around the vent.

Cinder Cone Volcanoes

Batholith

Coarse - grained, irregularly shaped, igneous rock mass that covers at least 100 km2, generally forms 10-30 km below Earth's surface, and is common in the interior of major mountain chains

Peridotite

Coarse-grained, dark greenish gray rock made up primarily of olivine with smaller amounts of pyroxene.

batholith

Coarse-grained, irregularly shaped, igneous rock mass that covers at least generally forms 10-30 km below Earth's surface, and is common in the interior of major mountain chains.

What do the collisions of this type produce?

Collisions of this type produced the volcanoes of the Andes Mountains in South America.

Also known as strato-volcanoes, these volcanoes include many of Earth's most destructive, including Mt. St. Helen's and Krakatoa.

Composite Volcanoes

Subduction zones are often lined with this type of volcano that dominates the Cascade mountain range.

Composite Volcanoes/ Startovolcanoes

This type of volcano forms from alternating layers of pyroclastic material and lava flows.

Composite Volcanoes/ Stratovolcanoes

What 4 landforms are created from ash and lava?

Composite volcanoes, lava plateaus, cinder cone volcanoes, and shield volcanoes

Ultramafic Rocks

Consist primarily of mafic minerals and contain less than 10 percent feldspar

Mafic rocks

Contain large proportions of pyroxense and olivines. These minerals are relatively poor in silica but are rich in magnesium and iron, from which they get their characteristic dark colors.

Diorite

Contains sill less silica and is dominated by plagioclase feldspar, with little or no quartz. Contain a moderate amount of the mafic minerals biotite, amphibole, and pyroxene. They tend to be darker than granite or granodiorite.

Volcanism

Describes all the processes associated with the discharge of magma, hot water, and steam

Divergent zones where lithosphere thinner and exert less pressure (cause of magma to form in notes)

Decrease in pressure

When do plutons cool?

Depending on their size and depth, they may not cool for thousands or millions of years.

Magnetometer

Device used to map the ocean floor that detects small changes in magnetic fields

These igneous intrusions cut through layers of sedimentary rock and may result from past fissure eruptions.

Dike

a pluton that cuts across pre-existing rock (layers)

Dike

How do dikes and sills differ?

Dikes are discordant and Sills are concordant. They are both tabular or sheetlike igneous bodies.

Crystallization

During crystallization, the water molecules take up fixed positions in the solidifying crystal structure, and they are n longer able to move freely, as they did when the water was liquid. All other liquids, including magmas, crystallize in this way. The first tiny crystals form a pattern. Other atoms or ions in the crystallizing liquid then attach themselves in such a way that the tiny crystals grow larger. Crystals grow large only if they have time to grow slowly. If the liquid solidifies very quickly, as a magma does when it erupts onto the cool surface of Earth, the crystals have no time to grow. Instead, a large number of tiny crystals form simultaneously as the liquid cools and solidifies.

What is another source of magma?

Earth's upper mantle, which is composed of rocks that contain mostly ferromagnesian silicates.

Type of lava: ash

Fine, rock particles (sand)

Intermittent volcano

Erupt at a fairly frequent intervals

Active volcano

Erupt constantly

Marine volcanoes

Erupting lava and other material piling up on an overriding plate to form these volcanoes

All crystaline rocks are igneous-True/False

False

All of the earth's internal heat was acquired very early in its history through meteoric impact and differentiation of the core. The earth's interior loses heat to space but does not currently receive heat through any known process- True/False

False

Igneous rocks include rocks deposited on lava flows by running water-True/False

False

In metamorphic rocks some melting is always required-True/False

False

Lithification is a metamorphic process-True/False

False

The 'texture' of a rock refers just to its feel-True/False

False

The colored strata layers of the Grand Canyon are said to be a form of foliation-True/False

False

The composition of a rock can be described as either being equant or inequant-True/False

False

When rock is melted within earth, typically the entire volume of rock is transformed from a solid state to a liquid- True/False

False

Pahoehoe

Fast, quick lava

Granite as slow cooling (evidence)

Fine-grained igneous rocks are evidence of former volcanism.

Extrusive Igneous Rocks

Fine-grained texture or glassy igneous rock formed from magma that erupts at Earth's surface as a lava and cools rapidly

Rapid cooling lava:

Forms either a fine-grained rock or a glassy one in which no crystals can be distinguished

What does the fractures in the crust allow magma to do?

Fractures in the crust allow magma to reach the surface.

Composite volcano

Generally cone shaped with concave slopes; built by violent eruptions of volcanic fragments and lava that accumulate in alternating layers

seafloor spreading

Harry Hess; occurs along the crest of oceanic ridges; newly formed melt slowly rises toward the surface; most melt solidifies in the lower crust, but some escape to the seafloor and erupts as lava

Dormant volcano

Have become inactive, but people are not certain that they will erupt

Extinct volcano

Have not erupted within recorded history

How is magma made?

Heated rock in the sub-ducted plate melts into magma

High percentages of silica is linked with this type of viscosity.

High Viscosity

Lava plateau

High level areas where thin runny lava flows out of several rocks, made up of layers of lava

Flows less easily (high silica low temperature)

High vicosity

Unusually hot regions of the Earth's mantle where high temperature plumes of magma rise to Earth's surface

Hot Spot

Which one is formed in the highest temperature, igneous metamorphic or sedimentary rocks?

Igneous rocks

How are igneous rocks classified

Igneous rocks can be divided into two broad textural classes: coarse-grained rocks, which are intrusive and therefore cooled slowly; and fine-grained rocks, which are extrusive and cooled rapidly. Igneous rocks can also be classified on the basis of their silica content using a scale that runs from felsic (rich in silica) to ultramafic (poor in silica).

Where do igneous rocks form?

Igneous rocks form at spreading centers where plates move apart, along convergent boundaries where one plate descends beneath another, and at "hot spots" where hot mantle material ascends to the crust.

Isochron

Imaginary line on a map that shows points of the same age; formed at the same time

What is the best known volcanic catastrophy?

In 79 A.D. Mount Vesuvius erupted destroying the thriving Roman communities. Pompei was buried in 3m of pyroclastic materials. Herculaneum was buried in 20m of pyroclastic materials. It has erupted 80 times since.

Seismic wave

In an earthquake, the energy waves that move outward from the earthquake focus and make the ground quake.

Magnitude

In earthquake studies, a measure of energy released by an earthquake, measured by the Richter scale.

Pyroclasts

In more violent eruptions, pyroclasts form when fragments of lava are thrown high into the air. Volcanic ash is made up of extremely small fragments, usually of glass, that form when escaping gases force a fine spray of magma from a volcano. Bombs are larger particles hurled from the volcano and streamlined by the air as they hurl through it. As they fall to the ground and cool, these fragments of volcanic debris may stick together to form rocks.

Plate

In plate tectonics, a section of the Earth's lithosphere (crust & upper mantle) that moves around

Subduction zone

In plate tectonics, the area where an ocean-floor plate collides with a continental plate, and the denser ocean plate sinks under the less dense continental plate

Divergent boundary

In plate tectonics, the boundary between two plates that are moving away from each other

Convergent boundary

In plate tectonics, the boundary between two plates that are moving toward each other

Vent

In volcanic regions, an opening in Earth's surface through which can flow lava, ash, cinders, smoke, & steam

Hot spots (cause of magma to form in notes)

Increase in temperature

(cause of magma to form in notes)

Increase in water in the asthenosphere

Increasing pressure will do this to the melting point of rocks.

Increase it (more temperature would be needed to melt a certain material)

pluton

Intrusive igneous rock bodies, including batholiths, stocks, sills, and dikes, formed through mountain-building processes and oceanic-oceanic collisions; can be exposed at Earth's surface due to uplift and erosion.

Pluton

Intrusive igneous rock body, including batholiths, stocks, sills, and dikes, forms through mountain - building processes and oceanic-oceanic collisions; can be exposed at earths surface due to uplift and erosion

What are pyroclastic materials?

It is lava flows that is forcefully ejected into the atmosphere as particles. Pyroclastic materials the measure less than 2mm are called volcanic ash.

What happens to iron and magnesium if minerals crystalize simultaneously along the two branches of Bowen's Reaction Series?

Iron and Magnesium are depleted because they are used up in ferromagnesian silicates where calcium and sodium are used up in plagioclase feldspars.

stock

Irregularly shaped pluton that is similar to a batholith but smaller, generally forms 10-30 km beneath Earth's surface, and cuts across older rocks.

Stock

Irregularly shaped pluton that is similar to a batholiths but smaller, generally forms 5-30 km beneath earths surface, and cuts across older rocks

Intrusive Igneous Rock

Is one that has forced its way into the surrounding rock (called the country rock) and solidified without reach Earth's surface

Rhyolite

Is the extrusive equivalent of granite. This light brown to gray rock has the same felsic compositon and light coloration as granite, but it is much more fine-grained. May rhyolites are formed largely or entirely of volcanic glass.

Bowen's Reactions Series is supposed to account for what?

It accounts for the derivation of intermediate and felsic magmas from mafic magma.

Pressure below spreading ridges decreases causing what?

It causes the temperature to exceed the melting temperature, because pressure decreases.

When does a conduit known as a lava tube within a lava flow form?

It forms when the margins and upper surface of the flow solidify.

What does Intermediate magma contain?

It has a composition between felsic and mafic magma.

What does a laccolith look like?

It has a flat floor and is domed up in its central part giving it a mushroom-like geometry.

What is crystal settling?

It involves the physical separation of minerals by crystilization and gravitational settling. Once magma forms, it's composition may change by crystal settling.

What is a crater?

It is a circular depression at the summit, which most volcanoes have.

What is a mantle plume?

It is a cylindrical plume of hot mantle rock that rises from perhaps near the core-mantle boundary.

What is a shield volcano?

It is a dome-shaped volcano with a low, rounded profile built up mostly by overlapping basalt lava flows.

What is a volcano?

It is a hill or mountain that forms around a vent where lava, pyroclastic materials, and gases erupt.

What is a hot spot?

It is a localized zone of melting below the lithosphere that probably overlies a mantle plume.

What is assimilation?

It is a process by which magma reacts with preexisting rock called country rock, with which it come in contact.

What is stopping?

It is a process where rising magma detaches and engulfs pieces of country rock.

A belt of volcanoes and plutons is a result of what plate movement?

It is a result of an oceanic plate being subducted beneath either a continental plate or another oceanic plate.

What is a cinder cone?

It is a small, steep sided volcano made up of pyroclastic materials resembling cinders that accumulate around a vent.

What is a sill?

It is a tabular or sheetlike concordant pluton.

What is a composite Volcano?

It is a volcano composed of lava flows and pyroclastic layers, typically of intermediate composition and mudflows.

What is a batholith?

It is an irregularly shaped discordant pluton with at least 100 km^2 of surface area.

What is the definition of magma?

It is any mass of molten rock material below Earth's surface.

What is welded tuff?

It is ash paricles that are fused together.

What is the reason lava and magma retain heat so well?

It is because rocks conduct heat so poorly.

What is magma composed of?

It is composed of silicon and oxygen with lesser amounts of several other chemical elements.

The fact that assimlation occurs is indicated by what?

It is indicated by inclusions, incompletely melted pieces of rock that are fairly common in igneous rocks.

Igneous Rock

It is linked to the rate, and therefore the place, of cooling.

What does Mafic Magma contain?

It is silica poor and contains proportionately more calcium, iron, and magnesium. (Bassalt-Gabbro are the aphanatic and phaneritic rocks that crystalize from mafic magma. Bassalt is aphanatic. Gabbro is Phanaritic.)

What does Felsic magma contain?

It is silica rich and contains considerable sodium, potassium, and aluminum, but little calcium, iron and magnesium.(Rhyolite-Granite are the igneous rocks that crystalize and form from Felsic magma.)

What is the longest recorded volcanic eruption in shield volcanoes?

It is the Kileuea volcano in Hawaii which has been erupting since January 3, 1983.

What is a volcanic pipe?

It is the conduit connecting the crater of a volcano with an underlying magma chamber.

What is rhyolite Tuff?

It is the consolidation of ash, which forms pyroclastic tuff which is silica rich and light colored.

What are lava flows?

It is the magma that does not reach the surface and issues forth as streams of lava.

What is a laccolith?

It is the overlying rocks bowing upward forming an igneous body.

What are discordant plutons?

It is the plutons with boundaries that cut across the country rock's layering.

What is viscosity?

It is the resistance to flow.

What is the term for volcanic smog that residents of Hawaii came up with?

It is vog.

What is the geothermal gradient?

It is when the Earth's temperature increases with depth which relates to the origin of magma.

What is an aphanatic texture in minerals?

It is where individual minerals are too small to be seen without magnification. They usually indicate an extrusive origin.

What are columnar joints?

It is where mafic lava flows have a distinctive pattern of columns bounded by fractures.

What is the definition of volcanism?

It is where magma and associated products ascend through the crust and extrude onto the Earth's surface. (the magma ascends through fracturing that occurs.)

What is a phaneritic texture in minerals?

It is where minerals are clearly visible. They usually indicate an intrusive origin.

What is a porphorytic texture in minerals?

It is where minerals of markedly different size are present in the same rock.

What is a pressure ridge?

It is where pressure on the solidified crust of a still-moving lava flow causes the surface to buckle.

The plagoiclase forming under the rapid cooling conditions is zoned. What does that mean?

It means that is has a calcium rich core surrounded by zones progresivley richer in sodium.

What does it mean if a volcano is active?

It means that it has erupted during historic time.

What does it mean if a volcano is dormant?

It means that it has not erupted during historic time but could in the future.

What does a concordant pluton mean?

It means that plutons can have boundries that parallel the layering in the country rock.

Some pegmatites are mafic or intermediate in composition meaning they are what kind of igneous rocks?

It means they are baggro and diorite pegmatites.

Where does most magma originate in correspondence to Earth?

It originates within the Earth's upper mantle or lower crust at or near divergent and convergent plate boundaries.

What is the volume of a magma chamber?

It ranges from a few to many hundreds of cubic kilometers of molten rock within the otherwise solid lithosphere.

What is a pegmatite igneous rock?

It refers to a particular texture rather than a specific composition, but most pegmatites are composed mostly of quartz, potassium felspar, and sodium rich plagioclase, thus corresponding closely to granite.

What happens if lava cools to fast?

It's constituent atoms do not have time to become arranged in the ordered, three-doimensional frameworks of minerals.

Uniformitarianism

James Hutton's principle that the physical, chemical, and biological laws that operate today have also operated in the geologic past (the present is the key to the past)

Mushroom shaped, these intrusions are bigger than sills, often up to 16 km across.

Laccolith

lens-shaped pluton with a round top and flat bottom. Mushroom Shape (shield shape; shield volcano)

Laccolith https://o.quizlet.com/qQTaXlE-tcsmFxjKjdsFYQ_m.jpg

intrusive (underground) igneous rock bodies

Pluton

Medium sized tephra

Lapilli

Caldera

Large crater, up to 50 km in diameter, that can form when the summit or side of a volcano collapses into the magma chamber during or after an eruption

caldera

Large crater, up to 50 km in diameter, that can form when the summit or side of a volcano collapses into the magma chamber during or after an eruption.

Plutons

Large igneous bodies formed deep in Earth's crust. They range in size from a cubic kilometer to hundreds of cubic kilometers.

Magma chambers

Large pools of molten rock that form in the lithosphere as rising magmas melt and push aside surrounding solid rock.

Where are large volcanoes found?

Large volcanoes are found along the Great Rift Valley in East Africa.

hot spot

Large, sloping volcano built by violent eruptions of volcanic fragments and lava that accumulate in alternating layers.

Slow cooling lava:

Larger crystals are formed

Aa and pahoehoe are types of these...

Lava Flows

Which eruptions are some of the most violent and destructive?

Lava dome eruptions.

What kind of eruptions are the most and least dangerous?

Lava flows are the least dangerous and explosive eruptions are very dangerous.

Tephra

Lava that is blasted into the air by violent volcanic eruptions & solidifies as it falls to the ground as ash, cinders, & volcanic bombs

Pipe

Long tube in the ground that connects magma chamber to surface

Rift valley

Long, narrow depression that forms when continental crust begins to separate at a divergent boundary

Fissures

Long, narrow vents

Flows easily (Low silica high temperature)

Low viscosity

Lava

Magma that flows out into earth's surface

All igneous rocks derive from?

Magma.

Magmas form in a number of geologic environments including?

Magmas can form in hot spots, divergent plate boundaries and subduction plates.

What are the major island arcs?

Major island arcs include apan,New Zealand, the Aleutiansand, and the Caribbean islands.

Where is a common place for cinder cones to form?

Many cinder cones form on the flanks or within the calderas of larger volcanoes and represent the final stages of activity, particularly in areas of basaltic volcanism.

Where do many volcanoes form near?

Many volcanoes form near converging plate boundaries,where two oceanic plates collide.

Fluid-induced melting

Melting of rock induced by the presence of water that lowers its melting point. Water content is a significant factor in the melting of sedimentary rocks, which contain an especially large volume of water in their pore spaces, more than is found in igneous or metamorphic rocks.

Magma

Molten, or hot and melted rock below earth's surface

Where was the worlds largest eruption since 1912?

Mount Pinatubo in the Pillippines erupted on June 15 in 1991 where huge quantities of gas and ash were discharged. 722 deaths.

Does the majority of magma reach Earth's surface?

NO. The majority of magma cools and crystalizes underground forming different types of igneous bodies called plutons.

Mineral

Naturally occurring; Generally inorganic; solid substance; orderly crystalline structure; definite chemical composition example: quartz, hornblende, feldspar

Does a mineral have to reach all three types of magma in order to crystalize?

No it could be at any type during crystalization and suddenly be ejected onto the surface as lava.

Does cool magma or lava move more readily than hotter magma or lava?

No it does not. It is the other way around.

This is the largest known volcano in the Solar System. (Don't need to know)

Olympus Mons (on Mars)

Granite

One of the most abundant intrusive igneous rocks, contains about 70 percent silica. Mineral composition includes abudant quart and orthoclase feldspar and a smaller amount of plagioclase feldspar. These light-colored felsic minerals give granite its pink or gray color. Granite also contains small amounts of muscovite and biotite micas and amphibole.

Does the lava in shield volcano's pose threats to humans?

No the lava usually rises to the surface with little explosive activity posing little danger to humans. They are usually quiet eruptions.

Do minerals crystalize simultaneously from cooling magma?

Not all of them crystalize simultaneously from cooling magma. They crystalize in a predictable sequence.

H20 and Co2 dissolved in magma. Easily escape basalt magma since so hot and fluid , explosive escape andesitic and rhyolitic magma since less hot and fluid (Extra info just type ok in box)

Ok

vent

Opening in Earth's crust through which lava erupts and flows out onto the surface.

Vent

Opening in earths crust through which lava erupts and flows out onto the surface

Vents

Openings through which volcanic materials erupt out

Hot, quick flowing lava on land forms ropelike in appearance

Pahoehoe https://farm3.staticflickr.com/2162/2342203011_3e07d5d9cf_m.jpg

Type of lava: cinders

Pebble-sized particles

Lava underwater forms pillow-like appearance

Pillow Lava/ Basalts https://o.quizlet.com/ztsP6aoQVUEUtPnIwwTH3Q_m.jpg

Divergent boundary

Place where two of earths tectonic plates are moving apart; is associated with volcanism, earthquakes, and high heat flow, and is found primarily on the sea floor

Convergent boundary

Place where two tectonic plates are moving toward each other; is associated with trenches, islands arcs, and folded mountains

Transform boundary

Place where two tectonic plates slide horizontally past each another; is characterized by long faults and shallow earthquakes

What are the only minerals in the Continuous Branch of Bowen's Reaction Series?

Plagioclase feldspars which are nonferromagnesian silicates are the only minerals.

What does plate movement cause?

Plate movements cause the crust to fracture.

What causes a decrease in pressure on the already hot rocks at dept, thus initiating melting?

Plate separation at ridges.

This godly name is the general term for underground igneous bodies of rock.

Pluton

What does lava harden into?

Rock

Tephra

Rock fragments, classified by size, that are thrown into the air during a volcanic eruption and fall to the ground

tephra

Rock fragments, classified by size, that are thrown into the air during a volcanic eruption and fall to the ground.

What happens to the melting temperatures of rocks at depth in Earth?

Rocks at depth are hot but remain solid because their melting temperature rises with increasing pressure.

Partial melting

Rocks do not melt completely because the minerals that compose them melt at different temperatures. The fraction of rock that has melted at a given temperature is called a partial melt.

Sedimentary rocks

Rocks made of bits and pieces of other rocks

Metamorphic rock

Rocks that were once igneous, sedimentary, or metamorphic rock that has been exposed to pressure or heat. Often forms under water

What strongly controls magma and lava's viscosity?

Silica content controls magma and lava's viscosity.

These large volcanoes have broad gentle slopes resulting from basaltic magma.

Shield Volcanoes

This is the largest type of all volcanoes.

Shield Volcanoes

What kind of volcanoes are the most common in ocean basins?

Shield Volcanoes

These flat intrusions form when magma squeezes into parallel cracks in between layers of sedimentary rock.

Sill

magma that intrudes parallel to layers of rock (typically horizontal; window sill)

Sill

Type of lava: bombs

Size of baseball oars

Aa

Slow, quiet lava

Stocks

Smaller plutons

Why is the processes in magma that brings about chemical change important?

So magma may evolve from one kind into another.

Where do some hot spot volcanoes lies?

Some hot spot volcanoes lie close to plate boundaries. Others lie in the middle of plate.

What are some volcanoes results?

Some volcanoes are the result of "hot spots" in Earth's mantle.

Cinder cone

Steep sided, generally small volcano that is built by the accumulation of tephra around the vent

cinder-cone volcano

Steep-sided, generally small volcano that is built by the accumulation of tephra around the vent.

The irregular shaped plutons are similar to, but smaller than batholiths...

Stocks

similar to batholiths but smaller in size (>100km2)

Stocks

Paleomagnetism

Study of earths magnetic record using data gathered from iron - bearing minerals in rocks that have recorded the orientation of earths magnetic field at the time of the formation

Fault

Surface along which rocks break & move.

Pyroclastic flow

Swift moving, potentially deadly clouds of gas, ash, and other volcanic material produced by a violent eruption

pyroclastic flow

Swift-moving, potentially deadly clouds of gas, ash, and other volcanic material produced by a violent eruption.

Slab pull

Tectonic process associated with convection currents in earths mantle that occurs as the weight of the subducting plate pulls the trailing lithosphere into a subduction zone

Ridge push

Tectonic process associated with convection currents in earths mantle that occurs when the weight of an elevated ridge pushes an oceanic plate toward a subduction zone

What are the most important controls on the mobility of magma and lava?

Temperature and composition.

This is another name for pyroclastic material, including particles of varied sizes.

Tephra

Some of the most economically important mineral deposits in the world are formed by differential settling of crystals in magma chambers. Examples would be:

The Bushveld deposit in South Africa and and the Stillwater deposit in Montana, just north of Yellowstone National Park.

Where does the Ring of Fire includes volcanoes?

The Ring of Fire includes the volcanoes along the coasts of North and South America and those in Japan and the Philippines.

Ring of Fire

The area around the Pacific plate where volcanoes & earthquakes are common due to tectonic movement

metamorphism

The changes in mineral composition and texture of a rock subjected to high temperatures and pressures within earth.

What are the common and uncommon places volcanism occurs?

The common places volcanism occurs are at divergent and convergent plate boundaries. The uncommon places volcanism occurs at are ocean basins and on continents that are not near either of these boundaries.

sorting

The degree of similarity in particle size in sediment or sedimentary rocks

Inner core

The dense, solid center of the Earth, formed mostly of iron & nickel.

Convection current

The driving force of plate tectonics, in which hot, plastic-like material from the mantle rises, moves horizontally, cools, and sinks back to the mantle

What happens if magma cools to rapidly?

The early formed minerals do not have time to react with the melt therefore the ferromagnesian silicates in the discontinuous branch can be in one rock.

What happens when atoms in a solid which are in constant motion are heated?

The energy of motion exceeds the binding forces and the solid melts.

How do scientists study volcanoes?

The eruptions according according to their violence and how often they erupt

Seafloor spreading

The hypothesis that new ocean crust is formed at mid - ocean ridges and distorted at deep sea trenches; occurs in a continuous cycle of magma intrusion and spreading

Batholiths

The largest plutons, are great irregular masses of coarse-grained igneous rock that, by definition, cover at least 100 km2

What happens to the continuous branch of Bowen's Reaction Series if it continues to cool?

The magma will continue to cool and the calcium-rich plagioclase will react with the melt, and plagioclase containing porportionatly more sodium crystalizes until all of the calcium and sodium are used up.

Basalt

The most abundant igneous rock of the crust, and it underlies virtually the entire seafloor. This dark gray to black rock is the fine-grained extrusive equivalent of gabbro.

What are dikes intruded into?

They are intruded into preexisting fractures pr where fluid pressure is great enough for them to form their own fractures as they move upward.

What are sills intruded into?

They are intruded into sedimentary rocks, and piles of volcanic rock. They are intruded between layers in country rock when the fluid pressure is great enough for the magma to actually lift the overlying rocks.

Earthquake

The movement of the ground caused by waves from energy released as rocks move along faults

Pangea

The name Alfred Wegener gave to the large landmass, made up of all continents, that he believed existed before it broke apart to form the present continents

What happens when an oceanic and continental plate collide?

The oceanic plate slides under the continental plate, this causes a volcano to form

Crust

The outermost layer of Earth, from 5 km to 60 km thick

What plays an important role in determining the mineral composition of igneous rocks?

The parent magma.

What is used to explain the origin of magma at subduction zones?

The phenomenon of partial melting is used to explain the origin of magma at subduction zones.

Focus

The point in the Earth's interior where earthquake energy is released

Epicenter

The point on the Earth's surface directly above an earthquake's focus

What happens to the pressure when magma rises toward the surface for a volcanic eruption?

The pressure is reduced and the contained gases begin to expand. This could expand big enough to cause an explosion (eruption).

Fractional crystallization

The process by which the crystals formed in a cooling magma are segregated from the remaining liquid rock.

Stokes' Law

The rate at which crystals settle depends both on their density and size and on the viscosity of the remaining magma. That rate can be calculated using a mathematical relationship:

parent rock

The rock from which a metamorphic rock formed.

Country Rock

The rock surrounding an igneous intrusion

Crater

The steep-walled depression at the top of a volcanic vent

What are plutons?

They are intrusive igneous bodies.

What are calderas?

They are larger rimmed depressions on volcano's. They form following voluminous eruptions where a magma chamber drains and the mountains summit collapses into the vacated space. ex(crater lake)

Plate tectonics

The theory that Earth's crust & upper mantle (lithosphere) are broken into sections, called plates, that slowly move around

Seafloor spreading

The theory that magma from Earth's mantle rises to the surface at mid- ocean ridges and cools to form new seafloor, which new magma pushes away from the ridge

Mantle

The thickest layer of Earth, between the outer core & the crust, described as plastic-like

Andesite

The volcanic equivalent of diorite. Andesite derives its name from the Andes, the volcanic mountain belt in South America.

The magma is thick and sticky when...?

There is a lot of silica

Geothermal energy

Thermal energy from magma bodies inside Earth used to produce electricity with very little environmental pollution

What do all volcano's have beneath the surface?

They all have conduits leading to a magma chamber beneath the surface.

What are fissure eruptions?

They are a volcanic eruption in which lava or pyroclastic materials issue from a long, narrow fissure (crack) or group of fissures.

What are lava domes?

They are bulbous steep-sided mountains formed by viscous magma moving upward through a volcanic conduit.

When are Plutonic and Intrusive igneous rocks formed?

They are formed when magma cools below the surface, that is, from magma intruded into the crust.

How are interconected pillows formed?

They are formed when the remaining fluid from inside one pillow lava breaks through the crust of the pillow where it repeats the process resulting in interconnected pillows.

What do we know about the origin of the largest plutons?

They are not fully understood yet.

What are basalt plateaus?

They are plateau built up by horizontal or nearly horizontal overlapping lava flows that erupted from fissures.

What are magma chambers?

They are the reservoirs where magma accumulates.

What are pyroclastic sheet deposits?

They are vast, sheetlike deposits of felsic pyroclastic materials erupted from fissures.

What are both obsidian and pumice varities of?

They are volcanic glass.

What are vesicles?

They area small holes or cavities formed by gas trapped in cooling lava.

What can some volcano eruptions be caused from?

They can be caused from the injection of sills.

What can the extrusive and intrusive members of each pair be distinguished by?

They can be distinguished by texture.

What are other things volcano's can errupt?

They can errupt lapilli-pyroclastic materials that measure from 2-64mm, blocks-angular pieces of rock ripped from volcanic conduit, and bombs- which have a twisted streamlined shape which shows they were ejected as globs of magma.

What kind of rocks does a pyroclastic or fragmental texture characterize?

They characterize igneous rocks formed by explosive volcanic activity.

How do Composite Volcanoes differ from Shield volcanoes and cinder cones?

They differ in shape and composition.

Where do magma chambers exist?

They exist below spreading ridges where the crust in thin. They are at a depth of about a few kilometers.

When do Intrusive igneous bodies called plutons form?

They form when magma cools below the Earth's surface.

How do all igneous rocks form?

They form when magma or lava cools and crystalizes, or by the consolidation of pyroclastic materials ejected during explosive eruptions.

How do lahar's form?

They form when rain falls on unconsolidated pyroclastic materials creating a muddy slurry that moves downslope.

What do the members of a pair of rocks have in common and what don't they have in common?

They have the same composition but different textures.

Igneous rocks look different depending on what?

They look different depending on where they are during the crystalizing stage.

What parts of the continent do igneous rocks make up?

They make up large parts of the continent and all of the oceanic crust, which forms continuously at divergent plate boundries.

Why do lava flows rarely cause fatalities?

They rarely cause fatalities because they move so slow and because they are fluid, they follow existing low areas. Once a volcano erupts, determining its path it easy leaving plenty of time for evacuation.

How long do lava flows and pyroclastic flow deposits remain hot for?

They remain hot for months or years.

What do geologists use to classify igneous rocks?

They use texture and composition.

Strombolian eruptions

Thick magma in the vent and builds pressure and this eruption turns into a cinder cone volcano

What is the discontinuous branch of Bowen's Reaction Series?

This branch contains only ferromagnesian silicates, where one mineral changes to another over specific temperature ranges. A temperature range has to be reached before a mineral will begin to crystalize.

Magmatic stopping

Three ways magma makes space for itself:

What happens through subduction?

Through subduction,the older,denser plate sinks into the mantle and creates a deep-ocean trench.

"All lava is magma is truer than "all magma is lava"-True/False

True

Bedrock covered in oil is not an outcrop of rock-True/False

True

Compaction and cementation is a sedimentary process-True/False

True

Sand is not a rock-True/False

True

Very early in earth's history, it was so hot that the surface was likely entirely molten-True/False

True

sediment

Unconsolidated particles created by the weathering and erosion of rock by chemicl precipitation from solution in water, or from the secreations of organisms, and transported by water, wind, or glaciers

hot spot

Unusually hot area in Earth's mantle that is stationary for long periods of time, where high-temperature plumes of mantle material rise toward the surface.

Hot spot

Unusually hot area in earths mantle where high - temperature plumes of mantle material rise toward the surface

The internal resistance to flow of a material is that minerals...

Viscosity

when the magma in a volcano conduit solidifies

Volcanic Neck https://o.quizlet.com/qQTaXlE-tcsmFxjKjdsFYQ_m.jpg

Where do volcanic belts form?

Volcanic belts form along the boundaries of Earth's plates.

Dacite

Volcanic equivalent of granodiorite

Lavas

Volcanic rocks formed from flowing lavas range in appearance from smooth and ropy to sharp, spiky, and jagged, depending on the conditions under which they are formed

What are extinct or inactive volcano's?

Volcano's that show no sign of ever erupting.

Where is another place that volcanoes form?

Volcanoes also form along diverging plate boundaries on land.

Are volcanic gases dangerous?

Yes. Most of them dissipate into the atmosphere really fast however on some occasions they have been fatal.

Is it common for the magma to cool to fast in the continuous branch of Bowen's Reaction Series?

Yes. Often times the cooling is too rapid for a complete transformation from calcium-rich to sodium-rich plagoiclase to take place.

temperature silica content

___________ and _______ affect the viscosity of magma

Oxide

a binary compound of oxygen

Magma

a body of molten rock found at depth, including any dissolved gases and crystals

unconformity

a break in the rock record produced by non deposition and erosion of rock units

Hydrolysis

a chemical weathering process in which minerals are altered by chemically reacting with water and acids

diagenesis

a collective term for all the chemical, physical, and biological changes that take place after sediments are deposited and during and after lithification

soil

a combo of mineral and organic matter, water and air, the portion of the rigolith that supports plant growth

interface

a common boundry where different parts of a system interact

Granitic

a compositional group of igneous rocks indicating that the rock is composed of almost all light colored silicates

Basaltic

a compositional group of igneous rocks indicating that the rocks contains substantial dark silicate minerals and calcium rich plagioclase fledspar

Bowens Reaction Series

a concept proposed by N. L. Bowen that illustrates the relationships between magma and the minerals crystallizing from it during the formation of igneous rocks

Mid Ocean Ridge

a continuous mountainous ridge on the floor of all the major ocean basins and varying in width from 500 to 5000 kilometers (300 to 3000 miles). The rifts at the crests of these ridges represent divergent plate boundaries.

rift valley

a deep, down-faulted structure that exists on the axis of most ridges which is a broad linear swell along divergent plate boundary

what is the definition of a caldera?

a depression that is formed when the sides or top of volcano collapse into the emptied magma chamber

Crater

a funnel-shaped depression at the summit of most volcanic cones, generally less than 1 km in diameter

Molecule

a group of atoms bonded together

Continental Drift

a hypothesis credited to alfred wegener, which suggested that all present continents once existed as a single supercontinent. Further beginning about 200 million years ago, the supercontinent began breaking into smaller continents, which then drifted to their present positions

Theory

a hypothesis that has survived extensive scrutiny when other competing hypotheses have been eliminated; well-tested and widely accepted view that the scientific community agrees best explains certain observable facts

Seafloor Spreading

a hypothesis, first proposed in the 1960s by Harry Hess, which suggested that new oceanic crust is produced at the crests of mid-ocean ridges, which are the sites of divergence.

Batholith

a large mass of igneous rock that formed when magma was emplaced at depth, crystalized, and subsquently exposed to erosion

breccia

a sedimentary rock composed of angular fragments that were lithified.

conglomerate

a sedimentary rock composed of rounded, gravel size particles

clastic

a sedimentary rock texture consisting of broken fragments of preexisting rocks

Mohs Hardness Scale

a series of 10 minerals used in determining hardness

island arc

a string of volcanoes that form as the result of subduction of one oceanic plate beneath a second oceanic plate

cross-bedding

a struture in which relativley thin layers are inclined at an angle to the main bedding. Cross-bedding is formed by currents of wind or water.

Viscosity

a substance's internal resistance to flow

viscosity

a substance's internal resistance to flow

viscosity

a substances internal resistance to flow

Periodic Table

a table of elements found on Earth.

Sill

a tabular igneous body that was intruded parallel to the layering of preexisting rock

hypothesis

a tentative or untested explanation for how or why things happen in the manner observed

Vesicular

a term applied to aphanitic igneous rocks that contain many small cavities called vesicles

foliation

a term for linear arrangement of textural features often exhibited by metamorphic rocks.

Condult

a tubelike structure that allows lava to reach the surface

conduit

a tubelike structure that allows lava to reach the surface

dike

a tubular shaped intrusive igneous feature that cuts through the surrounding rock

compaction

a type of lithification in which the weight of overlying material compresses more deeply buried sediment. It is most important in the fine grained sedimentary rocks like shale.

Caldera

a volcanic crater that has a diameter of >1 kilometer and is produced by a collapse following a massive eruption (3 types; crater lake, Hawaiian, and yellowstone)

volcano

a weak spot in the crust where magma has come to the surface

A sill is a. a sheetlike intrusion that lies parallel to surrounding layers of sedimentary rock b. a cooled layer of lava c. an intrusion formed within the magma chamber of a volcano d. a sheetlike intrusion that cuts across preexisting layers

a. a sheetlike intrusion that lies parallel to surrounding layers of sedimentary rock

c. komatiite d. rhyolite

a. andesite

Is a laccolith a. concordant or b. discordant as an intrusion?

a. concordant

As compared to coarse grained igneous rocks, all fine grained igneous rocks a. cool and solidify more quickly b. cool and solidify more slowly c. solidify at higher temps d. solidify at lower temps

a. cool and solidify more quickly

Which type of magma has the greatest silica content a. felsic b. intermediate c. mafic d. ultramafic

a. felsic

If a body of magma becomes for felsic, its viscosity will a. increase b. decrease c. stay the same

a. increase

When magma crystallizes, ____ are formed. a. intrusive igneous rocks, b. volatiles c. extrusive igneous rocks d. pyroclastic debris

a. intrusive igneous rocks

Due to fractional crystallization and assimilation of surrounding host rock, most magmas that rise slowly through the crust evolve chemically to become a. more felsic b. more mafic c. dominated by nonsilicate minerals

a. more felsic

In Bowen's discontinuous reaction series, the first mineral to crystallize from a mafic melt is a. olivine b. plagioclase c. pyroxene d. quartz

a. olivine

Stoping by magmas occurs when a. pieces of surrounding country rock are broken off and assimilated b. the magma stops flowing and starts to solidify c. the magma becomes fully solidified to form intrusive rock d. the magma alters a thin rind of surrounding country rock

a. pieces of surrounding country rock are broken off and assimilated

Cooling rate

affects crystal size

Differentiation

all of the processes by which earth came to its present interior structure

what is volcanism?

all the processes associated with the discharge of magma, hot fluids, and gases

If a body of magma is subjected to fractional crystallization, the rock that results is expected to be a. identical in chemical composition to the magma b. more mafic than the magma c. more felsic than the magma

b. more mafic than the magma

Composite Volcano

also called a stratovolcano, large, but smaller than a Shield Volcano, located at convergent boundaries, last as long as their is a convergent boundary going on, predominantly andesitic lava. Ex: Mount St. Helens

shock metamorphism

also known as impact metamorphism, shock affects on rocks

talus

an accumulation of rock debree at the base of a cliff

hotspot

an area where magma from deep within the mantle melts through the crust above it

magnitude

an estimate of the amount of energy released at the source of the earthquake; measured by the Richter scale which measures the amplitude of the largest seismic wave recorded on a seismogram; Moment magnitude measures the total energy released during an earthquake

spheroidal

any weathering process that tends to produce a spheroidal shape from an initially blocky shape.

Hot spots

areas in Earths mantle that are hotter than neighboring areas, are also the sites of volcanoes.

decompression melting

as material rises and the pressure decreases below a critical point, the solid rock melts spontaneously, without the introduction of any additional heat--this produces the greatest volume of magma anywhere on Earth

ophiolite suites

assemblages that consist of deep sea sediments, submarine basaltic lavas, and mafic igneous intrusions.

pillow lava

at the divergent boundary on the ocean floor, eruptions often form huge piles of lava

crater

at the top of a volcano, around the vent, a bowl-shaped depression is formed

radiation

atoms with unstable nuclei that break apart over time, producing smaller particles in a process called radioactivity

Most commonly, felsic igneous rocks a. contain more iron and magnesium than intermediate rocks b. are lighter in color than mafic rocks c. are darker in color than mafic rocks d. are found in oceanic crust

b. are lighter in color than mafic rocks

Coarse grained gabbro is most similar in mineral composition to fine grained a. andesite b. basalt c. komatiite d. rhyolite

b. basalt

If the volatile content of magma is increased, its viscosity will a. increase b. decrease c. stay the same

b. decrease

Is a dike a. concordant or b. discordant as an intrusion?

b. discordant

When rock is partially melted, the chemistry of the melt is a. more mafic than the original chemistry of the rock b. more felsic than the original chemistry of the rock c. identical to the original chemistry of the rock d. completely unpredictable

b. more felsic than the original chemistry of the rock

Bowen's continous reaction series describes the crystallization behavior of a single mineral a. olivine b. plagioclase c. pyroxene d. quartz

b. plagioclase

A blob like igneous rock body that has cooled beneath the surface of Earth is called a a. guyot b. pluton c. lava flow d. andesite

b. pluton

Pegmatites, which occur in dikes, are unusual among shallow intrusive rocks in that they _ a. possess porphyritic texture b. possess exceptionally coarse grains c. are mineralogically identical to the extrusive rock basalt d. are glassy, cooling so rpaidly that crystals do not have time to form

b. possess exceptionally coarse grains

The geotherm is the rate of change of a. pressure with depth in Earth's interior b. temp with depth in earth's interior c. temp with altitude in earth's atmosphere d. temp with latitude on earth's surface

b. temp with depth in earth's interior

discordant intrusions

batholiths and stocks (cut across layers of the county rock that they intrude)

principle of lateral continuity

beds originate as continuous layers that extend in all directions until they eventually thin out or grade into a different sediment type

compare and contrast batholith and laccoliths

both forms of pluton.both below earth's surface. batholith larger. laccoliths smaller and are lens shaped. both are generally comprised of granite

moho

boundary between the crust and the mantle; P wave velocities increase at the Mojo, Seismic waves refracts as they cross the Mojo

D" layer

boundary between the rocky lower mantle and the liquid outer core

crater

bowl-shaped depression that forms around the central vent at the summit of a volcano

Crater

bowl-shaped depression that forms at the summit of a volcano

crater

bowl-shaped depression that's forms around the central vent at the summit of a volcano

shield volcano

broad volcano with gently sloping sides built by nonexplosive eruptions of basaltic lava that accumulates in layers

Shield volcano

built by nonexplosive eruptions; accumulates in layers

All other factors being equal. intrusive rocks that form deep within earth __ than intrusive rocks that cool near the surface a. are more felsic b. contain a smaller proportion of volatiles c. cool more slowly d. cool more rapidly

c cool more slowly

Radioactive isotopes, differentiation of Earth's iron core, gravity-driven compression, and meteoric bombardment all caused early earth to a. glow brighter than the sun b. be much cooler than at present c. be much hotter than at present d. be much more oblong than at present

c. be much hotter than at present

Volatiles refer to substances that a. crystallize most rapidly out of a melt b. melt immediately upon contact with a hot body of magma c. have a tendency to evaporate and are stable as gases

c. have a tendency to evaporate and are stable as gases

Geologically, melts are equivalent to both a. felsic and mafic magmas b. felsic and mafic lavas c. lavas and magmas d. fine grained and coarse grained igneous rocks

c. lavas and magmas

The difference between lava and magma is that a. magma is light in color and lava is dark b. magma usually has mafic composition an lava usually has felsic composition c. magma is found beneath the Earth's surface, whereas lava has reached the surface d. magma flows more quickly than lava

c. magma is found beneath the Earth's surface, whereas lava usually has reached the surface

A volcano emits ash, which falls from the sky, settles in layers and is eventually cemented. The resultant rock is termed a. pumice b. granite c. tuff d. ignimbrite

c. tuff

Important volatiles in magmas include a. iron and magnesium rich minerals b. potassium and aluminum c. water and carbon dioxide d. ricrinitrotoluene and nitroglycerin

c. water and carbon dioxide

refraction

change in the direction of waves as they enter shallow water; the portion of the wave in shallow water is slowed which causes the waves to bend and align with underwater contours

contact metamorphism

changes in rock caused by the heat from a nearby magma body

Density

defined as mass per unit of volume; determines how plates react at subduction zones,

hydrothermal metamorphism

chemical alterations that occur as hot, ion rich water circulates through fractures in rock.

Ring of Fire

circum pacific ring of fire where most active volcanoes are found

gabbro

coarse-grained, dark gray intrusive igneous rock--abundant mafic minerals

peridotite

coarse-grained, dark greenish gray rock made up primarily of olivine with smaller amounts of pyroxene

Batholith

coarse-grained, irregularly shaped, igneous rock mass

batholiths

coarse-grained, irregularly shaped, igneous rock mass that covers at least 100 km2, generally forms 10-30 km below earth's surface, and is common in the interior of major mountain chains

upper mantle

composed of peridotite, an iron and magnesium rich rock ; extends from the Mojo to 660 km thick.

the most explosive volcanoes are known as...?

composite volcanoes

P waves

compression waves; can travel through all materials; first to arrive at a recording station but have the lowest amplitude.

Trace Elements

concentration of one type of rock

mafic rocks

contains large proportions of pyroxenes and olivine. relatively poor in silica but rich in magnesium and iron (dark in color)

diorite

contains less silica and is dominated by plagioclase feldspar, with little or no quartz.

These two things

control the force of a volcano's eruption.

batholith

course-grained, irregularly shaped igneous rock mass that covers at least 100 km squared, generally forms 10-30 km below earth's surface, and is common in the interior of major mountain chains

Mold

created when a shell is buried and then dissolved by underground water.

carbonic acid

created when carbon dioxide dissolves in raindrops

Cast

created when the hollow spaces of a mold are filled

A dike is a. a sheetlike intrusion that lies parallel to surrounding layers of sedimentary rock b. a cooled layer of lava c. an intrusion formed within the magma chamber of a volcano d. a sheetlike intrusion that cuts across preexisting layers

d. a sheetlike intrusion that cuts across preexisting layers

Igneous rocks a. are formed through the freezing of a melt b. can be produced at the surface of the earth as well as deep below the surface c. are the most common type of rocks within earth d. all of the above

d. all of the above

Obsidian a. is volcanic glass b. possesses conchoidal fracture c. typically is felsic in composition d. all of the above

d. all of the above

The formation of magma within earth is not caused by which of the following processes? a. decompression b. addition of volatiles c. transfer of heat from adjacent magma or very hot rocks d. loss of volatiles to the atmosphere

d. loss of volatiles to the atmosphere

Coarse grained granite is most similar in mineral composition to fine grained a. andesite b. basalt c. komatiite d. rhyolite

d. rhyolite

As compared to mafic igneous rocks, all felsic igneous rocks a. cool and solidify more quickly b. cool and solidify more slowly c. solidify at higher temps d. solidify at lower temps

d. solidify at lower temps

Mafic

dark silicates and calcium rich fledspar, higher density than granitic rocks, comprise the ocean floor and many volcanic islands

density

density of rocks increases towards the center of the planet; upper mantle rocks density=3.3 g/cubic cm; lower mantle rocks=5.6 and undergo mineral phase change

800 c and 1200 c

depending on their composition, most rocks begin to melt at temperature between

veins

deposits of the minerals found within a rock fracture that are foreign to the country rock.

Volcanism

describes all the processes associated with the discharge of magma, hot fluids, and gases

volcanism

describes all the processes associated with the discharge of magma, hot fluids, and gases

volcanism

describes all the processes associated with the discharge of magma, hot water, and steam

Lithology

descripition of a rocks physical characteritics

classification of sedimentary rocks

detrital, chemical, and organic

compression

differential stress that shortens a rock body

Agents of Chemical Weathering

dissolution when certain materials dessolve in water, oxidation when oxygen combines with iron to form iron oxide, hydrolysis when any substance reacts with water, spheroidal weathering wears down sharp edges making them rounded

Syncline

down folded or troughs of rock layers (youngest strata are in the center)

Basin

downwarped circular features; younger rocks are in the center (type of fold)

tephra

erupted materials from a volcano

tephra

erupted materials. It can be pieces of lava that solidified during the eruption, or pieces of the crust carried by the magma before the eruption

nonexplosive

eruption at divergent tend to be ________

andesitic

eruption intermediate

rhyolitic

eruption very

fold

evidence that rocks can bend without breaking; usually the result of deformation in high-temperature and pressure environmnets and compressional stress

Oblique- slip fault

exhibit both a strike-slip movement and a dip-slip movement

Shield

expansive, flat region composed largely of deformed igneous and metamorphic rocks

plutons

exposed at Earth's surface as a result of uplift and erosion and are classified based on their size, shape and relationship to surrounding rocks

lower mantle

extends from the transition zone to the liquid core; earths largest layer, 56% of earths volume; olivine and pyroxene are converted into perovskite.

flood basalts

extensive thick sheets of basalt form large plateaus

pegmatites

extremely coarse grained granite cutting across much finer grained country rock--crystallize from a water-rich magma in the late stages of solidification

subduction

happens when overall density must be greater than underlying asthenospher; lithosphere sinks into the mantle; lithospheric mantle drives subduction

Amber

hardened resin of ancient trees; effective at preserving insects

Shield volcanoes

have sides with gentle slopes. They are made of basaltic lava.

Cinder Cone Volcanoes

have steep sides and are generally small, composed of any type of magma depending on the location, has a short "life cycle" at most can last for decades. Ex: Paricutin (Mexico)

Composite volcanoes

have steep sides and are made of silica-rich lava and tephra. Their eruptive forces vary.

Cinder cone volcanoes

have steep sides. They are made of tephra, lava cooled into different size pieces.

infer the composition of the magma in the mt. vesuvius eruption in 79 AD. why?

high silica and high gas content. very explosive eruption.

Flood basalt

huge amounts of lava that erupt from fissures

flood basalt

huge amounts of lava that erupt from fissures

flood basalts

huge amounts of lava that erupt from fissures

Earth's Sphere

hydrosphere (the water portion); atmosphere (gaseous envelope); geosphere (solid earth); biosphere (totality of all plant and animal life on our planet)

Extrusive

igneous activity that occurs on earths surface

Intrusive

igneous rock that formed below earths surface

porphyry

igneous rock that has mixed texture in which large crystals gloat in a predominantly fine grained matrix

pressure water

in addition to to temperature, _______ and the presence of __________ also affect the formation of magma

denser hot mantle

in an oceanic- continental subduction zone, the ________ plate slides under the continental plate into the ________ ______

principle of superposition

in an undeformed sequence of sedimentary rocks, each bed is older than the one above and younger than the one below; this also applies to lava flows and beds of ash

Convection Currents

in the mantle, where warm, buoyant rocks rise and cool, dense rocks sink, is the underlying driving force of plate tectonics (the transfer of heat by the mass movement or circulation of a substance)

pressure

inceases in with depth due to weight of overlying rock and temperature also increases which causes substances to melt although the lower crust and upper mantle doesn't usually melt

principle of inclusions

inclusions are fragments of one rock unit that are enclosed within another rock unit; the rock containing the inclusion is younger

Trace fossils

indirect evidence of prehistoric life; includes: tracks, burrows, coprolites, and gastroliths

plutons

intrusive igneous rock body, including batholiths, stocks, sills, and dikes, formed through mountain-building processes and oceanic-oceanic collisions; can be exposed at the earth's surface due to uplift and erosion.

plate boundaries

most volcanos form at

pluton

intrusive igneous rock body, including batholiths, stocks, sills, and dikes, formed through mountain-building processes and oceanic-oceanic; can be exposed at earth's surface due to uplift and erosion

Pluton

intrusive igneous rock body; exposed due to uplift and erosion

Layers Of Earth

iron-rich core (outer and inner), mantle (upper and lower), and the thin crust

Stock

irregularly shaped pluton that is similar to a batholith but smaller

stocks

irregularly shaped pluton that is similar to a batholith but smaller, generally forms 5-30 km beneath Earth's surface, and cuts across older rocks

Stocks

irregularly shaped plutons that are similar to batholiths, but smaller in size

stock

irregularly sharped pluton that is similar to a batholith but smaller, generally forms 5-30 km beneath earth's surface, and cuts across older rocks

Viscosity

is a measure of a material's resistance to flow (ex: syrup is more viscous than water)

volcanic ash

is made up of extremely small fragments, usually of glass, that form when escaping gases force a fine spray of magma from a volcano

What is a lava tube?

it is a tube beneath the solidified surface of a lava flow through which lava moves also the hollow space left when the lava within a tube drains away.

What is magma mixing?

it is the process by whereby magmas of different composition mix together to yield a modified version of the parent magmas.

What is an ash flow?

it is when a cloud of ash and gas flows along or close to the land surface. They can move fast and cover vast areas.

caldera

large crater, up to 50km in diameter that can form when the summit or side of a volcano collapse into the magma chamber during or after an eruption

Caldera

large crater; can form when summit or side of a volcano collapses.

calderas

large craters, up to 50 km in diameter, that can form when the summit or side of a volcano collapses into the magma chamber during or after an eruption

plutons

large igneous bodies formed deep in earth's crust--they range in size from a cubic kilometer to hundreds of cubic kilometers

batholiths

large plutons are great irregular masses of coarse grained igneous rock that cover at least 100 km^2. they are thick, horizontal, sheetlike bodies extending from a funnel saved central region.

Monocline

large, steplike folds in otherwise horizontal sedimentary strata; as blocks of basement rocks are displaced upward, the ductile sedimentary strata drape over them

calderas

larger depressions that can be up to 50 km in diameter and often formed after the magma chamber beneath a volcano empties from a major eruption

bombs

larger particles hurled from the volcano and streamlined by the air as they hurtle through it

Batholiths

largest plutons, are irregularly shaped masses of coarse-grained igneous rocks that cover at least 100 km2 and take millions of years to form. Common in the interior of mountain chains

blocks

largest thrown from a volcano

volcanic rock

lavas--volcanic rocks formed from flowing lavas range in appearance from smooth and ropy to sharp and spiky

basaltic

less than 50% in silica content

granodiorite

light colored rock that looks something like granite

Felsic

light colored silicates, composed almost entirely of quartz and potassium fledspar, high silica content, major constituent of continental crust

types of coal

lignite, bituminous, antracite,

isoline

line on a chart or map connecting points of equal value

outer core

liquid based on the absence of S waves traveling through the core

lava

liquid magma that reaches the surface

basaltic

location both ocean and continental crust

rhyolitic

location continental crust

andesitic

location subduction zones

fissure

long cracks in Earth's surface

fissures

long cracks in earth

Fissure

long cracks in the earth

fissures

long cracks in the earth

liquefaction

loosely packed waterlogged sediments behave as fluid during the intense shaking of an earthquake

Burial metamorphism

low-grade metamorphism that occurs in the lowest layers of very thick accumulatios of sedimentary strata

mineral phase change

lower mantle rocks undergo this as minerals are compressed under higher pressures

lava

magma flowing out onto Earth's surface

fissures,cracks, and the rock

magma moves from a chamber deep within earth to earth's to what (3)

Lava

magma that reaches earth surface

geodynamo

magnetic field caused by spiraling columns of rising fluid in the outer core; primarily dipolar; patterns of convection change rapidly enough so that the magnetic field varies noticeably over our lifetime

dikes

major route of magma transport in the crust--they are sheetlike igneous bodies that cut across the layers in bedded country rock and are so discordant intrusions. form by forcing open existing fractures in the country rock, but more often create channels through new cracks opened by the pressure of rising magma

correlation

matching rocks of similar ages from different regions, provides a more comprehensive view of the rock record

thermal contraction

materials connect when they are cooled

thermal expansion

materials expand when they are heated

fluid induced melting

melting of rock induced by the presence of water that lowers its melting point--water content is a significant factor in the melting of sedimentary rock, which contain an especially large volume of water in their pore spaces, more than is found in igneous or metamorphic rocks

intermediate igneous rocks

midway between fells and mafic--these rocks are neither as rich in silica as the fells rocks nor as poor in it as the magic rocks

Permineralization

mineral rich groundwater flows through porous tissue and precipitates minerals. Ex: Petrified wood.

partial melting

minerals that compose rock melt at different temperatures. as temperature rises, some minerals melt and other remain solid.

turbidity current

mixture of sediment and water that carry sediments of a continental rise down submarine canyons

basalt

most abundant igneous rock of the crust, and it underlies virtually the entire sea floor (dark gray to black rock). fine-grained

oceanic-continental

most volcano located on the land result from what subduction

strata

parallel layers of sedimentary rocks

black smokers

particle filled clouds that are precipitated on the seafloor when hot groundwater dissolves ions of various metals from the rock—interactions between seawater and oceanic crust

volcano

parts of the plate melt and magma rises, eventually leading to the formation of what

relative dates

place rocks in a sequence of formation; Ex: The Hermit Shale is older than the Coconino Sandstone

Dike

pluton that cuts across preexisting rocks

dike

pluton that cuts across preexisting rocks and often forms when magma invades cracks in surrounding rock bodies

dike

pluton that cuts across preexisting rocks. often form when magma invades cracks in surrounding rock bodies. range in size from a few centimeters to several meters wide

Sill

pluton that forms when magma intrudes parallel rock layers

sill

pluton that forms when magma intrudes parallel rock layers

sills

pluton that forms when magma intrudes parallel rocks layers

epicenter

point on the ground surface directly above the focus

felsic rocks

poor in iron and magnesium and rich in fells minerals that are high in silica

Pyroclastic flow

potentially deadly clouds produced by a violent eruption

ultramafic rock

primary of mafic minerals and contain less that 10 % feldspar

Volcanism

processes associated with the discharge of magma, hot water, steam.

shear stress

produces a motion similar to slippage that occurs between individual playing cards when the top of the stack is moved relative to the bottom

Plate Tectonics

proposes that Earth's outer shell consists of individual plates that interact in various ways and thereby produce earthquakes, volcanoes, mountains, and the crust itself

tensional stress

pulls apart a rock and lengthens it

basaltic

quiet eruptions

extrusive igneous rock

rapid cooling at Earth's surface produced the fine grained texture or glassy appearance of extrusive igneous rocks

pyroclastic flows

rapidly moving clouds of tephra mixed with hot, suffocating gases

pyroclastic flows

rapidly moving clouds of tephra mixed with hot,suffocating gases

Scoria

reddish/brown porous rock from frothy basaltic and andesitic lava

mantle plume

regions of hotter than normal mantle rise, experience decompressing melting, create basalts that triggers hot-spot volcanism on the surface; mantle plumes concentrate under the which continental crust which traps heat in then mantle; eventually cause the overlying crust to dome and weaken

laccoliths

relatively small, mushroom- shaped pluton that forms when magma intrudes into parallel rock layers close to Earth's surface

laccolith

relatively small, mushroom-shaped pluton that forms when magma intrudes into parallel rock layers close to earth's surface

Igneous

rock formed from the crystallization of magma

Tephra

rock fragments thrown into the air during a volcanic eruption

tephra

rock fragments, classified by size that are thrown into the air during a volcanic eruption and fall to the ground

intrusive igneous rock

rock that has forced its way into surrounding rock, called country rock , and solidified without reaching Earth's surface

hot spots

unusually hot regions of Earth's mantle where high-temperature plums of magma rise to the surface

organic

sedimentary rock composed of organic carbon from the remains of plants that died and accumulated on the floor of a swamp. Coal is a primary example.

detrital

sedimentary rocks that form from the accumulation of materials that orginate and are transported as solid particles derived from both mechanical and chemical weathering

nonconformity

sedimentary strata overlay metamorphic or igneous rocks

S waves

shear waves; can only travel through solid material; second to arrive at a recording station.

sill

sheetlike body formed by the injection of magma between parallel layers of bedded country rock--sills are concordant intrusions, which means their boundaries lie parallel to the country rock layers, whether or not those layers are horizontal.

what is a broad gently sloping volcanoes with low energy eruptions?

shield volcano

Types of Volcanoes

shield volcanoes, cinder cones and composite volcanoes

andesitic

silica content 50 to 60%

rhyolitic

silica content is more than 60%

type of volcanic rock it forms as lava cools

silica content of magma determines not only its explosively and viscosity but also

stocks

small plutons

Mediterranean Belt

smaller belt that includes Mount Etna and Mount Vesuvius, two volcanoes in Italy. Outline corresponds to the boundaries between the Eurasian, African and Arabian Plates

ash

smallest fragments less than 2mm is called

Residual Soil

soil developed directly from the weathering of the bedrock directly below

transported soil

soil that forms unconsolidated deposits

pillow lavas

some magmas rise through the narrow cracks that open where the plates are spreading and erupts into the ocean, that form basaltic pillow lavas that cover the sea floor

hot spot

some volcanoes form at

absolute date

specific date something occurred

compression

squeezes a rock and shortens it

compressional stress

squeezes a rock and shortens it

cinder cone

steep -sided, generally small volcano that is built by the accumulation of tephra around the vent

submarine canyon

steep sided valley cut into the seafloor of a continental slope

cinder cones

steep sided, generally small volcano that is built by the accumulation of tephra around the vent

continental slope

steep structure that marks the boundary between the continental and oceanic crust

confining pressure

stres is applied equally in all directions

differential stress

stress is applied unequally in all directions

pyroclastic flow

swift-moving, potentially deadly clouds of gas,ash, and other volcanic material produced by a violent eruption

higher

temperature decreases the viscosity is what

lower

temperature increases the viscosity is what

size

tephra are classified by

composition of magma

the _____________ determines a volcanos explosively, which is how it erupts and how its lava flows

tensile strength

the amount of force something can withstand before breaking

half-life

the amount of time required for half of the radioactive isotope to decay; radioactive parents isotopes decay to stable daughter isotopes; when the ratio of parent to daughter is 1:1, on half life has passed

ring of fire

the circum pacific belt's other name

metamorphic grade (regonize rocks)

the degree thst which a parent rock changes during metamorphism. It varies from low grade (low temp and pressure) to high grade (high temp and pressure)

stress

the force that deforms rocks; when stresses acting on a rock exceed its strength, the rock will deform by flowing, folding, fracturing, or faulting; magnitude is a function of the amount of force applied to a given area.

recrystallization

the formation of new mineral crystals in a rock tend to be larger than the orginal crystals.

what is a hotspot?

unusually hot regions on the earth's surface. hot because of magma built up in the mantle. thin crust by hot spot.

Geothermal Gradient

the gradual increase in temperature with depth in the crust. The average is 30 degrees celcuis per kilometer in the upper crust

craton

the interior of a continent, the oldest part

the circum pacific belt

the largest of the 2 major convergent plate boundaries

Regolith

the layer of rocks and minerals fragments that nearly everywhere covers earths land surface.

covergent and divergent

the majority of volcanos form at what boundaries and what boundaries

viscosity

the measure of a liquid's resistance to flow, increases as silica content increases. important in the behavior of lavas

magma

the molten mixture of rock-forming substances,gases,and water from the mantle

increases

the more silica the viscosity what

water vapor

the more what added to the magma would melt at lower temperature

Silicate

the most common type of minerals. They account for >90% of Earth's crust. Silicon and oxygen make up the basic building blocks of silicate minerals

Paleomagnetism

the natural remnant magnetism in rock bodies. The permanent magnetization acquired by rock that can be used to determine the location of the magnetic poles and the latitude of the rock at the time it became magnetized

Pacific Ring of Fire

the outline of this belt corresponds to the outline of the Pacific Plate

fractional crystallization

the process by which the crystals formed in a cooling magma are segregated from the remaining liquid rock--this segregation happens in several ways, following a sequence commonly described as Bowen's reaction series

lithification

the process, generally involving cementation and or compaction, of converting sediments to solid rock

geothermal gradient

the profile of earths temperature at each depth; carries within earths interior (Crust: 30 C per km of depth. Mantle: 0.3 C per km— exception is the D"layer)

fissile

the property of splitting easily into thin layers along closely spaced, parallel surfaces, such as bedding planes in shale

Pangaea

the proposed supercontinent that 200 million years ago began to break apart and form the present landmasses

reflection

the redirection of some waves back to the surface when seismic waves hit a boundary between different earth materials

elastic

the rock returns to nearly its original size and shape when stress is removed

Ophiolite complex

the sequence of 4 layers composing the oceanic crust; Layer 1: deep sea sediments and sedimentary rocks. Layer 2: pillow basalts. Layer 3: numerous interconnected dikes called sheet dikes. Layer 4: gabbro

porphyroblasts

unusually large grains, are surrounded by fine grained matrix of ther minerals

lithosphere

uppermost part of the mantle that extends down to 200 km plus the crust

country rock

upward movement is accomplished by stoping, where the overlying blocks sink through the magma

decompression melting

upwards movement of earths mantle to an area of lower pressure

dome

upwarped circular features; oldest rocks are in the center (type of fold)

radiometric dating

uses the decay of isotopes in rocks to calculate the age of that rock

Texture

the size, shape, and distribution of particles that collectivly consistute a rock

mediterranean belt

the smaller belt of the 2 major convergent plate boundaries

paleontology

the study of fossils and history of life on earth

Mineralogy

the study of minerals

bathymetry

the topography (shape) of the ocean floor; early bathymetric profiles were used using echo sounders which bounced off an object to determine distance; Sonar is also used to measure distance to the ocean floor

tension

the type of stress that tends to pull a body apart

dacite

the volcanic equivalent of granodiorite

2

the volcanos associated with convergent plate boundaries form at how many major belts

composition

the what of magma determines the characteristics of a volcano's eruption

Vesicles

they are bubbles found inside of fossils/rocks

basaltic

this magma viscosity is low

angular unconformity

tilted rocks are overlain by flat lying rocks

fossil

traces or remains of prehistoric life preserved in rock

conduction

transfer of heat through a material; through the collision of atoms or through the flow of electrons; material conduct heat at different rates; conduction is not an efficient way to move heat around the earth (most rocks are poor conductors of heat)

convection

transfer of heat where hot materials replace cold material (or vice-versa); Primary means of heat transfer within the earth; convection cycles occur within the mantle and outer crust (mantle plumes are the upward flowing arm of the cycle); similar to a pot of boiling water; material must flow in a convection cycle

Surface waves

travel in rock layers just below the earths surface; 2 general directions of motion; one causes the ground to move up and down; similar to the movement of ocean cells; the second causes the ground to move side to side and causes the greatest destruction;lowest velocity, are the last to arrive at a recording station and have the highest amplitude.

Anticline

unfolded pr arched sedimentary layers (oldest strata are in the center)

Hot spot

unusually hot area in Earth's mantle

hot spot

unusually hot area in earth's mantle where high-temperature plumes of mantle material rise toward the surface

hot spots

unusually hot regions of Earth's mantle where high temperature plumes of magma rise to the surface

isotope

varieties of the same element that have as different mass numbers; their nuclei contains the same number of protons but different numbers of neutrons

Isotope

varieties of the same element that have different mass numbers, their nuclei contain the same number of protons but different number of neutrons

andesitic

viscosity intermidiate

rhyolitic

viscosity is high

Cinder Cone

volcano that is built by the accumulation of tephra around the vent

major belt

volcanoes associated with convergent plate boundaries form this

Pyroclastic

volcanoes eject pulverized rock and lava fragments called pyroclastic materials (particles range in size from fine dust, to sand-sized ash, to very large rocks)

Quiescent

volcanoes that are quiet. They do not erupt

asthenosphere

weak layer beneath the lithospheric mantle

magmatic stoping (how magma rises)

wedging open the overlaying rock, melting surrounding rock, breaking off large blocks of rocks (known as xenoliths)

conduit

when lava reaches the surface by traveling through a tube-like structure

vent

where lava emerges through an opening

magma chamber

where lava is formed and stored in a volcano

hypocenter (focus)

where rock slippage originates in the ground

active margin

where the oceanic lithosphere is being subducted beneath the continent: often associated with deep-ocean trenches; located primarily around the Pacific ocean; features include: deep-ocean trenches, abyssal plains, seamounts and guyots, oceanic plateaus

Volcanoes can occur

where two of earth's plates converge, or rub together.

Volcanoes can also occur

where two plates diverge, or move apart.

obsidian

wholly glassy volcanic rock type, that contains only tiny vesicles and is so solid and dense

index fossil

widespread geographically and limited to a short period of geological time

agents of erosion

wind, water, gravity, or ice wear away or break rocks

principle of cross-cutting relationships

younger features cut across older features