PLANET EARTH EXAM
Shallow water carbonate environments
-transportation: depends on depth of the water -deposits: various kinds of limestone
Approximately what percentage of Earth's surface is covered with water?
70%
________ metamorphism affects the greatest volumes of rock and produces the greatest variety in metamorphic rock types
A-Dynamothermal
________ commonly serves as a protolith in the formation of slate
A-Shale
Precipitation of gypsum due to evaporation of seawater produces which kind of sedimentary rock?
A-chemical
The image below shows a lava dome that never left the volcanic crater. What is the likely composition of the rocks that make up this lava dome?
A-felsic
The cloud that rises from the vent of an actively erupting volcano is composed of ________.
A-fine volcaniclastic debris (ash) suspended in the air
Siltstone or mudstone containing marine fossils likely formed in a ________ environment
A-shallow-marine
A mountain stream (high energy environment) a. Conglomerate b. Limestone c. Sandstone d. Shale
A. Conglomerate
A fold shaped like an elongate arch as pictured to the right is a a. anticline b. basin c. dome d. syncline
A. anticline
Because the velocity of sediment settling (deposition) is positively related to grain size for waterborne sediments, fluvial deposits are more likely than glacial deposits to _______ a. be well sorted b. include coarse grains, such as cobbles c. include fine grains, such as clay d. have angular grains
A. be well sorted
All basalts younger than 700,000 years old ____________. A. have normal magnetic polarity B. have reverse magnetic polarity C. are found on the ocean floor very far from mid-ocean ridges D. are found on the continents
A. have normal magnetic polarity
16. The age of oceanic crust ____________ with increasing distance from a mid-ocean ridge. A. increases B. decreases
A. increases
At a convergent plate boundary, two opposed plates ____________. A. move toward one another B. move away from one another C. slide past one another
A. move toward one another
An episode of mountain building is termed a(n)________ a. orogeny b. aureole c. phylogeny d. slickenside
A. orogeny
The image below of Death Valley, CA, shows a road that curves around an
Alluvial fan
The image below shows a series of graded beds. How many graded beds are shown?
B-. 3
What type of weathering are you likely to find occurring in areas with cold climates? a. hydrolysis b. frost wedging c. salt wedging d. dissolution
B. frost wedging
The average thickness of continental lithosphere is about ____________. A. 30 km B. 60 km C. 150 km D. 10,000 km
C. 150 km
Two major sources of energy, coal and oil shale, are considered _______ sedimentary rocks a. clastic b. biochemical c. organic d. chemical
C. organic
The structure in the picture to the right is called a _______ a. normal fault b. half-graben c. reverse fault d. both a and b
D. both a and b
The San Andreas fault in California is a _______ a. normal fault b. reverse fault c. left lateral strike-slip fault d. right lateral strike-slip fault
D. right lateral strike-slip fault
lithospheric plate--moving above the plume anchored into the deep mantle. active volcano overlies the hot spot--volcanic activity will cease--volcano overlies the hot spot. hot spot--succession of volcanoes along linear chain of islands & sea-mounts. rising mantle plume encounters continental lithosphere, high temps cause melting. melting occurs in the lower part of the lithosphere (in the mantle) mafic magma. melting in the upper part of the lithosphere (in the crust)--felsic magma. felsic magma--eruptions to be explosive form large volcanic depression--caldera.
Describe how a hot spot can form a sequence of volcanic islands on a moving oceanic plate
colors and size of crystals, geologists observe coarse-grained rocks by cutting a slab. Fine grained rocks--microscope
Describe how igneous rocks are classified
Using the Mohs hardness scale below, which of the following statements is FALSE?
Diamonds are twice as hard as apatite
the magma inflates a lump or buldge-shaped magma body, magma chamber grows layers tilt outward and dome shaped feature. Henry Mountains of southern Utah, uncovered by erosion, medium grained and porphyritic, intermediate composition.
Discuss the geometry of a laccolith
In the figure below, which letters represent the wave height and wavelength?
E and B
All volcanic eruptions pass through the crater at the volcanic summit-True/False
False
As minerals crystallize from cooling magma--chemical composition of the magma changes as minerals crystallize. Mafic minerals crystallize from magma--extract mafic components; magnesium, iron and calcium, remaining magma contains less of the elements. magma becomes less mafic (more intermediate or felsic). crystallization of mafic minerals is making the remaining magma less mafic.
How does crystallization of minerals change the composition of remaining magma?
________ commonly serves as a protolith in the formation of marble
Limestone
Biochemical Sedimentary rocks
Limestone and chert
Subsidence
The process by which the lithosphere sinks
Lithification
The transformation of loose sediment into solid rock though compaction and cementation -durring compaction buried sediment squeezes out water and air that is trapped between clasts and clasts press tightly together -during cementation the compacted sediment binds together to make coherent sedimentary rock
____________ commonly serves as a protolith in the formation of marble. a. Limestone b. Sandstone c. Shale d. Slate
a. Limestone
A fold shaped like an right-side-up bowl is a (an) ____________. a. basin b. dome c. syncline d. anticline
a. basin
As compared to aphanitic igneous rocks, phaneritic rocks are ____________. a. coarser grained b. finer grained c. more mafic d. more felsic
a. coarser grained
Trace amounts of impurity in a mineral can commonly produce significant differences in ____________ among individual crystals of this mineral. a. color b. specific gravity c. luster d. streak
a. color
If a body of magma becomes more felsic, its viscosity will ____________. a. increase b. decrease c. stay the same
a. increase
Magma tends to _____________. a. move upward, away from where it formed b. move downward, away from where it formed c. move laterally d. stay in one place
a. move upward, away from where it formed
Igneous rocks ________.
are formed by changing existing rock by the application of heat and pressure
The internal ordering of mineral crystals is detected using ____________. a. magnetic resonance imaging b. X-ray diffraction c. a scanning electron microscope (SEM) d. cathodized axial tomography
b. X-ray diffraction
Basaltic lavas that solidify at the surface before flow ceases fracture irregularly, producing a sharp surfaced lava rock named a. pahoehoe b. aa c. pumice d. hyaloclasite
b. aa
In 1902, a famous, deadly volcaniclastic flow killed thousands of people on the Caribbean island of a. puerto rico b. martinique c. aruba d. jamaica
b. martinique
Force per unit area is termed ____________. a. strain b. stress c. power d. work
b. stress
In a ____________ fault, the fault plane is less than 35° from horizontal and the hanging-wall block moves upward relative to the footwall block. a. detachment b. thrust c. reverse d. normal
b. thrust
generally, which type of earthquake waves travel fastest
body waves
Mt. Everest, the tallest mountain in the world, is located on the continent of ____________. a. North America b. Europe c. Asia d. Africa
c. Asia
Metamorphism at ocean ridges is mainly (a) contact (b) dynamic (c) hydrothermal (d) regional
c. hydrothermal
Geologically, melts are equivalent to both ____________ and ____________. a. felsic magma; mafic magma b. felsic lava; mafic lava c. lavas; magmas d. fine-grained igneous rocks; coarse-grained igneous rocks
c. lavas; magmas
The outer portion of a craton, where deformed rocks are covered by sediments, is termed the ____________. a. convergent margin b. shield c. platform
c. platform
A equant material subjected to confining pressure from burial is (a) flattened to a disk (b) elongated like French bread (c) remains equant
c. remains equant
What has the best cleavage (a) slate (b) phyllite (c) schist (d) gneiss (e) migmatite
c. schist
Which of the following minerals is softest? a. quartz b. calcite c. talc d. fluorite
c. talc
Calcite (CaCO3) is in which mineral class?
carbonates
As compared to the asthenosphere, the lithosphere is ________.
cooler and less able to flow
In the formation of gneiss from granite, distinctive compositional bands form because of ________.
crystals dissolving, with atoms and ions migrating and reorganizing as new crystals
The oldest basalts on the ocean floor are about ____________ years old. a. 4 billion b. 2.5 million c. 50 thousand d. 200 million
d. 200 million
Without plate tectonics, we would not have _______________. a. plates in constant motion b. mountain building c. formation of new oceans d. All of the above are correct.
d. All of the above are correct.
Hot spot volcanoes a. can arise form the ocean floor b. can arise on the continents c. may arise in the interior of lithospheric plates d. all of the above
d. all of the above
Metamorphism, in broadest terms, involves : . a..the settling of crystals within a melt as it cools b..the sorting of grains by size, as is accomplished by rivers and beach waves c..cementation of loose grains and precipitation of new minerals into pore spaces d..changes in mineralogy and texture in response to heat and stress
d. changes in mineralogy and texture in response to heat and stress
The mineral glaucophane is associated with (a) high temperature and low pressure (b) high temperature and pressure (c) low temperature and pressure (d) high pressure and low temperature
d. high pressure and low temperature
The densest layer of Earth is the ________. a. crust b. mantle c. outer core d. inner core
d. inner core
The protolith subjected to metamorphism ____________. a. is always metamorphic rock to begin with b. is always igneous rock c. is always sedimentary rock d. may belong to any of the three primary rock types
d. may belong to any of the three primary rock types
According to the figure below, fracture zones lay roughly ___________ to mid-ocean ridges. a. adjacent b. at an obtuse angle c. parallel d. perpendicular
d. perpendicular
Compared with the continental crust, the oceanic crust is ________.
denser
If you found tuff deposits at an ________ igneous setting, you could conclude that the source magma had a ________ viscosity.
extrusive; high
Which of the following minerals is more commonly known as table salt?
halite
Volcanoes that do NOT occur along either present or emergent plate boundaries are associated with ________.
hot spots
the point within earth where an earthquake takes place is termed the
hypocenter (focus)
All other factors equal, if a body of magma becomes more felsic, its viscosity will ________.
increase
Continental lithosphere ________.
is thicker than oceanic lithosphere
Moving away from its headwaters/source, the flow of a stream usually becomes more ________.
laminar
Compaction and cementation of grains occurs during ________.
lithification
Dissolution occurs when ________.
minerals are dissolved into water
Bowen's continuous reaction series describes the crystallization behavior of which single mineral (with variable chemical composition)?
plagioclase
The process of high-grade metamorphic rocks being altered to form low-grade metamorphic rocks is termed ________ metamorphism.
retrograde
Which earthquake severity scale measures the amplitude of deflection of a seismograph pen, standardized to an idealized distance of 100 km between epicenter and seismograph?
richter scale
which earthquake severity scale takes vibration caused only by the s waves into account when estimating the size of an earthquake
richter scale
If sea level continues to rise and covers the city of Miami, the Florida coast will become a(n) ________.
submergent coast
Pyrite (FeS2) is in which mineral class?
sulfides
Which of the following common minerals is softest?
talc
The breakdown of exposed rock into small fragments and dissolved ions is termed ________.
weathering
Marine Delta deposits
- large deltas are much more complex than lake deltas -deposits: a great variety of sedimentary rocks
Chemical Sedimentary rocks
-Evaporites: products of saltwater evaporation -Travertine: chemical limestone -Dolostone -Chert
Physical weathering
-root wedging -salt wedging -dissolution -oxidation
Mountain Stream Environment
-transportation: Fast moving water -forms gravel and boulder beds. Washes finer sediment downstream - deposits: breccia and conglomerate
Glacial Environments
-transportation: ice -deposits glacial till which is unsorted and unstratified -produces diamicton
River environment
-transportation: river channel -sediments transported: gravel, sand, silt, mud -coarser sediments: collect in cross-bedded rippled layers -finer sediment: settles along the banks or the floodplains -deposits: fluvial sediments, sandstone, siltstone, shale
Alluvial-fan environment
-transportation: slow-moving water -forms a wedge-shaped apron of gravel and sand -deposits: arkose and congolmerate
Lake environments
-transportation: still water -deposits: finely laminated shale
Sand-dune environment
-transportation: strong winds -forms large cross beds -deposits: well sorted sandstone
Deep-marine deposits
-transportation: turbidy currents -deposits: finely laminated mudstones, plankton shells settle to form chalk
Coastal Beach Sands
-transportation: waves -deposits: well rounded and sorted sandstone and well sorted medium-grained sandstone
A body of rock affected by tensile stress will likely undergo ____________. a. shortening b. stretching c. shear strain
...
Normal faults assume a more shallow dip angle with depth; when the fault plane becomes nearly horizontal, these faults are termed ____________. a. detachments b. decollements c. thrusts d. folds
...
5 steps of transformation from sediment to clastic sedimentary rock
1. weathering 2. eroison 3. transportation 4. deposition 5. lithification
An earthquake occurs with an epicenter in the town of New Madrid, Missouri, in the interior of the North American Plate. Where might the hypocenter of this earthquake plausibly be found
10 km south of new madrid
What is the percentage of dissolved salt in seawater?
3.5%
The circumference of Earth is most nearly ________.
40,000 km
the greatest earthquake ever recorded by seismographs occured in 1960 in chile and measured..
9.5 on the seismic moment magnitude scale
Using the figure below, which of the following lists correctly identifies the various seafloor landforms?
A = continental shelf, B = continental slope, D = continental rise, G = abyssal plain, C = mid-ocean ridge, F = trench, and E = volcanic arc
Delta
A wedge of sediment that accumulates where moving water enters standing water. Deltas are made up of 1. topset bed - gravel 2. foreset bed - gravel and sand 3. Bottomset bed -silt
Beach sediments travel ________ the ocean during a transgression and ________ the ocean during a regression
A-away from; toward
Which of the following is NOT part of the process that leads to the exhumation of metamorphic rocks?
A-continents squeezing together
Rhyolitic lavas ________.
A-do not flow as far from the vent as basaltic lavas do
Columnar joints form when ________.
A-during the final stages of cooling, a lava flow contracts, forming tall polygonal fractures
Slaty cleavage, schistosity, and compositional banding are all examples of ________.
A-foliation
The characteristic "rotten egg" smell of many active volcanoes is derived from ________.
A-hydrogen sulfide gas
Foliated metamorphic rocks possess ________.
A-mineral grains in preferred orientations or patterns of association (banding)
Thermal (contact) metamorphism produces ________.
A-nonfoliated rocks only
Which of the following describes the progression of rock types through increasing metamorphic grade?
A-shale slate phyllite schist
The tall polygonal features preserved in the ancient basalt flow in the image below formed because the lava ________.
A-shrank as it cooled, forming tall polygonal-shaped fractures
Stratification refers to ________.
A-the development of layering within sedimentary rocks
The image below shows ancient dunes exposed in Zion National Park in Utah. Using the interpreted portion of the image at the left, what was the dominant wind direction that formed these sedimentary structures?
A-toward the right
Within the sea floor, the rate of heat flow is greatest ____________. A. along mid-ocean ridges B. along fracture zones C. at the edges of ocean basins D. in the center of abyssal plains
A. along mid-ocean ridges
Most of the pulling force that drives plate motion is produced ____________. A. at mid-ocean ridges B. at subduction zones C. at collision zones D. in the interiors of continental plates
A. at mid-ocean ridges
The trend on the Earth's surface (identified as a compass direction) formed by the intersection of an inclined rock layer or a fault plane with a horizontal plane of the Earth's surface is called _______ a. axial trace b. direction of dip c. angle of dip d. strike e. plunge
A. axial trace
Cemented shells of marine organisms form which kind of sedimentary rock? a. biochemical b. clastic c. organic d. pelagic
A. biochemical
Subduction zones are ____________. A. convergent plate boundaries B. divergent plate boundaries C. transform plate boundaries
A. convergent plate boundaries
A long-lived block of continental crust found in the stable interior of a continent, dominated by ancient metamorphic rock covered by sediment a. craton b. epeirogeny c. fold-thrust belt d. monocline
A. craton
Under the theory of plate tectonics, the plates themselves are ____________. A. discrete pieces of lithosphere at the surface of the solid Earth that move with respect to one another B. discrete layers of lithosphere that are vertically stacked one atop the other C. composed only of continental rocks, which plow through the weaker oceanic rocks D. very thick (approximately one-quarter of Earth's radius)
A. discrete pieces of lithosphere at the surface of the solid Earth that move with respect to one another
At transform plate boundaries ____________. A. earthquakes are common, but volcanoes are absent B. volcanoes are common, but earthquakes do not occur C. both earthquakes and volcanoes are common
A. earthquakes are common, but volcanoes are absent
Thermal (contact) metamorphism occurs ______ a. in areas surrounding igneous intrusions b. only where gneiss is in contact with schist c. as a consequence of the sinking of a broad region to great depth d. only at the surface, where rock is in contact with the atmosphere
A. in areas surrounding igneous intrusions
At a subduction zone, the overriding plate ____________. A. is always composed of continental lithosphere B. is always composed of oceanic lithosphere C. may be composed of either oceanic or continental lithosphere
A. is always composed of continental lithosphere
Unlike the lithosphere, the asthenosphere ____________. A. is relatively weak and flows readily B. has a density similar to the core C. varies in thickness from place to place D. is relatively cool
A. is relatively weak and flows readily
Continental lithosphere ____________. A. is thicker than oceanic lithosphere B. contains more mafic rocks than oceanic lithosphere C. is denser than oceanic lithosphere D. contains no crustal material, consisting solely of lithified upper mantle
A. is thicker than oceanic lithosphere
Marine magnetic anomaly belts run parallel to ____________. A. mid-ocean ridges B. fracture zones C. continental coastlines D. continental shelves
A. mid-ocean ridges
The primary difference between lithospheric and asthenospheric mantle that gives rise to numerous divergent patterns of physical behavior, is ____________. A. physical state (the lithosphere is solid, and the asthenosphere is liquid) B. chemical composition (the lithosphere is mafic, and the asthenosphere is felsic) C. temperature (the lithosphere is cooler than the asthenosphere) D. chemical composition (the lithosphere is felsic, and the asthenosphere is mafic)
A. physical state (the lithosphere is solid, and the asthenosphere is liquid)
The chemical process in which grains come out of solution to form sedimentary rocks like limestone: a. precipitation b. evaporation c. deposition d. cementation
A. precipitation
The type of stress that causes the structure in the picture is _______ a. tensional b. compressional c. lithostatic d. hydrostatic
A. tensional
Which of the following is a type of physical weathering? a. thermal expansion b. dissolution c. oxidation d. hydration
A. thermal expansion
Regions of the sea floor with positive magnetic anomalies were formed during times when Earth's magnetic field ____________. A. was exceptionally strong B. was exceptionally weak C. had normal polarity D. had reversed polarity
A. was exceptionally strong
As compared to a slowly spreading mid-ocean ridge, a rapidly spreading ridge is ____________. A. wider B. narrower C. more silicic in lava composition
A. wider
The figure below shows two hypothetical streams that have identical cross-sectional areas but different channel shapes. Assuming all other factors are equal, stream ________ will have the fastest flow because of the difference in ________.
A; wetted perimeter
Evidence of paleomagnetism can be found in ________.
All of the above are correct
Which river has the greatest discharge of any stream on Earth?
Amazon
Which fault below would result from compressional stress?
B
Which transport medium carries the largest particles? (think about it!)
B-. ice in glaciers
Precambrian metamorphic rocks are exposed at the surface ________.
B-at places in continental interiors termed shields
Cemented shells of marine organisms form which kind of sedimentary rock?
B-biochemical
The image below shows a ________, which is a large piece of pyroclastic debris ejected during an eruption, with a smooth texture due to the fact that it was partially molten when ejected.
B-bomb
The removal of detritus from weathered rock at an outcrop is termed ________.
B-erosion
Rocks resulting from thermal (contact) metamorphism will NOT possess ________.
B-foliation
Based on your knowledge of volcanoes and volcanic products, you can say with confidence that the outcrop in the image below ________.
B-formed underwater at a mid-ocean ridge
Flint was prized in early human cultures becuase
B-they broke with conchoidal fracture and thus made good cutting tools.
Sea level rises locally, and marine sediments are deposited on top of terrestrial sediments during events termed ________.
B-transgressions
Grains become rounded primarily during ________.
B-transportation
When graded beds are observed in a rock outcrop, this tells geologists that a ________. (Pick the best answer!)
B-turbidity current deposited these beds, depositing coarser material first
If water is the transport mechanism of sediment, the grain size of sedimentary deposits most closely indicates the ________. (check your answer, the wording may be confusing!)
B-velocity of the water at the moment the sediment settled to the bottom
If a geologist found preserved mud cracks, he or she could conclude that the environment in which they formed ________.
B-was once covered in wet mud
Potassium feldspar reacts with water to form clay. This is an example of ________.
B-weathering
Sea-floor spreading is driven by volcanic activity ____________. A. in the middle of abyssal plains B. along mid-ocean ridges C. at the edges of continental shelves D. along fracture zones
B. along mid-ocean ridges
Most of the pushing force that drives plate motion is produced ____________. A. at mid-ocean ridges B. at subduction zones C. at collision zones D. in the interiors of continental plates
B. at subduction zones
A fold shaped like a right-side up bowl as illustrated on the right is a a. anticline b. basin c. dome d. syncline
B. basin
In humid (warm, damp) climates _______ weathering is dominant as compared to arid (dry) climates _______ weathering is dominant a. stress, strain b. chemical, mechanical c. strain, stress d. mechanical, chemical
B. chemical, mechanical
Which of the following is not a type of stress exerted on rocks? a. compression b cognitive c. tension d. shear
B. cognitive
When two bodies of continental lithosphere are pushed together at a convergent boundary, the result is ____________. A. subduction B. collision and mountain formation
B. collision and mountain formation
The application of ______ during metamorphism causes elongated crystals to align parallel with each other. When this happens, the rock develops _______. a. pressure; a homogeneous texture b. differential stress; foliation c. high temperatures; foliation d. pressure; foliation
B. differential stress;foliation
Mid-ocean ridges are ____________. A. convergent plate boundaries B. divergent plate boundaries C. transform plate boundaries
B. divergent plate boundaries
The apparent polar-wander path obtained from magnetite crystals in basalts on the North American continent is now interpreted to be the result of ____________. A. wandering of the geomagnetic north pole B. drifting of the North American continent
B. drifting of the North American continent
The distinction between joints and faults is that ______ a. faults are joints that are greater than one square meter in areal extent b. faults are fractures along which displacement has occurred; displacement does not occur along joints c. joints are fractures along which displacement has occurred; displacement does not occur along faults d. there is no distinction; the two terms are synonymous
B. faults are fractures along which displacement has occurred; displacement does not occur along joints
Beneath a blanket of sediments, oceanic crust is primarily composed of two rocks, ____________. A. granite and diorite B. gabbro and basalt C. sandstone and shale D. slate and gneiss
B. gabbro and basalt
Wegener's idea of continental drift was rejected by American geologists because ____________. A. his English was too poor to be understood by them B. he could not conceive of a valid mechanism that would cause continents to shift positions C. he had relatively little evidence supporting the existence of a supercontinent D. the apparent fit of continental coastlines is blurred when the margins are defined by the edges of continental shelves rather than at sea level
B. he could not conceive of a valid mechanism that would cause continents to shift positions
Orogenesis (mountain building) leads to the production of _________ a. metamorphic rocks b. igneous and sedimentary rocks c. metamorphic and igneous rocks d. igneous, metamorphic, and sedimentary rocks
B. igneous and sedimentary rocks
At a subduction zone, the downgoing (subducting) plate ____________. A. is always composed of continental lithosphere B. is always composed of oceanic lithosphere C. may be composed or either oceanic or continental lithosphere
B. is always composed of oceanic lithosphere
If we mentally align the continents to fit Wegener's concept of Pangaea, evidence of late Paleozoic glacial deposits ____________. A. is more difficult to explain than in the modern continental configuration B. is much more readily explained than in the modern continental configuration C. makes very little sense in either the Pangaea configuration or the modern configuration
B. is much more readily explained than in the modern continental configuration
The magnetic field of Earth in the geologic past is ____________. A. unknown, but it is assumed to have been identical to today's B. known to have been constant through geologic time, due to remnant magnetization of iron-rich minerals in rocks C. known to have experienced numerous polarity reversals, due to remnant magnetization of iron-rich minerals in rocks D. known to have been constant through time, on the basis of theoretical calculation
B. known to have been constant through geologic time, due to remnant magnetization of iron-rich minerals in rocks
Compaction and cementation of grains occurs during _______ a. erosion b. lithification c. transport d. weathering
B. lithification
Which of these properly illustrates the principle of isostasy? a. High-density crust floats on top of low-density mantle b. mountains stand high because they are gravitationally balanced by their deep crustal roots c. when weight is added to the crust, the crust responds by rebounding upward. d. when material is removed from the crust, the crust maintains the new, lower elevation.
B. mountains stand high because they are gravitationally balanced by their deep crustal roots
At a divergent plate boundary, two opposed plates ____________. A. move toward one another B. move away from one another C. slide past one another
B. move away from one another
Continental coastlines that occur within the interior of a tectonic plate are called ____________. A. internal margins B. passive margins C. active margins D. inert margins
B. passive margins
A sedimentary rock is: a. produced by the cooling of magma b. produced from weathered products of pre-existing rocks c. any hard, solid substance on the Earth's surface d. a naturally occurring, crystalline solid
B. produced from weathered products of pre-exisitng rocks
Two common metamorphic rocks that typically lack foliation are ______ and _______ a. slate; phyllite b. quartzite; marble c. gneiss; migmatite d. schist; metaconglomerate
B. quartzite; marble
_________ commonly serves as protolith in the formation of quartzite a. limestone b. sandstone c. shale d. gneiss
B. sandstone
Marine magnetic anomaly belts are widest when and where ____________. A. continents are joined to form supercontinents B. sea-floor spreading rates are relatively rapid C. sea-floor spreading rates are relatively slow
B. sea-floor spreading rates are relatively rapid
A body of rock affected by tensile stress (tension) will likely undergo ______ a. shortening b. stretching c. shear strain d. rotation
B. stretching
Oceanic lithosphere thickens away from the mid-ocean ridge primarily due to ____________. A. the addition of new crust due to hot-spot volcanism B. the addition of new crust due to sedimentation C. the addition of new lithospheric mantle as a result of cooling D. reasons that geologists cannot determine at present
B. the addition of new crust due to sedimentation
When graded beds are observed in a rock outcrop, this tells geologists that a _______ a. turbidity current deposited these beds, depositing finer material first b. turbidity current deposited these beds, depositing coarser material first c. slurry deposited these beds with little sorting d. glacier deposited these beds, depositing coarser material first
B. turbidity current deposited these beds, depositing coarser material first
Regions of the sea floor with negative magnetic anomalies were formed during times when Earth's magnetic field ____________. A. was exceptionally strong B. was exceptionally weak C. had normal polarity D. had reversed polarity
B. was exceptionally weak
In the figure below, which letters represent the crest and trough?
C and D
. ________ commonly serves as a protolith in the formation of marble
C-Limestone
In 79 C.E., the citizens of Pompeii in the Roman Empire were buried by pyroclastic debris derived from an eruption of ________.
C-Mt. Vesuvius
________ commonly serves as a protolith in the formation of quartzite.
C-Sandstone
The image below of Death Valley, CA, shows a road that curves around a(n) ________.
C-alluvial fan
Which environment would most likely produce sedimentary deposits characterized by poorly to moderately sorted, angular to subangular grains that consist of feldspar, quartz, and lithics (rock fragments)?
C-alluvial fan
A clastic rock composed of sand-sized grains derived from the physical weathering of granite and containing a sizable proportion of feldspar is termed ________.
C-arkose
The rapid, deep burial of sediments in an accretionary prism leads to the formation of a metamorphic rock termed ________.
C-blueschist
Broadly, metamorphism involves ________.
C-changes in mineralogy and texture in response to heat and stress
The image below shows an outcrop of coarse-grained sedimentary rock. Note the rock hammer for scale. What is the name of this rock type?
C-conglomerate
Pele's hair ________.
C-consists of thin strands of basaltic glass
Consult the figure below. Here, distinct internal laminations are inclined at an angle to the boundary of the main sedimentary layers. This is termed ________.
C-cross beds
A pre-existing body of gneiss is subjected to heat and forms a melt. Later, the melt cools and crystallizes to form a(n) ________ rock
C-igneous
The lithification of material from a pyroclastic flow forms a rock called ________.
C-ignimbrite
Thermal (contact) metamorphism occurs ________.
C-in areas surrounding igneous intrusions
Within a single mountain range, ________.
C-it is possible to find a variety of metamorphic rocks produced in distinct facies, including high-, intermediate-, and low-grade rocks
Compared to felsic lavas, mafic lavas have a ________ and flow more easily across the landscape
C-lower viscosity
The textural term for a basaltic lava flow that has a smooth, ropy appearance is ________.
C-pahoehoe
Ash, cinders, and blocks are all types of ________.
C-pyroclastic debris
Pulling a block of clay apart, resulting in the middle portion thinning and sinking, is an adequate analogy for ________.
C-rift basins and subsidence
A well-sorted, mature sandstone with asymmetric ripples was most likely deposited as sand by a ________.
C-river (far from source)
Biochemical limestones are dominated by carbonate mud and fragments of ________.
C-skeletons of marine invertebrates made of calcite and aragonite
The difference between tephra and tuff is that ________.
C-tephra is unlithified, whereas tuff is lithified
Volcanic bombs are ________.
C-volcanic fragments that were ejected while still soft or molten
The breakdown of exposed rock into small fragments and dissolved ions is termed ________.
C-weathering
The oldest sediments on the ocean floor are about ____________ years old. A. 50 thousand B. 4 billion C. 200 million D. 2.5 million
C. 200 million
Rocks resulting from thermal (contact) metamorphism will NOT possess a. a new mineral assemblage distinct from that found prior to intrusion b. larger crystal than those characterizing the country rock prior to intrusion c. foliation d. silicate minerals
C. Foliation
A desert with extensive sand dunes (moderate energy environment) a. Conglomerate b. Limestone c. Sandstone d. Shale
C. Sandstone
Currently, most geologists ____________. A. continue to reject continental drift B. agree that continental drift occurs, but they still do not understand why it occurs C. agree that continental drift occurs; the mechanisms that drive drift are at work in the ocean basins and upper mantle and were unknown in Wegener's time D. agree that continental drift occurs; the mechanisms that drive drift are at work in the lower mantle and outer core and were unknown in Wegener's time
C. agree that continental drift occurs; the mechanisms that drive drift are at work in the ocean basins and upper mantle and were unknown in Wegener's time
The youngest sea floor occurs ____________. A. along passive margins B. along active margins C. along mid-ocean ridges D. randomly over the entire ocean basin
C. along mid-ocean ridges
Compared with low-grade metamorphic rocks, high-grade rocks ________ a. always contain more quartz and feldspar b. are produced close to the surface but high in the stratigraphic column c. are produced at greater temperatures and pressures d. are produced at cooler temperatures but greater pressures
C. are produced at greater temperatures and pressures
An assemblage of rock structures that form on the continental side of a subduction zones above a detachment fault, due to compressional stress a. craton b. epeirogeny c. fold-thrust belt d. monocline
C. fold-thrust belt
Under which condition would a body of rock by most likely to exhibit plastic behavior? a. high rate of deformation b. low temperature c. high temperature d. low pressure
C. high temperature
The theory of plate tectonics ____________. A. incorporates continental drift but not sea-floor spreading B. incorporates sea-floor spreading but not continental drift C. incorporates and explains both sea-floor spreading and continental drift D. does not incorporate sea-floor spreading or continental drift
C. incorporates and explains both sea-floor spreading and continental drift
Marine magnetic anomalies result from sea-floor spreading in conjunction with ____________. A. global warming B. magnetic storms on the surface of the Sun C. magnetic polarity reversals D. apparent wander of the magnetic poles
C. magnetic polarity reversals
Tectonic plates might consist of ____________. A. continental lithosphere only B. oceanic lithosphere only C. oceanic or continental lithosphere or a combination of both D. either oceanic or continental lithosphere, but not both
C. oceanic or continental lithosphere or a combination of both
Which type of weathering process is happening to materials when they rust? a. hydrolysis b. hydration c. oxidation d. dissolution
C. oxidation
The primary difference between breccia and conglomerate is that breccia _______ a. is finer grained than conglomerate b. is coarser grained than conglomerate c. possesses more angular grains than conglomerate d. possesses more rounded grains than conglomerate
C. possesses more angular grains than conglomerate
Preexisting rock that is subsequently altered to form a metamorphic rock is termed a ______ a. xenolith b. source rock c. protolith d. phenocryst
C. protolith
It is called a _______ fault a. normal b. oblique-slip c. reverse d. strike-slip
C. reverse
Which list properly orders metamorphic rocks from lowest grade to highest grade? a. conglomerate, sandstone, siltstone, and shale b. shale, slate, phyllite, and quartzite c. slate, phyllite, schist, and gneiss d. gneiss, phyllite, schist, and slate
C. slate, phyllite, schist, and gneiss
At a transform plate boundary, two opposed plates ____________. A. move toward one another B. move away from one another C. slide past one another
C. slide past one another
The term for a change in shape induced by stress is a. plastic deformation b. pressure release c. strain d. metamorphosis
C. strain
Segments of the mid-ocean ridge system are offset. Between the offset segments we observe ____________. A. a second series of ridges, perpendicular to the main set B. deep-ocean trenches C. transform faults D. None of the above is correct.
C. transform faults
Sea level rises locally, and marine sediments are deposited on top of terrestrial sediments during events termed _______ a. cross bedding b. regressions c. transgressions d. turbidity currents
C. transgressions
The Wadati-Benioff zone is a belt of earthquakes found ____________. A. within an otherwise stable continental interior B. within an overriding plate at a subduction zone C. within a downgoing plate at a subduction zone D. along mid-ocean ridges
C. within a downgoing plate at a subduction zone
Organic Sedimentary rocks
Coal and oilshale
Conglomerate
Coarse grained clastic sedimentary rock consiting off rounded pebbles and cobbles
Breccia
Coarse grained sedimentary rock consisting of angular grains
Diamictite
Coarse grained sedimentary rock consisting of large clasts in a muddy matrix
Cross Beds
Cross beds form as a sand blows up the windward side of a dune or ripple and then accumulates on the slip face
It is unusual for ________ to carry grains larger than sand
D-. wind
What is the difference between the formation of chalk versus chert?
D-They are made of different source materials.
Basaltic lavas that solidify at the surface before flow ceases fracture irregularly, producing a sharp-surfaced, blocky, and irregular lava rock named ________.
D-a'a'
Mylonites, formed from dynamic metamorphism, typically do NOT display ________.
D-bands of randomly oriented mica grains
Which environment would most likely produce sedimentary deposits characterized by very well-sorted, very well-rounded grains that are nearly pure quartz?
D-beach
Lithified detritus (breakdown products of preexisting rocks) forms which kind of sedimentary rock?
D-clastic
Which of the following processes CANNOT occur in the formation of metamorphic rock?
D-complete remelting of the rock, followed by solidification to form a new rock
Basaltic lavas ________.
D-contain more iron and magnesium than rhyolitic lavas
Which of the following is NOT true? As compared to arkose, quartz sandstone ________.
D-contains more angular grains
Clastic sedimentary rocks are primarily classified on the basis of ________.
D-grain size
Regional metamorphism ________.
D-is another name for dynamothermal metamorphism
A fast-moving flow consisting of a mixture of water and volcaniclastic debris is termed a ________.
D-laha
What properties of the source magma lead to the formation of a shield volcano?
D-low viscosity and mafic composition
A protolith subjected to metamorphism ________
D-may belong to any of the three primary rock types
Preexisting rock that is subsequently altered to form a metamorphic rock is termed a ________.
D-protolith
A mixture of air, hot ash, and pumice lapilli that rushes down the side of a volcano in a scalding avalanche is termed a(n) ________.
D-pyroclastic flow
Of the three primary forms of subaerial volcanoes, ________ have the most gently sloping sides, due to the low viscosity of the basaltic lavas that form them.
D-shield volcanoes
Gases that are abundantly emitted by volcanoes include ________.
D-water vapor, carbon dioxide, and sulfur dioxide
A lake (low energy environment) a. Conglomerate b. Limestone c. Sandstone d. Shale
D. Shale
Foliation is ________ a. layering in igneous rocks b. alignment of any kind observed in any rock type c. layering observed in sedimentary rocks d. alignment of texture/minerals in metamorphic rocks
D. alignment of texture/minerals in metamorphic rocks
In the terminology of plate tectonics, an active margin is ____________. A. synonymous with "subduction zone" B. a 5-mile radius surrounding an active volcano C. a continental coastline that coincides with a plate boundary D. anywhere on Earth where earthquakes are especially frequent
D. anywhere on Earth where earthquakes are especially frequent
Broadly, metamorphism involves ______ a. the settling of crystals in a melt as it cools b. the sorting of grains by size, as accomplished by rivers and beach waves c. the cementation of loose grains and the precipitation of new minerals into pore spaces d. changes in mineralogy and texture in response to head and stress
D. changes in mineralogy and texture in response to heat and stress
Wegener proposed continental drift after he observed evidence from fossils, glacial deposits, and the fit of the continents that suggested all of the continents were once A. aligned north to south along the prime meridian during the late Cenozoic B. aligned east to west along the equator during the late Mesozoic through the Cenozoic C. combined to form a supercontinent (he termed Rodinia) in the Proterozoic D. combined to form a supercontinent (he termed Pangaea) in the late Paleozoic through the Mesozoic
D. combined to form a supercontinent (he termed Pangaea) in the late Paleozoic through the Mesozoic
Which of the following processes CANNOT occur in the formation of metamorphic rock? a. the realignment of minerals so that stye develop a preferred orientation b. the segregation of minerals into layers of different compositions c. the solid-state rearrangement of atoms or ions to create a new assemblage of minerals d. complete remelting of the rock, followed by solidification to form a new rock
D. complete remelting of the rock, followed by solidification to form a new rock
Within a single mountain range, a. only low-grade metamorphic rocks are likely to be found b. only high-grade metamorphic rocks are likely to be found c. only nonaffiliated metamorphic rocks are likely to be found d. it is possible to find a variety of metamorphic rocks produced in distinct faces, including high-, intermediate-, and low-grade rocks
D. it is possible to find a variety of metamorphic rocks produced in distinct faces, including high-, intermediate-, and low-grade rocks
The thickness of oceanic lithosphere is ____________. A. uniformly 100 km B. greatest at the geographic poles and least near the equator C. greatest near the mid-ocean ridges and thins out away from the ridges D. least near the mid-ocean ridges and thickens away from the ridges
D. least near the mid-ocean ridges and thickens away from the ridges
A protolith subjected to metamorphism _________ a. is always metamorphic rock b. is always igneous rock c. is always sedimentary rock d. may belong to any of the three primary rock types
D. may belong to any of the three primary rock types
A fold in the land surface whose shape resembles a carpet draped over stair step, usually forms over a fault that does not come to the surface a. craton b. epeirogeny c. fold-thrust belt d. monocline
D. monocline
Every plate boundary can be recognized by ____________. A. the presence of active volcanoes B. the presence of an earthquake belt C. a deep chasm which can be seen from space D. none of the above
D. none of the above
Which of these features would NOT help a geologist recognize a fault? a. different rock units juxtaposed against each other b. a small step on the landscape c. a shattered rock consisting of visible angular fragments d. regularly spaced quartz veins
D. regularly spaced quartz veins
The mid-ocean ridges are elevated above the surrounding sea floor because ____________. A. ridge rocks are hot and therefore of relatively low density B. the lithospheric plates are thickest at the ridges so they stand up taller C. rising ocean currents leave a vacuum above the ridge D. ridge rocks are mafic, whereas the ocean basin crust consists of ultramafic rock
D. ridge rocks are mafic, whereas the ocean basin crust consists of ultramafic rock
The figure to the right show the application of ________ a. tension b. pressure c. normal stress d. shear stress
D. shear stress
main difference:felsic; light colored abundant in quartz and feldspar. Mafic-- dark minerals rich in magnesium and iron
Describe the main differences between felsic and mafic rocks
begins with magma forming by melting at depth, followed by movement of the magma toward the surface and then solidification of the magma into solid rock. 1. melting beneath the surface in the deeper parts of the crust or in the mantle. source area--melting occurs, most magma result from partial melting leaving most source area unmelted. 2. separate pockets of magma may accumulate large volume of magma. 3. magma chamber--injection of smaller magma in sheetlike bodies, may solidify and never reach the surface. igneous rock--solidified at depth--plutonic rock and body of the rock forms a pluton. 4. magma rises through the crust, may stop in or pass through a series of magma chambers, intrusion--body of molten rock in the subsurface--magma intrudes into the rocks, solidifies below surface--intrusive rock. 5. magma chambers below the surface beneath a volcano, magma may solidify before the next batch arrives, crystallize while some rise to the surface, rising magma carry some early formed crystals all the way to the surface--porphyritic volcanic rock. 6. magma reaches the surface erupts as lava or volcanic ash--forms when dissolved gases in the magma expand and below the magma apart into small fragments of volcanic glass. forms on the surface--extrusive rock--extruded onto the surface
Describe the processes involved in forming igneous rocks
the rocks are all mafic. The mafic magma forms by partial melting of the ultramafic mantle. Upper part of the oceanic crust---basaltic lava flows, form series of overlapping mounds---pillows. rocks called---pillow basalts, uplifted above sea level. Thin, vertical intrusions of finely crystalline basalt cut across pillow basalts. Thin intrusions---dikes--closely spaced--called sheeted dikes. thin tab conduit through magma passed. Orientated parallel to oceanic rift. Sheeted dikes merge down into gabbro--magma chambers beneath the rift--light colored and dark crystals. Base of gabbro--base of the oceanic crust---ultramafic rocks of the mantle. evidence of having partially melted to form overlying mafic rocks in the crust (pillow basalts, sheeted dikes and gabbro)
Describe the types of igneous rocks that form along mid-ocean ridges
texture of a rock--refers to the sizes, shapes and arrangements of different components. The texture of an igneous rock depends on overall crystal size, variation within that rock and presence of other features; holes and rock fragments, most obvious texture; crystals that are visible or not. Visible crystals--phaneritic. microscopic crystals--fine grained volcanic ash, volcanic glass without any crystals--Aphanitic--magma solidifies too rapidly to grow, large crystals--coarse igneous rock--pegmatite. Coarse grained (coarsely crystalline) Medium grained rocks--crystals easily visible. Fine grained--crystals too small to see. Volcanic glass or mostly glassy with some crystals. Large crystals finer grained matrix--porphyritic
Describe the various textures displayed by igneous rocks
Why does differential weathering occur?
Different minerals have different resistances to weathering.
many hot spots--crustal expression of rising plume of hot mantle material, may begin at the core-mantle boundary & ascend through the lower mantle--asthenosphere. mantle plume encounters the lithosphere, causes melting of the overlying lithosphere and additional melting occurs by decompression. from the lithosphere the plume reach the surface--large volcanoes on the seafloor. Big Island of Hawaii & seafloor far to the southeast.
Explain a mantle plume and its magmatic expression in both oceanic and continental plates
all discovered faults ARE or ARE NOT likely to experience earthquakes in the next few hundred years
FALSE, ARE NOT
One of the reasons volcanic eruptions are so deadly is that there is no way to predict where an eruption will occur in the near future-True/False
False
T/F? All lithospheric plates are approximately the same size and contain a combination of oceanic and continental crust.
False
The eruption of Mt St Helens in 1980 was the greatest explosive eruption in the last 200 years of world data - True/False
False
Siltstone
Fine grained sedimentary rock consisting of silt-sized clasts
Your professor's last name in this class is:
Harris
Mid-ocean ridges (MORs), which are the sites of new oceanic crust formation, are linear mountain chains that run along divergent plate boundaries. Why does an MOR sit up higher than the surrounding oceanic crust?
Hot materials are less dense and expand, thus the new crust will sit higher than the surrounding crust.
they form when a hot but solid igneous rock contracts as it cools. the fractures carve out columns--5 or 6 sides, common in basaltic lava flow, felsic ash flows, sills, dikes and some laccoliths.
How do columnar joints form?
two continents; Asia and India converge--collision because continental crust--buoyant and difficult to subduct. plate may slide beneath the other--descending plates--continental rather than oceanic. 3. Magma by continental collision--don't reach the surface partly because they have pass through thick continental crust. relatively high water content compared to mantle-derived magma, pass through the wet solidus as rises. Continental collisions---don't have many volcanoes. 2. metamorphism--water bearing minerals and if the descending continental crust gets hot enough, partial melting--felsic magma. 1. continental collision-- one continental plate may slide beneath another continental plate. descending continental crust gets hotter and increases pressure
How does magma form during continental collisions?
the slower the magma cools the more time it has to form larger crystals. If magma cools quickly---small crystals
How does the rate of magma cooling affect the size of crystals?
magma created at convergent boundaries at subduction zones. about 1/5 of Earth's magma forms where an oceanic plate subducts into the mantle at an ocean-ocean or ocean-continent convergent boundary. Oceanic pate--oceanic crust and lithospheric mantle convgerges with another oceanic plate or with a continental plate, subduction occurs--descends both pressure & temperature increase. 2. existing minerals in the subducting plate convert into new ones--metamorphism. Water-bearing minerals; mica break down, forcing water out of the crystalline structure. water lowers the melting temperature of the mantle above subducting plate. If temps are high enough--melting occurs and mantle- derived magma rise into the overriding plate.
How is magma generated in a subduction zone?
Which of the following is NOT a characteristic of the extrusive igneous rock obsidian?
It likely cooled very slowly.
The entire state of Florida is composed of fossiliferous limestone, what does this imply about Florida during the recent past?
It was a submergent coast.
If a dam is installed across a river, what effect will this have on the coastline?
It will starve the coast of sediment, and the beaches will disappear.
At which of the following does an island volcanic arc occur in the present day?
Japan the Aleutian Islands of Alaska
Granite--(felsic) coarsely crystalline light colored igneous rock, contain some biotite and some white mica muscovite and garnet. Rhyolite--fine grained crystalline rock, contain glass, volcanic ash, pieces of pumice visible crystals (phenocrysts) quartz, feldspar or biotite. Intermediate; Diorite--between felsic/mafic compositions, plagioclase and amphibole. Andesite--fine grain--phenocrysts of cream color feldspar or dark amphibole. Mafic--coarsely crystalline, mafic rock, dark consist of pyroxene and mafic minerals along with calcium and plagioclase feldspar. Basalt--mafic lava rock, vesicles, phenocrysts of dark pyroxene, olivine. Ultramafic-- Peridotite--coarsely crystalline, contains more magnesium and iron-rich minerals especially green olivine, Upper mantle--peridotite.
List some common igneous rocks and a few characteristics of each
Obsidian (mostly felsic)-- shiny volcanic glass, forms when lava flow cools too rapidly to form crystals. Pumice (felsic)--volcanic rock, vesicles, floats on water, begins as volcanic glass, convert into microscopic crystals. Scoria (mafic)--volcanic rock many vesicles, mass of rock fragments. Pegmatite (any composition but mostly felsic)-- magma crystallizes deep within the crust--dissolved water that it grows, large crystals. Tuff (felsic to intermediate) can be also mafic- volcanic rock mix of volcanic ash, pumice crystals and rock fragments, thick pyroclastic flow, weight of overlying materials compacts ash and pumice into lenses forming welded tuff. Volcanic breccia (almost any composition)-- volcanic rocks with fragments break apart of the lava that solidifies during flow, fragmental rocks form from mixture of volcanic rock, ash and mud.
List the main characteristics of obsidian, pumice, scoria, tuff, breccia, and pegmatite, and indicate where each of these rock types fits into an igneous classification system based on composition
Sandstone
Medium to coarse grained sedimentary rock consisting of sand-sized grains.
What is a primary difference between phyllite and schist?
Mica crystals within schist are larger than those within phyllite.
The boundary between the crust and the mantle is marked by an abrupt change in seismic velocity called the
Moho
The boundary between the crust and the mantle is marked by an abrupt change in seismic velocity called the ________.
Moho
Igneous rocks form from
Molten rock cooling and forming crystals
If the wind is blowing parallel to a coast, will it create an upwelling current or downwelling current?
Neither; it will enhance the longshore current.
which type of earthquake has the highest velocity
P-wave
Ripple marks
Relatively small elongated ridges that form on a bed surface at right angles to the direction of current flow. -Asymmetric: current flows in the same direction and have steeper slope on the downstream side. -Symmetric: water flows in different directions back and forth.
________ commonly serves as a protolith in the formation of quartzite.
Sandstone
________ commonly serves as a protolith in the formation of slate.
Shale
a solidified magma chamber--pluton--cylindrical, sheetlike or very irregular in shape. Irregular plutons--vertical cylinders, less than 100 km2 is a stock.--magma solidified at depth and later was uplifted. Sheetlike plutons--tabular shape, horizontal, vertical or inclined, parallel to or cutting across layers. Batholith--more than 100km2, form from multiple magma emplaced into the same part of the crust. Huge gray granite -- Sierra Nevada batholith of California
Summarize the different geometries of large magma chamber and how they are expressed in the landscape
The deepest part of a curved stream channel, where the flow is fastest, is called the ________.
Thalweg
You are a coastal geologist trying to help a coastal community restore its sediment-starved beach. You decide that beach nourishment is the best option, so you order that dredge sediment from the nearest river be placed on the beach. The sediment is 70% silt and 30% sand. What will be the effect of using this sediment?
The silt will be washed away by the waves, leaving the beach no better off.
At a river delta, which of the following is NOT true?
The stream channel becomes very straight because of the large sediment load.
Why is the surface salinity in the tropics so much higher than that of the equator or high latitudes?
There is a higher evaporation rate and a lower rate of precipitation in the tropics.
What will eventually happen to the headlands in the figure below?
They will become a straight line of cliffs as rock is eroded away.
Hawaiian style effusive eruptions are greater threat to property than to human life - True/False
True
Shale
Very fine sedimentary rock consisting of clay and/or very fine silt
The image below shows a cross-sectional view of a typical subduction zone, with earthquake locations shown with small dots. The band of earthquakes that follows the shape of the downgoing plate is termed the ________.
Wadati-Benioff zone
Scientists believe that approximately 60 million years ago the closing of the Isthmus of Panama changed the climate of Earth so severely that winters in Europe became 10°C warmer than they had been. Why did this happen?
Warm Caribbean Sea waters were forced up into the north Atlantic Ocean.
Wegener's proposal that the continents had once fit together as a single supercontinent was rejected by geologists at the time because
Wegener could not provide a driving force
it rises into the overriding plate--oceanic plate or a continental plate. Magma modify the crust. Magma generates above the subducting slab--mafic composition--forms by partial melting or ultramafic mantle. partial melting may generate magma of intermediate composition. 2. overriding plate--continental plate, rising magma--thick continental crust that slows its upward journey. Heat surrounds the rocks--causing localized partial melting--felsic or intermediate magma. 3. some magma may never reach the surface, erupts, forming clusters or belts of volcanoes. Overlying crust is continental, volcanoes--mountain belt. Overlying crust is oceanic--individual volcanoes along an island arc. both settings--intermediate composition (andesite). island arcs--magma can be felsic, thicken the crust
What happens when subduction-derived magma encounters overlying crust?
Magma chamber- underground body of molten rock, very dynamic with magma evolving, crystallizing, being replenished by additions of new magma. 1. Large magma chambers can be consist of a single magma type, involve more than one influx of magma. 2. crystallization--early formed minerals that remove chemical components from the magma--sink or rise. 3. new pulse of magma rises into the chamber, mix with existing magma or remain distinct, adds a new pulse of thermal energy. 4. Partially crystallized magma--heated by new hotter pulse of magma. 5. melt the wall rocks. 6. partial melting of wall rocks--assimilated into the existing magma. 7. two magmas mix depends--relative densities, crystal content, viscosities and the temperature which they crystallize.
What is a magma chamber? and what are the processes that occur in one
a dike-- sheetlike intrusion cuts across any layers present in the host rocks, a sill-- intrusion that is parallel to layers in the host rocks. Dikes are steep because magma pushes through the rocks in horizontal direction rises vertically. Sills form by pushing adjacent rocks upward rather than sideways.
What is the difference between a dike and a sill and why does each of them have the orientation that it does?
two plates move away from one another (diverge) along mid-ocean ridges. mantle rocks; solid and crystalline not molten. mantle's high pressure and temperature rocks to flow as weak solid--crystalline structure, Parts of the athensophere are close to melting temperatures. 2. plates separate; solid asthenosphere rises to fill the area between the plates. rises, pressure decreases and the rock partially melts (decompression melting). 3. mafic magma rises away from the unmelted residue in the mantle accumulate in crust and upper mantle. 4. Magma rises upward through magma-filled fractures that form as plates pull apart. 5. older oceanic crust moves away from the ridge in conveyor belt manner as new oceanic crust forms along the axis of the ridge
Why does melting occur along mid-ocean ridges and why the resulting magmas are basaltic? (mafic)
Minerals are all naturally occurring solid substances with a definable chemical composition. They must also possess
a fixed crystalline structure (spatial arrangement of atoms and ions).
What physical property of the underlying rock would lead to the formation of a cliff over which a waterfall may form?
a high resistance to erosion
All else being equal, water will flow faster in a stream with ________ and a ________ wetted perimeter.
a straight channel; small
Cleavage in minerals refers to
a tendency to break along planes of weakness
Which transport medium carries the largest particles? a) ice in glaciers b) water in rivers c) water in lakes d) wind
a) ice in glaciers
Distinctive rock sequences on South America terminate at the Atlantic Ocean but reappear on the continent of ____________. a. Africa b. Australia c. Europe d. North America
a. Africa
How is chloride different from chlorine? a. Chloride is chlorine's anion. b. Chloride has more protons than chlorine. c. Chloride has fewer protons than chlorine. d. A and B are correct. e. A and C are correct.
a. Chloride is chlorine's anion.
Over 2,000 years ago, an ancient Greek astronomer concluded (correctly) that the ________. a. Earth is spherical b. Sun is the center of the whole Universe c. Earth orbits the Sun in a circular orbit d. Earth is the center of the Universe
a. Earth is spherical
In the heliocentric model ________. a. Earth orbits around the Sun b. the Sun orbits around Earth c. Earth is a stationary planet d. Mercury and Venus orbit around the Sun, but all other planets orbit around Earth
a. Earth orbits around the Sun
Aside from Earth, the terrestrial planets are ________. a. Mars, Mercury, and Venus b. Mars, Venus, and Jupiter c. Jupiter, Saturn, Uranus, and Neptune d. Mars and Saturn
a. Mars, Mercury, and Venus
Marble forms from a limestone protolith in BOTH contact and regional metamorphism (a) T (b) F
a. T
Sea-floor spreading is driven by volcanic activity ____________. a. along mid-ocean ridges b. in the middle of abyssal plains c. at the edges of continental shelves d. along fracture zones
a. along mid-ocean ridges
A metamorphic mineral change on a map is represented by (a) an isograd (b) the geotherm (c) a porphyroblast
a. an isograd
During a journey to the center of the Earth, one would experience temperature ________. a. and pressure both increasing b. and pressure both decreasing c. increasing, but pressure staying nearly the same d. remaining remarkably constant, but pressure increasing
a. and pressure both increasing
Rapid, deep burial of sediments in an accretionary prism leads to the formation of a metamorphic rock termed : . a..blueschist b..greenschist c..migmatite d..gneiss
a. blueschist
A body of rock to which a sudden, rapid stress has been applied is more likely to exhibit ____________ than is a body of rock subjected to a gradually applied stress. a. brittle behavior b. ductile behavior
a. brittle behavior
Wegener proposed continental drift after he observed evidence from fossils, glacial deposits, and the fit of the continents that suggested all of the continents were once ____________. a. combined to form a supercontinent (he termed Pangaea) in the Late Paleozoic through the Mesozoic b. combined to form a supercontinent (he termed Rodinia) in the Proterozoic c. aligned east to west along the equator during the Late Mesozoic through the Cenozoic d. aligned north to south along the prime meridian during the Late Cenozoic
a. combined to form a supercontinent (he termed Pangaea) in the Late Paleozoic through the Mesozoic
Squashing a fly with a flyswatter is an example of : . a..compression b..shear
a. compression
As compared to the rocks that make up the crust, Earth as a whole is ____________. a. considerably more dense b. considerably less dense c. slightly less dense d. about the same density
a. considerably more dense
PeleOs hair a. consistes of thin strands of basaltic pyroclastic debris b. acquires aerodynamic torpedo like shapes during flight out of the volcanic cent c. forms only at the leading edge of basaltic lava flows d. was instrumental in scoring the winning goal to defeat Uruguay in the 1958 World Cup finals
a. consistes of thin strands of basaltic pyroclastic debris
As compared to the amphibolite metamorphic facies, the greenschist facies : . a..consists of lower-grade rocks b..consists of higher-grade rocks c..is an identical temperature and pressure regime; greenschists and amphibolites bear different mineral assemblages only because of differences in protolith chemistry
a. consists of lower grade rocks
Basaltic lavas a. contain more iron an d magnesium than rhyolitic lavas b. contain more silica than rhyolitic lavas c. are more biscous than rhyolitic lavas d. contain a greater proportion of trapped volatiles than rhyolitic lavas
a. contain more iron an d magnesium than rhyolitic lava
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 temperatures d. solidify at lower temperatures
a. cool and solidify more quickly
A buried body of aragonitic limestone is recrystallized at low temperatures and pressures, producing calcite; this is an example of : . a..diagenesis b..erosion c..metamorphism d..weathering
a. diagenesis
A buried body of aragonitic limestone is recrystallized at low temperatures and pressures, producing calcite; this is an example of ____________. a. diagenesis b. erosion c. metamorphism d. weathering
a. diagenesis
Normal, reverse, and thrust are all examples of ____________ faults. a. dip-slip b. strike-slip c. oblique-slip
a. dip-slip
Rhyolitic lavas a. do not flow as far from the vent as basaltic lavas do b. cool much more slowly than basaltic lavas do c. are associated with volcanoes that almost never emit pyroclastic debris d. all of the above
a. do not flow as far from the vent as basaltic lavas
The apparent polar wander path obtained from magnetite crystals in basalts on the North American continent is now interpreted to be the result of ____________. a. drifting of the North American continent b. wandering of the geomagnetic North Pole
a. drifting of the North American continent
According to the Big Bang theory, our Universe is ________. a. expanding b. contracting c. static d. periodically contracting and expandingddd
a. expanding
A joint always occurs as a single, isolated plane within a rock. a. false b. true
a. false
An average everyday compass depicts inclination. a. false b. true
a. false
It is not the continents that move relative to a fixed pole, but rather it is the pole that moves relative to fixed continents. a. false b. true
a. false
Motion along all faults is either strike slip or dip slip; combinations of these two types of displacement are never found together in a single fault. a. false b. true
a. false
Mountain ranges are important sites for the formation of igneous and metamorphic rocks, but do not have any apparent relationship with the formation of sedimentary rocks. a. false b. true
a. false
Nearly all of the present mountain ranges are the products of single orogenic events. a. false b. true
a. false
Tectonic foliation, such as elongation of quartz grains, always occurs parallel to the original bedding plane of a body of rock. a. false b. true
a. false
Which type of magma has the greatest silica content? a. felsic b. intermediate c. mafic d. ultramafic
a. felsic
At continental rifts, vast bodies of basaltic lava flow forth from fissures, forming a. flood basalt b. pyroclastic flows c. ash fall tufts
a. flood basalt
Large igneous provinces are formed by ___________, which can flow tens to hundreds of kilometers. a. flood basalts b. sills c. super plumes d. None of the above are correct.
a. flood basalts
Beneath a blanket of sediments, oceanic crust is primarily composed of two rocks, ____________ and ____________. a. gabbro; basalt b. granite; diorite c. sandstone; shale d. slate; gneiss
a. gabbro; basalt
The central portion of high curvature on a fold is termed the fold ____________. a. hinge b. thorax c. limb d. midsection
a. hinge
Two types of bonds that depend upon polarity are ____________ and ____________. a. hydrogen bonds; van der Waals bonds b. ionic bonds; covalent bonds c. hydrogen bonds; metallic bonds d. ionic bonds; van der Waals bonds
a. hydrogen bonds; van der Waals bonds
For rocks at the surface, the true starting point for the rock cycle would be (a) igneous (b) sedimentary (c) metamorphic
a. igneous
Thermal (contact) metamorphism occurs ____________. a. in areas surrounding igneous intrusions b. only where gneiss is in contact with schist c. as a consequence of the sinking of a broad region to great depth d. only at the surface, where rock is in contact with the atmosphere
a. in areas surrounding igneous intrusions
When magma crystallizes, ____________ are formed. a. intrusive igneous rocks b. extrusive igneous rocks c. volatiles d. pyroclastic debris
a. intrusive igneous rocks
Most terrestrial volcanic glass a. is highly silicic in composition b. is coarse grained c. consists of microscopic crystals d. freezes from lavas with low viscosity
a. is highly silicic in composition
Diamonds are usually found in pipes 50 to 200 m across made of _____________. a. kimberlite b. graphite c. metamorphic rocks
a. kimberlite
A fast moving flow consisting of a mixture of water and volcaniclastic debris is termed a a. lahar b. glowing avalanche c. flood basalt d. stratovolcano
a. lahar
In the map below, the vertical, north-south trending fault is a ____________ fault. a. left-lateral strike-slip b. normal dip-slip c. right-lateral strike-slip d. reverse dip-slip
a. left-lateral strike-slip
The sides of a fold, where curvature is at a minimum, are termed ____________. a. limbs b. hinges c. axial planes d. branches
a. limbs
commonly serves as a protolith in the formation of marble. a..Limestone b..Sandstone c..Shale d..Slate
a. limestone
If you were using both a compass and a map marked with latitude and longitude to navigate, you might note the angle difference between your compass and what is marked on the map, called _____________. a. magnetic declination b. magnetic inclination c. magnetic reversal d. magnetic dipole
a. magnetic declination
What mineral is integral to paleomagnestim? a. magnetite b. potassium feldspar c. iron d. quartz
a. magnetite
A great boost in sea-floor exploration and a greater understanding of sea-floor bathymetry was a result of _______________. a. military needs in World War II b. military needs in World War I c. scientific advances in the 1920s d. scientific advances in the 1950s
a. military needs in World War II
Squashing a fly with a flyswatter is an application of ____________. a. normal stress b. shear stress
a. normal stress
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
. Thermal (contact) metamorphism occurs : . a..in areas surrounding igneous intrusions b..only where gneiss is in contact with schist c..as consequence of the sinking of a broad region to great depth d..only at the surface, where rock is in contact with the atmosphere
a. only where gneiss is in contact with schist
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
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
Which of the following minerals is hardest? a. quartz b. calcite c. talc d. fluorite
a. quartz
Dynamothermal (regional) metamorphism occurs when ____________. a. rock becomes buried deeply during continental collision and mountain building b. regression of the sea leads to erosion of sedimentary cover atop a body of rock c. the upper surface of a body of rock develops a thick soil profile d. a pluton causes metamorphism in a small surrounding region
a. rock becomes buried deeply during continental collision and mountain building
Dynamothermal metamorphism occurs when : . a..rock becomes buried deeply during continental collision and mountain building b..regression of the sea leads to erosion of sedimentary cover atop a body of rock c..the upper surface of a body of rock develops a thick soil profile d..a pluton causes metamorphism in a small surrounding region
a. rock becomes buried deeply during continental collision and mountain building
A sill is a (an)____________. a. sheet-like intrusion that lies parallel to surrounding layers of sedimentary rock b. cooled layer of lava c. intrusion formed within the magma chamber of a volcano d. sheet-like intrusion that cuts across preexisting layers
a. sheet-like intrusion that lies parallel to surrounding layers of sedimentary rock
A body of rock affected by compressive stress will likely undergo ____________. a. shortening b. stretching c. shear strain
a. shortening
The most abundant minerals belong to chemical group termed the ____________. a. silicates b. carbonates c. halides d. oxides
a. silicates
The most common minerals within Earth are ________. a. silicates b. carbonates c. oxides d. hydroxides
a. silicates
What has the best cleavage (a) slate (b) phyllite (c) schist (d) gneiss (e) migmatite
a. slate
A polished surface produced by scraping of rock along a fault is termed a (an) ____________. a. slickenside b. phylogeny c. orogeny d. aureole
a. slickenside
An aurora (shown below) is produced when ________. a. solar wind particles are directed toward the magnetic poles and excite atmospheric gases b. swamp gases rise from the arctic tundra and react with the upper atmosphere c. radiation in the Van Allen belts can be seen on a clear, cold night d. lightning travels from cloud to cloud rather than cloud to ground
a. solar wind particles are directed toward the magnetic poles and excite atmospheric gases
Mt Fuji in Japan is an example of a a. statovolcano b. cinder cone c. shield volcano
a. stratovolcano
Of the three primary forms of subaerial volcanoes, _ consist of alternating layers of tephra and solidified lava. a. stratovolcanoes b. cinder cones c. shield volcanoes
a. stratovolcanoes
Of the three primary forms of subaerial volcanoes, _ which sometimes referred to as composite volcanoes a. stratovolcanoes b. cinder cones c. shield volcanoes
a. stratovolcanoes
Right lateral and left lateral are both examples of ____________ faults. a. strike-slip b. dip-slip c. oblique-slip
a. strike-slip
A fold shaped like an elongate trough is a (an) ____________. a. syncline b. basin c. dome d. anticline
a. syncline
An island volcanic arc occurs at ____________. a. the Aleutian Islands of Alaska b. the Andes Mountains c. Hawaii d. Mt. St. Helens, Washington
a. the Aleutian Islands of Alaska
Compared to oceanic crust, continental crust is ________. a. thicker b. thinner c. about the same thickness d. Sometimes continental crust is thicker; sometimes oceanic crust is thicker. There is no consistent pattern.
a. thicker
. Gneiss typically forms under higher pressures than hornfels. a..true b..false
a. true
In nature most examples of minerals do NOT grow as large, well-formed, euhedral crystals. a. true b. false
a. true
Meteorite impacts have been known to induce metamorphism of sediments and rocks. a. true b. false
a. true
Meteorite impacts have been known to induce metamorphism of sediments and rocks. a..true b..false
a. true
Most fault surfaces, like joints, are roughly planar in orientation. a. true b. false
a. true
Two different distinct minerals may have the same chemical formula. a. true b. false
a. true
Very early in Earth's history, it was so hot that the surface was likely entirely molten. a. true b. false
a. true
Ash, cinders, and blocks are all types of a. volcaniclastic debris b. lava flows c. Peleos hair d. volcanos
a. volcaniclastic debris
Gases that are abundantly emitted by volcanoes include a. water vapor, carbon dioxide, and sulfur dioxide b. oxygen, ozone, and water vapor c. oxygen, hydrogen, and neon d. carbon dioxide, carbon monoxide, and oxygen
a. water vapor, carbon dioxide, and sulfur dioxide
Argillite is a low grade rock from (a) contact metamorphism (b) regional metamorphism (c) hydrothermal metasomatism
a.contact metamorphism
Which of these parts of the deep-ocean floor is flat and nearly featureless?
abyssal plain
Most of the ocean floor is made up of ________.
abyssal plains (4 to 5 km below sea level)
faults that have moved recently or are likely to move in the future are referred to as
active
The figure below shows a road in Death Valley, California, curving around a(n) ________.
alluvial fan
The youngest sea floor is typically found ________.
along mid-ocean ridges
a tsunami is
an earthquake-generated sea wave that can sometimes destroy coastal cities thousands of kilometers from its source
A guyot is ________.
an extinct oceanic hot-spot volcano that has subsided below sea level
During a journey to the center of the Earth, one would experience temperature ________.
and pressure both increasing
Igneous rocks ________.
are formed through the freezing or crystallization of a melt
Most commonly, felsic igneous rocks ________.
are lighter in color than mafic rocks
A clastic rock composed of sand-sized grains derived from the physical weathering of granite and containing a sizable proportion of feldspar is termed ________.
arkose
The lithosphere lies directly above the ________.
asthenosphere
Major oceanic surface currents travel ________.
at an angle to prevailing winds as a result of the Coriolis effect
Precambrian metamorphic rocks are exposed at the surface ________.
at places in continental interiors termed shields
Continental crust is typically 35-km thick, but may be up to ____________ thicker under mountain ranges. a. 200% b. 100% c. 50% d. 20%
b. 100%
Earth's surface is protected from solar wind and cosmic radiation by ________. a. Earth's gravitational field b. Earth's magnetic field c. a large, metallic shield launched into orbit by NASA in the 1960s d. a powerful stream of ions emitted by the Sun
b. Earth's magnetic field
Which plant genus dominated glaciated regions during the Late Paleozoic and Early Mesozoic? a. Neuropteris b. Glossopteris c. Quercas d. Ginkgo
b. Glossopteris
The father of the rock cycle was (a) Darwin (b) Hutton (c) Suess
b. Hutton
Olympus Mons, the largest known volcano in the Universe is found on a. Earth b. Mars c. Neptune d. Io, a moon of Jupiter
b. Mars
The boundary between the crust and the mantle is marked by an abrupt change in seismic velocity called the ________. a. transition zone b. Moho c. low-velocity zone d. crantle
b. Moho
Is it true that one can go straight from Sedimentary to Igneous on the rock cycle? (a) Y (b) N
b. N
____________ commonly serves as a protolith in the formation of quartzite. a. Limestone b. Sandstone c. Shale d. Slate
b. Sandstone
Cleavage in minerals refers to ____________. a. a tendency to break in an irregular pattern b. a tendency to break along planes of weakness c. the sharpness of edges between crystal faces d. the development of distinct crystal faces
b. a tendency to break along planes of weakness
Earthquakes only occur ____________ the brittle/ductile transition depth. a. below b. above c. at or near
b. above
Within the sea floor, the rate of geothermal heat flow is greatest ____________. a. at the edges of ocean basins b. along mid-ocean ridges c. along fracture zones d. in the center of abyssal plains
b. along mid-ocean ridges
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
Phyllite would most likely be found : . a..in an aureole around a cooled igneous intrusion b..at the eroding base of an ancient collisional mountain range c..at depth within the mid-ocean ridge system d..within a meteorite impact crater
b. at the eroding base of an ancient collisional mountain range
The region of thermally metamorphosed rock surrounding a cooled pluton is called a(n) : . a..shear zone b..aureole c..oriole d..oleo
b. aureole
If one were to ride a hot air balloon up into the atmosphere, one would experience the concentration of gases ________. a. becoming denser b. becoming less dense c. remaining the same d. increasing for the first 10 km, then starting to decline
b. becoming less dense
Marble and quartzite are nonfoliated rocks because : . a..they are never found beneath fault zones or collisional mountain ranges b..both are dominated by minerals that produce equant grains c..both are dominated by minerals with crystalline structures that cannot be dissolved d..dynamothermal metamorphism can break down the structures of their constituent minerals, but neither of these minerals is stable in that metamorphic environment
b. both are dominated by minerals that produce equant grains
According to the figure below, the Earth's magnetic reversals are likely due to ______________. a. lightning strikes b. changes in circulation patterns in the outer core c. meteorite impacts d. changes in circulation patterns in the inner core
b. changes in circulation patterns in the outer core
Minerals are classified into groups primarily on a basis of ____________. a. chemistry, specifically the cations within the chemical formula b. chemistry, specifically the anions within the chemical formula c. hardness; hard, soft, and medium are the three primary classes d. number of cleavage directions present
b. chemistry, specifically the anions within the chemical formula
Of the three primary forms of subaerial volcanoes, _ consist of a simple, conical pile of tephra. a. stratovolcanoes b. cinder cones c. shield volcanoes
b. cinder cones
Synthetically made glass and natural quartz crystals both exhibit a fracture pattern termed ____________. a. glassy b. conchoidal c. serpentine d. obtuse
b. conchoidal
The plate boundary that accumulates the most change from sedimentary to metamorphic is (a) divergent (b) convergent (c) transform
b. convergent
From left to right, correctly label each section of this slice of the Earth. Note that 1 starts at the surface of the Earth and 6 ends at the center of the Earth. a. crust, liquid outer core, transition zone, solid inner core, upper mantle, lower mantle b. crust, upper mantle, transition zone, lower mantle, liquid outer core, solid inner core c. crust, transition zone, upper mantle, lower mantle, liquid outer core, solid inner core d. transition zone, crust, liquid outer core, solid inner core, upper mantle, lower mantle
b. crust, upper mantle, transition zone, lower mantle, liquid outer core, solid inner core
In the formation of gneiss from granite, the distinctive compositional bands form due to : . a..crystals migrating within the rock b..crystals dissolving, and atoms and ions migrating and reorganizing as new crystals c..crystals melting, with new crystals solidifying in color bands d..the bizarre and seemingly unknowable nature of the blueschist metamorphic facies
b. crystals dissolving, and atoms and ions migrating and reorganizing as new crystals
If the volatile content of magma is increased, its viscosity will ____________. a. increase b. decrease c. stay the same
b. decrease
The metal alloy that makes up the core of Earth is ________, as compared to the rocky mantle. a. less dense b. denser c. very similar in chemistry and density d. distinct in chemistry but of very similar density
b. denser
The shape of Earth's magnetic field is approximately that of a ____________. a. monopole, as would be produced by just one pole of a magnet b. dipole, such as that produced by a bar magnet c. torus, a doughnut-shaped ring parallel to Earth's equator d. sphere, following the shape of Earth
b. dipole, such as that produced by a bar magnet
On a geologic map, if the contacts between sedimentary rock units form a bull's-eye pattern of concentric circles, with the oldest unit in the center, the underlying structure is a (an) ____________. a. syncline b. dome c. basin d. anticline
b. dome
A body of rock under high pressure is more likely to exhibit ____________ than is a body of rock at low pressure. a. brittle behavior b. ductile behavior
b. ductile behavior
A hot body of rock is more likely to exhibit ____________ than is a cold body of rock. a. brittle behavior b. ductile behavior
b. ductile behavior
Which type of metamorphism affects the greatest volumes of rock? a..thermal metamorphism b..dynamothermal metamorphism c..dynamic metamorphism
b. dynamothermal metamorphism
Nonviolent eruptions characterized by extensive flows of basaltic lava are termed a. pyroclastic b. effusive c. explosive
b. effusive
Five trillion atoms can fit into the head of an atom. Which of the following is in the correct order of smallest to largest? a. atom, nucleus, proton, electron b. electron, proton, nucleus, atom c. proton, electron, nucleus, atom d. atom, electron, nucleus, proton
b. electron, proton, nucleus, atom
Pillow basalts, shown below, attain their distinctive blob-like shapes because their parent lavas do not travel far prior to solidification. This is because the parent lavas ____________. a. are completely devoid of volatiles and thus travel slowly b. erupt underwater and thus cool very quickly c. are highly felsic and thus travel slowly d. are ultramafic and thus freeze at exceptionally high temperatures
b. erupt underwater and thus cool very quickly
The diamonds we see today do not display their natural crystal faces, but rather ____________, a typical engagement ring bearing 57 of them. a. faces b. facets c. cleavage planes d. facades
b. facets
A compass today points directly to geographic north. a. true b. false
b. false
A single mineral may take on multiple crystalline lattice structures. a. true b. false
b. false
All metamorphic rocks are formed within a fairly narrow range of temperature, approximately 400 to 600°C. a. true b. false
b. false
All metamorphic rocks are formed within a fairly narrow range of temperatures, approximately 400 to 600C. a..true b..false
b. false
All minerals are chemical compounds (composed of more than one element). a. true b. false
b. false
All minerals are held together by ionic bonds. a. true b. false
b. 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. a. true b. false
b. false
Diamond and graphite are both polymorphs of pure silicon. a. true b. false
b. false
It is rare for mineral crystals to display any sort of symmetry (invariance of pattern with respect to a transformation, such as rotation or mirror-image reflection). a. true b. false
b. false
Metamorphism brings changes in mineral arrangement and the texture of rocks, but it never leads to new mineral assemblages. a. true b. false
b. false
Metamorphism brings changes in mineral arrangement and the texture of rocks, but it never leads to new mineral assemblages. a., true b., false
b. false
Mountain ranges are associated with modern and ancient convergent-plate boundaries, but do not form in association with either divergent- or transform-plate boundaries. a. true b. false
b. false
The most useful diagnostic property of minerals is their color in a hand sample. a. true b. false
b. false
Theoretically, there is no reason why mountains substantially taller than Mt. Everest might not one day arise on Earth. a. true b. false
b. false
Topaz, with Mohs hardness of 8, is twice as hard as fluorite, with Mohs hardness of 4. a. true b. false
b. false
Wegener's evidence for a united Pangaea was so compelling that virtually all geologists agreed with the idea of continental drift during his lifetime. a. true b. false
b. false
Within a platform, sedimentary rocks always have a horizontal orientation. a. true b. false
b. false
Movement along faults often produces sharply angled rock fragments termed ____________. a. slickensides b. fault breccia c. fault gouge d. rock flour
b. fault breccia
The distinction between joints and faults is that ____________. a. faults are joints that are greater than one square meter in areal extent b. faults are fractures along which displacement has occurred; displacement does not occur along joints c. joints are fractures along which displacement has occurred; displacement does not occur along faults d. there is no distinction; the two terms are synonymous
b. faults are fractures along which displacement has occurred; displacement does not occur along joints
Slaty cleavage, schistosity, and compositional banding are all examples of : . a..mineral cleavage b..foliation c..recrystallization d..sedimentary structures
b. foliation
Slaty cleavage, schistosity, and compositional banding are all examples of ____________. a. mineral cleavage b. foliation c. recrystallization d. sedimentary structures
b. foliation
Minerals that do not possess cleavage are said to possess ____________. a. invulnerability b. fracture c. solidity d. massiveness
b. fracture
In which type of silicate are the greatest proportion of oxygen atoms shared by pairs of adjacent tetrahedra? a. chain silicates b. framework silicates c. sheet silicates d. Sharing of oxygen atoms does not occur in silicates.
b. framework silicates
Vesicles are a term used to describe a texture in __________ igneous rocks. a. crystalline b. glassy c. pyroclastic
b. glassy
Volcanoes that have submerged beneath the surface of the sea are termed ____________. a. fracture zones b. guyots c. mid-ocean ridges d. continental rises
b. guyots
All basalts younger than 700,000 years old ____________. a. are found on the continents b. have normal magnetic polarity c. are found on the ocean floor very far from mid-ocean ridges d. have reverse magnetic polarity
b. have normal magnetic polarity
Consult the figure below. Hot water reacting with crust is the basis for what type of metamorphism? a. contact b. hydrothermal c. regional d. shock
b. hydrothermal
A body of gneiss is subjected to heat and forms a melt. Later the melt cools and crystallizes to form a (an) ____________. a. metamorphic rock b. igneous rock c. sedimentary rock
b. igneous rock
A body of gneiss is subjected to heat and forms a melt. Later the melt cools and crystallizes to form a(n) : . a., metamorphic rock b., igneous rock c., sedimentary
b. igneous rock
The lithifiication of material from pyroclastic flow forms a rock called a. metabasalt b. ignimbrite c. migmatite d. tuff
b. ignimbrite
The age of oceanic crust ____________ with increasing distance from a mid-ocean ridge. a. decreases b. increases
b. increases
A mineral within a metamorphic rock that can be used to provide a narrow constraint on the temperature and pressure of formation of the rock is termed a(n) : . a..thermineral b..index mineral c..mafic mineral d..halide mineral
b. index mineral
Consult the figure below. A mineral within a metamorphic rock that can be used to provide a narrow constraint on the temperature and pressure of formation of the rock is termed a (an) ____________. a. thermineral b. index mineral c. mafic mineral d. halide mineral
b. index mineral
A majority of the melts in the Earth form through the partial melting of ultramafic mantle rock. These newly formed magmas are ____________. a. ultramafic b. mafic c. felsic d. intermediate
b. mafic
Hot, liquid rock beneath Earth's surface is termed ________. a. lava b. magma c. volatiles d. mantle
b. magma
Volcanoes that do NOT occur along either present or emergent plate boundaries are associated with ____________. a. continental rifts b. mantle hot spots c. mid-ocean ridges d. subduction zones
b. mantle hot spots
Net chemical change in metamorphic rock induced by reaction with hot groundwater is termed : . a..foliation b..metasomatism c..anachronism
b. metasomatism
Marine magnetic anomaly belts run parallel to ____________. a. continental coastlines b. mid-ocean ridges c. continental shelves d. fracture zones
b. mid-ocean ridges
When rock is partially melted, the chemistry of the melt is ____________. a. more mafic than the original chemistry of the rock that was partially melted b. more felsic than the original chemistry of the rock that was partially melted c. identical to the original chemistry of the rock that was partially melted d. completely unpredictable (it could be more mafic or more felsic)
b. more felsic than the original chemistry of the rock that was partially melted
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
Shear stress at sufficient depth within a fault plane can induce ductile shear, forming a fine-grained metamorphic rock named ____________. a. migmatite b. mylonite c. gneiss d. ignimbrite
b. mylonite
Burial metamorphism produces : . a..foliated rocks only b..nonfoliated rocks only c..both foliated and nonfoliated rocks
b. nonfoliated rocks only
Burial metamorphism produces ____________. a. foliated rocks only b. nonfoliated rocks only c. both foliated and nonfoliated rocks
b. nonfoliated rocks only
Thermal (contact) metamorphism produces : . a..foliated rocks only b..nonfoliated rocks only c..both foliated and nonfoliated rocks
b. nonfoliated rocks only
Thermal (contact) metamorphism produces ____________. a. foliated rocks only b. nonfoliated rocks only c. both foliated and nonfoliated rocks
b. nonfoliated rocks only
The most recently formed portion of any crystal is always found ____________. a. deep within the interior b. on the outer edges
b. on the outer edges
Minerals utilized by humans as a source of metal are termed ____________. a. metallic minerals b. ore minerals c. source minerals
b. ore minerals
The silica tetrahedron that forms the backbone of all the silicate minerals is composed of silicon and what other element? a. magnesium b. oxygen c. iron d. carbon
b. oxygen
Bowen's continuous reaction series describes the crystallization behavior of a single mineral (with variable chemical composition), ____________. a. olivine b. plagioclase c. pyroxene d. quartz
b. plagioclase
The silicate mineral that is found in the greatest variety of igneous rocks is ____________. 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 ____________. 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 rapidly that crystals do not have time to form
b. possess exceptionally coarse grains
The ____________ of new solid grains called _____________ results from oversaturated solutions. a. precipitate; precipitation b. precipitation; precipitate
b. precipitation; precipitate
The process of low-grade metamorphic rocks being altered to form high-grade metamorphic rocks is termed : metamorphism. a..foliated b..prograde c..retrograde d..dynamic
b. prograde
The process of low-grade metamorphic rocks being altered to form high-grade metamorphic rocks is termed ____________ metamorphism. a. foliated b. prograde c. retrograde d. dynamic
b. prograde
Terrestrial planets are mainly composed of ________ while Jovian planets are made dominantly of ________. a. volatiles; rock and metals b. rock and metals; volatiles c. refractory materials; volatiles and metals d. volatiles and metals; refractory material
b. rock and metals; volatiles
commonly serves as a protolith in the formation of quartzite. a..Limestone b..Sandstone c..Shale d..Slate
b. sandstone
Consult the figure below. Marine magnetic anomaly belts are widest when and where ____________. a. sea-floor spreading rates are relatively slow b. sea-floor spreading rates are relatively rapid c. continents are joined to form supercontinents
b. sea-floor spreading rates are relatively rapid
During the exhumation phase of mountain development, the next stop on the cycle would be (a) igneous (b) sedimentary (c) metamorphic
b. sedimentary
Consult the figure below. Spreading peanut butter on bread is an application of ____________. a. normal stress b. shear stress
b. shear stress
Spreading peanut butter on bread is an application of : . a..compression b..shear stress
b. shear stress
Volatile materials can exist as a gas at Earth's surface. Which of the following is NOT a volatile material? a. water b. silicon c. hydrogen d. carbon dioxide
b. silicon
Valleys and hillsides carved by glaciers are generally more ____________ in comparison to those produced by rivers and streams. a. shallow sided b. steep sided
b. steep sided
Change in shape, induced by stress, is termed ____________. a. metamorphosis b. strain c. plastic deformation d. pressure release
b. strain
The geotherm is the rate of change of ____________. a. pressure with depth in Earth's interior b. temperature with depth in Earth's interior c. temperature with altitude in Earth's atmosphere d. temperature with latitude on Earth's surface
b. temperature with depth in Earth's interior
The difference between tephra and tuff is that a. tephra is created in ash falls, whereas tuff is created in pyroclastic flows b. tephra is unlithified, whereas tuff is lithified c. tephra is always silicic, whereas tuff is always basaltic d. all of the above
b. tephra is unlithified, whereas tuff is lithified
A continental volcanic arc occurs at ____________. a. the Aleutian Islands of Alaska b. the Andes Mountains c. Hawaii d. Japan
b. the Andes Mountains
If one were to see a comet passing by Earth, it is likely that this comet originated from ________. a. the asteroid belt b. the Kuiper belt c. a neighboring galaxy d. interplanetary space
b. the Kuiper belt
With regard to minerals, hardness refers to ____________. a. the ability to resist breaking when being struck with a hammer b. the ability to resist being scratched by other substances c. the ability to resist chemical reactions with other substances d. an absence of cleavage
b. the ability to resist being scratched by other substances
Minerals in geodes (see below) form spectacular euhedral crystals because ____________. a. all of the elements incorporated in the crystals are in plentiful supply b. the crystals have abundant room to grow in their hollow surroundings c. minerals within geodes are always framework silicates d. minerals within geodes always contain iron
b. the crystals have abundant room to grow in their hollow surroundings
Differentiation of the core from the mantle early in Earth's history was possible because the planet was ________ at the time. a. very cold b. very hot c. very small d. the only planet in the Solar System
b. very hot
The geocentric model was developed during the time of the ancient Greeks. This model ________. a. was abandoned during the time of the Roman Empire and would never be widely held again b. was held to be true by thinkers throughout the Middle Ages, up until the Renaissance c. was rediscovered by the Polish astronomer Copernicus and has been the accepted model of the Universe ever since d. has been proven by NASA space images
b. was held to be true by thinkers throughout the Middle Ages, up until the Renaissance
Beneath a blanket of sediments, oceanic crust is primarily composed of ________.
basalt
The form and topography (depth profile) of the ocean floor is termed ________.
bathymetry
Decay of radioactive isotopes, differentiation of Earth's iron core, gravity-driven compression, and meteoric bombardment all caused early Earth to ________.
be much hotter than at present
Which environment would most likely produce sedimentary deposits characterized by very well-sorted, very well-rounded grains that are nearly pure quartz?
beach
Why is a spring tide so much higher than a normal high tide?
because the Sun is aligned with the moon
If one were to ride a hot air balloon up into the atmosphere, one would experience the concentration of gases ________.
becoming less dense
Geologists call individual layers of sedimentary rocks ________, whereas several of them together are called ________.
beds; strata
With regard to minerals, hardness refers to the ability to resist
being scratched
Cemented shells of marine organisms form which kind of sedimentary rock?
biochemical
which type of fault does NOT have a fault trace
blind fault
The rapid, deep burial of sediments in an accretionary prism leads to the formation of a metamorphic rock termed ________.
blueschist
earthquake waves that pass through the interior of earth are termed
body waves
Which of the following is NOT a way for minerals to crystallize?
bonding carbon to oxygen atoms to form organic compounds
body waves include
both S- and P- waves
faulting and earthquakes are examples of
brittle behavior
Which environment would most likely produce sedimentary deposits characterized by very well-sorted, very well-rounded grains that are nearly pure quartz? a) glacier b) alluvial fan c) beach d) river
c) beach
The sedimentary rocks breccia and conglomerate most commonly form in a ________ environment. a) beach b) lake c) mountain stream d) deep-ocean basin
c) mountain stream
Two major sources of energy, coal and oil shale, are considered ________ sedimentary rocks. a) clastic b) biochemical c) organic d) chemical
c) organic
A well-sorted sandstone with asymmetric ripples was most likely deposited as sand by a ________. a) river (near source) b) glacier c) river (far from source) d)alluvial fan
c) river (far from source)
According to the figure below, Earth's magnetic poles move constantly, but don't seem to stray farther than about ____________ from the geographic poles. a. 500 km b. 1,000 km c. 1,500 km d. 2,000 km
c. 1,500 km
The circumference of Earth is most nearly ________. a. 400 km b. 4,000 km c. 40,000 km d. 4,000,000 km
c. 40,000 km
Deformation brought on by orogeny can ____________. a. produce folds in rock b. produce faulting in rock c. All of the above are correct. d. metamorphose rock
c. All of the above are correct.
The figure below shows a moving source of light with four stationary observers at different locations. Which observer will see red-shifted light from the moving source a. A b. B c. C d. D
c. C
A famous example of hot-spot volcanism occurs at ____________. a. the Aleutian Islands of Alaska b. the Andes Mountains c. Hawaii d. Mt. St. Helens, Washington
c. Hawaii
The term and concept of sea-floor spreading (see figure below) was developed by _____________. a. Wegener and Dietz b. Hess and Wegener c. Hess and Dietz d. Wegener
c. Hess and Dietz
Late Paleozoic glacial deposits are NOT found in which of the following places? a. India b. South America c. North America d. southern Africa
c. North America
____________ commonly serves as a protolith in the formation of slate. a. Limestone b. Sandstone c. Shale d. Slate
c. Shale
An important contribution made by Copernicus is his (correct) assertion that the ________. a. Earth is spherical b. Sun is the center of the whole Universe c. Sun is the center of the Earth's orbit d. Earth is the center of the Universe
c. Sun is the center of the Earth's orbit
Our sun belongs to a galaxy known as ______________. a. Andromeda b. Cepheus c. the Milky Way d. the Stratosphere
c. The Milky Way
The discovery that each continent had different and separate polar wander paths proved that _____________. a. both the poles and continents move b. the poles move c. Wegener was right: continents move
c. Wegener was right: continents move
The eruption of Mt St. Helens killed a geologist stuyding the volcano because a. the geologist disregarded orders to keep a safe distance from the vent b. the eruption produced a greater volume of ash than anyone predicted c. a landslide produced a lateral blast of volcaniclastic debris that no one had anticipated d. lahars swept down all sides of the volcano and buried all towns within 100 km
c. a landslide produced a lateral blast of volcaniclastic debris that no one had anticipated
Foliated metamorphic rocks possess : . a..leafy plant fossils (ancient foliage) b..a homogeneous texture resulting from randomly oriented grains c..a planar fabric consisting of mineral grains in preferred orientations or preferred patterns of association (banding) d..minerals precipitated directly from sea water
c. a planar fabric consisting of mineral grains in preferred orientations or preferred patterns of association
Foliated metamorphic rocks possess ____________. a. leafy plant fossils (ancient foliage) b. a homogenous texture resulting from randomly oriented grains c. a planar fabric consisting of mineral grains in preferred orientations or preferred patterns of association (banding) d. minerals precipitated directly from sea water
c. a planar fabric consisting of mineral grains in preferred orientations or preferred patterns of association (banding)
Iceland rises above the Atlantic Ocean as a result of a. normal mid ocean ridge activity b. a submarine hot spot located within the interior of the plate c. a submarine hot spot located along a mid ocean ridge d. subduction of an oceanic plate underneath the continental Eurasian plate
c. a submarine hot spot located along a mid ocean ridge
Currently, most geologists ____________. a. agree that continental drift occurs; the mechanisms that drive drift are at work in the lower mantle and outer core and were unknown in Wegener's time b. continue to reject continental drift c. agree that continental drift occurs; the mechanisms that drive drift are at work in the ocean basins and upper mantle and were unknown in Wegener's time d. agree that continental drift occurs, but they still do not understand why it occurs
c. agree that continental drift occurs; the mechanisms that drive drift are at work in the ocean basins and upper mantle and were unknown in Wegener's time
A fold shaped like an elongate arch is a (an) ____________. a. basin b. dome c. anticline d. syncline
c. anticline
Compared to low-grade metamorphic rocks, high-grade rocks : . a..always contain more quartz and feldspar b..are produced closer to the surface, high in the stratigraphic column c..are produced at greater temperatures and pressures d..are produced at cooler temperatures, but greater pressures
c. are produced at greater temperatures and pressures
Consult the figure below. Compared to low-grade metamorphic rocks, high-grade rocks ____________. a. always contain more quartz and feldspar b. are produced closer to the surface, high in the stratigraphic column c. are produced at greater temperatures and pressures d. are produced at cooler temperatures, but greater pressures
c. are produced at greater temperatures and pressures
The lithosphere lies directly above the ________. a. transition zone b. crust c. asthenosphere d. lower mantle
c. asthenosphere
Precambrian metamorphic rocks are exposed at the surface : . a..on Mars and Venus, but nowhere on Earth b..at places in continental interiors termed platforms c..at places in continental interiors termed shields d..at the bottom of the deep sea
c. at places in continental interiors termed shields
On a geologic map, if the contacts between sedimentary rock units form a bull's-eye pattern of concentric circles, with the youngest unit in the center, the underlying structure is a (an) ____________. a. syncline b. dome c. basin d. anticline
c. basin
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
Dynamothermal (regional) metamorphism produces ____________. a. foliated rocks only b. nonfoliated rocks only c. both foliated and nonfoliated rocks
c. both foliated and nonfoliated rocks
Dynamothermal metamorphism produces : . a..foliated rocks only b..nonfoliated rocks only c..both foliated and nonfoliated rocks
c. both foliated and nonfoliated rocks
When in contact with hydrochloric acid, which mineral gives off bubbles of carbon dioxide gas? a. quartz b. halite c. calcite d. fluorite
c. calcite
Explosive or voluminous eruptions may cause the volcano to collapse on the floor of the now empty magma chamber, producing a broad depression termed a a. crater b. lahar c. caldera d. fissure
c. caldera
The development of a preferred orientation of large, flaky mica crystals within metamorphic rock is termed : . a..slaty cleavage b..phyllitic luster c..schistosity d..compositional banding
c. compositional banding
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
As compared to the asthenosphere, the lithosphere is ________. a. cooler and more able to flow b. hotter and more able to flow c. cooler and less able to flow d. hotter and less able to flow
c. cooler and less able to flow
Regions of continents that have not been subjected to orogeny during the past one billion years are termed ____________. a. accreted terranes b. exotic terranes c. cratons
c. cratons
Natural glass is NOT considered a mineral because it ____________. a. is not produced by geologic processes b. is organic c. does not have a fixed crystalline structure d. can be made synthetically as well as being a naturally occurring substance
c. does not have a fixed crystalline structure
Differential stress will cause crystals to align in a preferred orientation unless the crystals are : . a..primarily mica b..platy c..equant d..elongate
c. equant
Gemstones are commonly found in pegmatites, which are igneous rocks that are ____________. a. exceptionally mafic b. extrusive, forming from lava c. exceptionally coarse grained d. exceptionally fine grained
c. exceptionally coarse grained
If you found tuff deposits at an ___________ igneous setting, you could conclude that the lava had a ___________ viscosity content. a. intrusive; high b. intrusive; low c. extrusive; high d. extrusive; low
c. extrusive; high
The smoky cloud that rises from the vent of an actively erupting volcano is composed of a. smoke from wildfires inside the volcano chimney b. smoke from wildfires on the outer slopes of the volcano that become funneled into the crater c. fine volcaniclastic debris suspended in the air d. a continouus fountain of dark, basaltic lava
c. fine volcaniclastic debris suspended in the air
Rocks resulting from thermal (contact) metamorphism will not possess : . a..a new mineral assemblage distinct from that found prior to intrusion b..larger crystals than those characterizing the country rock prior to intrusion c..foliation d..silicate minerals
c. foliation
Rocks resulting from thermal (contact) metamorphism will not possess ____________. a. a new mineral assemblage distinct from that found prior to intrusion b. larger crystals than those characterizing the country rock prior to intrusion c. foliation d. silicate minerals
c. foliation
As compared to subaerial basaltic lavas, submarine basaltic lavas differ in that they a. always produce violent pyroclastic debris flows b. produce large crystals of pyroxene and plagioclase c. form pillow like mounds because they cannot flow as far from their source d. all of the aboce
c. form pillow like mounds because they cannot flow as far from their source
Ore minerals, such as galena and hematite, tend to be distinct in their very ____________. a. dark coloration b. diamond-like crystal habit c. great specific gravity d. vitreous luster
c. great specific gravity
Which common mineral is found in most kitchens? a. flour b. sugar c. halite d. mustard
c. halite
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
Wegener's idea of continental drift was rejected by American geologists because ____________. a. his English was too poor to be understood by them b. he had relatively little evidence supporting the existence of a supercontinent c. he could not conceive of a valid mechanism that would cause continents to shift positions d. the apparent fit of continental coastlines is blurred when the margins are defined by the edges of continental shelves rather than sea level
c. he could not conceive of a valid mechanism that would cause continents to shift positions
The Hawaiin island chain is an example of a a. island volcanic arc b. continental volcanic arc c. hot spot island chain d. stratovolcano assembly
c. hot spot island chain
By far the most common elements in the Universe and in our Solar System are ________. a. nitrogen and oxygen b. iron and manganese c. hydrogen and helium d. hydrogen and oxygen
c. hydrogen and helium
A volcanic neck, such as that seen at Shiprock, New Mexico (below), is a (an) ____________. a. sheet-like intrusion that lies parallel to surrounding layers of sedimentary rock b. cooled layer of lava c. intrusion formed within the magma chamber of a volcano d. sheet-like intrusion that cuts across preexisting layers
c. intrusion formed within the magma chamber of a volcano
The difference between lava and magma is that magma ____________. a. is light in color, whereas lava is dark b. usually has mafic composition, whereas lava usually has felsic composition c. is found beneath the Earth's surface, whereas lava has reached the surface d. flows more quickly than lava
c. is found beneath the Earth's surface, whereas lava has reached the surface
If we mentally align the continents to fit Wegener's concept of Pangaea, evidence of Late Paleozoic glacial deposits ____________. a. is more difficult to explain than in the modern continental configuration b. makes very little sense in either the Pangaea configuration or the modern configuration c. is much more readily explained than in the modern continental configuration
c. is much more readily explained than in the modern continental configuration
Within a single mountain range, : . a..only low-grade metamorphic rocks are likely to be found b..only high-grade metamorphic rocks are likely to be found c..it is possible to find a variety of metamorphic rocks produced in distinct facies, including high-, low-, and intermediate-grade rocks
c. it is possible to find a variety of metamorphic rocks produced in distinct facies, including high, low, and intermediate grade rocks
Within a single mountain range, ____________. a. only low-grade metamorphic rocks are likely to be found b. only high-grade metamorphic rocks are likely to be found c. it is possible to find a variety of metamorphic rocks produced in distinct facies, including high-, low-, and intermediate-grade rocks
c. it is possible to find a variety of metamorphic rocks produced in distinct facies, including high-, low-, and intermediate-grade rocks
For the majority of minerals, the streak color obtained when the mineral is scratched against a porcelain plate is ____________. a. likely to be diagnostic only if the mineral is hard enough to scratch porcelain b. more variable than the color in a hand sample among crystals c. less variable than the color in a hand sample among crystals d. always dark brown or black
c. less variable than the color in a hand sample among crystals
The shininess of a mineral is a helpful diagnostic property termed ____________. a. color b. specific gravity c. luster d. streak
c. luster
The difference between magma and lava is ____________. a. magma cools more rapidly than lava b. magma is found at the surface, whereas lava is found below the surface c. magma is found beneath the surface, whereas lava is found at the surface d. There is no difference; the two terms mean the same thing.
c. magma is found beneath the surface, whereas lava is found at the surface
What does an ordinary compass indicate? a. magnetic inclination b. magnetic declination c. magnetic north d. true north
c. magnetic north
Marine magnetic anomalies result from sea-floor spreading in conjunction with ____________. a. magnetic storms on the surface of the Sun b. global warming c. magnetic polarity reversals d. apparent wander of the magnetic poles
c. magnetic polarity reversals
Injecting hot fudge into ice cream is an appropriate analogy for which cause of magma melt? a. Melting due to a decrease in pressure b. melting due to an addition of volatiles c. melting due to heat transfer from rising magma d. All of the above are correct.
c. melting due to heat transfer from rising magma
A buried body of shale is subjected to differential stress at temperatures greater than 200C, causing clay minerals to grow in preferred orientation and producing slate. This is an example of : . a..diagenesis b..erosion c..metamorphism d..weathering
c. metamorphism
A buried body of shale is subjected to differential stress, causing clay minerals to realign and produce slate; this is an example of ____________. a. diagenesis b. erosion c. metamorphism d. weathering
c. metamorphism
Clay minerals within a buried body of shale are recrystallized at 400C and high pressure to form mica, producing a rock called phyllite; this is an example of : . a..diagenesis b..erosion c..metamorphism d..weathering
c. metamorphism
Clay minerals within a buried body of slate are recrystallized at high temperatures and pressures to form mica, producing a rock called phyllite; this is an example of ____________. a. diagenesis b. erosion c. metamorphism d. weathering
c. metamorphism
A primary difference between phyllite and schist is : . a..schist contains mica, but phyllite contains only clay b..phyllite contains mica, but schist contains only clay c..mica crystals within schist are larger than those within phyllite d..mica crystals within phyllite are larger than those within schist
c. mica crystals within schist are larger than those within phyllite
A primary difference between phyllite and schist is ____________. a. schist contains mica, whereas phyllite contains only clay b. phyllite contains mica, whereas schist contains only clay c. mica crystals within schist are larger than those within phyllite d. mica crystals within phyllite are larger than those within schist
c. mica crystals within schist are larger than those within phyllite
If a body of igneous (source) rock is subjected to partial melting, the magma that is produced is expected to be ____________. a. identical in chemical composition to the source rock b. more mafic than the source rock c. more felsic than the source rock
c. more felsic than the source rock
In 79 CE, the citizens of Pompeii in the Roman Empire were buried by pyroclastic debris derived from an eruption of a. mt. olympus b. olympus mons c. mt. vesuvius d. mt. st. helens
c. mt. vesuvius
Presently, Earth's atmosphere is dominated by which two gases? a. hydrogen and helium b. oxygen and carbon dioxide c. nitrogen and oxygen d. carbon dioxide and sulfur dioxide
c. nitrogen and oxygen
It is possible for offset along an oblique-slip fault to have both ____________ and ____________ components. a. normal; reverse b. right-lateral; left-lateral c. normal; left-lateral
c. normal; left-lateral
An episode of mountain building is termed a (an) ____________. a. phylogeny b. aureole c. orogeny d. slickenside
c. orogeny
Which common gemstone results from biomineralization? a. diamonds b. garnets c. pearls d. sapphires
c. pearls
Which of the following is NOT a mineral? a. quartz b. diamond c. petroleum d. gold
c. petroleum
A geologist's compass differs from the more widely known orienteering compass in that the geologist's compass ____________. a. contains a barometer that warns the geologist of approaching storms b. can chemically analyze rock samples in the field c. possesses an inclinometer, allowing the user to measure dip and plunge angles d. needle points directly toward geographic north rather than geomagnetic north
c. possesses an inclinometer, allowing the user to measure dip and plunge angles
The preexisting rock that is subsequently altered to form a metamorphic rock is termed a ____________. a. parent rock b. source rock c. protolith d. premetarock
c. protolith
The preexisting rock which is subsequently altered to form a metamorphic rock is termed a : . a..parent rock b..source rock c..protolith d..premetarock
c. protolith
Two common metamorphic rocks that typically lack foliation are : . a..slate and phyllite b..gneiss and migmatite c..quartzite and marble d..schist and metaconglomerate
c. quartzite and marble
Two common metamorphic rocks that typically lack foliation are ____________ and ____________. a. slate; phyllite b. gneiss; migmatite c. quartzite; marble d. schist; metaconglomerate
c. quartzite; marble
The process of high-grade metamorphic rocks being altered to form low-grade metamorphic rocks is termed : metamorphism. a..foliated b..prograde c..retrograde d..dynamic
c. retrograde
The process of high-grade metamorphic rocks being altered to form low-grade metamorphic rocks is termed ____________ metamorphism. a. foliated b. prograde c. retrograde d. dynamic
c. retrograde
Mt. Kilimanjaro and the Basin and Range Province are the result of _____________. a. converging plates b. subducting plates c. rifting d. None of the above are correct.
c. rifting
: commonly serves as a protolith in the formation of slate. a..Limestone b..Sandstone c..Shale d..Gneiss
c. shale
Olympus Mons, the largest known Volcano in the Universe, is an example of a a. stratovolcano b. cinder cone c. shield volcano
c. shield volcano
Of the three primary forms of subaerial volcanoes, _ have the most gently sloping sides, due to the low viscosity of the basaltic lavas which form them. a. stratovolcanoes b. cinder cones c. shield volcanoes
c. shield volcanoes
Of the three primary forms of subaerial volcanoes, _ are the largest in area a. stratovolcanoes b. cinder cones c. shield volcanoes
c. shield volcanoes
Regions where Precambrian metamorphic rocks are exposed at the surface are termed ____________. a. convergent margins b. platforms c. shields
c. shields
Which list properly orders metamorphic rocks from lowest to highest grade? a. conglomerate, sandstone, siltstone, shale b. shale, slate, phyllite, quartzite c. slate, phyllite, schist, gneiss d. gneiss, phyllite, schist, slate
c. slate, phyllite, schist, gneiss
Which list properly orders metamorphic rocks from lowest to highest grade? a..conglomerate, sandstone, siltstone, shale b..shale, slate, phyllite, quartzite c..slate, phyllite, schist, gneiss d..gneiss, phyllite, schist, slate
c. slate, phyllite, schist, gneiss
On a geologic map, if the contacts between sedimentary rock units form a series of parallel lines, with the youngest unit in the center, the underlying structure is a (an) ____________. a. basin b. dome c. syncline d. anticline
c. syncline
If a geologist discovered coal in a modern-day cold, snowy location, he or she could conclude that _____________. a. this discovery was anomalous b. the area was once covered with an ocean c. the area was once covered with swamps and/or jungles d. a meteorite must have struck the area
c. the area was once covered with swamps and/or jungles
By deep-sea drilling, the Glomar Challenger proved the theory that if the model of sea-floor spreading was correct, then sea-floor sediment should be ____________ and ____________ as one moves away from the spreading axis. a. thinner; younger b. thinner; older c. thicker; older d. thicker; younger
c. thicker; older
Evidence that glaciers once covered an area might include ______________. a. backwash and grabens b. backwash and striations c. till and striations d. till and grabens
c. till and striations
A volcano emits ash, which falls from the sky, settles in layers, and is eventually cemented. The resulting rock is termed ____________. a. pumice b. granite c. tuff d. ignimbrite
c. tuff
Substances that can be transformed to a gas at relatively low temperatures are termed ________. a. glasses b. melts c. volatiles d. mineraloids
c. volatiles
What was unusual about the 1986 disaster around Lake Nyos in Cameroon a. a volcanic eruption involved a lateral blast of volcaniclastic debris that no one anticipated b. pyroclastic flows buried surrounding villages, reminiscent of the burial of Pompeii 1900 years earlier c. volcanically derived carbon dioxide gas bubbled from the lake and suffocated people and animals nearby d. a slurry of lava and lake water flowed rapidly outward form the lake and buried surrounding villages
c. volcanically derived carbon dioxide gas bubbled from the lake and suffocated people and animals nearby
Important volatiles in magmas include ____________. a. iron- and magnesium-rich minerals, such as olivine b. potassium and aluminum c. water and carbon dioxide d. trinitrotoluene and nitroglycerin
c. water and carbon dioxide
Ash and lava fragments that cascade down the sides of a volcano eventually settle and lithify to form ____________. a. basalt b. andesite c. welded tuff d. ash-fall tuff
c. welded tuff
The image below shows a mineral with hydrochloric acid applied to it. What mineral is this?
calcite
The image below shows a mineral with hydrochloric acid applied to it. What mineral it this
calcite
Which of the following is NOT true? A 100-year flood ________.
cannot occur in successive years
Which of the following are NOT considered sediments?
cemented grains
Broadly, metamorphism involves ________.
changes in mineralogy and texture in response to heat and stress
Lithified detritus (breakdown products of preexisting rocks) forms which kind of sedimentary rock?
clastic
As compared to aphanitic igneous rocks, phaneritic rocks are ________.
coarser grained
Trace amounts of impurity in a mineral can commonly produce significant differences in __________ among individual crystals of this mineral.
color
a coiled aoring would be useful in illustrating a
compressional wave
Synthetically made glass and natural quartz crystals both exhibit a fracture pattern termed
conchoidal fracture
The image below shows a mineral specimen of quartz. What is the term for the smoothly curving, clamshell-shaped surface on the sample below? (glassy rock)
conchoidal fracture
The image below shows an outcrop of coarse-grained sedimentary rock. Note the rock hammer for scale. What is the name of this rock type?
conglomerate
As compared to the rocks that make up the crust, Earth as a whole is ________.
considerably more dense
Braided streams ________.
consist of a series of intertwined channels that are overloaded with sediment
The presence of vesicles in an igneous rock is evidence that the source melt ________.
contained dissolved volatiles
The shallowest portions of an ocean found along the margins of continents are the ________.
continental shelves
medium and deep focus earthquakes occur along
convergent plat boundaries only
earthquakes are likely to occur along
convergent, divergent, and transform plate boundaries
All other factors being equal, intrusive rocks that form deep within Earth ________ than intrusive rocks that cool near the surface.
cool more slowly
Of the three primary compositional layers of the Earth (crust, mantle, core), which is the thickest layer?
core
Consult the figure below. Here, distinct internal laminations are inclined at an angle to the boundary of the main sedimentary layers. This is termed ________.
cross beds
From left to right, correctly label each section of this slice of the Earth. Note that 1 starts at the surface of the Earth and 6 ends at the center of the Earth.
crust, upper mantle, transition zone, lower mantle, liquid outer core, solid inner core
The outer edge of a meander, where material is being eroded, is a(n) ________.
cut bank
What type of sediment is typically found in lake bottoms? a) sand b) gravel c)silt d) clay/mud
d) clay/mud
Which of the following is NOT true? As compared to arkose, quartz sandstone ________. a) is likely to be found farther away from weathering granitic source rock b) is considered to be more compositionally mature c) does not contain significant amounts of feldspar d) contains more angular grains
d) contains more angular grains
Compaction and cementation of grains occurs during ________. a) transportation b) erosion c) weathering d) lithification
d) lithification
If a geologist found preserved mud cracks, he or she could conclude that the environment in which it formed_____________. a) was the site of a mass extinction event b) was once covered by a glacier c) has been subjected to a major climate change event d) was once covered in wet mud
d) was once covered in wet mud
Orogenesis (mountain building) leads to the production of ____________. a. metamorphic rocks only b. igneous rocks only c. sedimentary rocks only d. All of the above are correct
d. All of the above are correct
Which of the following is part of the process that leads to the exhumation of metamorphic rocks? a. continents squeezing together b. mountain belts collapsing c. erosion d. All of the above are correct
d. All of the above are correct
____________ may help a geologist recognize a fault. a. Displacement b. Fault scarps c. Breccia d. All of the above are correct
d. All of the above are correct
Evidence for a united Pangaea comes from the fossil record of which type(s) of organisms? a. plants b. large terrestrial animals c. freshwater animals d. All of the above are correct.
d. All of the above are correct.
Evidence of paleomagnetism can be found in _________________. a. basalt that has cooled from lava b. any rock with magnetic minerals present c. sedimentary rocks where minerals form from ion-bearing groundwater d. All of the above are correct.
d. All of the above are correct.
Igneous rocks ____________. a. are formed through the freezing of 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 are correct.
d. All of the above are correct.
In silicate minerals, tetrahedra may be coordinated to form ____________. a. long one-dimensional chains b. extensive two-dimensional sheets c. massive three-dimensional frameworks d. All of the above are correct.
d. All of the above are correct.
Large igneous provinces can cause ______________. a. sea level rise b. climate change c. extinction d. All of the above are correct.
d. All of the above are correct.
Metamorphism may be induced by ____________. a. contact with a hot pluton b. contact with hot groundwater c. heat and pressure associated with deep burial d. All of the above are correct.
d. All of the above are correct.
This map depicts earthquakes, which coincide with areas where ___________. a. volcanoes also regularly occur b. movements of the crust take place c. rocks break and move d. All of the above are correct.
d. All of the above are correct.
Viscosity depends on ____________. a. temperature b. volatile content c. silica content d. All of the above are correct.
d. All of the above are correct.
Which of the following is NOT a factor controlling the cooling rate of magma? a. depth of intrusion b. shape and size of magma body c. presence of circulating groundwater d. All of the above are factors.
d. All of the above are factors.
The change in wavelength (and, therefore, frequency) of waves that happens if the source of the waves is moving is explained by the ________. a. Big Bang theory b. nebular theory c. expanding Universe theory d. Doppler effect
d. Doppler effect
Scientists believe that the Moon formed due to a large planetesimal colliding with the Earth because it has a composition similar to ________. a. other meteors b. other comets c. Earth's crust d. Earth's mantle
d. Earth's mantle
Which of the following is NOT a mineral? a. petroleum (oil), which is a liquid b. cubic zirconia, which is a synthetic diamond substitute that is not found in nature c. ice, which is water in the solid state d. Neither A nor B are minerals; however, C is a mineral.
d. Neither A nor B are minerals; however, C is a mineral.
The single property that can be used to identify any mineral is ____________. a. color b. luster c. cleavage d. None of the above are correct; multiple properties must be used to diagnose a mineral.
d. None of the above are correct; multiple properties must be used to diagnose a mineral.
Consult the figure below. Abundant swamps led to the formation of coal during the Late Paleozoic in which of the following places? a. southern Africa b. India c. South America d. North America
d. North America
____________ commonly serves as a protolith in the formation of phyllite. a. Limestone b. Sandstone c. Shale d. Slate
d. Slate
Which national park is home to a large volcanic caldera formed through a very large explosive eruption 630,000 years ago? a. Acadia b. Carlsbad Caverns c. Great Smoky Mountains d. Yellowstone
d. Yellowstone
Minerals are all naturally occurring solid substances with a definable chemical composition. They must also possess ____________. a. an ability to be synthesized in the laboratory as well as being found in nature b. metallic elements, such as iron, calcium, or magnesium c. metallic luster d. a fixed crystalline structure (spatial arrangement of atoms and ions)
d. a fixed crystalline structure (spatial arrangement of atoms and ions)
Metamorphism may be induced by : . a..contact with a hot pluton b..contact with hot groundwater c..heat and pressure associated with deep burial d..all of the above
d. all of the above
Pahoehoe a. forms when basaltic lava flows cease flowing and solidify simultaneously b. has a smoother texture than aa c. is easier to walk on than aa is d. all of the above
d. all of the above
Whether an eruption will primarily produce lava flows or pyroclastic debris is influenced by a. the viscosity of the lava b. the composition of the lava c. the proportion of volatiles within the lava d. all of the above
d. all of the above
The thickness of clay and planktonic microskeletons is greatest ____________. a. along fracture zones b. along mid-ocean ridges c. in the center of abyssal plains d. at the edges of ocean basins
d. at the edges of ocean basins
Limestone reefs and salt deposits are important rocks in the reconstruction of Earth history because they ____________. a. automatically provide age information; all such deposits occurred between 200 and 400 million years ago b. are deposited in warm climates today, but there is good reason to think that they were deposited in cold climates millions of years ago c. imply that ancient human societies had access to good snorkeling and premium margaritas d. can be used to infer the ancient climate of the Earth; they are deposited in environments that are restricted to warm climate
d. can be used to infer the ancient climate of the Earth; they are deposited in environments that are restricted to warm climate
The theory of plate tectonics is a theory because it _____________. a. was discovered so long ago b. is widely accepted c. is not widely accepted d. cannot be directly proven
d. cannot be directly proven
Spreading rates along mid-ocean ridges have ____________. a. been remarkably constant through time b. changed through time, and today vary between 1 and 10 m/yr c. changed through time, but are the same everywhere on Earth today d. changed through time, and today vary between 1 and 10 cm/yr
d. changed through time, and today vary between 1 and 10 cm/yr
Metamorphism, in broadest terms, involves ____________. a. the settling of crystals in a melt as it cools b. the sorting of grains by size, as is accomplished by rivers and beach waves c. cementation of loose grains and precipitation of new minerals into pore spaces d. changes in mineralogy and texture in response to heat and stress
d. changes in mineralogy and texture in response to heat and stress
In ancient Greece, Eratosthenes measured the difference in angles of the Sun's rays in two different locations in Egypt at the same time to calculate the ________. a. rate of rotation of the Earth b. distance from the Earth to the Moon c. distance from Earth to the Sun d. circumference of the Earth
d. circumference of the Earth
Which of the following processes CANNOT occur in the formation of metamorphic rock? a. realignment of minerals so that they develop a preferred orientation b. segregation of minerals into layers of different compositions c. solid-state rearrangement of atoms or ions to create a new assemblage of minerals d. complete remelting of the rock, followed by solidification to form a new rock
d. complete remelting of the rock, followed by solidification to form a new rock
Which of the following processes cannot occur in the formation of metamorphic rock? a..realignment of minerals so that they develop a preferred orientation b..segregation of minerals into layers of different compositions c..solid-state rearrangement of atoms or ions to create a new assemblage of minerals d..complete remelting of the rock, followed by solidification to form a new rock
d. complete remelting of the rock, followed by solidification to form a new rock
According to Wegener, puzzle pieces are to a jigsaw puzzle as ____________ is/are to Pangaea. a. plate tectonics b. sea-floor spreading c. continental drift d. continents
d. continents
The mineral assemblage within metamorphic rock is : . a..always identical to that found within the protolith b..dependent only on the mineral assemblage of the protolith c..dependent only on the temperature and pressure of formation d..dependent on both the mineral content of the protolith and the temperature and pressure of formation
d. dependent on both the mineral content of the protolith and the temperature and pressure of formation
The mineral assemblage within metamorphic rock is ____________. a. always identical to that found within the protolith b. dependent only on the mineral assemblage of the protolith c. dependent only on the temperature and pressure of formation d. dependent on both the mineral content of the protolith and the temperature and pressure of formation
d. dependent on both the mineral content of the protolith and the temperature and pressure of formation
A fold shaped like an upside-down bowl is a (an) ____________. a. syncline b. anticline c. basin d. dome
d. dome
Humans first realized that the Earth was spherical ________. a. as a result of the voyages of Christopher Columbus b. when Magellan's crew was able to sail completely around the world c. during the Renaissance d. during the time of Aristotle in ancient Greece
d. during the time of Aristotle in ancient Greece
Regions of the sea floor with positive magnetic anomalies were formed during times when Earth's magnetic field ____________. a. was exceptionally strong b. was exceptionally weak c. had reversed polarity d. had normal polarity
d. had normal polarity
The blueschist facies is a metamorphic realm of : . a..high temperature and pressure b..low temperature and pressure c..high temperature but relatively low pressure d..high pressure but relatively low temperature
d. high pressure but relatively low temperature
Because of the Doppler effect, a light- or sound-emitting object moving toward you has a _______ compared to a stationary object. a. higher amplitude b. lower frequency c. lower amplitude d. higher frequency
d. higher frequency
Regional metamorphism : . a..takes place at cool temperatures and low pressure b..takes place at cool temperatures but high pressure c..is another name for thermal metamorphism d..is another name for dynamothermal metamorphism
d. is another name for dynamothermal metamorphism
Regional metamorphism ____________. a. takes place at cool temperatures and low pressure b. takes place at cool temperatures but high pressure c. is another name for thermal metamorphism d. is another name for dynamothermal metamorphism
d. is another name for dynamothermal metamorphism
The balance between the weight of a mountain range and the buoyancy provided by the underlying mantle is termed ____________. a. homeostatic equilibrium b. osmotic equilibrium c. punctuated equilibrium d. isostatic equilibrium
d. isostatic equilibrium
In Wegener's evidence for continental drift, continents were proposed to fit together, such as the east coast of South America with the __________________ and the upper west coast of Africa with the _______________. a. west coast of Europe; east coast of South America b. lower west coast of Africa; east coast of South America c. west coast of Europe; east coast of North America d. lower west coast of Africa; east coast of North America
d. lower west coast of Africa; east coast of North America
Where Earth's magnetic dipole intersects with the surface of the planet is called the ___________. a. geographic pole b. magnetic dipole c. magnetic inclination d. magnetic pole
d. magnetic pole
The protolith subjected to metamorphism : . a..is always metamorphic rock to begin with b..is always igneous rock c..is always sedimentary rock d..may belong to any of the three primary rock types
d. may belong to any of the three primary rock types
In a ____________ fault, the fault plane is nonvertical and the hanging-wall block moves downward relative to the footwall block. a. detachment b. reverse c. thrust d. normal
d. normal
Eratosthenes was the first person to accurately estimate the size of Earth. He accomplished this feat by ________. a. sailing around the world and estimating his average rate of travel b. comparing the length of an Earth day with the distance between the Earth and the Sun c. measuring the severity of the greatest earthquakes d. observing shadows simultaneously cast at two different cities that were separated by a known distance
d. observing shadows simultaneously cast at two different cities that were separated by a known distance
Mylonite will be found (a) in contact with plutons (b) in hydrothermal deposits (c) between schist and phyllite (d) on fault zones (e) in bolide impact craters
d. on fault zones
The process of differentiation results in all of the following EXCEPT ________. a. denser materials becoming concentrated near the cores of planets b. rocky material forming the mantles of planets c. planets becoming approximately spherical d. planets forming atmospheres
d. planets forming atmospheres
The apparent tendency of the north (or south) magnetic pole to vary in position over time is termed ____________. a. magnetic declination b. dipole c. magnetic inclination d. polar wander
d. polar wander
Bombs, ash, and cinders are all examples of ____________. a. intrusive igneous rocks b. hot spots c. volatiles d. pyroclastic debris
d. pyroclastic debris
The greatest hazard to human life associated with volcanoes is a. flowing lava b. volcanic gas c. falling ash d. pyroclastic flows
d. pyroclastic flows
In a ____________ fault, the fault plane is greater than 35° from horizontal and the hanging-wall block moves upward relative to the footwall block. a. detachment b. normal c. thrust d. reverse
d. reverse
Coarse-grained granite is most similar in mineral composition to fine-grained ____________. a. andesite b. basalt c. komatiite d. rhyolite
d. rhyolite
Which two gems are special versions of the common mineral corundum (Al2O3)? a. emeralds and rubies b. emeralds and sapphires c. aquamarines and emeralds d. sapphires and rubies
d. sapphires and rubies
A dike is a (an) ____________. a. sheet-like intrusion that lies parallel to surrounding layers of sedimentary rock b. cooled layer of lava c. intrusion formed within the magma chamber of a volcano d. sheet-like intrusion that cuts across preexisting layers
d. sheet-like intrusion that cuts across preexisting layers
The hot spot track associated with the Hawaiian Islands and Emperor Seamounts a. shows that the Pacific plate has been stationary of the last 30 million years b. occurs along a divergent plate boundary c. occurs along a convergent plate boundary d. shows that the Pacific Plate has been moving northwest for the last 30 million years
d. shows that the Pacific Plate has been moving northwest for the last 30 million years
commonly serves as a protolith in the formation of phyllite. a..Limestone b..Sandstone c..Shale d..Slate
d. slate
In regard to the cooling of molten rock, a __________ volume and a __________ shape cools faster. a. larger; spherical b. larger; pancake c. smaller; spherical d. smaller; pancake
d. smaller; pancake
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 temperatures d. solidify at lower temperatures
d. solidify at lower temperatures
The color of a mineral in powdered form is termed ____________. a. color b. specific gravity c. luster d. streak
d. streak
Pillow lavas are associated with a. continental rhyolitic eruptions b. continental basaltic eruptions c. submarine rhyolitic eruptions d. submarine basaltic eruptions
d. submarine basaltic eruptions
The New Age practice of surrounding one's self with crystals has a strong positive effect on ____________. a. mental health b. the immune system's response to illness c. the prospects for world peace d. the bank accounts of rock shop owners
d. the bank accounts of rock shop owners
Earth's geothermal gradient is the rate of temperature change incurred by ________. a. increasing altitude in the atmosphere b. increasing depth at ocean trenches c. traversing from either pole toward the equator d. traversing down within Earth's interior
d. traversing down within Earth's interior
The magnetic field of Earth in the geologic past is ____________. a. known to have experienced numerous polarity reversals, due to remnant magnetization of iron-rich minerals in rocks b. known to have been constant through geologic time, due to remnant magnetization of iron-rich minerals in rocks c. known to have been constant through time, on the basis of theoretical calculations d. unknown, but it is assumed to have been identical to today's
d. unknown, but it is assumed to have been identical to today's
At the surface, potassium feldspar reacts with water to form clay; this is an example of : . a..diagenesis b..erosion c..metamorphism d..weathering
d. weathering
At the surface, potassium feldspar reacts with water to form clay; this is an example of ____________. a. diagenesis b. erosion c. metamorphism d. weathering
d. weathering
The density of seawater increases with ________ temperature and ________ salinity.
decreasing; increasing
The mineral assemblage within metamorphic rock is ________.
dependent on both the mineral content of its protolith and the temperature and pressure of formation
complete melting-- composition identical to that of the source. most rocks melt by partial melting--felsic minerals melt at lower temperatures than mafic minerals, partial melting produces magma more felsic than the source. overall composition of the mantle is ultramafic----partial melting--mantle--mostly mafic. felsic source area; continental crust is melted, magma will be felsic---intermediate source is almost melted--intermediate composition.
describe how melting can influence magma composition
magma cools and solidifies from the outside--magma cool--mafic minerals crystallize first, composition of remaining magma less mafic (more felsic) partial crystallization of mafic magma--produces magma of more intermediate composition. Heavy mafic minerals may sink through the magma and collect in layers at the bottom--crystal settling--lower parts of the magma chamber more mafic, remaining felsic. Felsic crystals may be less dense than magma--float upward--top of magma chamber more felsic. Magma mixing--two different magmas come into contact and mix, producing magma has composition intermediate between the two magmas. Mafic magma -- hotter than melting temperature of felsic rocks so mafic can melt felsic wall rocks..---- wall rocks around a magma melt--incorporated into the magma by assimilation.
describe how partial crystallization, assimilation, and magma mixing can change a magma
Thermal energy; heat moves from the hotter interior to the cooler surface. Heat flow--2 adjacent masses have different temperatures. Three ways: 1) Conduction- heat transfer by direct contact. 2) Radiant Heat transfer-- heat radiates through the air. 3) Convection-- heat transfer by flow of a liquid or by solid but weak material, material flows in a circular path--convection cell. Via plate tectonics-- solid asthenosphere rises beneath mid-ocean ridge, hot rocks--convection adding material to the oceanic lithosphere. Sea-water; hot crust of mid-ocean ridge; hotter and and rises; convection cell helps cool the oceanic crust. newly created lithosphere cool by conduction of heat to cooler rocks and sea-water. underlying asthenosphere cools, hardens and part of the lithosphere, cooled oceanic lithosphere subducts back into the asthenosphere.
describe three ways that heat is transferred from a warmer mass to a cooler one and an example of conduction and convection by plate tectonics
The application of ________ during metamorphism causes elongated crystals to align parallel with each other. When this happens, the rock develops ________.
differential stress; foliation
In the figure provided below, what type of igneous intrusion is the vertical rock unit shown by letter A?
dike
the quantity of offset that occurs along a fault is termed
displacement
A high grade metamorphic rock that can be formed from intense shearing is (a) phyllite (b) schist (c) slate (d) migmatite (e) gneiss
e. gneiss
how can damage and injury be minimized in areas prone to seismic activity
earthquake zoning, egnineering controls and warning systems
the point on earths surface directly above the point where an earthquake occurs is termed
epicenter
The removal of detritus from weathered rock at an outcrop is termed ________.
erosion
Pillow basalts attain their distinctive blob-like shapes because their parent lavas do not travel far prior to solidification. This is because the parent lavas ________.
erupt underwater and thus cool very quickly
The tall polygonal features preserved in the ancient basalt flow in the image below formed because the lava
erupted underwater and cooled rapidly, forming many fractures
When the sea level rises, an ocean may invade a river valley, producing a nearshore body of water of mixed and variable salinity termed a(n) ________.
estuary
viscosity--measure of materials resistance to flow. viscous magma--does not flow easily, fluid (less viscous) magma flows more easily. controlled by temperature, composition and crystal content. viscous magma strongly resists flowing, erupts on the surface it does not spread out, piles up forming mounds or domes of lava. Fluid (less viscous)--flows more easily and may spread out in thin layers on the surface, travel longer distances from its source and cover large areas with lava. Temperature; low temp-- temperature of magma--important control factor of viscosity, barely hot enough to be molten, flows only with difficulty, very viscous. High Temperature; very hot, low viscosity flows very easily. Mafic magma--hotter than felsic--less viscous than felsic if two are at the same temperature. Composition: Abundant Silicate Chains--- Silicon and oxygen tetrahedra long silicate chains that don't move easily out of the way. Felsic and most intermediate magmas have high silicon and oxygen content--very viscous. Few silicate chains---mafic magma contains less silicon/oxygen than intermediate or felsic, less connected--less viscous, flows more easily. Volatiles-- abundance of silicate chains--water dissolved in magma disrupts long chains decreasing the viscosity. water and other volatiles decrease viscosity. Percentage of Crystals: Abundant crystals; magma cools, crystals begin to form, flow slowly, more viscous (has more resistance to flow)O than magma with fewer crystals. Few crystals--few crystals has few internal obstructions and flows more easily (less viscous), smoothly, flow faster and farther
explain the factors that control the viscosity of a magma
mafic minerals (olivine and pyroxene) are the first to crystallize from mafic-magma, typically don't crystallize from felsic magma. Amphibole and Biotite--intermediate composition but also present in mafic rocks or felsic, crystallize at temperatures lower than olivine and pyroxene. Plagioclase feldspar--calcium rich or sodium rich, crystallizes at high temperature sometimes with olivine and pyroxene. Plagioclase with less calcium--lower temperatures. Light color felsic minerals quartz, K-feldspar and muscovite crystallize at low temperatures, only minerals form from felsic magma--lack chemical components required to grow mafic minerals.
explain the order in which minerals crystallize from a magma (Bowen's Reaction Series) and compare it to the order in which they melt
1. a small volcano--partially eroded revealing cross section, many necks form as erosion wears down a volcano exposing the harder, more resistant rocks that solidified inside the magnetic conduit of the volcano. 2. magnetic conduits forming well beneath the volcano.
explain two ways that a volcanic neck can form
The vast majority of mineral types _____________ . a. are quite common b. are rare c. form under special conditions d. occur in a variety of rock types e. A and D are both correct. f. B and C are both correct.
f. B and C are both correct.
Which of the following is NOT a way crystals can form? a. solidification of a melt b. precipitation from solution c. solid-state diffusion d. biomineralization e. precipitation from gas f. None of the above are correct.
f. None of the above are correct.
The diamonds typically seen in engagement rings today do not display their natural crystal faces but rather __________, which are made by grinding the gem on a spinning lap.
facets
a surface along which rock on opposed sides is offset by earthquake induced slip is called a
fault
the intersection between a fault plane and the ground surface is called the
fault trace
Which type of magma has the greatest silica content?
felsic
The density of rocks is generally related to composition. Which of the following choices places rock compositions in order of increasing density?
felsic, intermediate, mafic, ultramafic
The flat-lying area surrounding a river channel is termed the ________.
floodplain
Rip currents ________ the shoreline.
flow directly away from
Longshore currents ________ the shoreline.
flow parallel to
Slaty cleavage, schistosity, and compositional banding are all examples of ________.
foliation
Which of the following statements is NOT true? Hornfels facies ________.
form at high pressures but low temperatures
Pirate streams ________.
form when headward erosion causes one stream to intersect another
a primary force opposing motion on all faults is
friction
A __________ is a mineral-lined cavity in a rock.
geode
Vesicular is a term used to describe a texture in ________ igneous rocks.
glassy
As compared to ultramafic rocks, mafic rocks have a ________.
greater proportion of silica
A small mountain stream will have a ________ competence and a ________ capacity than the Mississippi River.
greater; lower
Because of wave refraction, erosion along an irregular coastline is ________.
greatest along headlands
at any point along the surface of an oblique (nonvertical fault), the
hanging wall lies vertically above the footwall
Meandering streams ________.
have a channel that is highly sinuous (curvy)
Volatiles refer to substances that ________.
have a tendency to evaporate into gases
short term predictions of earthquake behavior
have been largely unreliable
Ephemeral streams ____________.
have flowing water either episodically or during only a portion of the year
High tide will be ________ during a full moon than normally.
higher
Consult the figure below. Hot water reacting with the crust is the basis for what type of metamorphism?
hydrothermal
Which transport medium carries the largest particles?
ice in glaciers
What type of rock forms by the solidification of a melt?
igneous
Thermal (contact) metamorphism occurs ________.
in areas surrounding igneous intrusions
The deepest segments of the ocean floor are found ________.
in trenches associated with subduction zones
The discharge of a river traveling through a temperate region will typically ________ downstream; the discharge of a river traveling through an arid region will typically ________ downstream.
increase; decrease
Along beaches, groins have ________.
increased erosion rates immediately down current from the groin
With increasing distance from a mid-ocean ridge, the age of oceanic crust ________.
increases
A mineral within a metamorphic rock that can be used to provide a narrow constraint on the temperature and pressure of rock formation is termed a(n) ________ mineral.
index
on december 26 2004 a magnitude 9 earthquake generated a tsunami that devastated coastlines on the
indian ocean
The densest layer of Earth is the ________.
inner core
Chemical weathering involves the breakdown of material due to ________.
interaction with water or air
When magma crystallizes, ________ are formed.
intrusive igneous rocks
Unlike the lithosphere, the asthenosphere ________.
is able to flow over long periods of time
At a subduction zone, the downgoing (subducting) plate ________.
is always composed of oceanic lithosphere
Regional metamorphism ________.
is another name for dynamothermal metamorphism
long term prediction of earthquake behavior
is based on past activity, works on assumtion that past activity in a spot means future activity, and includes the notion of seismic gaps, places where an earthquake is overdue
The Moho ________.
is found deeper underneath continents than under oceans
The stream gradient of most rivers ________.
is greater near the source than near the mouth
Diamonds are usually found in (Hint: Igneous rock in which diamonds are usually embedded with)
kimberlite
Ore minerals, such as galena, tend to be different from typical minerals (such as quartz) in that they have a
large specific gravity
sandy substrate is susceptible to
liquification during an earthquake
earthquakes are a result of
lithosphere plate movement
The formation of magma within Earth is NOT caused by which of the following processes?
loss of volatiles to the atmosphere
The sea surface salinity is ________ at the mouth of the Amazon River and ________ in the Dead Sea.
low; high
The difference between magma and lava is ________.
magma is found beneath the surface, whereas lava is found at the surface
If you were using both a compass and a map marked with latitude and longitude to navigate, you might note the angle difference between your compass and what is marked on the map, called ________.
magnetic declination
Marine magnetic anomalies result from seafloor spreading in conjunction with ________.
magnetic polarity reversals
Where Earth's magnetic dipole intersects with the surface of the planet is called the ________.
magnetic pole
according to the moment magnitude scale (Mw), a magnitude 8 earthquake would be 1,000 times greater than a..
magnitude 5 earthquake
V-shaped stream valleys result from the downcutting of stream erosion and ________.
mass wasting on the valley sides
aftershocks following a major earthquake
may continue for days after the initial earthquake mostly much smaller than the original earthquake may occur on same fault as original earthquake or different fault
which earthquake intensity scale assesses the effects of an eathquake on humans and human made structures
mercalli scale
which earthquake severity scale varies from locality to locality for a single earthquake
mercalli scale
What type of rock forms when preexisting rocks undergo changes in response to a modification of their environment, without first melting?
metamorphic rocks
Bioturbation is the ________.
mixing of sediment by burrowing organisms
In general, if a body of igneous (source) rock is subjected to partial melting, the magma that is produced is expected to be ________.
more felsic than the source rock
Saline ocean water is ________ dense than fresh water and provides ________ buoyancy to objects floating in it
more; more
The sedimentary rocks breccia and conglomerate most commonly form in a ________ environment.
mountain stream
Magma tends to ________.
move upward, away from where it formed
At the equatorial ocean basins, the sea surface temperatures may reach 25°C or greater. What is the range of temperatures for the seafloor, approximately 45 km below?
near freezing (1°C-2°C)
if during an earthquake, a footwall slides upward relative to a hanging wall, the fault is termed
normal
Eratosthenes was the first person to accurately estimate the size of Earth. He accomplished this feat by ________.
observing shadows simultaneously cast at two different cities that were separated by a known distance
movement on a fault
occur without generating earthquakes
Runoff is NOT commonly derived from ________
ocean currents
Which of the following minerals is a silicate?
olivine
Within a meander, where is sediment most likely to be deposited?
on the inner banks of the meander
A wave will disturb the water to a depth equal to ________.
one-half of its wavelength
Two major sources of energy, coal and oil shale, are considered ________ sedimentary rocks.
organic
Geologists refer to an exposure of bedrock on the surface as a(n)
outcrop
Which layer of Earth does NOT contain silicate minerals?
outer core
all else being equal, an earthquake that strikes in eastern USA would produce shaking that would be felt
over a greater distance than one on the western USA
A meander that is cut off to become completely isolated from the main channel but which retains water is a(n) ________.
oxbow lake
Which type of weathering process is happening to materials when they rust?
oxidation
The tetrahedral structure that forms the backbone of all silicate minerals is composed of silicon and what other element?
oxygen
Along a uniform and steep slope of relatively weak substrate, a ________ drainage network is expected.
parallel
With time, a river may erode terrain to produce a low-lying plain that lies close to the base level, which is termed a(n) ________.
peneplain
You have just bought your dream home along a coastline, but you notice that the beach in front of your new house is slowly disappearing. You decide to solve this by building a groin. Winds blow predominantly from east to west, so where do you place your groin?
perpendicular to the shore to the east of your house
Which of the following is NOT a mineral?
petroleum
The inner edge of a meander, where sediment is deposited, is a(n) ________.
point bar
The figure below is an aerial photograph of a meandering stream. The light-colored features labeled with arrows below are ________.
point bars
A facet is a __________ on a gem
polished surface
When a solution becomes oversaturated, new solid particles are said to (Hint: process that leads to the formation of thick layers of salt along the banks of Dead Sea)
precipitate from the solution
Minerals that grow around volcanic vents MOST likely form by
precipitation from a gas
surface waves
produce most of the damage to buildings during earthquakes
The process of low-grade metamorphic rocks being altered to form high-grade metamorphic rocks is termed ________ metamorphism.
prograde
Preexisting rock that is subsequently altered to form a metamorphic rock is termed a ________.
protolith
Bombs, ash, and cinders are all examples of ________.
pyroclastic debris
Waves ________.
refract so as to impact the shore in a nearly parallel manner
what geological settings would you expect to produce seismic activity
rift valley, basin, and collisional mountain belt
A well-sorted sandstone with asymmetric ripples was most likely deposited as sand by a ________.
river (far from source)
A "bird's foot" delta configuration, similar to that of the Mississippi River delta, forms when the ________.
river current exceeds the oceanic current
What type of weathering are you most likely to find occurring on the coast?
salt wedging
Ultimately, the base level of a stream valley can be no lower than ________.
sea level
Consult the figure below. Marine magnetic anomaly belts are widest when and where ________.
seafloor spreading rates are relatively rapid
The majority of the rocks that occur at the surface of Earth are ________.
sedimentary rocks
Which of the following forms either by the cementing together of grains broken off preexisting rocks or by the precipitation of mineral crystals out of water solutions at or near the Earth's surface?
sedimentary rocks
which earthquake severity scale takes into account the type of rock that has been fractured
seismic moment magnitude scale
vertical motion seismographs record earthquakes through the production of a squiggly diagram called
seismogram
geologists who specifically study earthquakes are called
seismologists
Which of the following describes the progression of rock types through increasing metamorphic grade?
shale -> slate -> phyllite -> schist
The mineral olivine is in the __________ mineral class.
silicate
Potassium feldspar (KAlSi3O8) is in which mineral class?
silicates
The mantle is composed almost entirely of the mineral class
silicates
The mineral class that makes up more than 95% of rocks in the continental crust is termed the
silicates
The most common minerals within Earth are ________.
silicates
In the figure provided below, what type of igneous intrusion is the horizontal rock unit shown by letter A?
sill
A mineral property defined by the density of the mineral sample divided by the density of water (1.0 g/cm3) is
specific gravity
All else being equal, water will flow faster in a stream that has a ________, which is typically found near the river's ________.
steep stream gradient; source
The color of a mineral in powdered form is termed
streak
seismic retrofitting is the process of
strengthening existing buildings and structures
periods of intermittent sliding on a fault as a result of the release of stress during episodes of displacement, followed by stress buildup to the point that the fault is reactivated is termed
strick slip behavior
If a fault is nearly vertical in orientation and the two walls of rock on opposite sides slide past one another horizontally, the fault is termed
strike slip
Death Valley is currently sinking partly due to the weight of continuously accumulating sediment shed from the mountains that border the valley. What phenomenon is this an example of and what depositional environment is created by the sediment deposition?
subsidence and alluvial fans
light colored minerals which is felsic like quartz, K-feldspar and Na-rich plagioclase feldspar reside in silica-rich felsic and some intermediate rocks, but are uncommon in mafic rocks, which contain less silica. Biotite--many felsic rocks but it and amphibole are more abundant in intermediate rocks. Mafic minerals--pyroxene and Olivine along with Ca-Rich plagioclase are dominant in mafic and ultramafic rocks.
summarize the main minerals that are present in felsic, intermediate, mafic and ultramafic rocks
As compared with metamorphism, diagenesis ________.
takes place at lower temperatures and pressures
Which river is a threat to capture the flow of the Mississippi River through avulsion and stream piracy?
the Atchafalaya River
Oceanic lithosphere thickens away from the mid-ocean ridge primarily due to ________.
the addition of new lithospheric mantle as a result of cooling
virtually all of the deaths attributed to major earthquakes have resulted from
the collapse of buildings
Stratification refers to ________.
the development of layering within sedimentary rocks
if, during and earthquake, a hanging wall slides upward relative to a footwall, the fault is termed thrust if
the fault is shallow
if, during and earthquake, a hanging wall slides upward relative to a footwall, the fault is termed reverse if
the fault is steep
Barrier islands are constantly moving in the direction of ________.
the longshore drift
Geological evidence suggests that many millions of years ago, the Amazon basin drained toward the west rather than the east. What caused this drainage reversal?
the rise of the Andes Mountains
According to Archimedes' principle of buoyancy, an iceberg sinks until ________.
the total mass of the water displaced equals the total mass of the whole iceberg
Viscosity does NOT depend on ________.
the total volume of the magma body
Compared to oceanic crust, continental crust is
thicker
Compared to oceanic crust, continental crust is ________.
thicker
Compared with the continental lithosphere, the oceanic lithosphere is ________.
thinner
how many seismic stations are necessary to find the epicenter of an earthquake
three
earthquakes that occur in a band called a wadati benioff zone can be used to
track the motion of subducted oceanic lithosphere
Sea level rises locally, and marine sediments are deposited on top of terrestrial sediments during events termed ________.
transgressions
Chemically precipitated limestone that forms in caves or around hot springs is termed ________.
travertine
The atmosphere is divided into several distinct layers. Beginning with the layer in which we live, they are, in order, ________.
troposphere, stratosphere, mesosphere, and thermosphere
The primary stream fed by tributaries within a dendritic drainage network is termed a _________ stream.
trunk
When graded beds are observed in a rock outcrop, this tells geologists that a ________.
turbidity current deposited these beds, depositing coarser material first
The total sediment load of a stream consists of all of following EXCEPT the ________ load.
turbulent
Which of the following lists compositions in order of increasing silica content?
ultramafic, mafic, intermediate, felsic
If a geologist found preserved mud cracks, he or she could conclude that the environment in which they formed ________.
was once covered in wet mud
Very early in Earth's history (during the Hadean Eon), the Earth ________.
was so hot that it was, at times, completely molten
Retrograde metamorphism will not occur unless an increased amount of ________ is added to the system.
water
Potassium feldspar reacts with water to form clay. This is an example of ________.
weathering
Which of these areas of the United States would you expect to have the highest occurance of seismic activity
west
The shape of a delta is primarily determined by ________.
whether river currents, wave-driven currents, or tidal currents are locally predominant