Geo L 102

Formation of large grains in an igneous rock is aided by

very slow cooling inside the Earth

Well-rounded grains in a clastic sedimentary rock indicate

numerous collisions between particles during extensive transportation.

Lahars

Volcanic mudslides that can bury entire towns

Arid regions may be

All of these

The ground shakes during an earthquake because of

seismic waves

If a runner dashes 500 meters, how many feet has he run?

1,640.42

What is true of a clastic sedimentary rock?

Mineral grains can come from many different previously existing rocks.

Oceanic crust is _____ than continental crust.

More dense

Contact metamorphism

Occurs where rocks are subject to elevated temperatures without changes in pressure or stress

What changes take place during chemical weathering?

The mineralogy of previously existing rocks changes.

What does the term metamorphic grade refer to?

The degree to which a metamorphic rock's protolith has changed

Foliation and lineation are terms that describe

The orientation of minerals in metamorphic rocks

Continental crust is _____ then oceanic crust.

Thicker

Shoreline features are

among the most rapidly changing landscapes

Landforms in arid regions are more _________ than in humid regions because ____.

angular; soil creep is less common

Most earthquakes are

concentrated at plate boundaries

What is the equation for density? [density]

density = mass / volume

Groundwater is the part of the hydrosphere in which water

flows through fractures in bedrock seeps into pores in sediment and rocks Correct! all of these may leak into the ground from streams

The intensity of an earthquake is a measure of

how much damage the earthquake caused

The magnitude of an earthquake is a measure of

how much energy was released during the fault that produced the earthquake

Death Valley is a local arid region. Which of the following are true (its fine to use Google here)?

it has alluvial fans there is an area in Death Valley that has an elevation below sea level it is a desert that can get temperatures over 120 degrees Fahrenheit there are salt flats in Death Valley that form when lakes dry up and leave behind salts

The texture of a rock includes the ________ of its constituent grains.

size, shape, and orientation

(a) Along the coast, waves carry sand into deeper, quieter water, where it accumulates and gradually becomes buried. A rock formed from sand grains cemented together is sedimentary . (b) Thick flows of glowing red lava engulf farms and villages on the flanks of Mt. Etna, a volcano in Sicily. The cold, black rock formed when these flows are cool enough to walk on is (c) The broad tundra plains of northern Canada expose gray, massive rock that formed many kilometers below a mountain belt. This rock, exposed only after the overlying rock was stripped away, is

(a) sedimentary (b) igneous (c) metamorphic

(a)Describe sedimentary rocks in 1-2 sentences (b)Describe igneous rocks in 1-2 sentences: (c)Describe metamorphic rocks in 1-2 sentences:

(a)form at or near the Earth's surface from either grain cementation or mineral precipitation (b)form through the cooling and solidification of molten rock (lava or magma) (c)form when already existing rocks are subjected to high temperatures and pressures

Bridget has 2 gallons of milk in her fridge. How many liters does she have?

7.57

You just got back from a trip to Las Vegas, you traveled 575 miles round trip, how many kilometers did you travel?

925.35

Which property of a protolith may charge during metamorphism?

All of the possible answers are correct: Grain size Grain shape Mineralogy

What does the assemblage of minerals in a metamorphic rock help to determine?

All of the possible answers are correct: The chemical composition of a protolith The temperature at which metamorphism took place The pressure at which metamorphism took place

The place where two plates move apart is called a:

Divergent boundary

The mid-ocean ridge occurs along a:

Divergent boundary where sea-floor spreading takes place

The interaction of plates on opposite sides of a transform fault results in

Dynamic metamorphism

Lava Domes

Made of lava, often from in the craters of other volcanoes

Pieces of Earth's crust move on top of the:

Mantle

Are the strata along the hinge of the anticline younger or older than the strata on the exposed part of the limbs, as seen in the map-view surface?

Older

What changes take place during physical weathering?

Rocks are broken into smaller pieces.

(a) Which is younger? The inclined beds in Figure 17.1 or the layer that cut them? [ Select ] ["The layer that cuts the inclined beds is younger", "The inclined beds are younger than the layer that cuts them"] (b) Why can't the principle of superposition be used here? [ Select ] ["It CAN be uesd!", "The beds aren't horizontal"]

The layer that cuts the inclined beds is younger The beds aren't horizontal

The water table separates

a zone where all pores are saturated with water from one in which some are filled with air

In a basin surrounded completely by mountains (like Death Valley), streams

all of these

Which of the following might clastic sedimentary rocks contain?

all of these types of clasts

What can the formation of a sedimentary rock involve?

all possible answers are correct: transportation of fragments of rock weathered from previously existing rocks consolidation of many shells precipitation of minerals when water evaporates

Ash falls

ash 'raining'; down from the atmosphere

Organize the following Earth "spheres" in order from least dense to most dense: cryosphere, lithosphere, hydrosphere, and atmosphere

atmosphere = atmospher Second lease dense = cryosphere Second most dense = hydrosphere Most dense = lithosphere

Streams in arid regions may

flow only during the rainy season erode by the same processes as do streams in humid regions Correct! all of these leak water into the water table during dry seasons

The [ Select ] ["head or source", "channels", "meanders", "mouth"] of a stream is where it begins, and its [ Select ] ["tail", "valley", "bottom", "mouth"] is where it flows into another body of water.

head or sourcee mouth

Properties required for a material to be an aquiferinclude

high porosity and high permeability

Which would make the best aquifer?

loose sand and gravel

In identifying a rock, a geologist (or geology student) must consider its

mineral content and texture.

A fine-grained texture most likely formed when a magma cooled

quickly, close to the Earth's surface.

Angular grains in a clastic sedimentary rock indicate

rapid, typically short-distance transport.

The grain size of an igneous rock is determined by the

rate of cooling, which controls the amount of time crystals have to grow.

Rocks that are forming today

recycle materials from previously existing rock.

Longshore drift is when

sediment is moved along the shoreline obliquely

Most fossils are found in sedimentary rocks because

sedimentary rocks form in the same environment where the plants and animals lived and died.

The difference between sills and dikes is that

sills are parallel to layering in surrounding rocks while dikes cut across the layering.

Sediment particles move in a stream by

sliding rolling Correct! all of these bouncing

Physical weathering in arid regions is

slower than in humid regions because some processes are less effective

A travel-time curve shows graphically

the velocities of the different kinds of seismic waves

The minimum number of seismic stations needed to locate an earthquake is

three

A place where an unusually hot part of the mantle rises through the crust causing volcanic activity is called a:

Hot spot

Cinder Cones

Made of fine-grained pyroclastic material; peaceful eruptions

Subduction is when:

One plate slides under another

The first seismic wave to reach the surface is usually the

P-wave

Collision of two continental plates would cause

Regional metamorphism

The place where two plates collide is called a:

Convergent boundary

Pyroclastic flows

clouds of hot ash, steam, and gas that race down the sides of volcanoes at extremely high speeds and can flatten entire cities

The water table is lowered

during periods of drought

A glassy texture is most characteristic of

igneous rocks.

The farther an earthquake epicenter is from a seismic station

the greater the delay time between arrival of P-and S-waves

Shorelines may be composed of

trees, marsh grass, coral Correct! all of these solid rock sand and gravel

A porphyritic texture indicates that an igneous rock likely had

two different cooling rates.

Properties required for a material to be an aquatardinclude

very low permeability

During transmission of a P-wave, particles in a rock_________ as the energy passes through the rock.

vibrate parallel to the direction in which the wave is traveling

On the 405 freeway one can travel 65 miles per hour (mph), how many kilometers per hour (kph) is the car travelling? [ Select] How many feet per second (ft/sec) is the car travelling? [ Select ]

104.6 kph 95.3 ft/sec

What is an igneous rock?

A rock formed from cooled magma or lava

Which of the following is a possible origin of a metamorphic rock?

A sedimentary rock is buried deeply beneath other sedimentary rocks.

Why is quartz one of the most abundant minerals?

All of the possible answers are correct: It is resistant to weathering. It can form in igneous, sedimentary, and metamorphic rocks. It is made of the two most abundant elements in the Earth's crust.

Where two plates rub past each other in opposite directions is a

Transform boundary

What does VEI stand for? *Make sure you spell correctly - Canvas won't give partial credit*

Volcanic Explosive Index

Are the strata along the hinge of the syncline younger or older than the strata on the exposed part of the limbs, as seen in the map-view surface?

Younger

a. What is the name of the plate on which the United States resides? b. What is the name of the plate on which Los Angeles resides? c. Do these plates consist of continental lithosphere? Oceanic lithosphere? Or both? d. Where does the lithosphere of the Atlantic Ocean form? e. What plate boundary occurs along the west coast of South America? Convergent f. Is the west coast of Africa a plate boundary?

a. North American b. Pacific c. Both d. Mid Atlantic Range e. Convergent f. No

Wind erodes solid rock by

abrasion

Sedimentary rocks are formed in horizontal layers called

beds

Sedimentary rocks are unique in that they form

by processes that operate at or near the Earth's surface.

Streams are able to carry clasts ranging from mud to medium sized boulders depending on their

energy / strength of flow

Explosive blasts

extremely loud sounds indicating the releast of energy - these sound waves can knock down trees

Solidified lava flows and volcanic ash deposits are examples of

extrusive igneous rocks.

Tides are caused by

gravity from the sun and the moon

Stratovolcano

has violent eruptions, made of both lava and pyroclastic material; steepest slopes

Glassy igneous rocks

have no minerals

Karst topography includes which of the following

possible formation of caves possible formation of sinkholes Correct! all of these groundwater erosion of material below the surface

Igneous rock forms by

solidification of magma at the surface or within the Earth.

All of the following properties of a mineral can be observed or measured when the mineral is found in a rock, EXCEPT its

specific gravity

A shoreline that appears to be drowned because the land sinks or sea level rose is called a [ Select ] ["submergent", "emergent"] shoreline. A shoreline that appears to have risen above sea level because the land has been uplifted or sea level has fallen is called a [ Select ] ["submergent", "emergent"] shoreline.

submergent emergent

Sea-level changes along a coastline may be caused by

tectonic subsidence tectonic uplift Correct! all of these melting or growth of polar ice caps

The epicenter of an earthquake is

the point at Earth's surface closest to where the rock broke

The focus of an earthquake is

the point below Earth's surface where energy was released

The texture of a rock is controlled by

the process by which it forms.

The gradient of a stream is

the steepness of its path through the landscape

Wind erosion and deposition is more important in arid regions than in humid regions because

there is no soil moisture to hold sand grains together at the ground surface

Which factors can control shoreline evolution?

tidal range weather, wind, climate tectonic activity material of the shoreline

During transmission of an S-wave, particles in a rock_________ as the energy passes through the rock.

vibrate perpendicular to the direction the wave is traveling

Liquefaction occurs during earthquakes when

vibration causes water to coat sediment grains, greatly lessening friction

Tsunamis are the result of

volcanic eruptions and earthquakes in the ocean

Ripple marks are the result of ________ during deposition.

water or wind currents

Streams deposit sediment when

water slows down

The dominant cause of erosion along lake and ocean shorelines is

waves

A mature clastic sedimentary rock is characterized by what properties?

well-rounded grains, good sorting, and minerals resistant to chemical weathering

Waves are caused by

wind

(a) An intrusive rock that cuts across other rock units (Fig. 17.3 a) must be [ Select ] ["younger", "older"] than the units is cuts across. (b) A fault (Fig. 17.3 b) must be younger than the rock it offsets. (c) The processes that folded the sedimentary rocks in Fig. 17.3 c must be [ Select ] ["younger", "older"] than the rocks. Why can't you use the principle of original horizontality to determine the relative ages of the sedimentary layers in this photograph? [ Select ] ["The rocks are too folded to use the principal of original horizontality", "You CAN use original horizontality here."] (d) Using your knowledge of the cross-cutting nature of contact metamorphism, how could you tell whether the basalt was a lava flow or a sill? If only the bottom contact is baked its a lava flow, but if the bottom and top contacts are baked its a sill

younger Answer 2:Correct!younger Answer 3:Correct!younger Answer 4:Correct!The rocks are too folded to use the principal of original horizontality Answer 5:Correct!If only the bottom contact is baked its a lava flow, but if the bottom and top contacts are baked its a sill

Which is older, the granite pictured in the handout or the xenoliths? Explain. Xenoliths because they must have formed before the host rock (b) Clasts in sedimentary rocks must be [ Select ] ["older", "younger"] than the sedimentary rock in which they are included. Explain. [ Select ]

Answer 1:Xenoliths because they must have formed before the host rock Answer 2:older Answer 3:They must be older because they were formed, eroded, and made into a new sedimentary rock

Dynamic metamorphism

Caused by shear stress as blocks of rocks grind past each other in fault zones

In what way(s) does the formation of a metamorphic rock differ from that of a sedimentary or igneous rock?

Changes from the previously existing rock from which it forms all take place in the solid state.

Intrusion of granite into layers of sedimentary rock would cause

Contact metamorphism

What causes the tectonic plates to move?

Convection in the mantle

What is the difference between an igneous intrusive rock and in igneous extrusive rock?

Intrusive rocks form within the earth while extrusive rocks come out onto the surface

Quartz is not a good index mineral because

It is stable over a very wide range of temperatures and pressures

What textures can be used to describe igneous intrusive rocks?

Relatively larger crystals (phaneritic and aphanitic) because they had a long time to form large crystals

What textures can be used to describe igneous extrusive rocks?

Relatively small crystals (glassy or porous) because they cooled quickly at the earth's surface

The process that continually adds new crust is:

Sea-floor spreading

The ring of fire is a ring of volcanoes and earthquakes that occur along:

Plate boundaries

The fact ice floats on top of water is like the fact that:

The less dense crust sits on top of the mantle

How is the distribution of the Earth's spheres related to their relative densities?

The spheres are more dense towards the center of the Earth

Metamorphic index minerals help geologists determine

The temperature and pressure conditions during metamorphism

The agents that cause metamorphism include all except which of the following?

Time

Shield Volcanoes

Formed by eruptions of high fluid lava, broad and gentle slopes

Which of the following rock / mineral types would make a good tombstone in an arid region but not in a humid region?

marble, because it's really strong but can be dissolvedby rain

Which rock transformation(s) can occur in the rock cycle?

metamorphic rocks into different metamorphic rocks sedimentary rocks into different sedimentary rocks sedimentary rocks into metamorphic rocks igneous rocks into sedimentary rocks sedimentary rocks into igneous rocks metamorphic rocks into igneous rocks igneous rocks into different igneous rocks metamorphic rocks into sedimentary rocks igneous rocks into metamorphic rocks

During transmission of a Raleigh wave, particles in a rock_________ as the energy passes through the rock.

move in a circular path

Chemical weathering in arid regions is

much less effective because there is little water available