GEOL 102 final

three

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

emergent

A shoreline that appears to have risen above sea level because the land has been uplifted or sea level has fallen is called a

the velocities of the different kinds of seismic waves

A travel-time curve shows graphically

specific gravity

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

Non-conformity

An erosional surface separating igneous rocks from sedimentary rocks.

Luster: non-metallic Hardness: 2.5-3 Streak: brown or green Color: brown, black, or green Cleavage / fracture type: perfect in one direction Other identifying properties: can be peeled into sheets Mineral chemical formula: K(Mg,Fe)3AISi3O10(OH)2

Biotite

7.57

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

have no minerals.

Glassy igneous rocks

Principle of Inclusions

Inclusions within a rock must have existed before the rock they are in formed, so they must be older.

Luster: non-metallic Hardness: 6.5-7 Streak: colorless to light green Color: green Cleavage / fracture type: conchoidal Other identifying properties: stubby crystals Mineral chemical formula: Fe2SiO4/Mg2SiO4

Olivine

very low permeability

Properties required for a material to be an aquatard include

high porosity and high permeability

Properties required for a material to be an aquifer include

Luster: metallic Hardness: 6-6.5 Streak: black Color: brassy yellow Cleavage / fracture type: conchoidal Other identifying properties: commonly 12 sided or cubes Mineral chemical formula: FeS2

Pyrite

waves

The dominant cause of erosion along lake and ocean shorelines is

sea-floor spreading

The process that continually adds new crust is

plate boundaries

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

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

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

Grain size Grain shape Mineralogy

Which property of a protolith may charge during metamorphism?

Sorting: poorly Grain Size: pebble Angularity: sub rounded Transport history: turbulent river or ocean waves

conglomerate

Describe metamorphic rocks in 1-2 sentences

form when already existing rocks are subjected to high temperatures and pressures

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

igneous

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

metamorphic

Sorting: well Grain Size: silt to medium sand Angularity: subrounded to angular Transport history: turbulent river or ocean waves

quartzite graywacke

Sorting: moderately Grain Size: coarse sand Angularity: angular Transport history: turbulent river or ocean waves

sandstone

igneous rocks

A glassy texture is most characteristic of

two different cooling rates.

A porphyritic texture indicates that an igneous rock likely had

Disconformity

A separation between parallel beds where some of the older rocks were removed by erosion before the younger ones were desposited.

submergent

A shoreline that appears to be drowned because the land sinks or sea level rose is called a

younger

An intrusive rock that cuts across other rock units must be _____ than the units it cuts across.

rapid, typically short-distance transport.

Angular grains in a clastic sedimentary rock indicate

found at the north and south polar regions characterized by large amounts of sand characterized by mostly rocks landscapes

Arid regions may be

Conformable (no unconformity)

Beds that conform to, or have the same shape and orientation as the others near them.

Luster: non-metallic Hardness: 3 Streak: white or colorless Color: usually white or colorless Cleavage / fracture type: 3 directions not equal to 90 degrees Other identifying properties: reacts with HCI Mineral chemical formula: CaCO3

Calcite

Luster: metallic Hardness: 3.5-4 Streak: black Color: brassy yellow Cleavage / fracture type: rarely seen Other identifying properties: tarnished look Mineral chemical formula: CuFeS2

Chalcopyrite

older They must be older because they were formed, eroded, and made into a new sedimentary rock

Clasts in sedimentary rocks must be _____ than the sedimentary rock in which they are included.

despression

Concentric hachured contour lines indicate a _____

thicker

Continental crust is _____ then oceanic crust.

downstream

Contour lines form a V when they cross a stream. The open part of the V faces the _____ direction

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 it has alluvial fans there is an area in Death Valley that has an elevation below sea level

Death Valley is a local arid region. Which of the following are true?

form through the cooling and solidification of molten rock (lava or magma)

Describe igneous rocks in 1-2 sentences

form at or near the Earth's surface from either grain cementation or mineral precipitation

Describe sedimentary rocks in 1-2 sentences

Both

Do these plates consist of continental lithosphere? Oceanic lithosphere? Or both?

vibrate parallel to the direction in which the wave is traveling

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

The orientation of minerals in metamorphic rocks

Foliation and lineation are terms that describe

very slow cooling inside the Earth.

Formation of large grains in an igneous rock is aided by

Luster: metallic Hardness: 5.5-6.5 Streak: reddish brown Color: black to red Cleavage / fracture type: rarely seen Other identifying properties: metallic or earthy luster Mineral chemical formula: Fe203

Hematite

Contour lines that are closer together are steeper, while contours that are further apart are flatter.

How does the spacing of the contour lines show the difference between gentle and steep slopes?

1,640.4

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

Principle of Cross-Cutting Relationships

If one rock cuts another, it must be younger than the rock it cuts.

solidification of magma at the surface or within the Earth.

Igneous rock forms by

possible formation of sinkholes groundwater erosion of material below the surface possible formation of caves

Karst topography includes which of the following

angular soil creep is less common

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

vibration causes water to coat sediment grains, greatly lessening friction

Liquefaction occurs during earthquakes when

Luster: metallic Hardness: 6 Streak: black Color: iron black Cleavage / fracture type: rarely seen Other identifying properties: magnetic Mineral chemical formula: Fe304

Magnetite

The temperature and pressure conditions during metamorphism

Metamorphic index minerals help geologists determine

concentrated at plate boundaries

Most earthquakes are

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

Most fossils are found in sedimentary rocks because

Luster: non-metallic Hardness: 2-2.5 Streak: white or colorless Color: colorless, tan, brown Cleavage / fracture type: perfect in 1 direction Other identifying properties: can be peeled into sheets Mineral chemical formula: KAI2(AISi3O10)(OH)^2

Muscovite

0.132

My dog drank 500 mL of water this morning, how many gallons of water did it drink?

more dense

Oceanic crust is _____ than continental crust.

Principle of Superposition

Older sedimentary rocks will be at the bottom of a sequence, while the youngest ones will be at the top.

slower than in humid regions because some processes are less effective

Physical weathering in arid regions is

Mantle

Pieces of Earth's crust move on top of the

water or wind currents

Ripple marks are the result of ________ during deposition.

recycle materials from previously existing rock.

Rocks that are forming today

Angular unconformity

Rocks that have been tilted and now contact different beds above with a different amount of tilt.

tectonic subsidence tectonic uplift melting or growth of polar ice caps

Sea-level changes along a coastline may be caused by

sliding rolling bouncing

Sediment particles move in a stream by

Principle of Original Horizontality

Sedimentary rocks are almost always deposited in flat beds.

beds.

Sedimentary rocks are formed in horizontal layers called

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

Sedimentary rocks are unique in that they form

Luster: non-metallic Hardness: 1 Streak: white or colorless Color: green, grey, white Cleavage / fracture type: perfect in one direction Other identifying properties: greasy feel Mineral chemical formula: Mg3Si4O10(OH)2

Talc

head or source mouth

The _____ of a stream is where it begins, and its _____ is where it flows into another body of water.

time

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

seismic waves

The ground shakes during an earthquake because of

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

The magnitude of an earthquake is a measure of

divergent boundary where sea-floor spreading takes place

The mid-ocean ridge occurs along a

the process by which it forms.

The texture of a rock is controlled by

during periods of drought

The water table is lowered

volcanic eruptions and earthquakes in the ocean

Tsunamis are the result of

a contour represents a unique elevation and you can't have two elevations at the same point

Two different contour lines cannot cross because

0.8

Using the equation from the answer above, what is the density of a block of wood that has a mass of 16 grams and a volume of 20 cm3?

If only the bottom contact is baked its a lava flow, but if the bottom and top contacts are baked its a sill

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?

4 cm^2

What is the area of the square with 2 cm sides?

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

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

density = mass / volume

What is the equation for density?

length x width x height

What is the equation for volume?

Pacific

What is the name of the plate on which Los Angeles resides?

North American

What is the name of the plate on which the United States resides?

2.5

What is the sinuosity of a stream that has a straight-line length (from head to mouth) of 4 miles and a stream channel length of 10 miles?

8 cm^3

What is the volume of the cube with 2 cm sides?

Mineral grains can come from many different previously existing rocks.

What is true of a clastic sedimentary rock?

Convergent

What plate boundary occurs along the west coast of South America?

transform boundary

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

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

Which factors can control shoreline evolution?

loose sand and gravel

Which would make the best aquifer?

abrasion

Wind erodes solid rock by

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

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

925.4

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

younger younger

A fault must be _____ than the rock it offsets. The processes that folded the sedimentary rocks must be _____ than the rocks.

quickly, close to the Earth's surface.

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

2.7

A lava flow in Hawaii traveled at a speed of 6 mph, how fast was the lava flowing in meters per second (m/sec)?

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

A mature clastic sedimentary rock is characterized by what properties?

hot spot

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

much less effective because there is little water available

Chemical weathering in arid regions is

Regional metamorphism

Collision of two continental plates would cause

mountain / hill

Concentric contour lines indicate a _____

move in a circular path

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

vibrate perpendicular to the direction the wave is traveling

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

Luster: metallic Hardness: 2.5 Streak: gray Color: lead gray Cleavage / fracture type: 3 directions at 90 degrees Other identifying properties: commonly in cubic crystals Mineral chemical formula: PbS

Galena

Luster: non-metallic Hardness: 7 Streak: white / colorless Color: many colors Cleavage / fracture type: conchoidal Other identifying properties: 12 sided crystals Mineral chemical formula: complex

Garnet

seeps into pores in sediment and rocks flows through fractures in bedrock may leak into the ground from streams

Groundwater is the part of the hydrosphere in which water

Luster: non-metallic Hardness: 2 Streak: white or colorless Color: colorless, white, grey Cleavage / fracture type: perfect in one direction Other identifying properties: clear crystals Mineral chemical formula: CaSo4-2H20

Gypsum

Luster: non-metallic Hardness: 2.5 Streak: white or colorless Color: usually colorless, white Cleavage / fracture type: 3 directions at 90 degrees Other identifying properties: salty taste Mineral chemical formula: NaCl

Halite

Luster: non-metallic Hardness: 5-6 Streak: colorless to light green Color: dark green to black Cleavage / fracture type: 56 degrees and 124 degrees Other identifying properties: elongate crystals

Hornblende / amphibole

evaporate to produce salt flats in the basin deposit alluvial fans, partially filling the basin with sediment form playa lakes

In a basin surrounded completely by mountains, streams

mineral content and texture

In identifying a rock, a geologist must consider its

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

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

Contact metamorphism

Intrusion of granite into layers of sedimentary rock would cause

No

Is the west coast of Africa a plate boundary?

Principal of Lateral Continuity

Layers of sedimentary rocks are continuous until they encounter other solid bodies or processes.

sediment is moved along the shorelines obliquely

Longshore drift is when

104.6 kph 95.3 ft/sec

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

atmosphere cryosphere hydrosphere lithosphere

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

Luster: non-metallic Hardness: 6 Streak: white or colorless Color: colorless, salmon, gray, white, green Cleavage / fracture type: 2 directions at 90 degrees Other identifying properties: stubby prismatic crystals Mineral chemical formula: KAISi308

Orthoclase / potassium feldspar

Luster: non-metallic Hardness: 6 Streak: white or colorless Color: colorless, white, grey, black Cleavage / fracture type: 2 directions at 90 degrees Other identifying properties: striations on one of the cleavage planes Mineral chemical formula: CaI2Si208/NaAI2Si308

Plagioclase feldspar

Luster: non-metallic Hardness: 5-6 Streak: colorless to light green Color: dark green to black Cleavage / fracture type: 87 degrees and 93 degrees Other identifying properties: elongate crystals

Pyroxene / Augite

Luster: non-metallic Hardness: 7 Streak: white / colorless Color: many Cleavage / fracture type: conchoidal Other identifying properties: elongate 6 sided crystals Mineral chemical formula: SiO2

Quartz

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

Quartz is not a good index mineral because

among the most rapidly changing landscapes

Shorelines features are

sand and gravel trees, marsh grass, coral solid rock

Shorelines may be composed of

extrusive igneous rocks.

Solidified lava flows and volcanic ash deposits are examples of

energy / strength of flow

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

water slows down

Streams deposit sediment when

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

Streams in arid regions may

one plate slides under another

Subduction is when

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

The difference between sills and dikes is that

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

The epicenter of an earthquake is

the less dense crust sits on top of the mantle

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

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

The farther an earthquake epicenter is from a seismic station

P-wave

The first seismic wave to reach the surface is usually the

the point below Earth's surface where energy was released

The focus of an earthquake is

the steepness of its path through the landscape

The gradient of a stream is

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

The grain size of an igneous rock is determined by the

how much damage the earthquake caused

The intensity of an earthquake is a measure of

Dynamic metamorphism

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

convergent boundary

The place where two plates collide is called a

divergent boundary

The place where two plates move apart is called a

steepness steep surfaces flatter surfaces

The spacing between contour lines on a map reveals the _____ of the ground surface. Closely spaced contour lines indicate _____ and widely spaced contour lines indicate _____

size, shape, and orientation

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

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

The water table separates

gravity from the sun and the moon

Tides are caused by

wind

Waves are caused by

numerous collisions between particles during extensive transportation.

Well-rounded grains in a clastic sedimentary rock indicate

naturally occuring homogeneous formed by geologic processes soild ordered internal arrangement of atoms definable chemical composition

What are the six criteria that define a mineral?

transportation of fragments of rock weathered from previously existing rocks consolidation of many shells precipitation of minerals when water evaporates

What can the formation of a sedimentary rock involve?

Convection in the mantle

What causes the tectonic plates to move?

The mineralogy of previously existing rocks changes.

What changes take place during chemical weathering?

Rocks are broken into smaller pieces.

What changes take place during physical weathering?

The chemical composition of a protolith The temperature at which metamorphism took place The pressure at which metamorphism took place

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

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

What does the term metamorphic grade refer to?

A rock formed from cooled magma or lava

What is an igneous rock?

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

What textures can be used to describe igneous extrusive 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 intrusive rocks?

Mid Atlantic Ridge

Where does the lithosphere of the Atlantic Ocean form?

Xenoliths because they must have formed before the host rock

Which is older, the granite or the xenoliths?

Their minerals form by precipitation of ions from water. Their minerals form from ions dissolved from previously existing minerals during chemical weathering. Their minerals form with a crystalline texture.

Which of the following describes the formation of chemical sedimentary rocks?

A sedimentary rock is buried deeply beneath other sedimentary rocks.

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

fragments of volcanic glass rock fragments made up of several minerals individual mineral grains separated from previously existing rocks during weathering

Which of the following might clastic sedimentary rocks contain?

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

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

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

Why is quartz one of the most abundant minerals?

Sorting: poorly Grain Size: sand to pebble Angularity: angular Transport history: turbulent river or ocean waves

breccia

Sorting: well Grain Size: fine sand Angularity: hard to see Transport history: quiet lake or slow stream

sandstone

Sorting: well Grain Size: clay or silt Angularity: hard to see Transport history: quiet lake or slow stream

shale