Earth 001 Midterm

Which igneous texture is characterized by two distinctively different crystal sizes?

porphyritic

Pebbles caught in swirling eddies of water best describe ________.

potholes

Which of the following is created when a glacier acts as a dam, blocking the flow of a river or melting glacial water?

proglacial lakes

Which the following are the positively charged particles in an atom's nucleus?

protons

____ exhibits a conchoidal fracture

quartz

You are handed a sample of an unknown silicate mineral. Which two elements must it contain?

silicon and oxygen

The difference between a continent and a microcontinent is ________.

size

Slabs of oceanic lithosphere sink at subduction zones because the subducted slab is denser than the underlying asthenosphere. In this process, called ________, Earth's gravity tugs at the slab, drawing the rest of the plate toward the subduction zone.

slab pull

An igneous rock that cools rapidly is likely to have ________ crystals

small

A rapidly moving ocean wave generated by an earthquake that is capable of inflicting heavy damage in coastal regions is called a(n) ________.

tsunami

To transform an igneous rock into a sedimentary rock, which of the following processes must take place?

weathering, transport, deposition, and lithification

Which of the following is the best example of an active continental margin?

west coast of South America

The average rate of seafloor spreading in modern oceans is ________.

5 centimeters per year

________ was an aquatic reptile that lived in South America and Africa during the Permian period.

Mesosaurus

The ________ today marks the location of the rift along which Africa separated from South America.

Mid-Atlantic Ridge

________ are nearly horizontal, concordant bodies that form when magma exploits weaknesses between sedimentary beds or other structures.

Sills

Which one of the following most accurately describes the volcanoes of the Hawaiian Islands?

Volcanoes are fed by a long-lived hot spot below the Pacific lithospheric plate.

Pyroclastic flows primarily contain pumice, vesicular pyroclastic material, and ________.

a cloud of low-density hot expanding gases

A detrital sedimentary rock with large angular fragments is called a(n) ________.

breccia

Confining pressure results from the ________ of rocks

burial

If you were on a geology field trip in an area of glacial deposition, how would you distinguish between samples of till and stratified drift?

by comparing their grain size and sorting

The skeletal remains of plankton make up the sedimentary rock ________.

chalk

Which of the following minerals comprises just one element?

diamond

Old Faithful, a ________ in Yellowstone National Park, erupts steam and hot water.

geyser

A landscape dominated by U-shaped valleys and pyramid-shaped mountains is most likely formed due to ________.

glaciation

Which of the following rock types represents the highest grade of metamorphism?

gneiss

Which of the following lava compositions has the greatest viscosity?

felsic

Most karst topography forms in ________.

limestone

To be classified as a batholith a plutonic body must have surface exposure greater than ________ square kilometers.

100

The Amazon River has ________ times as much discharge as the Mississippi River. 6

12

The Last Glacial Maximum occurred ________ years ago.

18,000

The age of the oldest sediments recovered from deep-ocean drilling was ________.

180 million years ago

Transform plate boundaries account for approximately ________ of all plate boundaries.

20%

If a mineral has a specific gravity of 3, it must be ________ times as dense as water.

3

About what percentage of Earth's land surface is covered by deserts?

30%

Approximately how much more energy is released in an earthquake of Richter magnitude 6.5 than in a magnitude 5.5 earthquake?

32

An atom's mass number is 13 and its atomic number is 6. How many neutrons are in its nucleus?

7

The Mississippi River Delta system contains a series of ________ coalescing subdeltas

7

The average number of storm-related deaths attributed to flooding from 1985 to 2014 was ________.

83

In the early part of the twentieth century, ________ argued forcefully for the idea of continental drift

Alfred Wegener

The ________ was created when Pangaea broke apart.

Atlantic Ocean

________ form from the coalescence of multiple alluvial fans.

Bajadas

Limestone is dominated by the mineral ________.

Calcite

Limestone is most similar to the mineral ________.

Calcite

________ are formed when groundwater dissolves cavities into limestone.

Caverns

________ are erosional features produced by valley (alpine) glaciers.

Cirques

________ and ________ are the most common forms of lithification.

Compaction; cementation

________ bonding is the sharing of valence atoms between a pair of atoms.

Covalent

________ is a general term that refers to all changes in the shape, position, or orientation of a rock mass.

Deformation

________ is the general term that refers to all changes in the shape, position, or orientation of a rock mass.

Deformation

________ is the process by which liquid water changes into water vapor.

Evaporation

________ is an eruption in which lava is extruded from narrow fractures in the crust.

Fissure eruption

________ is located in tiny pore spaces between grains of soil and sediment, underground.

Groundwater

Which of the following was a main objection to Alfred Wegener's continental drift hypothesis?

He couldn't provide a credible mechanism.

________ tend to increase the explosive potential of a magma body beneath a volcano by the greatest amount.

High viscosity and lots of dissolved gas

The collision of the subcontinent of India and Asia started forming the ________ approximately 50 million years ago.

Himalayan Mountains

Which of the following best defines the relationship between minerals and rocks?

In a mineral, atoms are bonded in a regular, repetitive, internal structure; a rock is a lithified or consolidated aggregate of mineral grains.

An example of a modern convergent boundary would be ________.

India slamming into Asia

Which one of the following statements is true about the crust?

It is the thinnest of the major subdivisions.

________ are fractures along which no appreciable displacement has occurred.

Joints

________ are steep-sided hills composed mostly of stratified drift.

Kames

The Appalachian Mountains were formed when ________ and ________ collided more than 250 million years ago.

North America; Africa

What element is the most abundant in Earth's crust by weight?

Oxygen

Which kind of seismic wave is fastest moving?

P waves

________ glaciers form when one or more ________ glaciers merge and are no longer confined.

Piedmont; valley

________ is a vesicular rock with an andesitic or rhyolitic composition.

Pumice

________ occur in which the hanging wall block moves up relative to the footwall block.

Reverse Faults

________ is the process of sand grains bouncing or rolling along the surface.

Saltation

How is desert different from steppe?

Steppe is more humid than desert.

The eruption at Mount St. Helens is most similar to which volcanic eruption?

Tambora, Indonesia

A mineral's resistance to breaking, bending, or cutting is defined as

Tenacity

________ is another name for pyroclastic materials

Tephra

How does the East African Rift relate to plate tectonics?

The rift lies on a continental rift where two plates are diverging

If accumulation exceeds ablation in a glacial budget, which of the following will happen?

The terminus will move downhill ("advance").

A transform plate boundary is characterized by ________.

a deep, vertical fault along which two plates slide past one another in opposite directions

Imagine that you were given a ship equipped with a device that could measure how deep the water is. You are asked to use this ship to find a subduction zone. What would you look for as you sailed around the world's oceans?

a deep-ocean trench

Sediment scraped off the subducting plate builds up in a(n) ________.

accretionary wedge

A(n) ________ is a cone of debris that forms where an ephemeral stream emerges from the confines of the canyon. Its runoff spreads over the gentler slopes at the base of the mountains and quickly loses velocity, dumping most of its sediment load within a short distance

alluvial fan

Magma that might have cooled slowly to produce a diorite is instead erupted at Earth's surface. It would chill rapidly and produce a(n) ________.

andesite

Ephemeral streams typically flow after heavy rainstorms in ________ climates

arid

The distance between a seismological recording station and the earthquake source is determined from the ________.

arrival times of P and S waves

In an area of alpine glaciation, sinuous, sharp-edged ridges called ________ and sharp, pyramid-like peaks called ________ are common features.

arêtes; horns

The ________ is weaker and less rigid than the overlying lithosphere

asthenosphere

Which of the following terms means "weak sphere"?

asthenosphere

Shield volcanoes like Mauna Loa mostly comprise ________.

basaltic lava flows

When mantle peridotite partially melts beneath an oceanic ridge, ________ magma is produced.

basaltic or mafic

Building a dam on a stream raises its ________, causing it to cease erosion and begin to deposit sediment.

base level

Gravel would most likely exist in the ________ of a river.

bed load

Dredging a stream or river is an example of ________.

channelization

Rock salt and rock gypsum are examples of ________ sedimentary rocks.

chemical

Due to the arrangement of weaker bonds in their crystal lattice, the tendency of certain minerals to break along smooth, parallel planes is known as ________.

cleavage

Biotite has which of the following types of cleavage?

cleavage in one direction

Granite is ________.

coarse-grained and dominated by quartz and feldspar crystals

How do calderas form?

collapse of a partially emptied magma chamber

The most violent volcanic activity is associated with ________.

composite volcanoes

Drawdown of groundwater due to heavy pumping from a well may result in a(n) ________, a "dimple" in the water table.

cone of depression

Which rock type is most likely to have been deposited in a high-energy environment (such as a very turbulent stream)?

conglomerate

An igneous rock that shows a vesicular texture ________.

contains many small holes, like Swiss cheese

Some kind of ________ (upward movement of less dense material and downward movement of more dense material) appears to drive the motion of plates.

convection

Most orogenesis occurs along ________ plate boundaries

convergent

Granite and gabbro have a similar ________.

course-grained texture

A hazard people face when crossing a glacier is falling into a ________, a large crack that extends through the zone of fracture.

crevasse

The terms bladed, fibrous, cubic, and platy describe ________.

crystal habit

Calcium and sodium ions make up much of the ________ of streams.

dissolved load

Continental rifts are associated with ________ plate boundaries

divergent

Decompression melting is responsible for generating magma at ________ plate boundaries.

divergent

The greatest volume of magma is produced at ________.

divergent plate boundaries

A sinuous ridge composed of sand and gravel is a(n) ________; it is a deposit made by streams flowing in tunnels within or beneath glacial ice.

esker

Which of the following minerals is a silicate (a mineral containing a silicon-bearing ion)?

feldspar

Which of the following silicate minerals is the most abundant in Earth's crust?

feldspars

The Columbia Plateau in the northwestern United States is an excellent example of ________.

flood basalts

In contact metamorphism, ________ is the dominant agent of change.

heat

A ________ is a long-lived, stationary, magma source deep in the mantle, well below the base of the lithosphere

hot spot

The area of crust directly above a rising mantle plume is a(n) ________.

hot spot

Chemical weathering would be most effective ________.

in a warm, wet climate

A rainshadow desert forms ________.

in places where mountain ranges act as barriers to the movement of water vapor

Where do crevasses form?

in the zone of fracture

Desert regions that exhibit a discontinuous pattern of ephemeral streams that do not flow out of the desert to the ocean are said to have a(n) ________.

interior drainage

Earth's core is interpreted to consist mainly of ________.

iron and nickel

A crystal of potassium feldspar (KAlSi3O8) will produce a variety of weathering products after it is weathered. Which of the following is not a product that results from the weathering of potassium feldspar?

iron oxides

A glaciers downstream end

is in the zone of wastage

Before sedimentary rock can be formed, sediment must be produced (weathered from preexisting rocks), transported, deposited, and ________.

lithified

An igneous body injected between sedimentary strata that arches the bedrock above while the bottom layers remain relatively flat is called a ________.

laccolith

________ is a type of volcanic mudflow.

lahar

The San Joaquin Valley experienced a phenomenon called ________ due to excessive groundwater pumping

land subsidence

A horizontal conduit that allows lava to flow from a volcanic vent is called a ________.

lava tube

One potential source of groundwater contamination would be ________.

leaking septic tank

Sand is deposited on the ________ side of a dune.

leeward

Dust storms are most likely to deposit windblown silt, commonly called ________.

loess

A cross-sectional view of a stream from its headwaters to its mouth is called a(n) ________.

longitudinal profile

The appearance or quality of light reflected from the surface of a mineral is known as ________.

luster

Which of the following is a nonfoliated metamorphic rock?

marble

The downslope movement of rock or soil due to the influence of gravity is ________.

mass wasting

Which one of the following mineral groups exhibits a sheet-like silicate structure?

micas

________ is the study of minerals.

mineralogy

Most silicate minerals form from ____

molten rock

According to the ________, the Earth and solar system began to form nearly 5 billion years ago from the gravitational collapse of a huge cloud of dust and gases.

nebular theory

Where is the epicenter of an earthquake?

on Earth's surface, directly above the hypocenter

Coal primarily comprises ________.

organic matter

The ________ is a layer in Earth's interior that is in a liquid state.

outer core

Which of the following elements has the most valance electrons in its outermost shell?

oxygen

Which type of basaltic lava flow has a fairly smooth, unfragmented, ropy surface?

pahoehoe

Which of the following was missing from Alfred Wegener's hypothesis?

paleomagnetic data from ocean crust

Most magma is generated in Earth's upper mantle by ________ of solid rock.

partial melting

The east coast of present-day North America is a good example of a(n) ________ continental margin.

passive

Which of the following drainage patterns forms on highly fractured bedrock?

rectangular

If you want to melt a rock, even partially, there are three methods you can employ. Which of the following is not a way that melting is triggered in rocks in the Earth?

removing water

An aggregate of one or more minerals is called a(n) ________.

rock

A detrital sedimentary rock dominated by sand is a ________.

sandstone

Most rock outcrops (about 75% of the total) are ________.

sedimentary

The record of an earthquake obtained from a seismic instrument is a(n) ________.

seismogram

Exfoliation domes are formed from which of the following processes?

sheeting

Where the water table intersects Earth's surface, a(n) ________ results.

spring

A(n) ________ is defined as a semiarid climate.

steppe

Composite volcanoes are also known as ________.

stratovolcanoes

Feldspar minerals can look very similar to each other, what would you look for to differentiate plagioclase feldspar from potassium feldspar?

striations on plagioclase feldspar

A volcanic island arc is the result of ________.

subduction of oceanic crust underneath continental crust

Cooler, older, oceanic lithosphere sinks into the mantle at ________.

subduction zones along convergent plate boundaries

On a typical seismogram, ________ will show the highest amplitudes.

surface waves

Which kind of seismic wave is responsible for the most shaking (and thus, the most damage to human structures)?

surface waves

Cirques often contain small lakes called ________.

tarns

A crustal block bounded by faults whose geologic history is distinct from the histories of adjoining crustal blocks is called a(n) ________.

terrane

The longest topographic feature on Earth's surface is ________.

the oceanic ridge system

Processes that occur at or near Earth's surface and are powered by ________.

the sun

The San Andreas fault in California is a good example of a ________ plate boundary.

transform

The ability of a mineral to transmit both light and an image in the mineral is described as ________.

transparent

Plants consume water during photosynthesis. They also release it to the atmosphere during ________.

transpiration

Which of the following is a chemical sedimentary rock?

travertine

Seismologists use a method called ________ to pinpoint the epicenter of an earthquake by using three or more seismic stations.

triangulation

Which of the following is the least effective agent of erosion?

wind

Most lava flowing from a cinder cone volcano spills from the ________.

unconsolidated base of the cone

Mt. Kilimanjaro and Mt. Kenya are ________ that occur along the East African Rift.

volcanoes

V-shaped valleys would most likely contain ________.

waterfalls

Which of the following properties would be least useful for identifying a sample of calcite?

white color

The Mississippi Delta is an example of which of the following?

zone of deposition