GEOL test 2

Flood basalts influence life on Earth because:

All of these

Which of the following occurs in a lava tube?

All of these.

Which of the following is a correct statement about resources in sedimentary rocks?

Groundwater mostly resides in the pore spaces between grains and in fractures.

Which of the following is a good interpretation of the environmental significance of an attribute of a sedimentary rock?

Large cross beds in well-sorted sandstone usually indicate deposition by wind.

What was the most damaging type of eruption that occurred at Vesuvius in Italy?

One or more pyroclastic flows hit the city of Pompeii.

How does the strength of continental crust vary with depth?

Rocks become stronger with depth and then get weaker deep in the crust.

How would the force and stress on the wooden pillar in this figure change if the stone weight was the same size but the wooden pillar was narrower?

The force would remain the same, but the amount of stress would increase.

Which of the following is NOT true about flood basalts?

They are fed from large interconnected composite volcanoes.

Which of the following is least likely to be a volcano?

a hill capped by volcanic rocks

The eruption that occurred on Mount St. Helens was triggered by:

a huge landslide caused a lateral blast that knocked down trees and buildings.

What type of eruption formed this felsic volcanic breccia?

a lava that broke apart while it flowed

What is the interpreted origin for magma that forms flood basalts?

a rising mantle plume

From the answers provided, select the oldest environment represented by this rock sequence.

a river system

What kind of metamorphic rock is formed where rocks have been heated but not deformed?

a rock with metamorphic minerals but no foliation or lineation

Which of the following is a hazard but not a risk, according to the textbook?

a scoria cone that erupts hot molten fragments on an unpopulated Pacific island

Which of the following factors makes a site near a volcano relatively more dangerous?

a site that is within a valley that drains the volcano

Which of the following statements best summarizes the history of the entire sequence?

a transgression followed by a regression

Which of the following is the best indicator that a volcano might be very dangerous?

a volcano that contains andesite and welded tuffs

Which of the following factors indicates a high risk for volcanic mudflows or lahars?

a volcano with a thick covering of snow or ice

Which of the following environments would likely have clasts smaller than sand?

a weak current

This photograph shows chert. How does it form?

accumulation of silica-rich organisms or mixing of seawater and groundwater

Gradational boundaries between different sedimentary rock types can form from:

all of these

Hazards associated with basaltic lava flows and eruptions are:

all of these

If you were designing a rock that would be easily weathered, which of the following characteristics would it have?

all of these

What marks the boundary between the Mesozoic and the Cenozoic (called the K-P boundary)?

all of these

Which of the following are associated with turbidity currents?

all of these

Which of the following is a common metamorphic process?

all of these

Which of the following processes produce sedimentary clasts?

all of these

Which of the following structures can be related to or can occur close to faults?

all of these

Which of the following does NOT match a sedimentary rock with a possible metamorphic equivalent?

all of these are correct matches

What is the main cause of uplift during a continental collision?

an almost doubling of the thickness of continental crust

Which of the following is NOT a way in which sandstones are commonly expressed in the landscape?

as outcrops that show evidence of being dissolved during weathering

What is the typical setting for fold and thrust belts?

associated with convergent plate boundaries

shield volcano eruption

basaltic lava flows

Eruptions of scoria cones are commonly associated with:

basaltic lava flows and lava fountains

Which of the following environments would most likely consist of sand and/or rounded cobbles?

beach at A

what are ways we map and investigate the seafloor?

bouncing sound waves from a ship off the bottom, driving holes in to the seafloor, satellite, seismic surveys

Which environment is least likely to deposit siltstone or shale?

channel of a braided river

in a lagoon, what type of sedimentary material and rock would be found?

clay and sand with remains of marine animals; shale and sandstone

The main cause of caldera collapse is:

collapse of the roof of a magma chamber as magma erupts

The most dangerous type of volcano is a:

composite volcano

This relatively large, symmetrical volcano contains interlayered lava flow, pyroclastic deposits, and volcanic mudflows. What kind of volcano is it?

composite volcano

What type of sedimentary material and rock does a reef produce?

coral, shells, and remains of other marine organisms; limestone

Which environment is most likely to deposit a breccia?

debris flow

Which of the following hazards is probably NOT associated with this volcano?

destruction by fast-moving lava

What type of weathering is best expressed in this weathered limestone?

dissolution

Which of the following is most likely to occur at deep crustal levels?

ductile behavior

This dark gray igneous rock is glassy and elsewhere contains small vesicles and flow bands. What kind of eruption probably formed this rock?

eruption of high-viscosity lava in a dome

A lava flow forms from which type of lava?

eruption of low-viscosity, mafic lava

what can be observed on a seismic-refelction profile?

faults, folds, shape of seafloor, orientation of rocks

What types of rocks would be most common in a composite volcano?

felsic and intermediate lava flows and tephra

Highly viscous magma probably has a _____ composition and would form which type of rock?

felsic or intermediate; rhyolite or andesite

Shield volcanoes commonly involve:

fluid lava flows

When basaltic lava reach the ocean they:

form pillow basalts

Which of the following times indicates a regression?

from unit 5 to unit 6

In what environments does high pressure/low temperature metamorphism occur?

in a subduction zone or accretionary prism

If you were looking for graded beds, where would be a good place to look?

in a submarine fan

What has happened to the Pacific Ocean in the last 200 million years?

it became smaller as the Atlantic Ocean opened

volcanic dome eruption

lava and ash

Scoria cone eruption

lava fountain

Low viscosity magma has a _____ composition and would form which type of rock?

mafic; scoria

limestones equivalent is

marble

Which of the following is characteristic of a transgression?

marine sedimentary facies move toward the land

In what environments does low pressure/high temperature metamorphism occur?

near magma but at shallow levels

The deepest parts of the seafloor are:

oceanic trenches

Which of the following processes is NOT considered physical weathering?

oxidation

How does iron formation form?

precipitation from seawater early in Earth's history

Which of the following is NOT a typical match between the type of eruption and resulting rock type?

pyroclastic flow-scoria

sandstones equivalent is

quartzite

Does the change from the thick gray shale to the overlying sandstone indicate a transgression or a regression?

regression

This dark gray igneous rock is glassy and elsewhere contains small vesicles and flow bands. What type of rock is this?

rhyolite or obsidian

Which of the following is the most used sedimentary resource?

sand and gravel

shales equivalent is

schist and gneiss

Which of the following is NOT a type of carbonate rock?

shale

Which of the following rocks is composed of the smallest sedimentary clasts?

shale

Which of the following places would NOT be a good place to visit a reef?

shallow, clear waters off Iceland

This volcano is broad and low, and is composed of basaltic lava flows. What kind of volcano is it?

shield volcano

Which of the following volcanoes is generally the largest?

shield volcano

a meandering river would have what type of sedimentary material and which type of rock would it form?

silt and sand; siltstone and sandstone

what is the correct order from least metamorphosed to most metamorphosed? gneiss schist slate phyllite

slate phyllite schist gneiss

Which numbered area on this geologic map of North America consists of recently added tectonic terranes?

southern Alaska

What is the plate-tectonic setting of Mount Rainier?

subduction beneath the Pacific Northwest

What part of North America contains the oldest exposed rocks?

the Canadian Shield

What typically happens to the size, shape, and sorting of clasts as they are transported from steep mountains toward more gentle settings?

the clasts become more rounded

Imbricated clasts in this river means that:

the current flowed from right to left

Which of the following interpretations is consistent with the character and sequence of rocks in this figure?

the lower part of the section is consistent with deposition of marine layers over sand dunes

A lava solidifies into nonvesicular basalt instead of vesicular basalt because:

the magma has a low content of gas

Which of the following is a characteristic of fine-grained clastic rocks?

the rocks tend to be easily eroded

Which of the following is NOT a characteristic of a volcanic dome?

they are one of the largest types of volcanoes

composite volcano eruption

viscous, felsic lava