EAPS 100 Homework Questions

In the above diagram of a river system where are most sedimentary clasts/grains produced?

1

_______ is a rock formed from solidification of magma that forms during partial melting of the Earth's mantle? Please fill in the blank with the best answer choice.

Basalt

The above photograph shows a vertical magmatic dike cutting across horizontal sedimentary layers. Which of the labeled rocks is the youngest based on the principle's of superposition and cross cutting relationships?

D

Which of the following areas is most at risk for the development of a debris flow?

D

The Earth's mantle is composed of a rock called peridotite. It can begin melting through which of the following processes?

Decreasing pressure, while keeping temperature constant

The organisms that produce shells made out of calcium carbonate are utilizing what component of seawater?

Dissolved ions

The Alaska volcano observatory is one of the largest observatories in the United States, despite the fact that Alaska does not have any major cities adjacent to a major volcano. Why is so much effort put into monitoring Alaskan volcanoes?

Explosive eruptions can disrupt international air travel and Alaska lies along a common flight path between North America and Asia

What is the reason why faults tend to move intermittently (stick-slip behavior) instead of continuously?

Friction

Which process typically leads to the concentration of elements like gold, silver, and copper into economically viable deposits?

Hydrothermal activity around crystallizing magma

What are the three main types of rock?

Igneous, metamorphic, sedimentary

What magma property listed below would not lead to explosive volcanic eruptions?

Low viscosity (flows with relative ease)

Which location would be the safest place to build a house on the Big Island of Hawaii. Remember, this island has several active volcanoes that produce basaltic lava flows?

On a ridge on a non-volcanically active part of the island

A cooling magma begins to grow crystals. We can say that this magma is ________ the crystallizing mineral. Please fill in the blank with the best answer choice below.

Saturated with respect to

What is the most common class of mineral within the Earth's crust? Hint: Remember the most common elements in the Earth's crust.

Silicate Minerals

Sandstone is a sedimentary rock largely composed of sand-sized sedimentary clasts/grains. Which of the following environments is not a place where you would expect sand to be deposited and eventually form sandstone?

The deep ocean far from any land

Researchers have documented that magnetic minerals within the seafloor form zones that sometimes point toward the modern north pole and sometimes point toward the modern south pole. These zones form linear belts parallel to mid-ocean ridges. Which of the following is an observation regarding these zones that supports the idea of seafloor spreading?

The zones are symmetrical about the mid-ocean ridge

The smallest repeatable unit in a crystalline sold is known as the _________? Please fill in the blank with the best answer choice.

Unit cell

If you see a sequence of sedimentary rocks that changes from bottom to top: 1) conglomerate, 2) sandstone, and 3) limestone containing marine fossils, what is a plausible sequence of ancient depositional environments for that area?

1) River bed, 2) Beach, 3) Reef

The above image shows all of the different tectonic plates (the boundaries are shown by dark blue and brown lines). Which location is least likely to experience a major earthquake? Note: I'm not asking whether a location has 0% chance of an earthquake, only the location that is least likely to have an earthquake.

A

You walk up to this outcrop of sedimentary rocks. You know from previous observations that they have not been rotated or overturned. Using the principle of superposition, which of the labeled layers is the oldest?

A

Continental collisions lead to the development of what type of topographic feature at the surface of the Earth?

A major mountain range

Ionic bonding occurs when ______? Please fill in the blank with the best answer choice.

Atoms lose or gain valence electrons to make positively or negatively charged ions that can then bond

Plate tectonics modulates Earth's climate through all of the following processes except which one?

Burning fossil fuels

One by-product of burning fossil fuels for energy is the release of ________. Please fill in the blank with the best answer choice.

CO2 (carbon dioxide)

The process through which loose sediment becomes a rock is known as lithification. _______ is the process that occurs when fluids precipitate new minerals in the pore spaces between sedimentary clasts/grains and leads to lithification.

Cementation

You observe the volcanic eruption above. Based on the shape of the mountain and the eruptive style, what tectonic setting are you in?

Close to a subduction zone

Coal is a sedimentary rock composed of organic matter and frequently contains plant fossils. Which of the following statements can we infer to be true about the depositional environment in which coal formed?

Coal was originally deposited in a biologically productive terrestrial ecosystem.

In what tectonic setting might you find many reverse faults?

Convergent boundary

Which of the following is not a line of evidence used to support the idea of seafloor spreading?

Earthquakes that occur far from mid-ocean ridges

What process causes the Hawaiian islands to go from high volcanic mountains to very low-lying, small islands over long periods of time?

Erosion

Alfred Wegener's proposal for continental drift was rejected during his own lifetime (b. 1880, d. 1930) for which of the following reasons?

He did not have a explanation for how the continents had moved

Chemical weathering is a major process during which rock is broken down through chemical reactions and dissolved ions are incorporated into natural waters. Which of the following parameters will lead to increased chemical weathering if all other variables are kept the same?

Increasing surface area

Heating a magma will ________ crystallization and solidification into a rock. Please fill in the blank with the best answer choice.

Inhibit

The above limestone contains fossil shells from marine organisms. What is not a reasonable inference about the environment in which this sedimentary rock was originally deposited?

It was originally deposited high in the mountains.

What is the name for a mud flow that is composed of volcanic debris?

Lahar

What process leads to partial melting of the Earth's mantle and the production of large volumes of basaltic magma at mid-ocean ridges?

Melting triggered by decompression as the Earth's mantle flows upward

Do volcanoes that dominantly erupt basaltic magma tend to pose an acute threat to human life?

No, people can typically get out of the way of lava flows. However, infrastructure might be damaged.

Mid ocean ridges are underwater mountain ranges, where new oceanic crust is produced. If you were to dredge pieces of rock from a modern mid-ocean ridge, which of the rocks below would be most likely?

Pillow basalt

Oil is composed of organic matter that has been buried in a sedimentary sequence and has experienced elevated temperatures during lithification. Which organism produced the organic matter that goes on to make oil?

Plankton

Coal is composed of fossil organic matter and is used as fuel for many of the power plants in the USA. From which organisms did this organic matter originate?

Plants

Which of the following processes is not an example of mechanical weathering?

Rainwater infiltrating a crack and dissolving rock

Minerals do not have _________?

Randomly arranged atoms

All of the following, except which answer choice, might indicate that magma is moving beneath a volcano?

Several consecutive sunny days

What are the two most common elements in Earth's crust?

Silicon (Si) and Oxygen (O)

Which type of seismic wave is most damaging to human infrastructure?

Surface waves

Hotspot volcanism typically makes linear chains of volcanoes that get progressively younger in one direction. What would best describe the orientation of these features?

The chain of volcanoes lies parallel to the direction of motion for the tectonic plate on which they are built

Locations where tectonic plates slide past one another along a vertical plane are known as what type of plate boundary?

Transform Boundary

You work at the a volcano observatory. Over the past several days you have monitored GPS data indicating that the volcano is inflating. Over the same period of time you have monitored numerous small earthquakes. Another scientist at the observatory reports that the gases emitted from several hot springs have changed to different chemical compositions. Do you recommend that the government evacuate the towns that are adjacent to the volcano?

Yes, the risk of eruption is elevated

In the above photograph is the fault older or younger than the sedimentary rocks?

Younger

Geologists think that hotspots form over what type of feature?

a 'plume' of hot material that has risen from deep within the Earth, potentially from the boundary between the Earth's mantle and core

The above photograph shows a mountain composed of sedimentary rock. The principle of lateral continuity allows you to assume that a single layer represents ________ as you trace it across the photograph.

approximately the same period of time

Lava flows, pyroclastic flows, and lahars are all different types of volcanic hazards. All of these hazards will ________ to minimize their gravitational potential energy. Please fill in the blank with the best answer choice.

flow downhill

In order to sequester organic carbon in sediments at the bottom of the ocean, production of organic carbon through _________ must be greater than consumption of organic carbon through ________. Please fill in the blanks with the best answer choice.

photosynthesis; respiration

Which of the following locations on the surface of the Earth has the lowest gravitational potential energy? Hint: Where is most sediment ultimately deposited?

the bottom of the ocean

Use the labels on the above cross section of a delta and associated sedimentary deposits to answer the following question. Where would you most likely find sedimentary deposits composed of the smallest clasts/sedimentary grains?

4

How would you characterize this volcano based on its shape and eruptive style?

A composite volcano

Clastic rocks are distinguished from crystalline rocks in that they are composed or weathered bits of rock (clasts) that have been transported as sediment and deposited in a location that is different from where their constituent rocks formed. What is one feature of clastic rocks that you could use to distinguish them?

Clastic rocks are typically composed of rounded clasts

The above fault separates several sedimentary layers. Using the information from the video segments, how would you classify this fault? Hint: Identify the orientation of the fault, the footwall and hanging wall, and the sense of separation of sedimentary layers across the fault.

Normal fault

The San Andreas fault marks a transform boundary between the North American and Pacific tectonic plates. Los Angeles lies to the west of this fault and is part of the Pacific plate. Based on the lecture materials, where will Los Angeles be transported over the next ~50 million years?

Northwest towards Alaska

Which of the following best describes the force that drives plate tectonics?

Plates are pulled by oceanic crust that is metamorphosed into very dense rock during subduction

Diamonds are made from carbon with an isotopic signature that is consistent with an origin as ancient life-forms. What process could have brought organic carbon deep into Earth's interior to provide the carbon needed to create diamonds?

Subduction

Alfred Wegener proposed that the continents had once been joined into a super continent and then drifted apart. Which of the following was a line of evidence that he used to make this proposal?

The coastlines of continents look like they fit together in the past, Fossils of certain species seem to form continuous habitat zones if continents were once joined, Locations where there is evidence for tropical or glacial environments could be restored to low and high latitudes, respectively, if the continents were once joined together and had drifted apart

A river requires _______ to transport large pieces of rock (i.e., sedimentary clasts) when compared to smaller clasts. Please fill in the blank with the best answer choice.

faster flowing water

The thickness of sedimentary rocks on the seafloor _________ with distance from mid-ocean ridges. This observation indicates that the seafloor gets progressively older with distance from the mid-ocean ridge and is one of the lines of evidence for seafloor spreading. Please fill in the blank with the most appropriate answer choice.

increases

Seafloor spreading at mid-ocean ridges is a mechanism that produces new oceanic crust. This process also allows adjacent tectonic plates to __________. Please select the best answer choice to fill in the blank.

move apart

Which of the following is not a mineral?

A cubic zirconia (ZrO2) crystal grown in a laboratory

Which of the following is least likely to trigger a mass wasting event from a steep slope?

A drought

Samples of the Earth's mantle are brought to the Earth's surface through rare volcanic eruptions. One example of this process are kimberlite eruptions, which erupt from deep in the Earth's interior and can breach the surface with extremely high eruption velocities. We have studied these type of volcanic eruptions in detail because they also transport the mineral _________, which only forms at extremely high pressures, to the Earth's surface. Please fill in the blank with the best answer choice.

Diamond

The unit cell leads to all of the following mineral properties except which one?

Mineral size

You observe the sequence of sedimentary rocks in the above photograph. Using the principle of original horizontality, what can you infer about the history of this location?

The sedimentary rocks have been rotated from their original orientation.