Geology Final

An earthquake occurs with an epicenter in the town of New Madrid, Missouri, in the interior of the North American Plate. Where might the focus (aka hypocenter) of this earthquake plausibly be found?

20 km beneath New Madrid

According to the moment magnitude (Mw) scale, a magnitude eight earthquake releases approximately _____ times more energy than a magnitude seven event.

32

What is a polymorph? Provide an example of two minerals that are polymorphs with each other.

A polymorph is two or more minerals having the same chemical composition but different crystalline structures. Diamond and Graphite.

A dark-colored layer of mixed mineral and organic matter defines the ___________ soil horizon

A soil horizon

What is a triple junction? Provide an example of a triple junction. Would you like to visit this triple junction?

A triple junction is three different plates coming together at a certain point. There is a triple junction in Cape Mendocino, California. Yes I would visit here because then I'm in California and can go to the beach.

Why was asbestos useful to humans? Why is this material (asbestos) no longer utilized in construction?

Asbestos is a general term for a group of silicate minerals that readily separate into thin, strong fibers. As a result of this, these fibers are flexible, heat resistant, and relatively chemically inert, giving them many uses like strengthening concrete, producing fireproof fabrics, and insulating boilers and pipes. This material is no longer utilized in construction because the thin fibers that asbestos is comprised of could get inhaled through particles in the air and since those fibers are so strong, they would stay in your lungs for life causing various types of lung cancer.

An irregular-shaped and blob-like igneous rock body that the result of copious quantities of magma cooling beneath the surface of Earth is a _____

Batholith

Rank the following sediments from largest (#1) to smallest (#6)

Boulder, Cobble, Pebble (gravel), Sand, Silt, Clay

What is the Moho?

Boundary between the crust and mantle

Imagine you are holding a rock composed of small sand and gravel grains cemented together. What subclassification of sedimentary rock is this?

Clastic

___ is one method modern farmers can use to fight soil erosion.

Contour farming, Filter strips, No-till farming, Maintain riparian habitats nears streams and rivers

Identify the three basic layers of the Earth. Start with the outer layer, then middle and finally the center.

Crust Mantle Core

Plants and their roots are the only organisms capable of breaking down solid rock

False

Which type of magma has the greatest silica content?

Felsic

The point within Earth where an earthquake takes place is termed the ___

Focus

Under which of the following conditions does metamorphism occur?

High pressure High Temp High Pressure low temp low pressure high temp low pressure low temp

Which of the following reservoirs holds most of the Earth's freshwater resources?

Ice caps and glaciers

All other factors being equal, if a body of magma becomes more felsic, its viscosity will ___

Increase

Which of the following layers is composed of solid iron, nickel, and sulfur?

Inner Core

The origin of the Serpent Mound structure in south-central Ohio has been disputed for many years. Carlton et al. (1998) reported finding evidence of shock quartz metamorphism from drill cores taken from the middle of the mound. What type of metamorphism took place here?

Instantaneous metamorphism

Using bullet points, compare and contrast intrusive and extrusive igneous rocks (minimum of three comparative points).

Intrusive rocks cool underground while Extrusive rocks cool at the surface Intrusive rocks develop from magma and Extrusive rocks develop from lava Intrusive rocks cool quickly while Extrusive rocks take a long time to cool down Intrusive rocks have small crystal sizes while Extrusive rocks have large crystal sizes

Compaction and cementation of grains occur during __

Lithification

Which of the following terms refer to the fusion of the upper mantle and the crust?

Lithosphere

Waters that are flowing in nature are best defined as:

Lotic

In __________, rock breaks down into solid fragments by physical processes that do not change the rock's chemical composition

Mechanical Weathering

Which earthquake scale is used to assess the effects of an earthquake on humans and human-made structures?

Mercalli

In _______, the mobility of electrons in the outermost shell allows materials with these types of bonds to be malleable and act as good conductors of electricity and heat.

Metallic bonding

Concisely, use bullet points to define the major characteristics of a mineral.

Minerals are naturally occurring Crystalline structure Set Chemical Formula They are solids Inorganic

Which of the following does NOT affect soil thickness?

Number of different animals in the area

Which of the following layers are (likely) responsible for the generation of the Earth's magnetic field?

Outer core

When a loop of a meandering river becomes isolated a(n) __________ forms

Oxbow lake

What element bonds with a silicon atom to form the "silicate" tetrahedron?

Oxygen

Body waves include ________.

P waves and S waves

The work of geologists over the years has supported Wegener's contention that the current continental masses were assembled in a single supercontinent, which Wegener called...

Pangea

Is an active or passive plate margin most likely to contain a continental shelf?

Passive

Generally, which type of earthquake waves travel with the slowest velocity?

R wave and L wave

As igneous rocks cool they record two pieces of information. What are they?

Record of the Earth's magnetic field The geologic age of the rock

____ occurs over an extensive area of the crust and is associated with plate convergence, collision and subduction.

Regional Metamorphism

During an earthquake, if the hanging wall slides upward relative to the footwall, the fault is termed a ________ fault if the fault is steep (closer to vertical than horizontal). Refer to the figure below for an example of such a feature.

Reverse

____ commonly serves as a protolith in the formation of quartzite.

Sandstone

Which type of rock is formed by precipitation of minerals from a solution?

Sedimentary

_____ is the second most abundant element, by weight, in the Earth's crust.

Silicon

Briefly, explain how sources of carbon can be transported to depths of 150 km below the surface for diamond formation. How do the diamonds return to the surface (or closer to the surface)?

Sources of carbon can be transported to the depths of 150 km below the surface for diamond formation due to subduction, carrying organic substances that will eventually form carbon. From there, the diamonds return to the surface with the help of volcanic explosions and magma chambers (or close enough that we can drill into the Earth and find them near the surface).

At a ________________, oceanic crust is consumed back into the asthenosphere

Subduction Zone

How was the Great Blue Hole formed?

The Great Blue Hole was formed as a limestone cave during the last ice age and believed to have been created by a sea level increase, resulting in a giant hole.

Consider the Super Deep Hole in Germany and answer the following: Maximum temperature? Maximum depth? What does the Earth sound like?

The maximum temperature of the Super Deep Hole in Germany was recorded at 265 degrees Celsius. The maximum depth reached 9,100 meters. Supposedly, the Earth sounds like a distant thunderstorm or heartbeat.

What is the name of the mine in Ohio that produces much of the salt we use comes from? What is most of that salt used for? During what geologic period did the salt accumulate? What kind of environment was present in Ohio when this salt deposit formed?

The name of the mine in Ohio that produces much of the salt we use comes from Whiskey Island Salt Mine. Most of that salt is used for deicing roads across the United States. It was during the Silurian Period that the salt accumulated. When this salt deposit formed, Ohio had a tropical environment with plenty of coral reefs.

Contrast oceanic and continental crust. Provide at least four points of contrast between the two.

The oceanic crust is thinner and the continental crust is thicker. The oceanic crust is more dense while the continental crust is less dense. The oceanic crust is made of Basalt and continental crust is made of Granite. Finally, the oceanic crust is younger (around 130 million years old) and the continental crust is older (around 4.0 billion years old).

Why is the oldest oceanic lithosphere less than 200 million years old?

The oceanic crust never achieves old age (geologically speaking) because it is constantly being recycled back into the Earth at convergent boundaries (e.g., subduction zones) and recycled. Continental crust is not subducted and recycled because it is less dense and significantly older than oceanic crust.

On the seismogram of an earthquake recorded at a seismic station in Paris, France, the S-wave arrives 6 minutes after the P-wave. On the seismogram recorded at a station in Mumbai, India, for the same earthquake, the difference between the P-wave and S-wave arrival times is 4 minutes. Which station is closer to the epicenter? From the information provided, can you pinpoint the location of the epicenter and the focus depth? Explain.

The station in Mumbai, India is closer to the epicenter of the earthquake because it took less travel time for the P and S waves. With the information provided, we cannot pinpoint the location of the epicenter and the focus depth because the Triangulation method requires at least 3 points and we were only given 2.

Identify the three major forces of weathering and sediment transport on Earth. Place an "*" next to the force that was very influential in Ada starting about 2,000,000-10,000 years ago.

The three major forces of weathering and sediment transport on Earth are Wind, Water, and *Ice* (in the form of *glaciers*).

What happens to S waves when they hit the boundary between the mantle and the outer core?

They are reflected

How do pressure and temperature change with increasing depth in the Earth?

They both increase

Which of the following minerals is the hardest according to Mohs scale of mineral hardness? Calcite Quartz Fluorite Topaz Talc

Topaz

Depositions of angular and poorly sorted sediments should be close to their weathered parent material.

True

What are two methods (one natural and one artificial) used by humans to mitigate flood hazards?

Two methods used by humans to mitigate flood hazards are (artificial) building dams to stop the flow of water and (natural) using floodplains to absorb most of the water.

What are two natural resources extracted from some of these deep holes?

Two natural resources extracted from some of these deep holes are diamonds and copper.

Magma/Lava viscosity does NOT depend on __

Volume of the magma

The natural breakdown of exposed rock into small fragments and dissolved ions is termed ______

Weathering

When two oceanic plates collide which one is subducted into the mantle? Why?

When two oceanic plates collide, the older oceanic plate will be subducted into the mantle because it is more dense than the younger plate.

Urban development can lead to increased risk of flooding by ____

a. compressing underlying sediment, causing subsidence b. increasing surface runoff and flood intensity c. channeling runoff more quickly to rivers and streams through storm drains. d. destroying riparian wetlands and developing floodplains which naturally absorb much of the flood water

Which of the following is the most common type of watershed or drainage network?

dendritic

Meandering streams ____

have a channel that is highly sinuous (curvy)

not done yet

i know

still not done

ik

A piece of concrete from a driveway is NOT considered a sedimentary rock because it ___

is not naturally occurring

The difference between magma and lava is that _____

magma is found beneath the surface, whereas lava is found at the surface

Gold is an example of (a(n)) ______________, quartz is a ______________, and galena is a _____________

native element; silicate mineral; sulfide mineral

Flow through a meander in a stream results in erosion on one bank and deposition of a(n) __________ on the other bank.

point bar

An igneous rock with a mixed texture of coarse crystals (phenocrysts) surrounded by fine crystals (groundmass) is termed ____

porphyritic

Sediment transport by intermittent bouncing and skipping along a stream bed is:

saltation

Foliate metamorphic rock derived from shales, in order of increasing metamorphic grade, are _____

slate, phyllite, and schist or gneiss

Death Valley in California is one of the flattest, hottest and driest spots in the world. Summer air temperatures commonly reach 50 C and the rainfall averages less than 5-cm per year. In this xeric environment, what type of weathering would you expect to find?

very slight weathering, mostly by wind

Important gaseous volatiles in magmas include...

water vapor and carbon dioxide