EES 112 FINAL

Earthquakes occur at which of the following plate boundaries?

(all of the above) divergent(spreading center) , transform and convergent

Soft parts of organisms may be preserved (fossilized) by:

(all of the above) freezing , desiccation and being embedded in amber

Which of the following can be caused (i.e. triggered) by an earthquake?

(all of the above) intense ground shaking, tsunami and landslide

Major sedimentary depositional environments include:

(all of the above) streams , deserts , lakes and oceans

Which of the following has been used to try and predict earthquakes that may occur in the near future?

(all of the above): foreshocks, changes in water well levels , group uplift and tilting and animal behavior

A rock is radiometrically dated to determine its age. The laboratory doing the dating discovers that the rock currently has 200 atoms of radioactive parent isotope and 600 atoms of stable daughter product. Assuming that the rock had 800 atoms of radioactive parent isotope and 0 atoms of daughter product at the time it formed, how old is the rock, if the half-life of the radioactive isotope is 1,000,000 years?

2,000,000 years

What is the minimum number of seismographs needed to locate an earthquake?

3

Based on radiometric age dating, what is the age of the Earth?

4.6 billion years.

Which of the following cannot be dated with Potassium/Argon (K/Ar) dating?

Clam shell.

Which of the following types of sediment is most likely to be found in the deep ocean?

Clay

Which of the following cannot be dated with Radiocarbon (C-14) dating?

Granite

Hot spots may be used to track tectonic plate movement over geologic time. Which of the following is an example of hot spot activity discussed in the lecture and the textbook?

Hawaiian islands chain.

When water saturated sediment suddenly loses its strength because of ground shaking during an earthquake, considerable damage may result to structures built on such sediment as the buildings settle into the earth. This phenomenon is known as:

Liquefaction

Andesite (a rock intermediate in composition between basalt and rhyolite) commonly forms in the following geological environment.

NOT andesite may form in all of the location cite above

Graded bedding, cross-bedding, ripples, and mudcracks are sedimentary structures that

NOT are composed primarily of quartz rich sandstones

In which of the following environments would you expect to find ripples?

Not beach sands , maybe dune sands?

Which of the following is the fastest type of seismic wave and can travel through solids, liquids, and gases?

Primary (or P) waves.

An example of a divergent plate boundary on continental lithosphere would be

Red Sea

Perhaps the world's most famous example of a transform plate boundary, located in California, is the:

San Andreas fault.

Which of the following is most accurate concerning fault creep?

Seismologists are generally relieved to see evidence of considerable fault creep because it indicates that the fault segment is not locked and is less likely to be building up the amount of strain energy necessary for a large magnitude earthquake.

Transform plate boundaries are formed from the following type of fault.

Strike-slip fault.

When an oceanic plate collides with another oceanic plate, which of the following will occur?

Subduction of one of the plates.

In developing the Theory of Continental Drift, which of the following lines of evidence was not available to Alfred Wegener?

Symmetrical magnetic "striping" of the sea floor rocks indicating that the continents are spreading apart.

You find a sandstone that is composed of sand grains that are very angular in shape. Which of the following is the most accurate statement about the depositional environment of the rock?

The sand composing the sandstone was transported a short distance prior to deposition.

A fracture in the Earth's crust along which displacement occurs is called a fault.

True

Biogenic sedimentary rocks are composed of the remains of organisms (i.e. fossils).

True

Earthquakes are vibrations of the Earth caused by a rapid release of energy.

True

Seismologists like to see a seismic gap along a fault segment because it indicates that no major earthquakes have occurred there for awhile and therefore are unlikely to occur in that area in the future.

True

The Mercalli Intensity scale is used to measure the amount of damage (destruction) caused by an earthquake.

True

The principle stating that the geological processes operating on Earth today are the same geological processes that operated on Earth in the geologic past (i.e. the present is the key to the past) is known as:

Uniformitarianism

Which of the following types of seismic waves travel through the Earth's interior?

a and b (i.e. both Secondary and Primary waves).

A trace fossil may include all of the following except:

a clam shell.

One of the destructive products associated with composite volcano eruptions is a lahar. A lahar is:

a mudflow originating on the slope of a volcano when ash and debris become saturated with water.

California is susceptible to the hazard of tsunamis. What is a tsunami?

a seismic sea wave usually generated by displacement along a fault on the seafloor. These waves, if sufficiently large, can inundate low lying coastal areas, killing many people and causing considerable destruction.

What type of volcano is Mt. St. Helens?

andesitic stratovolcano.

A fossil is best defined as:

any evidence of past life.

The rigid, rocky plates at the Earth's surface move over a soft, semi-molten, deformable layer of the Earth known as the:

asthenosphere

The first step in forming a clastic sedimentary rock is the process of weathering. Weathering is:

both of the above

The lithosphere is composed of the:

both of the above

Which of the following radioactive isotopes is most useful for dating a very young sample (<20,000 years) of wood?

carbon-14

Volcanic arcs are associated with the following type of plate boundary?

convergent

An igneous rock with large crystals indicates that, when it was formed, the rock:

cooled and crystallized slowly.

A gastrolith is a type of rock formed when glaciers erode underlying bedrock. When the glacier melts, it exposes highly polished rocks called gastroliths.

false

At the time Wegener published his book The Origin of Continents and Oceans in 1915 the geologic community viewed his proposal of continental drift as one of the greatest scientific discoveries of the century.

false

Basalt is formed deep within the Earth by slowly cooling magma until it solidifies.

false

Gondwanaland refers to the sub-supercontinent formed by the connected landmasses of South America, Africa, Antarctica, Australia and India.

false

Lava is a molten material below the Earth's surface, while magma was a molten material at the Earth's surface.

false

Subduction zones occur at divergent plate boundaries.

false

The Hawaiian Islands formed as a result of volcanic activity at the boundary of two oceanic plates.

false

Using the Principle of Cross-cutting relationships, a geologic feature (such as a fault) that cuts through another geologic feature (such as a layer of rock) must be older than the geologic feature being cut.

false

oceanic crust is composed of

gabbro and basalt

Granite and rhyolite have the same mineral composition. However, rhyolite is fine-grained, whereas granite is coarse-grained. Based on the texture of these two rock types we can conclude that:

granite forms deep in the Earth by cooling magma slowly while rhyolite forms at the Earth's surface by cooling lava rapidly.

Evaporites are chemically deposited sedimentary rocks. They form from precipitation of minerals out of concentrated solutions. An example of an evaporite is:

halite (table salt).

Most fossils are the preserved:

hard parts of organisms.

Where would you find a playa?

in a desert

The Principle of Superposition recognizes that:

in an undisturbed sequence of sedimentary rocks, the oldest rocks are on the bottom of the sequence and the youngest are at the top.

Which of the following is the correct sequence of layers from the middle of the earth to the earth's surface?

inner core , outer core , mantle and crust

Which of the following volcanic eruptive products poses the least hazard to human life?

lava flows

Stratovolcanoes (i.e. Composite volcanoes) are typically composed of:

layers of pyroclastic material and viscous andesitic lava flows.

The intensity (e.g. explosiveness) and type of volcanic eruptions depend on:

magma viscosity and amount of dissolved gases in the magma (both of the above)

When a continental tectonic plate collides with another continental tectonic plate, which will occur?

mountain building

When fine sediment (silt and clay) is deposited in water, and then the water evaporates exposing the sediment to the air, the following sedimentary structure may form.

mudcracks

An erosional contact between an intrusive igneous rock that is overlain by sedimentary rock is known as a(n):

nonconformity.

Which of the following is a body fossil?

not bones maybe clam shell

Which type of tectonic plate is denser than the other?

oceanic plate

Approximately 250 million years ago, all continents on Earth were united in one large landmass (or supercontinent) called:

pangaea

Which of the following lava compositions indicates the correct order (left to right) of decreasing viscosity?

rhyolite, andesite, basalt.

Pieces of rock found inside of other rocks are called inclusions. If you have a granite with a piece of sandstone included within it, which of the two rocks is older?

sandstone

Most fossils are found in:

sedimentary rocks.

What is the correct clastic rock sequence that indicates increasing grain size of the sediment forming the rock?

shale, sandstone, conglomerate

Which of the following clastic sedimentary rock sequences represents increasing grain size of the rock, from left to right?

shale, sandstone, conglomerate.

The volcanoes forming the big island of Hawaii are:

shield volcanoes

Which of the following produces a more explosive type of an eruption?

stratovolcanoes

The Richter scale is one method used to describe the magnitude of an earthquake. The magnitude of an earthquake is a measure of:

the energy released by the earthquake.

The Principle of Uniformitarianism states that:

the geologic processes that operate on Earth today are the same processes that operated on Earth in the geologic past (i.e. the present is the key to the past).

An epicenter is:

the point on the earth's surface directly above the focus of an earthquake

Localized environmental features such as lagoons, deserts, and lakes can be identified in the rock record by studying

the sedimentary rock record

When glaciers melt they leave behind ridges of poorly sorted, conglomerate (gravel) called:

till (i.e. moraines).

A clastic rock formed of fine-grained sediment like clay suggests a depositional environment with little or no current velocity.

true

A fossil may be defined as any trace of past life.

true

A gastrolith is an example of a trace fossil.

true

A half-life is the amount of time it takes for one half of a radioactive parent isotope to decay (i.e. change into) its stable daughter product(s).

true

A noted strike-slip fault in California is the San Andreas fault.

true

An unconformity is a period of erosion or nondeposition in the rock record.

true

Braided streams are common in mountainous areas where there is a large supply of fairly coarse-grained sediment, where water discharge is variable throughout the year and stream gradients are high.

true

Index fossils are species that existed for a short period of time on Earth and thus are useful for determining the age of the rocks in which they are preserved.

true

Mantle convection causes the movement of tectonic plates around the Earth's surface.

true

Petrified wood is formed by the process of permineralization, which is a form of petrifaction.

true

Radioactive decay of elements in the Earth's interior is what produces the heat necessary for plate tectonics to occur.

true

Radiometric age dates suggest that the Moon, Earth and meteorites are all about the same age.

true

Sedimentary particles (e.g. sand grains) that are well rounded and well sorted indicate that the sediment was transported a long distance before being deposited.

true

The three types of tectonic plate boundaries are known as convergent, divergent, and transform.

true

Wegener's continental drift hypothesis was weakened by the fact that he could not provide a mechanism for moving continents.

true

With regard to human safety, pyroclastic flows are one of the most dangerous products of a volcanic eruption.

true

The Himalayan Mountains are the result of:

two continental plates colliding.

When an oceanic tectonic plate collides with a continental tectonic plate, which of the following might occur?

volcanic activity , earthquakes and subduction of the oceanic plate under the continental plate.

Which of the following eruptive products can affect people 10s to 100s of miles away from a volcanic eruption?

volcanic ash

Plate tectonics causes the following geological processes on Earth.

volcanic eruptions , earthquakes and mountain building

Cooling and crystalization of lava at the Earth's surface will produce a:

volcanic rock

Magma (or lava) contains several types of gases. The most abundant gas produced during a volcanic eruption is:

water vapor.