Geology free exam questions

Crust is made of silica tetrahedra (SiO4)

46% of the continental crust is oxygen, while only 21% of the atmosphere is oxygen. How could this be?

The magma becomes more silica-rich

Considering Bowen's reaction series, how does the process of fractional crystallization affect the composition of a cooling mafic magma?

Composition, density, thickness

Continental crust differs from oceanic crust in which of the following characteristics:

Weathering of continental rocks

From where does the calcium in seawater come?

Both grain size and foliation coarseness increase.

How do crystal size and foliation change with increasing intensity of metamorphism?

4.54 billion years old

How old is our solar system?

13.7 billion years old

How old is the universe?

At the bottom of the sequence

In an undisturbed sequence of sedimentary rocks where do the oldest rock strata occur?

Subduction zones

In which plate-tectonic environment do earthquakes occur at the greatest depths?

Tensional forces, compressive forces

Normal faults are caused by _________, and reverse faults are caused by _________.

amplify, stabilize

Positive feedbacks tend to _____changes in the system and negative feedbacks tend to _____the system against change

Faunal succession

Select the principle of relative dating that is most useful in correlating rock strata among widely separated areas (regionally).

Infrared radiation

Solar radiation absorbed by the Earth's ground surface is reemitted as __________.

Continental drift and seafloor spreading

The Theory of Plate Tectonics involves which of the following?

at the Earth's surface, directly above the focus

The epicenter of an earthquake is always located:

Angular unconformity

The following picture illustrates which type of geologic feature, highlighted by the yellow lines?

The shield

The oldest portion of the North American continent is:

Protons

The periodic table of elements is arranged in order of the number of ______ in a particular atom.

Strike

The yellow line in the figure below identifies the _______.

Solid only

Through which of the different states of matter can S waves travel?

Carbonates

To which class of minerals do calcite and aragonite, the most common minerals that form the rock limestone, belong?

False

True for false: The image below displays "graded bedding". To generate this sedimentary structure, the velocity of water flow must have increased from bottom to top.

False

True or False: All minerals exhibit cleavage?

False

True or False: Current surface temperatures are the highest they have been in Earth's history.

True

True or False: On average, the depth of the oceans below sea level is greater than the elevation of the continents above sea level.

False

True or False: the igneous rocks that form sills are considered extrusive igneous rocks.

Number of protons

What do all isotopes of any given element have in common?

about 20 km

What is the approximate amount of elevation change (relief) between the highest (Mt. Everest) and lowest (Marianas Trench) points on the surface of the Earth?

Silicon-oxygen tetrahedron

What is the fundamental building block of the silicate minerals?

Self replication + Self regulation

What is the simplest definition of life that we discussed in class?

Solar energy

What powers the Earth's climate system?

High porosity, high permeability

What properties of a geologic material make the best aquifer?

Decrease in pressure

What triggers the mantle melting that occurs beneath mid-ocean ridges?

Velocity measured with redshift & distance measured with star brightness

What two phenomena have been used to prove the Big Bang Theory?

Coastal beach

Which is a likely environment in which a quartz sandstone could have been deposited?

All of them

Which kind of plate boundary is associated with Earthquake activity?

Convergent, divergent and transform

Which kinds of plate-tectonic boundaries are associated with earthquake activity?

Slate, phyllite, schist, gneiss

Which list places foliation textures in order of increasing metamorphic grade (low grade to high grade)?

Surface wave, S wave, P wave

Which list places the different kinds of seismic waves in order of increasing velocity of travel (from slowest to fastest)?

Shale

Which of the following geologic materials makes the best aquiclude?

silicate weathering

Which of the following is a sink of atmospheric carbon dioxide?

Sunlight, warm water, calm seas (all)

Which of the following is critical to the growth of coral reefs?

Along the Andean Trench

Which of the following locations would you expect to find water saturated sediments being transported down to the upper mantle?

The youngest rocks occur in the center and the limbs dip toward the center.

Which of the following statements about synclines is TRUE?

Millions of years

Which of the following timescales seem most appropriate for the completion of a Wilson Cycle?

Sedimentary rocks

Which rocks preserve a record of ancient climate conditions and climate change?

Inner planets are smaller and of higher density than the outer planets.

Which statement comparing the inner planets to the outer planets is true?

It is less dense than the cooler rock surrounding it

Why is molten magma rising to the surface at divergent plate boundaries?

Well rounded and well sorted

By the time sediments reach the ocean basins, they have become:

Divergent

At which kind of plate tectonic boundary is the upper part of the mantle rising?

270 million years ago

Approximately when was the formation of the Pangaea supercontinent complete?

4%

About how much of Earth's water is fresh water?

About 150 million years ago

About when did the modern-day Atlantic Ocean first begin to form?

Rocks get older further from the axis and are mirrored on each side of the ridge

Absolute ages obtained from igneous rocks samples recovered from mid-ocean ridges reveal that:

150 mya

According to the reconstructed history of continental movements, about when did the modern-day Atlantic Ocean first begin to form?

Shallow crust

Brittle fracture of rocks is mostly likely to occur where in the Earth?

Variability + Natural Selection

Evolution can be described by the following conceptual equation: