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: