Geo Final Exam
Bowen's reaction series tells us that mafic minerals such as olivine and pyroxene crystallize from the magma chamber at higher temperatures than felsic minerals such as K-feldspar and quartz. If a magma undergoes fractional crystallization during cooling, the remaining magma will be ______ than the parent magma.
more felsic
In the map of Earth above, what is the direction of the trade winds in zone C between the equator and 30 degrees N latitude?
northeast
In order to make a sodium (Na) chlorine (Cl) bond in NaCl, _____________.
one electron is transferred from the sodium atom to the chlorine atom
When a piece of a meander becomes separated from the stream it is a(n) ____________.
oxbow lake
A greenhouse gas absorbs thermal radiation strongly and can keep the earth's surface warm. Which of the following is NOT a greenhouse gas?
oxygen (O2)
Two metabolic processes that have changed the world based on the geological records of the Earth's history. The initial rise of oxygen in the Earth's atmosphere is believed to be linked to ____________.
photosynthesis that released oxygen into the ocean and eventually to the atmosphere
Which sediment characteristics best describe glacial till?
poorly sorted, poorly stratified
Silicate minerals commonly exist in igneous rocks and can be used to classify the compositions of the igneous rocks. Which of the following silicate minerals is commonly found in mafic igenous rocks?
pyroxene
Which of the following minerals below is most resistant to chemical weathering?
quartz
Which of the following minerals crystallizes from a magma at the lowest temperature?
quartz
A Wilson cycle is initiated by what plate tectonic process?
rifting
The San Andreas fault is an example of a _______ fault.
right-lateral strike-slip
Which of the following unfractured rocks has the highest porosity?
sandstone
The region below the water table is the _____________.
saturated zone
The area on the surface of the Earth where P waves and S waves are not recorded by seismograms following an earthquake event are reffered to as______________.
shadow zones
What type of earthquakes would most likely occur in the middle of a divergent boundary?
shallow focus earthquakes caused by normal faulting
What type of earthquakes would happen on a lateral fault?
shallow focus earthquakes caused by strike-slip faulting
Which of the following sedimentary rock groups are most abundant?
siltstones, mudstones, and shales
The Earth's magnetic field shields the surface of the Earth from ________________________.
solar winds with charged particles
There are three types of plate tectonic boundaries. The convergent boundary occurs when two plates collide against each other. Which of the following is a type of convergent plate boundary?
subduction zone
Fe2+ and Mg2+ caions are similar in size and both have a +2 positive charge. Therefore, we would expect iron and magnesium to _______.
substitute for each other easily in silicate minerals
Metamorphic facies are indicative of particular tectonic environments, and can, therefore, be clues to the (pressure and temp) history of the rock. Geologists define the metamorphic facies by
suites of minerals
The Big Bang Theory indicates the universe originated as a single concentration of mass energy that rapidly expanded. Which of the following evidence supports this idea?
the Doppler redshift of the universe
Magnetic mapping of the ocean floor revealed a pattern of symmetric "stripes" with alternating polarity, centered along the mid-ocean ridges. These indicate the magnetic reversal of the Earth's magnetic field when _______.
the Earth's magnetic north and south poles flip
Which of the following mountain ranges is the product of continent-continent convergence?
the Himalayas
What is the Earth's albedo?
the fraction of solar energy reflected by the Earth's surface and clouds
Which of the following Earth systems powers the Earth's magnetic field that can protect life on Earth's surface from harmful cosmic rays?
the geodynamo system in the Earth's core
Which of the following earth systems powers the Earth's magnetic field?
the geodynamo system in the Earth's core
In an anticline, ____________.
the oldest rocks occur in the center and the limbs dip away from the center
The major classification of igneous rocks is dependent on texture and _____________.
the relative proportions of silicate minerals
The rise of oxygen level in the atmosphere is an important step in the history of geobiology in the Earth's history. The observation of the Banded Iron Formations (BIFs) represents a critical scientific support for the rise of the oxygen level in the ocean bc ____________________.
the rise of the oxygen level in the ocean allowed iron minerals in the BIFs to precipitate at the bottom of the ocean
Based on the geometry of the surface and water table depicted in the cross section below, which of the following statements is true?
the stream is gaining water from the groundwater
The greenhouse effect describes ______________.
the way in which the Earth's atmosphere traps heat
The bowl shape of the bedrock beneath the ice dome of Greenland is a result of?
the weight of the ice sheet in the middle of the Greenland
The principle of superposition states that _______________.
undisturbed sedimentary layers get progressively younger from bottom to top
The region above the water table is the ______________>
unsaturated zone
As waves approach a beach, the rows of waves gradually bend to a direction more parallel to the shore. This change in direction is called _____________.
wave refraction
Which one of the following statements about ocean waves approaching shore is TRUE?
waves approaches shore.... -wave period is same -wavelength decreases -velocity decreases -height increases
The oldest oceanic crust on Earths surface contains rocks as old as approximately_________.
200 million years in the Pacific plate
What is the average rate at which temperature increases with depth in the earth's crust?
30 degrees C /km
About how thick is the Antartica Ice sheet at its thickest point?
3000-4000 meters
The oldest continental crust contains rocks as old as ____________.
4 billion years
A rock formed with 100 atoms of a radioactive parent element but contains only 25 radioactive parent atoms today. Let's assume that the rock did not contain any daughter isotopes to start with. If the half-life for the radioactive element is two billion years, how old is the rock?
4 billion years old
Carbon has an atomic number of 6 and an atomic mass of 12.011. The atomic mass (weight) is the sum of the number of protons and the number of neutrons in the nucleus. We also know that carbon has a number of isotopes. These statements mean that carbon atoms have _______.
6 protons and a number of isotopes with different neutrons
What is the approximate silica content of a granite?
70%
Which of the following best describes an andesite?
A fine-grained, intermediate igneous rock
Which of the following will decrease the rate of chemical weathering of a rock at the Earth's surface?
decreasing the temperature
What one of the following geological features is NOT expected at Passive Continental Marigns?
deep-sea trench but you do see continental slope, continental shelf, submarine canyon
Continental and oceanic crusts cover the Earth's crustal surface. The oceanic crust is _____ than the continental crust.
denser, thinner
What two measurements describe the orientation of a fault plane at a given location?
dip and strike
Due to the Coriolis effect, any large-scale current of air moving toward high latitude from the equator is deflected to the ____________ in the northern hemisphere.
east
Point B, the location on the surface above the focus, is called the earthquake ___________.
epicenter
At the bend in a river, ___________ occurs on the outside of the bend and ____________ occurs on the inside.
erosion, deposition
The three domains of life are
eukarya, bacteria, archaea
Point C is called the
fault scarp
What type of rock makes up the Columbia Plateau of Oregon and Washingthon?
flood basalts
Point A, where slip initiated during the earthquake is called the ________.
focus
In which of the following subsystems is the Earth's magnetic field generated?
geodynamo system
Geologists have used the principle of uniformitarianism to understand geological activities preserved in the rock records. According to the principle of uniformitarianism, ___________.
geologic processes we observe today have operated in the past
Mineral Definition: A naturally occuring inorganic element or compound having an orderly internal structure and charactristic chamical composition, crystal form, and physical properties. Based on the definition, whihc of the following substances is NOT considered a mineral?
glassy materials in fast cooling basalt
We can classify igneous rocks by their textures and compositions. For example, felsic igneous rocks contain very high amount of K-feldspar and silica. Which of the following rocks has the highest silica content and is a felsic rock?
granite
Which of the following correctly lists the three rock types in order of increasing P-wave velocity?
granite -> gabbro -> peridotite
You find an igneous rock containing large, interlocking crystals of quartz, feldspar, and muscovite. The rock you have found is most likely granite. Which one fo the following statement about granite is FALSE?
granite is very abundant in the oceanic crust bc it contains lots of quartz and feldspar
The Principle of Original Horizontality was proposed by the Danish geologist pioneer Nicholas Steno (1638-1686). The Principle is commonly used in studying sedimentary rocks. Which of the following statements about the principle are FALSE?
Based on the principle, young rocks are buried under old rocks
What causes tides?
gravity from the moon and sun
The largest freshwater (in liquid water only) reservoir in the hydrologic cycle is
groundwater
Which of the following represents the boundary between the saturated and unsaturated zones?
groundwater table
Radioactive isotope dating is commonly used in geology to understand the ages of minerals and rocks. The parent radioactive isotope decays into the daughter isotope at a constant rate. The decay rate is measured by the amount of time required for half the remaining mineral to decay. This decay rate is called _____________.
half-life
A number of variables can affect the deformation behavior of rocks in the crust. A sample of sandstone has deformed brittlely during a lab experiment. If we wish our next sample of sandstone to deform plastically (ductile deformation) rather than brittlely, we should conduct the next experiment at _____________.
higher temp and higher surrounding pressure
The Hawaiian islands are very far away from the continents, but there are active volcanoes in the region. These islands formed __________ over a period of geological times.
hot spot volcanism
The giant outer planets are composed mostly of _______.
hydrogen and helium
The periodic table is commonly used to understand the properties of elements and their compounds in earth materials. How are the elements organized in the periodic table.
in order of increasing number of protons
Where are the oldest rocks in North America located?
in the Canadian Shield
The mineralogy of terrestrial planets evolves as a consequence of a range of physical, chemical, and biological processes. Based on the statement, the number of minerals in the Earth would ________ as the planet evolves through time.
increase
Lithification in sedimentary rocks include burial, compaction, and cementation. Burial of sediments results in __________.
increasing pressure and increasing temp
How do crystal size and foliation change with increasing intensity of metamorphism?
Both grain size and foliation coarseness increase
Solar radiation absorbed by the Earth's ground surface is reemitted as ____________.
infrared radiation
Seismic studies of the earth have shown that the platnet's interior is made of a few layers with distinct seismic signatures and chemical compositions. The major layers of the planet include (from innermost to the outermost layers) ____________.
inner core, outer core, mantle, crust
The Earth's core is made up primarily of ________.
iron
On a map of the seafloor such as the Atlantic oceanic crust, the boundaries between the normally magnetized oceanic crust and reversely magnetized oceanic crust are called _______ because they represent the same _______ of the rocks.
isochrons: ages
What principle is based on the continents being less dense than the underlying mantle?
isostacy
The structure of atoms is mainly made of the inner nucleus with protons and neutrons, and the outer orbiting electrons. An element is defined by the number of protons, but can have various numbers of neutorns. What is the name for atoms of the same element that have different numbers of neutrons?
isotopes
Earth's interior is made of a few distinct layers separated by discontinuous boundaries in seismic wave and geochemical studies. Which statement below is FALSE?
Earth's core is mostly made of iron-nickel alloy. The outer core is solid and the inner core is liquid.
Which of the following metamorphic facies represents the highest pressure metamorphism (metamorphic grade)?
Eclogite
Which of the following metamorphic facies represents the highest pressure metamorphism?
Eclogite
Which of the following statements about radioactivity is FALSE?
Energy is consumed during radioactive decay
Which of the following statements is FALSE about igneous rocks?
Gabbro is a coarse-grained, felsic, and extrusive rock
Which one of the following events can NOT trigger Tsunami waves in the ocean?
Gravity pull from the Moon and the Sun
Which of the following statements regarding porosity and permeability is TRUE?
High porosity rocks generally have high permeability
Isostasy is the balance (equilibrium) between buoyancy forces that push a continent up and down. Let's use water and ice as an example to understand isostasy. We know that ice flows on water bc it is less dense. Elevation of an ice cube is a function of the density difference and thickness of the ice layer. Which of the following statements is FALSE?
Ice is ~10% lighter in density than water. Thus, ~90% of the ice cube will submerge under water.
A number of geological principles such as Principle of Superpostion, Principle of Original Horizontality, and Principle of Faunal Succession have been used to understand geological records in rock formations. Based on these principles, which one of the following statements is TRUE?
In a sequence of undisturbed layered rock, the oldest rocks are on the bottom
Where do trade winds occur?
In the tropics or from 30S ->0->30N latitude
Waller Creek is a stream systems running through UT campus. The stream's discharge during a heavy rainfall would ______________.
Increase with increasing the velocity of the stream
Which region of the Earth consists primarily of solid iron?
Inner core
Magma generated in the Earth's interior rises because it is ______ than the surrounding rocks.
less dense
Continents are thicker and older than oceanic crusts bc they are generally made of _______________ rocks.
lighter felsic
In what type of rock do most caves and Karst topography form?
limestone
______________ layers found in the rock record at the Cretaceous-Tertiary boundary provide evidence of an asteroid impact.
Iridium
About what percentage of the Earth's total surface energy input is heat flowing from the Earth's deep interior?
Less than 1% (almost negligible)
Meandering streams (meanders) commonly occur at which of the following environments?
Low-velocity and low sediment streams in the flat floodplains.
Which one of the following statements about the three rock types is FALSE?
Mafic minerals are more stable and can be commonly found in sedimentary rocks
Compared to the visible part of the electromagnetic spectrum, infrared radiation has _____________________.
longer wavelengths and lower energies
The stream current near the point bar has ________ than that on the opposite side of the stream.
lower velocity, lower sediment load
Seismic stations record P- and S-wave arrival times and intensities. Which scientific method do seismologists like Prof. Steve Grand of the UT Austin use to model the seismic velocities of the P- and S- waves inside the mantle?
Plate reconstruction method through time to deduce the speed of plate motion and thus seismic speeds
The basic building blocks to all silicates are the SiO4 tetrahedra that are linked in a variety of way in three dimensions. Which one of the following statements about major silicate minerals is FALSE?
Pyroxene is a single-chain silicate and has the chemical formula of (Mg,Fe)2SiO4
Which of the following conditions favors the folding of rocks rather than the faulting of rocks?
Rapid accumulation of compressive stress
Which one of the following phenomena led to the conclusion that the outer core is liquid?
S wave shadow zone
Fossils are most common in which types of rocks?
Sedimentary Rocks
Foliated metamorphic rocks are classifide by the nature of their foliation, crystal size, and segregation of minerals that are all related to the metamorphic grade. Which of the following orders has an increased intensity of metamorphism?
Slate, Schist, Gneiss, Migmatite
Volcanic rocks derived from the Yellowstone hot spot get progressively older to the southwest. Based on this information in which direction is the North American plate moving?
Southwest
Mantle upwelling in response to the pulling apart at spreading (divergent) ridges results in decompression melting of the upper mantle peridotite. Partial melting of an ultramafic rock at high temps results in melting of mafic minerals with a basaltic composition. In which tectonic setting are you most likely to find abundant basaltic volcanism as a result of the mantle upwelling?
Spreading center (Mid-Atlantic ridge)
In the geologic maps, strikes and dips are used quite often to depict the orientations of rock formations. Which one of the following statements is NOT correct?
Strike and dip can be used to inform us about the relative age of rocks
One particular group of bacteria, the cyanobacteria or "blue-green algae," have left a fossil record that extends far back into the Precambrian - the oldest cyanobacteria-like fossils are nearly 3.5 billion years old, among the oldest fossils currently known. ___________________ record the presence of microbial mats during the Archean.
Stromatolites
In which plate-tectonic environment do earthquakes occur at the greatest depths?
Subduction zones
Which of the following explains why the Sahara desert of Africa exists?
The Sahara lies near 30N latitude
In which region of the Earth is conduction the dominant heat transfer mechanism? What about convection?
The crust The outer core/mantle
As the distance to an earthquake increases, _____________________.
The elapsed time before the S waves arrive increases
Based on the Plate Tectonics Theory, the Earth's lithosphere is broken up into approximately a dozen pieces of large plates. Which one of the following statements is FALSE about the Plate Tectonics Theory?
The lithosphere rides on top of the asthenosphere, but can NOT penetrate the asthenosphere at subduction zones bc it is too RIGID
Which of the following statements about the age of the Earth and Moon is TRUE?
The moon was formed slightly after the Earth was formed some 4.5 Ga ago.
Which one of the following statement about Earth's inner core is NOT true?
The temperature of the inner core is slightly above the melting temperature of Fe-Ni alloy
Why do the Great Basin and Mojave deserts of western North America exist?
The two deserts lie in the rain shadow of coastal mountains
Which of the following energy sources powers the geodynamo, the generation of Earths magnetic fields?
Thermal cooling from the outer core to the lower mantle and the crystallization of the inner core (Latent heat)
In which direction are winds that blow from low latitude towards higher latitude deflected by the Coriolis effect?
Toward the east in both hemispheres
The only other planet in the solar system besides the Earth thought to be tectonically active is _____________.
Venus
Which planet is surrounded by a hot atmosphere of carbon dioxide and clouds of sulfruic acid?
Venus
What happens to the period of a wave as it approaches the shoreline?
Wave period remains the same
Which of the following relationships best explains the link between global sea level and polar ice extent?
When temp drops, sea level drops and the oceans become more saline
The effects of the collision of a large Mars-sized body with the Earth about 4.5 Ga is proposed to have caused _______________________.
all of the above - a magma ocean to form at the Earth's surface - an increase in the Earth's speed of rotation - the Earth's spin axis to tilt
Much of a desert's surface consists of sand, gravel and rock rubble bc _____________.
all of the above - clay minerals form slowly in a desert environment - wind blows away clay and soil before it can accumulate to great thickness - vegetation is sparse and cannot prevent erosion of soil
Why does an increase in atmosphere CO2 lead to increased rates of erosion in the lithosphere?
all of the above - increased atmosphere CO2 warms the climate - Increased CO2 affects pH (acid content) of water - Increased CO2 absorbs more infrared radiation in the atmosphere
The stream discharge is expressed as volume per unit time (cubic feet per second. The stream discharge increases with increasing which one of the following factors?
all of the above - width of the stream channel - velocity of the stream - depth of the stream channel
Groundwater supplies can be contaminated by _______________.
all of the above - lead and other heavy metals - nitrates from fertilizers - microorganism from septic systems
The Milankovitch cycles are dependent on the Earth's ___________.
all of the above - orbital eccentricty - precession - angle of tilt on the rotation axis
Stanley Miller's experiments to explore life-building chemical reactions that took place on the primitive earth were able to generate ___________________.
amino acid
Sedimentary rocks provide a record of ancient tectonic events (mountain building and erosion), fossil record and evolution of life, the history of the past climate changes etc.They are commonly found on the Earth's surface bc sedimentary processes take place___________.
at or near the Earth's surface
How do rock particles move during the passage of an S wave through the rock?
back and forth at right angles to the direction of wave travel
The Earth's upper mantle is mainly made of peridotite, an ultramafic igneous rock with lots of olivine crystals. Which type of magma can be produced when the upper mantle undergoes decompression melting of the upper mantle peridotite at mid-ocean ridges?
basaltic
What types of lavas are erupted at mid-ocean ridges?
basalts
Which of the following radioactive isotopes is the most useful for dating very young (<10,000 years old) wood and charcoal?
carbon-14
Which of the following statements regarding carbon dioxide is true?
chemical weathering reduces the amount of CO2 in the atmosphere
Which of the following particles would have the lowest settling velocity?
clay
Which mineral or mineral group occurs exclusively in sedimentary rocks?
clay minerals
Estimate the sea level rise if all of the ice in Antartica were to be melted away because of the global warming? For simplicity In your estimation, lets use the following numbers: Antartica ice is abut 30 million km^3; the surface area of Earths oceans is about 300 million km^2.
0.1 km
The stream discharge is expressed as volume per unit time (cubic feet per second). The stream discharge increases with increasing velocity, width, and depth of the stream. If the velocity of the stream increases by a factor of TEN and the depth increases by a factor of TEN during a flood, the total dischrage of the stream increases by how much?
100
Alpine (valley) glaciers originate in mountains where temperature is low and precipitation is sufficient. At the temperature regions between 30 to 60 degrees in latitude, at what altitude (elevation) does the snow line lie?
1000-5000 meters
Unconformity is the surface between two layers that were laid down in a broken sequence. Which of the following statements about the unconformity are TRUE?
All of the Above - Angular unconformity is an unconformity in which younger sediments rest upon the eroded surface of tilted or folded older rocks - Disconformity is an unconformity between beds that are parallel - Nonconformity is an unconformity between stratified rocks above and unstratified igneous or metamorphic rocks below
Which one of the following statement about the age of the geological event is true?
All of the above - The earth was formed about 4.6 billion years ago - The oldest rocks on the continental crust were about 4 billion years old - the oldest rocks on the oceanic floor were about 180 million years old
The study of sedimentary rocks helps geoscientists determine ____________.
All of the above - ancient ocean environments -former plate tectonic events - history of climate change
Ground water resource is not limitless. Excessive pumping of a well during a drought will lead to a deepening of the cone of depression. This in turn can cause:
All of the above - land surface subsidence -water table decrease - your well and your neighbor's well to go dry
Building Blocks of Life include:
All of the above - water - carbon, hydrogen, and oxygen -nutrients and energy
Melting occurs when a solid (rock) becomes a liquid (melt: magma). There are a number of pressure, temperature, and compostioinal conditions that can cause a rock to melt. Which one of the following conditions can cause a rock to melt in the Eath's deep interior?
All of the above -addition of volatiles such as water into the rock - decompression (a decrease in pressure) - an increase in temperature
The orographic precipitation is used to explain why the California coast is wet and the interior is dry, because
air can hold less water when it cools
What types of lavas are erupted at Andes?
Andesites
Where is largest mass of ice on Earth located?
Antartica
Polymorphism means "many forms". In mineralogy it means that a single chemical compositition can exist with two or more different crystal structures; however, each of the structures is only stable at a certain pressure and temperature conditions. _____________ and ____________ are NOT an example of polymorphs.
Chert, Calcite
The impact site for the giant Cretaceous-Tertiary asteroid is know as the _____________ crater.
Chicxulub
What volcano represents a major hazard to the cities of Seattle and Tacoma in Washington state?
Mt. Rainer
Which region in the Earth consists primarily of liquid iron and nickel alloy
Outer Core
Which region in the earth is molten?
Outer core
Which one of the following is a major agent of erosion and deposition in desert environments?
Wind
Based on the Plate Tectonics Theory, the Earth's surface is covered by a dozen bug plates. These plates are moving at an average speed of approximately _____________ a year.
a few centimeters to ten centimeters
A geothermometer is ____________.
a mineral assemblage that reveals the maximum temp attained by a rock
Which of the following slopes of unconsolidated material will be the least stable?
a slope greater than the angle of repose
If an earthquake occurred in Seattle, Washington, how long would it take for the first seismic waves to arrive at a seismograph station is Miami, Florida, approximately 5000 kilometers away? Note that one can use the speed of the primary P wave to answer this question.
about 8 minutes
There are three types of plate tectonic boundaries. Which of the following types of tectonic forces at the plate boundary tends to squeeze or shorten a rock body?
compressive forces
The lowering of the water table near the well is called a ________________.
cone of depression
What type of metamorphism is caused by igneous intrusions?
contact metamorphism
Metamorphic Grade refers to the intensity of metamorphism n the formation of the metamorphic rocks. Which one of the following geological locations do you expect to find higher-grade metamorphic rocks?
continental collisions in plate boundaries where pressure and temp are high (such as the Himalayas)
if one were to start from the east coast of North America and descend into the Atlantic Ocean, one would travel along the ________.
continental shelf then the continental slope then the contental rise
What type of plate boundary is depicted in the cross section?
convergent
The Mohorovicic discontinuity coincides with the _________ boundary.
crust-mantle
The volcanism at spreading centers occurs as a result of __________ melting.
decompression