Physical Geology Final
The conglomerate is younger than 100 million years.
A clast (inclusion) of granite found in a conglomerate is determined to be one hundred million years old. What does this information suggest about the conglomerate?
A strike line's orientation with respect to north
A compass is used to measure the angle of ____.
radiometric
A fossil is determined to be 175,000 years old. This is an example of a(n) ____ date.
metamorphic facies
A group of metamorphic rocks that formed under broadly similar temperature and pressure conditions is a(n) ____.
for the mass of a sample to decrease by half
A half-life is the amount of time required ____.
nonconformity
A hiatus between igneous or metamorphic rocks and sedimentary rocks is represented in the rock record by a(n) ____.
Continental accretion
Continents grow by a process called ____.
is more likely to affect poor people because they cannot afford to build on the most stable slopes
Damage to homes by mass wasting ____.
Is any change in the volume or shape of rocks
Deformation ____.
Zone of rubble along a fault
Fault breccia is a ____.
Fault scarp
Faults that penetrate the surface may show a ____.
The rock was subjected to heat and differential pressure
Foliation indicates that ____ during metamorphism
the rock was subjected to heat and differential pressure
Foliation indicates that ____ during metamorphism
The principle of uniformitarianism
Geologists use ____ and their knowledge of present-day depositional processes to make determinations about a rock's depositional environment.
Turbidity currents deposit coarse and then fine sediments
Graded bedding forms when ____.
Is an area in which little P-wave energy is recorded by seismographs
P-wave shadow zone____
Are two types of body waves
P-waves and S-waves ____.
Under all circumstances
P-waves travel faster than S-waves ____.
under all circumstances
P-waves travel faster than S-waves ____.
At high latitudes
Permafrost is primarily found ____.
20
Permafrost lies beneath ____ percent of the land surface on Earth.
great size variation
Poorly-sorted sediment has ____.
organisms stop accumulating carbon-14 when they die
Radiocarbon dating is possible primarily because ____.
hydrothermal
Reaction of country rock with solutions from a cooling magma is known as ____ alteration.
Occurs over a large area
Regional metamorphism ____.
occurs over a large area
Regional metamorphism ____.
150 million years
Suppose an isotope has a half-life of 50 million years, and 1/8 of the sample remaining consists of that isotope. What is the age of the rock from which it was taken?
dry lubricants and abrasives
Two economically important metamorphic minerals are graphite and corundum, which can be used, respectively, for ____.
False
Various colors of slate result from differing intensities of deformation.
tend to have symmetrical profiles
Wave-formed ripple marks ____.
The magnitude of the last recorded earthquake
What factor is least likely to affect earthquake intensity?
the magnitude of the last recorded earthquake
What factor is least likely to affect earthquake intensity?
4.6 billion years
What is the approximate age of Earth?
alpha decay
What is the loss of two protons and two neutrons from the nucleus called?
creep
What type of mass wasting is responsible for the greatest amount of property damage?
Th-234
When an atom of Uranium-238 undergoes alpha decay, it becomes ____.
becomes a completely different element
When an atom undergoes alpha or beta decay, it ____.
The collision of two continental plates
When an isolated mountain range occurs in the interior of a continent, one may infer that the range formed by ____
slate, phyllite, schist, gneiss
Which list of foliated rock types is arranged correctly according to increasing coarseness of texture?
rockfall
Which of the following is a rapid mass movement?
The principle of fossil succession
Which principle states that fossil assemblages succeed one another through time in a regular and predictable order?
It lowers the average slope of a hill.
Why does benching reduce the risk of mass movements?
Formations
____ are a type of lithostratigraphic unit with distinctive upper and lower boundaries.
Slump
____ is a slow movement along a curved surface that typically involves poorly consolidated material.
Rock slide
____ is an example of a slide that occurs along a planar surface.
Stratigraphy
____ is the study of the composition, origin, areal distribution, and age relationships of layered rocks.
Slope-stability
____ maps help planners and developers make decisions about where to site roads, utility lines, and buildings to avoid potential damage from mass movement.
Isostatic rebound
____ occurs when Earth's crust rises back up to its equilibrium level after the unloading of glaciers or sediments.
Are composed of larger particles
crescent shaped areas where material has pulled away from Earth
Beneath mountains
The thickest crust found is ____.
Raleigh; Love
The two types of surface waves are ____and ____ waves.
General term for mass movements of earth materials
"Landslide" is a ____.
coquina
A rock composed almost entirely of fragmented seashells is called ____.
well-sorted
A sedimentary rock in which all the grains are about the same size can be characterized as ____.
Indicate the likelihood and potential severity of future earthquakes
A seismic risk map can be used to ____.
indicate the likelihood and potential severity of future earthquakes
A seismic risk map can be used to ____.
Shear strength
A slope material's strength and cohesion, the amount of internal friction between grains, and any external support of the slope define that slope's ____.
Is a special case of a reverse fault where the dip is less than 45o
A thrust fault ____.
1811 New Madrid
A very strong earthquake recorded in North America was the intraplate quake known as the ____ earthquake.
95
Almost ____ % of earthquakes take place along plate boundaries.
most common along convergent plate margins
Although metamorphism is associated with all three types of plate boundaries, it is ____.
Has the oldest rocks at its core
An anticline ____.
hornfels
An example of a nonfoliated metamorphic rock is ____.
The P-S time interval increases
As S- and P-waves travel farther, ____.
Accretionary wedge
At an oceanic - oceanic plate boundary, a subduction complex, also called a(n) ____, is formed.
False
Because large intrusions, such as batholiths, have such a large surface area they cool quickly and only a relatively small area of surrounding rock undergoes metamorphism.
Mantle; 80%
Below the outermost layer of Earth lies the ____, which accounts for more than ____ of Earth's volume.
evidence of an ancient subduction zone
Blueschist facies indicate ____.
contains a small amount of carbonic acid
Calcium carbonate readily dissolves in water that ____.
crystalline
Chemical sedimentary rocks can have a clastic texture or an interlocking grain texture called ____.
The gravel becomes rounded very quickly during transport.
Conglomerate is common, but sedimentary breccia is not. Why?
Is usually described as "granitic"
Continental crust ____.
derived from parent material and usually classified by the size of their constituent particles
Detrital sedimentary rocks are ____.
horsts; grabens
Differential movement on faults has produced uplifted blocks called ____ and down-dropped blocks called ____.
typically occurs when two plates collide
Differential pressure ____.
contact metamorphism only
Divergent plate boundaries are characterized by ____.
Distinct changes in the rock record
Divisions in geologic time represent ____.
Cause shaking and damage to structures
During an earthquake, seismic waves ____.
To achieve equilibrium with its new environment
During metamorphism, the original rock undergoes changes ____.
to achieve equilibrium with its new environment
During metamorphism, the original rock undergoes changes ____.
has both liquid and solid components
Earth's core ____.
Is also known as thermal metamorphism
False
Water adds weight and reduces friction.
How does water contribute to mass wasting?
epicenter
If the P-S time intervals are known from at least three seismograph stations, the ____ of any earthquake can be determined.
Periods of heavy rainfall
In La Conchita, California, landslides have been precipitated by ____.
reverse
In a ____ fault the hanging wall block moves up relative to the footwall block.
Hanging wall goes up relative to the footwall
In a reverse fault, the ____.
lived during a brief period of geologic time
Index, or guide, fossils are most useful because they ____.
Occur when there is stress caused by compression
Intraplate earthquakes ____.
cementation
Lithification of sand and gravel requires both compaction and ____.
Migrate from igneous intrusions into the surrounding rock
Many ore deposits result from contact metamorphism during which hot, ion-rich fluids ____.
Metamorphosed limestone or dolostone
Marble is ____.
Sea level falls with respect to a continent
Marine regression occurs when ____.
Deposition occurs during a time when sea level rises and the shoreline moves inland
Marine transgressions are created when ____.
Clay-rich layers
Mass wasting is most likely to occur on slopes with ____.
Gravitational force exceeds shear strength
Mass wasting occurs when ____
Are formed under conditions of high temperatures and pressures
Metamorphic rocks ____.
True
Metamorphic rocks are very common in the crystalline basement rocks of shields.
while rocks remain solid
Metamorphism takes place ____.
has both igneous and metamorphic characteristics
Migmatite ____.
Of the convergence along plate margins
Most earthquakes occur along the circum-Pacific belt primarily because ____.
Is made up of rock fragments
Most gravel ____.
weathering
Most mass wasting is enhanced or promoted by ____.
tensional
Normal faults are caused by ____ stress.
Inject fluid into fractured rocks
One possible way to decrease the magnitude of an earthquake is to ____.
Contain fossils that are rare or absent in other types of rocks
One reason that sedimentary rocks are important in deciphering Earth history is that they ____.
fossil data, rock types, and key beds
Rock units can be correlated best by examining ____.
Horizontally and then were tilted into their current orientation
Rocks that are tilted were deposited ____.
crescent shaped areas where material has pulled away from Earth
Scarps are ____.
are features that form as a result of physical or biological processes operating in a depositional environment
Sedimentary structures ____.
Regions of the continents where basement rocks are widely exposed
Shields are ____.
area of exposed Precambrian crystalline igneous and high-grade metamorphic rocks that form tectonically stable areas
Shields are ____.
Deformation caused by stress
Strain is ____.
Strike slip
The San Andreas Fault is a ____ fault.
Is very likely to have a large earthquake in the foreseeable future
The Seattle, Washington area ____.
peridotite
The composition of the mantle is primarily ____.
Cannot be used in areas where the original rocks were pure quartz sandstone
The concept of metamorphic facies ____.
Decreases with distance from the intrusion
The degree of metamorphic change within an aureole ____.
decreases with distance from the intrusion
The degree of metamorphic change within an aureole ____.
Building retaining walls
The effects of mass wasting can be minimized by ____.
superposition, fossil succession and correlation
The geologic time scale was initially put together by ____.
Compression-induced
The largest mountains on continents are formed by ____ deformation.
The crust and upper mantle
The lithosphere is made up of the ____.
the crust and upper mantle
The lithosphere is made up of the ____.
eons
The longest divisions of geologic time are called ____.
The energy released
The magnitude of an earthquake measures ____.
running water
The most common and effective agent for transporting sediment is ____.
carbonate
The most common chemical sedimentary rocks are ____.
radiometric dating of rocks and fossils
The most useful method for dating the oldest events on Earth is ____.
Erosion at the base of a slope
The primary cause of slumps is ____.
lateral continuity
The principle of ____________________ states that rock layers extend laterally in all directions unless or until they terminate in one of a number of natural means.
makes up a single metamorphic zone
The region between two adjacent isograds ____.
Long line oriented in the appropriate compass direction
The special symbol to indicate a strike on a geologic map is a ____.
