Exam 3 (ch6-11)
magnitude of the second largest recorded earthquake
9.2
magnitude of the largest recorded earthquake
9.5
the weight stays fixed in space, while the drum and paper move.
A mechanical seismograph consists of a pen attached to a suspended weight, and a rolling drum with paper attached. During an earthquake:
rock bends elastically before breaking; the sudden break and/or frictional sliding causes earthquakes.
According to the "elastic rebound theory" of earthquake generation . .
one whose foundation is built on an exposure of granite bedrock
All else being equal, which building would more likely survive a large earthquake?
differential stress / preferred orientation
Application of _________ during metamorphism causes inequant grains to align parallel to each other; when this happens, minerals in the rock develop __________.
"ancient" (3.8 to 2.5 Ga)
Archean eon
coral mounds and/or calcite shell fragments
Biochemical limestone can consist of . . .
Lithification, Deposition, Transportation, Erosion, Weathering
Clastic sedimentary rocks are created by
chemical / gypsum / halite
Evaporites are a type of _______ sedimentary rock. Examples can consist of ______ and/or ______ ?
P (primary) waves
Fastest type of wave, so arrives first (larger velocity)
"hell" (4.6 to 3.8 Ga)
Hadean eon
transgression
If sea level rises, so the shoreline migrates inland, a ______________ has occurred
Processes seen today are the same as those of the past. Geologic change is slow; large changes require a long time. Therefore, there must have been a long time before humans.
James Hutton's principle of uniformitarianism
contact metamorphism.
Metamorphism due to heat alone, without differential stress, is called...
quartzite / marble
Metamorphism of sandstone produces ________ , whereas metamorphism of limestone produces __________ .
normal / fault scarp
On a _________ fault, the hanging-wall block slips down the surface of the fault, relative to the footwall. If the fault displaces the ground surface, a _________ develops.
Diagenesis
Physical, chemical, and biological changes to sediment
"before life" (2.5 to 0.542 Ga)
Proterozoic eon
clastic / shale
Sedimentary rocks formed through cementation of formerly loose grains of sediment derived from weathering of preexistent rock are called _______ sedimentary rocks. A very fine-grained example, which typically splits into thin sheets, is called ________ .
S waves
Slower than P wave, arrives second (larger amplitude)
is a measure of the amplitude of vibrations recorded by a seismograph
The "intensity" of an earthquake . . .
epicenter
The point on the surface of the Earth that lies directly above the place where a slip on a fault occurs is the ____ .
D. precipitation of cement
The process of erosion does NOT include which of the following? A. glacial ice plowing sediment away from its original depositional setting B. gravity-driven tumbling off a cliff C. removal of debris by wind or running water D. precipitation of cement
the difference in the arrival times of the P- and S-waves, as recorded at three different stations
To locate the epicenter of an earthquake, what information do you need
earthquakes at subduction zones
Tsunamis can be caused by . . .
The former display preferred orientation and/or compositional banding, whereas the latter do not
What is the difference between foliated and non-foliated metamorphic rocks?
Coherence: sediment consists of loose grains, sedimentary rock consists of a solid aggregate
What is the difference between sediment and sedimentary rock?
E. all of the above
What phenomena can cause the mineral assemblage in a protolith to change into a metamorphic mineral assemblage? A. a change in pressure B. a change in temperature C. shear stress D. infiltration by supercritical (hot and pressurized) fluids E. all of the above
. rock #1 was subjected to higher temperatures than rock #2.
When we say that metamorphic rock #1 is "higher grade" than metamorphic rock #2, we mean that . . .
P-waves / S-waves / surface waves
Which is the correct sequence of seismic waves that will be recorded at a distance from the epicenter from first to arrive to last?
the growth of ice crystals in cracks to wedge the cracks open
Which of the following is NOT a manifestation of chemical weathering?
a protolith undergoes change in the solid state
Which of the following phrases correctly completes the following sentence? During metamorphism, ________ . A. glass changes by first melting and then solidifying B. rock reacts with air and water at the Earth's surface C. sediment undergoes compaction and cementation D. a protolith undergoes change in the solid state
C. both A and B
Which of the following processes contribute to lithification? A. compaction and consolidation (removal of water and air between the grains) B. cementation by minerals precipitated from groundwater C. both A and B
Earthquakes occur in discrete belts, along plate boundaries
Which statement about the distribution of earthquakes on Earth is correct?
false
With existing technology, it is possible to predict earthquakes to within a few days
4.57 Ga
age of earth
distance
amplitude decreases with...
Chile, 1960
biggest earthquake recorded
Organic
carbon-rich remains of once living organisms
Regression
exposure due to sea level fall
Transgression
flooding due to sea-level rise
find s and p waves. convert to distance. draw a circle from radius. intersection is epicenter
how do you find the epicenter of an earthquake
Clastic
loose rock fragments (clasts) cemented together
Biochemical
mented shells of organisms
Chemical
minerals that crystallize directly from water
Foliation
parallel surfaces or layers in metamorphic rocks
"visible life" ( 542 Ma to present)
phanerozoic eon
hypocenter/focus
point where rupture starts
quartz
rocks made of SiO2
Limestone
sedimentary rocks made of CaCO3
Deposition
settling out of the transporting fluid
amplitude
strength of shaking
Epicenter
surface projection of hypocenter
Lithification
transformation into solid rock
surface waves
waves with the largest amplitude
earlier than 3.8 Ga
when did life first appear on earth
