Earth Science (Exam 2)

25 July 2022
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question
Which of the following statements is part of the continental drift hypothesis? CHOOSE ALL THAT APPLY.
answer
The continents of South America and Africa fit together like pieces of a jigsaw puzzle. A single supercontinent consisting of all Earth's landmasses once existed.
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How does the lithosphere differ from the asthenosphere? CHOOSE ALL THAT APPLY.
answer
The lithosphere tends to break, while the asthenosphere tends to flow. The lithosphere overlies the asthenosphere.
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Why are oceanic ridges more elevated than the rest of the sea floor?
answer
Ridges are elevated because the rocks are hot.
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Where does new lithosphere form?
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at divergent plate boundaries
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Which of the following locations is a modern-day example of an active continental rift?
answer
East Africa and the Red Sea
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Where would you expect to see deep ocean trenches?
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oceanic-oceanic convergent boundaries
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Which of the following features is considered a destructive plate margin?
answer
subduction zone
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What happens to the lithosphere at transform plate boundaries?
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Lithosphere is neither destroyed nor created, simply maintained or conserved.
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What is a hot spot?
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an area of volcanism created by a mantle plume
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Which of the following processes drive plate tectonics? CHOOSE ALL THAT APPLY.
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subduction convection
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What causes an earthquake?
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Earthquakes result when a block of rock rapidly slips past another along a fault plane.
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What is the difference between the epicenter and the focus of an earthquake?
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The epicenter is the surface location of an earthquake and is located above the focus.
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Which of the following terms are types of seismic waves? CHOOSE ALL THAT APPLY.
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surface waves primary waves secondary waves
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The Modified Mercalli Intensity Scale is used to measure _______
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the amount of damage caused by an earthquake
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Earthquakes with a Richter magnitude of less than ______ are generally not felt by humans.
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2.0
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Which of the following does NOT determine the amount of destruction caused by seismic shaking?
answer
type of fault
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What is a tsunami wave?
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massive ocean waves usually triggered by underwater earthquakes
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The location of earthquake epicenters closely correlates with the __________________.
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edges of the plates
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What are the major zones of Earth's interior?
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crust, mantle, core
question
Which of the following statements best describe the continental crust and oceanic crust?
answer
Continental crust is thicker than oceanic crust.
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What primary factors determine the nature of volcanic eruptions? CHOOSE ALL THAT APPLY.
answer
dissolved gases composition temperature
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What are the names of the two types of lava flows?
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aa and pahoehoe
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What term describes hot mixtures of gas, ash, and pumice that race down the flanks of volcanoes at speeds up to 125 mi/hr?
answer
pyroclastic flow
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lava
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hot molten or semifluid rock erupted from a volcano or fissure, or solid rock resulting from cooling of this.
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pahoehoe flow
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basaltic lava forming smooth undulating or ropy masses. Smooth, shiny, or swirled surface.
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aa flow
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Basaltic lava forming very rough jagged masses with a light frothy texture. Lava with a rough surface.
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lahar
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type of mudflow or debris flow composed of a slurry of pyroclastic material, rocky debris, and water. Flows down from a volcano, typically along a river valley.
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How do Hawaiian-type calderas form?
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when magma gradually drains away from the magma chamber, causing the summit to collapse
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Which of the following are tabular, intrusive bodies?
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dikes and sills
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Which of the following terms describes an intrusive body?
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pluton
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Rocks melt due to the introduction of water mainly at ______________ .
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subduction zones
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In what ways can magma be generated from solid rock? CHOOSE ALL THAT APPLY.
answer
added water content increased temperature decrease in pressure
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What type of magma is considered to be intermediate in composition?
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andesitic
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Rhyolitc
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Igneous, volcanic rock, of felsic composition.
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Basaltic
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a dark gray to black dense to fine-grained igneous rock that makes up most of the ocean floor and is the most common type of lava.
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Granitic
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light colored, coarse grained igneous rock consisting mostly of quartz, feldspars, and micas.
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Peridotitic
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dense, coarse-grained igneous rock consisting mostly of the minerals olivine and pyroxene.
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Batholiths, such as those that make up the Sierra Nevada Mountains of California, form at great depth in the crust. How could they have been exposed at the surface?
answer
uplift and erosion
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_____ is the principle that explains why materials uplift to a certain elevation.
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Isostasy
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Using what you know about isostasy, how would the crust behave if a large glacier were removed?
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The crust would move up in elevation.
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If the Rocky Mountains were eroded, what would happen to the roots of the mountains?
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The roots would rebound upward.
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Which mountainous range is not the result of continental collision?
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Cascades
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The Ural Mountains were formed by the collision of which continents?
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Europe and Asia
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Which mountain range, formed via continental convergence, developed just before the Appalachians of North America?
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Caledonian Mountains
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Which feature would you expect to find associated with continental collisions?
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reverse faults
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What type of tectonic activity led to the formation and uplift of the Andes on the western margin of the South American Plate?
answer
formation of a volcanic arc
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Which of the following scenarios best describes the deformation that will occur in different parts of the crust?
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Brittle deformation is dominant in the shallow crust; ductile deformation is dominant in the deep crust.
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Which of the following is an example of how rocks will respond to compressional stress? (Note: there may be more than one correct answer.)
answer
reverse faulting folding
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Which tectonic stress will result in a lengthening of the crust?
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tension
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Which of the following statements best describes the orientation of rock layers for a structural dome or structural basin?
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Rock layers wrap around a single point.
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If strike and dips symbols were placed on a map of a basin, which way would the dips point?
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Dips point down toward the center.
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Which type of fold has rocks folding up in the middle?
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anticline
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What type of geologic faulting and folding structure is revealed by the rock layers in the road cut at the Sideling Hill placemark?
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syncline
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Which of the following terms is the best geologic description for the feature seen in the vicinity of the Compression placemark?
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anticlinal valley
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What type of fault is responsible for the stream pattern found in the Offset Streams folder?
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strike-slip
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What do geologists call small accreted crustal fragments that have a geologic history distinct from adjacent blocks?
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terranes
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Which is not an example of a small crustal fragment that could collide with a continental landmass, forming mountainous topography?
answer
the British Isles
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Which tectonic process has formed the mountain belts along the coasts of Alaska and British Columbia?
answer
Small crustal fragments have been accreted on the northwestern margin of the North American Plate.
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As an island arc system collides with the edge of a continental landmass, which tectonic scenario would be the result?
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The island arc is peeled off the oceanic plate and a volcanic arc is produced by subduction.
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When a terrane impacts the margin of a continental plate, what is the fate of the oceanic plate upon which the terrane has been traveling?
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The terrane cannot be subducted, which causes the oceanic plate on which it has been traveling to break off and continue downward beneath the continental crust.
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What is the geologic term for folded rocks with the bend at the bottom?
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syncline
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What are stromatolites?
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mats of blue-green algae that grew in mounds up from the sea floor
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What does a turbidite sequence consist of?
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a blanket of sand overlain by a sheet of mud
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What caused metamorphism to occur in the Blue Ridge District during the Alleghanian Orogeny?
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strong differential stress generated by compressional stress as rocks were thrust westward
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When did Pangea begin to break into smaller fragments?
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180 million years ago
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Which mountain range marks the boundary between the Indian and Eurasian Plates?
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Himalayas
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What kind of tectonic boundary is currently responsible for creating the Himalayas?
answer
Continent-Continent Convergent Boundary
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What geologic features were created in the Eurasian Plate when India underthrust beneath it?
answer
thrust faults thicker continental crust
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As India moves northward, China and Southeast Asia are being relocated to the east and southeast because of "escape tectonics." What feature is allowing them to "escape"?
answer
strike-slip faults
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When the Indian Plate collided with Eurasian Plate, why didn't it subduct?
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The Indian Plate is too buoyant. The Indian Plate is too thick.
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Which of the following statements best describes Wegener's idea of continental drift?
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Continents were formerly in different positions on the Earth and have shifted to their present locations over time.
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How was the fossil record of ancient life used to support Wegener's hypothesis about Pangaea?
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Fossils of identical organisms were found on several continents, indicating the continents were once joined.
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Late Paleozoic sedimentary rocks often contain extensive coal seams that were used to support the existence of Pangaea. What would the climate have been at that time and at the location where the coal deposits were formed, and what would it indicate about the continent's past latitude?
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Warm, humid climate near the Equator
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When matching up once-joined continents such as South America and Africa, the coastlines do not fit together as nicely as the continental shelves. Why might this be the case?
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The continental shelves are the edges of the continent. The shoreline simply shows where the sea level is in relation to topography.
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What evidence supports that the glaciers on the southern continents were once part of a single, massive ice sheet?
answer
Striations
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Which of the following lithospheric plates is not included among the seven largest?
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the Philippine plate
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Earth's lithospheric plates are composed of crust and which of the following layers?
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the outermost portion of the mantle
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Which of the following processes can be observed at the margins of lithospheric plates?
answer
All of the responses are correct.
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In studies of rock obtained from ocean basins all over Earth, the oldest ages obtained are approximately 200 million years before the present. Why have no older oceanic rocks been discovered?
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Due to tectonic activity, rocks on the ocean floor are continually recycled.
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Currently the Juan de Fuca plate is interacting with the North American plate where inland volcanoes and deep focus earthquakes are occurring. What type of plate boundary is this?
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a convergent plate boundary
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Where are tectonic plates located?
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at Earth's surface
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What are the three types of plate boundaries?
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divergent, convergent, and transform
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Which of the following statements about earthquakes with magnitude greater than 4.0 is most accurate?
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Earthquakes with magnitude greater than 4.0 occur in a pattern than correlates closely with plate boundaries.
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Which plate boundary is NOT associated with volcanic eruptions?
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transform
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Which phenomenon can explain the presence of volcanoes in the middle of the Pacific Ocean?
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hot spots
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Which type of plate boundary is most closely associated with uplifting continental regions and mountain building?
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convergent boundaries
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Name the correct order of rifting events.
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crustal upwarp, rift valley, linear sea, ocean
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The Gulf of Aden represents which part of the rifting sequence?
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linear sea
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The timing of __________ and continental breakup strongly correlate.
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flood basalt formation
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What feature connects the South American ParanΓ‘ and African Entedeka flood basalts?
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seamount chains
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What sequence of rocks would you expect rift valley evolution to produce, from oldest to youngest?
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volcanic rocks, clastic sedimentary rocks, deep sea sedimentary rocks
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Earth's outer layer is composed of seven dominant plates. What is the name of this rigid outer layer?
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lithosphere
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What type of plate interaction produces the San Andreas Fault?
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plates sliding past one another
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The bend in the stone walls in the town of Hollister, California are a result of
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a fault creep along the Calaveras Fault
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The offset of Wallace Creek is caused by __________.
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right-lateral movement along the San Andreas strike-slip fault
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What causes an earthquake such as the one that occurred in San Francisco in 1906?
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As plates move, stress builds up at the boundary. When the boundary eventually snaps, energy is released as an earthquake.
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What is the relationship between the crust and the lithosphere?
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All of the crust is contained within a larger layer called the lithosphere.
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What is the relationship between the mantle and the lithosphere?
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Some of the mantle is contained within a smaller layer called the lithosphere.
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What is the relationship between the mantle and the asthenosphere?
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All of the asthenosphere is contained within a larger layer called the mantle.
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What surface feature provides evidence for the location of hot spots?
answer
volcanoes within tectonic plates
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When will a hot spot volcano become extinct?
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when the volcano is carried away from the hot spot by the tectonic plate
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What surface feature would you expect to form if both a hot spot and a tectonic plate are stationary?
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a single volcano
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The point within Earth from which earthquake wave energy radiates is known by which of the following terms?
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focus
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On average, how many damaging earthquakes occur each year?
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1000
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Most earthquakes are the result of movement along which of the following features?
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faults
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During the 1906 San Francisco earthquake, the Pacific Plate moved 4.7 meters (15 feet) north relative to the North American Plate. Which of the following types of stress was exerted on the rocks during this earthquake?
answer
shear stress
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Which of the following events allows rocks on either side of a fault to rebound elastically, causing an earthquake?
answer
Friction along the fault plane is overcome.
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Which of the following describes the type of deformation experienced by rocks before an earthquake?
answer
slow deformation
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How are elastic rebound and elastic deformation different?
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Elastic deformation causes objects to bend, whereas rebound causes objects to return to their original shape.
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Elastic deformation before an earthquake is like _______, whereas rupture is like__________.
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stretching a rubber band; breaking a rubber band
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What will happen to a straight fence that undergoes elastic strain during an earthquake?
answer
The fence will bend in the direction of stress.
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Which of the following is a characteristic of an S wave?
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"shaking" particle motion at right angles to the direction of wave travel
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What best describes the movement of P waves?
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compression and expansion
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Amongst all seismic waves, surface waves __________.
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have the slowest velocity
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The names primary and secondary refer to ___________.
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wave speed
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What is a seismograph?
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an instrument used to record earthquake waves
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What is the underlying principle of seismograph construction?
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A heavy weight suspended within a moving box needs to overcome inertia, resulting in a slight delay in the motion of the weight after the box moves.
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When will the first earthquake waves arrive at a seismograph station?
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a short time after the earthquake occurs
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How long does it typically take for the first earthquake waves to arrive at a seismograph that is some distance away from the epicenter after the earthquake occurs
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several minutes
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Which of the following responses best describes the epicenter of an earthquake?
answer
The point on Earth's surface directly above the focus of an earthquake.
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In calculating the location of the epicenter of an earthquake, which of the following factors is most useful?
answer
the difference in arrival time of P and S waves
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In addition to a travel-time graph, at least how many seismograph stations are needed to determine the location of the epicenter of an earthquake?
answer
three
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As the distance between the epicenter of an earthquake and a seismograph station increases, so does the difference in the arrival times of the P and S waves. What causes this?
answer
P waves are faster than S waves
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Which statement provides the best explanation of why most earthquakes occur at plate boundaries?
answer
Plate boundaries are locations on Earth where portions of the lithosphere interact as they move past each other.
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Which of the following best describes liquefaction?
answer
the transformation of stable soil into loose, liquefied material that is able to rise toward Earth's surface
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Describe how sand volcanoes form.
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An earthquake causes loose, saturated sandy material to liquefy, shoot upward through fractures of a confining unit, and eventually erupt at the surface.
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__________ in the sandy layer causes the ground to subside after sand volcanoes form.
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Tighter packing
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Structures built on __________ will become unstable during an earthquake.
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loose, saturated sediments
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Which layer of Earth possesses the greatest thickness?
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mantle
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Which of the following rocks best represents the typical composition of oceanic crust?
answer
basalt
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Which region of Earth is composed of abundant amounts of granite?
answer
continental crust
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What is the major source of energy that drives the movements of the lithospheric plates on Earth?
answer
thermal energy from within Earth
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The magnetic field of Earth is thought to originate in which of the following layers?
answer
outer core
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Which of the following responses best describes why the lithospheric plates are able to move around on the surface of Earth?
answer
Because the asthenosphere is composed of weak, hot, and dense rock, the cold, rigid, less dense lithospheric plates are capable of moving on it.
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How do we know that the outer core of Earth is liquid?
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A shadow zone exists where S waves do not arrive on the side of Earth opposite the focus of an earthquake.
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What is the term for a tabular igneous pluton that occurs in an orientation that is discordant with the bedding surfaces of adjacent sedimentary rocks?
answer
dike
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What is the term for a tabular igneous pluton that occurs in an orientation that is concordant with the bedding surfaces of adjacent sedimentary rocks?
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sill
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Which of the following terms is best described as a massive pluton?
answer
batholith
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Batholiths are known to form the cores of mountain ranges such as the Sierra Nevada. What is the implication of this observation?
answer
Because batholiths form deep within Earth, the occurrence of one at the surface implies that it has since been uplifted and/or the rocks above have been removed.
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While working in the field, you find a dike cutting across some sedimentary rocks. What grain size would you expect to find in this pluton?
answer
fine-grained
question
Which of the following types of magma has the highest viscosity?
answer
rhyolitic
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In addition to viscosity, which of the following parameters has an influence on whether a volcanic eruption will be effusive or violent?
answer
amount of gas in the magma
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Which of the following types of lava will most likely lead to a volcanic eruption of an effusive nature?
answer
basaltic
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The subduction of oceanic crust under continental crust predominantly produces which of the following types of volcanic eruption?
answer
violent and explosive
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A hot spot that occurs in oceanic crust is likely to produce which of the following types of eruptions?
answer
quiet and effusive
question
The production of magma (magmatism) at divergent boundaries is characterized by which of the following? Select the two that apply.
answer
Melting caused by decompression. Outpourings of lava/magma originating from the mantle.
question
small waves of sand that form linear patterns perpendicular to the movement or flow of water or wind. They can be asymmetrical in shape, indicating unidirectional flow, or symmetrical (called oscillating), which indicates a "sloshing" back and forth of water.
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Ripple marks
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forms as sand particles are continuously moved up and over a sand ripple or dune. This feature indicates the direction of movement of water or wind. This type of structure can only be seen in a cross section of sediment or sedimentary rock.
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Cross-bedding
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indicate that the sediment was alternating between wet and dry. Mud cracks are produced by the shrinking of fine sediment as it slowly dries.
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Mud cracks
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dry, flat lakebeds found in the interiors of desert basins. The little precipitation in deserts pools in the basin centers and evaporates. Mud cracks and evaporites are common in playas.
answer
Playas
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fan-shaped sediment bodies formed from the deposition by mountain streams as they exit the range front and enter basins. Coarse and large sediments settle quickly at the mountain front, while smaller particles "fan" out onto the basin floor.
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Alluvial fans
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Large sedimentary slopes that extend from desert mountain fronts formed by the coalescence of alluvial fans.
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Bajadas
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Isolated, remnant knobs; exposures of rock that represent what's left of an old mountain range now drowning in its own sediments.
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Inselbergs
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Which of the following features at Yellowstone National Park is evidence for a magma chamber beneath the park?
answer
Geysers and hot springs (steam) Rising (or bowing upward) ground near Yellowstone River Welded tuff
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Which of the following pieces of evidence for a past volcanic eruption are present at Yellowstone National Park?
answer
A caldera rim Pyroclastic material Lava flows
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Yellowstone is best described as which of the following?
answer
An active volcano that has erupted in the last 1 million years
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Which of the following was a stage in the formation of Yellowstone caldera?
answer
Crust bows upward above a magma chamber.
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What is piled up along the cone of SP Crater that causes it to be so steep?
answer
cinders
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What causes vesicles to form in lava?
answer
trapped gas bubbles
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What is the difference between aa lava and pahoehoe lava?
answer
Aa lava has a prickly texture; pahoehoe has a smooth, ropy texture.
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What is one way that cinder cones differ from composite and shield volcanoes?
answer
Cinder cones are smaller than composite and shield volcanoes.
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Which one of the following statements is NOT true about andesite and basalt?
answer
Basaltic lava is thicker than andesitic lava
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What lies underneath volcanic features at Earth's surface?
answer
magma chambers and volcanic conduits
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What is the difference between a dike and a sill?
answer
A dike intrudes across sedimentary layers, and a sill intrudes between sedimentary layers.
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What is the difference between a dike and a sill?
answer
Dikes crosscut sedimentary layers; sills pry between horizontal layers.
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What is a volcanic conduit called after the conduit has solidified and been exposed by erosion?
answer
volcanic neck
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Why are volcanic rocks often exposed at Earth's surface as hills, ridges, and mountains surrounded by areas of lower elevation?
answer
Volcanic rocks are often more resistant to erosion than surrounding rock.
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What is a magma chamber called after the conduit has solidified and been exposed by erosion?
answer
batholith
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Why are the dikes and sills so easily distinguished in Sinbad Country?
answer
Basalt and the hardened, baked zones are more resistant to erosion than the sedimentary rocks.
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Why are sills only located fairly close to the Earth's surface?
answer
Sills form as magma intrudes with enough force to overcome the weight of the rocks above.
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Why don't the baked zones along the edges of the dikes and sills show evidence of metamorphism?
answer
They weren't under enough pressure and didn't remain hot for a long enough period of time.
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Approximately how long did it take for the magma that fed each dike in Sinbad Country to be injected?
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The magma was injected in a matter of hours to days.
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Henri Becquerel discovered
answer
radioactivity
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Who used radioactive decay to measure the age of rocks and minerals?
answer
Rutherford and Boltwood
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Who determined Ur-Pb, which gave a date of 1.64 billion years?
answer
Boltwood
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Radioactivity is _______.
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the spontaneous decay of an atom's nucleus to a more stable form.
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The heat from radioactivity______.
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Helps explain why the Earth is still warm inside.
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Radioactivity provides geologists_________.
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-with a powerful tool to measure -absolute ages of rocks and past geologic events.
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An element may have different atomic weights due to variations in the number of________.
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neutrons in the nucleus
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Atoms of the same element with differing atomic weights are called __________.
answer
isotopes
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Different isotopes of the same element__________.
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-Have different atomic mass numbers. -but behave the same chemically
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Geologists use decay rates of unstable isotopes to___________.
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determine absolute ages of rocks.
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Half-life of a radioactivity isotope is ___________.
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the time it takes for one half of the atoms of the original unstable parent isotope to decay to atoms of a new more stable daughter isotope.
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In radioactivity decay, during each equal time unit one half-life ____________.
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the proportion of parent atoms decreases by 1/2.
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By measuring the parent/ daughter ratio and knowing the half-life of the parent, geologists can calculate__________.
answer
the age of a sample containing the radioactive element.
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The parent/daughter ratio is usually determined by ________________.
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a mass spectrometer an instrument that measures the proportions of atoms with different masses.
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What materials can be dated?
answer
Most radiometric dates are obtained from igneous rocks.
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Lithosphere
answer
consists of the crust and uppermost part of the mantly, strong outermost shell
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Asthenosphere
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lower part of the mantle; weak because it is almost melted and under great pressure
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oceanic crust
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thin (basalt)
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continental crust
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thick less dense (granite)
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Types of rocks (3)
answer
Igneous Sedimentary Metamorphic
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Igneous
answer
rocks that have solidified from a molten state. Plutonic (intrusive)- solidifies as it cools before it reaches the earth's surface. Volcanic (extrusive)-reached the earth's surface before it hardened.
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sedimentary
answer
eroded from preexisting rocks and transported as sediment, then lithified.
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metamorphic
answer
resulting from changes in preexisting rocks due to pressure, heat and chemical changes.
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Absolute or Radiometric Age Dating
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uses isotopes and radioactive decay to date igneous rocks.
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Relative Age Dating
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uses fossils and stratigraphic laws to determine the relative ages of rock strata.
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Stratigraphic Laws
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basic geological principles that geologists use to decipher the 3 dimensional and time relationships of rock layers.
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Stratigraphic Principles (7)
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1. Law of Superposition 2.Law of Original Horizontality 3.Law of Lateral Continuity 4. Law of Cross-Cutting Relationships 5. Law of Uniformitarianism 6. Law of Inclusions 7. Law of Faunal Succession
question
Who discovered how to tell relative time with stratigraphic laws?
answer
Nicolas Steno
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Law of Superposition
Law of Superposition
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in any undisturbed succession of stratified rocks, the oldest are at the bottom, and the youngest is at the top.
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Law of Original Horizontality
Law of Original Horizontality
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all sedimentary rocks are originally deposited horizontally.
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Law of Lateral Continuity
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sedimentary rocks are laterally continuous over large areas.
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Simple types of Folding
answer
Anticline Syncline
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Who discovered the Principle of Cross-cutting Relationships and Law of Uniformitarianism
answer
James Hutton
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Principle of Cross-cutting Relationships
Principle of Cross-cutting Relationships
answer
an igneous intrusion or a fault must be younger than the rocks it intrudes or displaces.
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Principle of Uniformitarianism
answer
Principle that suggests that all of the past geologic history can be interpreted and understood in terms or geologic processes going on and, in many cases, observable at the present day.
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Who popularized the Law of Uniformitarianism?
answer
Sir Charles Lyell
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Law of Inclusions
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rock fragments that are present in another rock, must be older than the rock containing the fragments.
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Law of Faunal Succession
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fossil groups are succeeded by other fossil groups through time.
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Who proposed theory of continental drift?
answer
Alfred Wegener
question
Continental Drift
answer
-All continents had been joined together in a supercontinent (Pangaea) which broke apart forming other continents. -The continents then migrated to all regions of the globe through continental drift -Recieved blistering ridicule from geologists.
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Who proposed first geologic time scale based on radioactivity and suggested mechanism for continental drift = convection currents in the mantle?
answer
Arthur Holmes
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Who unified theory of plate tectonics?
answer
Harry Hess
question
Plate Tectonic Theory
answer
1. The outer portion of the crust and uppermost mantle (lithosphere) is composed of rigid units called plates. 2. The plates move. 3. Most of the world's large-scaled geological activity occurs near or at plate boundaries. 4. The interior of the plates are relatively quiet with fewer and milder earthquakes and volcanoes than at plate boundaries.
question
Hydrothermal Vents and Black Smokers
Hydrothermal Vents and Black Smokers
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1. Cold seawater sinks down through cracks in the crust. 2. Oxygen and potassium are removed from the seawater. 3. Calcium, sulfate, and magnesium are removed from the fluid. 4. Sodium, calcium, and potassium from the surrounding crust center the fluid. 5. The fluids have reached their highest temperature. Copper, zinc, iron, and sulfur from the crust dissolve in the fluids. 6. Hot fluids carrying dissolved metals rise up through crust.
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Types of Plate Boundaries (3)
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Divergent Convergent Transform
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Divergent
Divergent
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Moving away from each other
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Convergent
Convergent
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Move toward each other
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Transform
Transform
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Slide along the side of each other
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Convergent Boundaries
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-Oceanic/Oceanic -Oceanic/Continental -Continental/Continental
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Oceanic/Oceanic
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Ocean crust colliding with oceanic crust
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Oceanic/Continental
Oceanic/Continental
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Continental crust colliding with oceanic crust
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Continental/Continental
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Continental crust colliding with continental crust
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What is evidence of Plate Movement?
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-Same fossil species on different continents -Rock formation same on different continents -Magnetic polarity indicates an increasing age away from spreading centers -Hot spots
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Types of Seismic Waves (3)
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Surface Body
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Surface waves (2)
Surface waves (2)
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Travel along the Earth's surface; slowest of all the seismic waves Rayleigh waves Love waves
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Rayleigh waves
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Move vertically (like a wave on water)
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Love waves
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Move sideways with no vertical movement
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Body Waves (2)
Body Waves (2)
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Primary wave (P) Shear waves (S)
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Earthquake magnitudes represent ________.
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The amount of shaking and energy released by different earthquakes.
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Where were the strongest ground motions ever recorded in an American City?
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Northridge, CA