Geology Exam 3
What sequence of rocks would you expect rift valley evolution to produce, from oldest to youngest?
volcanic rocks, clastic sedimentary rocks, deep sea sedimentary rocks
Which statement regarding Baja Mexico and the city of Los Angeles is correct?
Both are located on the Pacific Plate.
What are the properties of the mantle?
Contains a weak layer below the lithosphere contains rocks rich in magnesium and iron both liquid and solid components
Which response best explains the absence of volcanoes and earthquakes at a passive continental margin?
Earthquakes and volcanoes are rare due to the distance from any active boundaries.
Which of the following best describes the pattern of heat flow through the lithosphere?
Heat flow is high where crust is being created
What are the properties of the crust?
Is earth's stiff, ridged, and rocky shell solid Part of this layer has a relatively homogenous composition, while another part is composed by many types of rocks
Which of the following is a true statement regarding the Farallon Plate?
It was an oceanic plate that used to exist between the Pacific and North American Plates.
How is ocean depth calculated by sonar?
Ocean depth is calculated by the time it takes sound waves to travel from the ship to the seafloor and back to the ship again.
Identify which seismic waves can pass through the core?
P wave
Which of the following statements describes the relationship between the strengths of rocks and how close the temperature is to the melting point of iron?
Rocks that are cold, or further away from the melting point of iron, are strong. Rocks that are warm, or close to the melting point of iron, are weak.
Which of the following is true regarding shallow subduction angles?
Sediment and seamounts are scraped from the downgoing plate to produce an accretionary wedge.
Which of the following describes a seismic reflection survey?
Seismic signals produced from an explosion travel to the ocean floor, penetrate some layers, and reflect back to a receiver.
Which of the following correctly describes the Atlantic and Pacific continental margins?
The Atlantic is a passive margin, and the Pacific is an active margin.
What happened to the Farallon Plate approximately 20 million years ago?
The San Andreas and Queen Charlotte Faults were established where it was subducted beneath the North American plate
What happens to the ridgedness as we go down earths layers?
The ridgedness increases
Choose the true statement regarding the continental shelf.
The shelf represents the flooded portions of continents
Which statement best explains the formation of seamounts?
They represent volcanoes situated over mantle plumes that have since moved away from their source of magma and subsided.
Which of the following best describes what occurs during convection?
Warmer, less dense material rises
What does the iron melting curve tell us about the state of rocks in the Earth?
When the iron melting curve is to the right of the geotherm, rocks are solid. When the iron melting curve is to the left of the geotherm, rocks are molten.
Which feature would you expect to find at the mouth of a submarine canyon?
a deep sea fan
Strike-slip faulting of the Queen Charlotte and San Andreas fault systems shows __________.
a right lateral sense of motion
Turbidity currents travel from the shelf through __________, creating deep sea fans
canyons
Determine which type of heat transfer occurs in each layer or at D'' layer?
conduction
Determine which type of heat transfer occurs in each layer or at inner core?
conduction
Determine which type of heat transfer occurs in each layer or at the boundary between mantle and lithosphere?
conduction
What are properties of the core?
contains iron and nickel
Moving off the east coast of North America, identify the sequence of environments you would encounter as you move deeper into the Atlantic Ocean.
continental shelf, continental slope, continental rise, abyssal plain
Which is not one of the three broad zones describing the ocean floor?
continental slope
Determine which type of heat transfer occurs in each layer or at the mantle?
convection
Determine which type of heat transfer occurs in each layer or at outer core?
convection and conduction
The plate boundary in the U.S. Pacific Northwest is _____, while most of the California coast is characterized by a _____ plate boundary.
convergent; transform
Name the correct order of rifting events.
crustal upwarp, rift valley, linear sea, ocean
Satellites record slight variations on the sea surface using radar. What do these slight variations represent?
features on the seafloor
The timing of __________ and continental breakup strongly correlate.
flood basalt formation
The Gulf of Aden represents which part of the rifting sequence?
linear sea
Which of the following layers contains mostly molten or liquid rock?
outer core
What feature connects the South American Paraná and African Entedeka flood basalts?
seamount chains
What type of ocean exploration technique is the best for determining potential oil and gas reservoirs?
seismic reflection survey
Name all of the ocean bottom features shown in the image of the Los Angeles coast produced by the multibeam sonar?
shelf, canyons, slope, rise
If the subduction angle is steep, the overriding plate may undergo __________.
subduction erosion
Identify which seismic waves cannot pass through the core?
surface wave and S wave
The speed at which seismic waves travel through Earth's layers depends largely on _____.
the temperature and composition of the material
Which coast represents an active continental margin?
the west coast of South America