Chapter 18 Flashcards
What is a Submarine Canyon?
A B shaped valley that run across continental shelves and down continental slopes.
What are Abyssal fans?
Great fan shaped deposit of sediment on the deep sea floor at the base of many submarine canyons.
what feature is present at active continental margins but not at passive continental margins?
oceanic trench
What is a Turbidity Current?
A flowing mass of sediment-laden water that is heavier than clear water and therefore flows downslope along the bottom of the sea or a lake.
What is Passive continental margin?
A margin that includes a continental shelf, continental slope, and continental rise that generally extends down to an abyssal plain at a depth of about 5 kilometers.
What is continental rise?
A wedge of sediment that extends from the lower part of the continental slope to the deep-seafloor.
What is a contour current?
A bottom current that flows parallel to the slopes of the continental margin.
What is an active continental margin?
A margin consists of a continental shelf, a continental slope, and an oceanic trench.
What is an oceanic trench?
A narrow, deep trough parallel to the edge of a continent or an island arc.
What is a mid-oceanic ridge?
A giant mountain range that lies under the ocean and extends around the world.
What is a rift Valley?
A tensional valley bounded by normal faults. rift valleys are found at diverging plate boundaries on continents and along the crest of the mid-oceanic ridge.
What are fracture Zones?
Major line of weakness in Earth’s crust that crosses the mid-oceanic ridge at approximately right angles.
What are seamounts?
Conical undersea mountains that rise 1,000 meters above the sea floor. Some rise above sea level to form islands.
WHat are guyots?
Flat-topped seamount.
What is reef?
A resistant ridge of calcium carbonate formed on the sea floor by corals and coralline algae.
