Exam 15: Ocean Basins

What is a rock dredge?

What is a rift valley?

Where is the deepest place on Earth, and how deep is the ocean floor below sea level?

Oceans cover about ____ percent of Earth's surface.

What is a large piece of space debris, such as an asteroid or comet, that crashes into a planet?

What are carbonate platforms and where are modern-day examples found?

Compare and contrast seamounts and long island chains.

Active continental margins where an oceanic plate sinks into the mantle are called ____ zones.

The Atlantic Ocean opened as the supercontinent Pangaea rifted apart about 250 million years ago.

____ are a form of sediment gravity flows in which a turbulent mixture of sediment and seawater, which is more dense than seawater alone, flows downslope along the seafloor.

At seafloor vents, bacteria produce energy from hydrogen sulfide in a process called ____.

When two oceanic plates converge, the sinking plate pulls the sea floor down to create ____.

Trenches along subduction zones form because the two plates are spreading apart.

If the Earth is around 4.6 billion years old, why is the oldest oceanic crust no older than 200 million years?

What is the composition and density of the continental crust and oceanic crust?

Mid-Ocean Ridges are examples of _______________ plate boundaries.

Oceanic crust is ____ than continental crust and therefore ____ isostatically.

Sediment gravity flows can erode steep-sided valleys in the seafloor called ____.

What are the two types of sediment in the uppermost layer of the oceanic crust and where are they found?

Discuss the three factors that contribute to sinking after a volcanic island forms.