Chapter 10

what causes the seafloor to deepen across a typical continental slope?

a and b only. a) thinning of continental crust because of normal faults, b) a transition from continental crust to oceanic crust

what processes can occur in front of or behind some island arcs?

a and b only. a) trench rollback, b) back-arc rifting

what is a popular model for the formation of an atoll?

a volcanic island forms subsides

in the atlantic ocean, where is the oldest oceanic crust?

abyssal plain next to the continents

what are some uses of magnetic reversals?

all of the above.

why are the patterns showing the age of the seafloor symmetrical in the Atlantic Ocean but not the Pacific Ocean?

both A and B. A) spreading along the Atlantic ridge added seafloor to plates on both sides, B) subduction has consumed large areas of old oceanic crust in the Pacific

if you were looking for graded beds, where would be a good place to start?

in a submarine fan

what has happened to the Pacific Ocean in the last 200 million years?

it became smaller as the Atlantic Ocean opened.

if you drilled into an oceanic plateau, what would you most likely find?

large amounts of basalt derived from melting in the mantle.

how do most oceanic islands and seamounts form?

they are constructed by volcanic eruptions that first occur under water