To help you master concepts from Chapter 18 (The Sea Floor), take this sample examination. Bon Voyage!

1			Most ocean water probably came from: Need a Hint?
			A)	comets impacting Earth's surface.
			B)	volcanic degassing of the planet.
			C)	rain falling into the ocean basins.
			D)	melting of polar ice caps.
2			Which is true of the continental shelf? Need a Hint?
			A)	it is a shallow submarine platform at the edge of continents.
			B)	it slopes very gently seaward.
			C)	it has variable width.
			D)	all of these.
3			The average slope angle of the continental shelf is: Need a Hint?
			A)	0.1 degree
			B)	10 degrees
			C)	1 degree
			D)	0.01 degree
4			The average slope of the continental slope is: Need a Hint?
			A)	1-2 degrees.
			B)	4-5 degrees.
			C)	10-12 degrees.
			D)	more than 30 degrees.
5			Great masses of sediment-laden water that are pulled by gravity are called: Need a Hint?
			A)	turbidity currents.
			B)	mud flows.
			C)	debris flows.
			D)	none of these.
6			Oceanic trenches: Need a Hint?
			A)	are narrow deep troughs.
			B)	parallel the edges of continents and island arcs.
			C)	are typically 8-10 km deep.
			D)	all of these.
7			Which is characteristic of mid-ocean ridges? Need a Hint?
			A)	shallow focus earthquakes.
			B)	high heat flow.
			C)	basalt eruptions.
			D)	all of these.
8			Reefs parallel to the shore but separated by a broad lagoon are called: Need a Hint?
			A)	fringing reefs
			B)	barrier reefs.
			C)	atolls.
			D)	patch reefs.
9			Pelagic sediment could be composed of: Need a Hint?
			A)	red clay.
			B)	volcanic ash.
			C)	siliceous ooze
			D)	all of these.
10			The portion of the continental margin that marks the true edge of the continent is: Need a Hint?
			A)	continental shelf.
			B)	continental slope.
			C)	continental rise.
			D)	abyssal plain.
11			Fragments of ocean floor that escape subduction are known as: Need a Hint?
			A)	ophiolites.
			B)	migmatites.
			C)	granulites.
			D)	guyots.
12			The continental rise is: Need a Hint?
			A)	a wedge of sediment at the base of the continental slope.
			B)	an uplifted portion of the continent.
			C)	a portion of the mid-ocean ridge.
			D)	a flat-topped seamount.
13			Geologically quiet coasts are termed: Need a Hint?
			A)	Active continental magins.
			B)	Atolls.
			C)	Passive continental margins.
			D)	Subduction zones.
14			Abyssal plains are formed by: Need a Hint?
			A)	deposition from turbidity currents over time.
			B)	slow accumulation of pelagic sediment.
			C)	deposition of sediment from rivers.
			D)	none of these.
15			The deepest portions of the ocean basins are: Need a Hint?
			A)	ocean trenches.
			B)	mid-ocean ridges.
			C)	abyssal plains.
			D)	continental slopes.
16			Active volcanoes are associated with: Need a Hint?
			A)	Active continental margins.
			B)	Ocean islands.
			C)	Mid-Ocean Ridges.
			D)	all of these.
17			Guyots are: Need a Hint?
			A)	active volcanoes.
			B)	extinct volcanoes.
			C)	stratovolcanoes.
			D)	coral reefs.
18			Oceanic fracture zones are associated with: Need a Hint?
			A)	transform faults.
			B)	convergent plate boundaries.
			C)	fringing reefs.
			D)	manganese nodules.
19			Terrigenous sediment in the ocean: Need a Hint?
			A)	is derived from erosion of the continents.
			B)	is derived from volcanic eruptions.
			C)	is composed of shells of microscopic organisms.
			D)	is precipitated from seawater.
20			The oldest seafloor on Earth is not more than: Need a Hint?
			A)	200 million years old.
			B)	2 billion years old.
			C)	20 million years old.
			D)	2 million years old.