Geology 300, Physical Geology Spring 2019 Quiz Chapter 18, Seafloor Name MULTIPLE CHOICE. Choose the one alternative that best completes the statement or answers the question. 1) Abyssal fans are made up of sediment that has moved down submarine canyons A) deep sea B) land-derived C) continental slope D) abyssal E) marine pelagic 2) Turbidity currents are great masses of sediment-laden water that are pulled downhill by. A) Earth's rotation B) landslides C) submarine canyons D) gravity E) earthquakes, storms, volcanic eruptions 3) A(n) continental margin usually lacks a continental rise and an abyssal plain and is associated with convergent plate boundaries. A) subducting B) remote C) active D) transform E) passive 4) Earthquakes, volcanoes, Benioff seismic zones, and island arcs are all associated with this sea floor feature. A) oceanic trench B) passive margin C) seamounts D) guyots E) abyssal plains 5) Geologists' ideas about the composition of ocean crust are greatly influenced by the study of. A) the asthenosphere B) ophiolites C) continental volcanoes D) the Mohorovicic discontinuity E) chert 6) Turbidity currents flow down the continental slope until they come to rest on. A) the continental shelf B) the mid-oceanic ridge C) the abyssal plain D) a submarine trench E) a guyot Page 1 of 5 Compiled by: A. Reed Last saved: 1/29/2019 Print Date: 1/29/2019
7) Most geologists think that the flat summits of seamounts. A) are remnants of the continental shelf B) are remnants of plateau basalts C) were eroded flat by wave action D) are fault surfaces E) are uplifted sea floor 8) The crests of mid-oceanic ridges are commonly associated with. A) Benioff zones B) rift valleys C) pelagic sediments D) abyssal plains E) barrier reefs 9) A basic tool for indirectly studying the sea floor is the, which measures water depth. A) gravimeter B) submersible C) echo sounder D) drilling ship E) rock dredge 10) Water depth increases over a continental shelf to the outer edge depth of to meters. A) 400; 500 B) 500; 600 C) 100; 200 D) 300; 400 E) 200; 300 11) are rounded masses of rock that form when molten lava erupts into cold water. A) Sheeted dikes B) Gabbro mountains C) Pillow lava D) Dunite dikes E) Columnar basalts 12) is an island on a mid-oceanic ridge. A) Madagascar B) Hawaii C) Cuba D) Japan E) Iceland 13) In a passive continental margin, there is a lack of. A) seamounts B) guyots C) no riverine discharge D) earthquakes, volcanoes, and young mountain belts E) sediments 14) Oceans cover percent of the Earth's surface. A) 80 B) 50 C) 70 D) 90 E) 60 Page 2 of 5 Compiled by: A. Reed Last saved: 1/29/2019 Print Date: 1/29/2019
15) are V-shaped valleys that run across continental shelves and down continental slopes. A) Submarine canyons B) Guyots C) Fracture zones D) Submarine trenches E) Rift valleys 16) parallel the shore, but are separated from it by wide, deep lagoons. A) Barrier reefs B) Guyot reefs C) Atolls D) Fringing reefs E) Patch reefs 17) proposed that the three types of coral reefs are related to each other by subsidence of a central volcanic island. A) Charles Darwin B) Alred Wegner C) Diane Carlson D) Charles Plummer E) Charles Lyell 18) is the name applied to hot springs on the seafloor where 350 degree Celsius metal-rich solutions are discharged into the cold waters of the ocean. A) Black smokers B) Fumaroles C) Hot spots D) Ophiolites E) Andesite 19) The continental rise typically ends at a(n) at a depth of about 5 kilometers. A) trench B) abyssal plain C) mid-oceanic ridge D) slope E) continental slope 20) Oceanic trenches are marked by. A) no seismicity B) low heat flow C) positive gravity anomalies D) high heat flow E) shallow depths 21) A is a bottom flowing current that flows parallel to the slopes of the continental margins. A) surface current B) density flow C) turbidity current D) coriolis current E) contour current Page 3 of 5 Compiled by: A. Reed Last saved: 1/29/2019 Print Date: 1/29/2019
22) Many guyots and seamounts are aligned in chains (for example the Hawaiian Islands and Emperor seamounts) that form major. A) Benioff zones B) trench systems C) aseismic ridges D) continental rises E) mid-ocean ridges 23) Mid-oceanic ridges are often marked by lines of that carry and precipitate metals. A) seismic ridges B) ocean trenches C) ocean currents D) submarine volcanoes E) hot springs 24) currents are bottom currents that flows parallel to the slopes of the continental margin. A) Abyssal B) Newfoundland C) Contour D) Turbidity E) Gulf Stream Page 4 of 5 Compiled by: A. Reed Last saved: 1/29/2019 Print Date: 1/29/2019
1) B 2) D 3) C 4) A 5) B 6) C 7) C 8) B 9) C 10) C 11) C 12) E 13) D 14) C 15) A 16) A 17) A 18) A 19) B 20) B 21) E 22) C 23) E 24) C Page 5 of 5 Compiled by: A. Reed Last saved: 1/29/2019 Print Date: 1/29/2019