Question 1

___________are highly detrimental to healthy growth of coral reefs.

Accepted Answer

A)  Warm water temperatures 
B)  Vigorous wave action and water circulation 
C)  Clear, sunlit waters 
D)  Nutrient- rich waters, cloudy with luxuriant plankton growth

Question 2

_________sediments represent weathered rock and mineral particles eroded mainly from land areas.

Accepted Answer

A)  Biogenous 
B)  Terrigenous 
C)  Hydrogenous 
D)  Exogenous

Question 3

On average, the slope across a continental shelf is about ____________.

Accepted Answer

A)  0.001° 
B)  1° 
C)  5° 
D)  1.5°

Question 4

In terms of distinctiveness in depth and ruggedness, the three different regions of the seafloor are: __________.

Accepted Answer

The answer of In terms of distinctiveness in depth and...

Question 5

What thicknesses of unconsolidated sediment typically covers the deep abyssal plains?

Accepted Answer

A)  about 1500 to 4500 metres 
B)  <100 metres 
C)  about 5000 to 9000 metres 
D)  about 500 to 1000 metres

Question 6

Which ocean floor sediment type includes manganese nodules?

Accepted Answer

A)  biogenous 
B)  orogenous 
C)  terrigenous 
D)  hydrogenous

Question 7

How do calcareous oozes form?

Accepted Answer

A)  The particles settle out from calcite- rich turbidity currents at depths greater than 4,500 metres. 
B)  The particles are precipitated in the water column below the depth of sunlight penetration and then sink to the bottom. 
C)  The particles are precipitated by deep- ocean, bottom- dwelling, carbon- fixing bacteria. 
D)  The particles are biogenically or chemically precipitated in warm, surface waters and sink to the bottom.

Question 8

What is the magma source for mid- ocean ridge basalt?

Accepted Answer

A)  by spontaneous melting in mafic magma chambers within oceanic crust 
B)  along block faults by frictional heating deep in the oceanic lithosphere 
C)  It all comes from Hawaii then flows out laterally along the ridge system. 
D)  decompression melting in the shallowest part of the asthenosphere beneath the ridge

Question 9

Graded bedding is _____________.

Accepted Answer

A)  an upwards decrease in clastic particle size within a single sediment layer 
B)  a Canadian quality- rating scale for different brands of mattresses 
C)  an accumulation of sedimentary beds beginning with sandy beds at the bottom and ending with clayey beds at the top 
D)  the layering in coral limestone produced by the combined chemical action of living coral animals and submarine, hot spring emissions

Question 10

___________consists of diatom and radiolarian remains.

Accepted Answer

A)  Terrigenous ooze 
B)  Reddish clay ooze 
C)  Siliceous ooze 
D)  Calcareous ooze

Question 11

Which of the following about deep ocean trenches is false?

Accepted Answer

A)  They are sites where plates plunge back into the mantle. 
B)  They are geologically very stable. 
C)  They are long and narrow depressions. 
D)  They may act as sediment traps.

Question 12

Which is the best description of a mid- ocean ridge?

Accepted Answer

A)  50- 200 metre- wide rough mounds of metal sulphides that encircle the globe continuously for more than 70,000 kilometres 
B)  narrow ridges 5- 10 km wide, 3- 4 kilometres high, and 10- 50 km long with active erupting volcanoes every 1- 2 kilometres of ridge length 
C)  1000 to 4000 kilometre wide, block faulted regions of sparsely sedimented, basaltic seafloor raised 2- 3 kilometres above the regional abyssal plains 
D)  thick sequences of folded and faulted sedimentary rocks pushed up 500- 1000 metres above the regional seafloor

Question 13

Trenches are often parallel to, and genetically related to ________.

Accepted Answer

A)  volcanic island arcs or continental margin mountain belts with active volcanism 
B)  hot spot volcanic island chains 
C)  mid- ocean ridges 
D)  oceanic transform faults

Question 14

Seamounts ____________.

Accepted Answer

A)  are submarine canyons found near Australia 
B)  form only in the Pacific Ocean basin 
C)  are a special type of oceanic trench 
D)  are volcanoes that form on the ocean floor

Question 15

Which ocean floor sediment type includes quartz sand?

Accepted Answer

A)  terrigenous 
B)  orogenous 
C)  biogenous 
D)  hydrogenous

Question 16

The largest regions underlain by deformed marine sediments occur on____________ .

Accepted Answer

A)  mid- ocean ridges 
B)  deep ocean basins 
C)  active continental margins 
D)  passive continental margins

Question 17

Where in the oceans are biologic communities thriving without sunlight?

Accepted Answer

A)  in shallow water, coral reefs 
B)  in muds of deep- ocean trenches 
C)  around fissure vents for flood basalts 
D)  around seafloor, hot spring vents in areas of active volcanism

Question 18

Water depths and seafloor bathymetry (submarine topography) are now routinely determined by____________

Accepted Answer

A)  computerized, satellite- mounted, weighted lead- lines 
B)  ship- mounted radar with fiber- optical satellite uplink systems 
C)  ship- mounted or towed echo sounders 
D)  by satellite- linked, laser reflector systems

Question 19

________is the oceanward edge of a continental shelf.

Accepted Answer

A)  The top of the abyssal plain 
B)  The base of the continental rise 
C)  The deepest portion of a deep- ocean trench 
D)  The top of the continental slope

Question 20

Which one of the following statements concerning actively spreading mid- ocean ridges is false?

Accepted Answer

A)  They are places where young lithosphere is added to the edges of spreading, oceanic plates. 
B)  Sediments include thick siliceous ooze deposits and sandy turbidite beds. 
C)  Terrigenous sediment coverings are very thin or absent. 
D)  They are sites for submarine eruptions of basaltic lava.

Exam 2: Minerals: the Building Blocks of Rocks