Chapter 8: Mountains, Basins & Continental Margins

The average thickness of oceanic crust is:

7 km

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

A volcanic island forms and subsides.

If it contained oil, which layer would most likely produce an oil seep on the surface?

A, a permeable sandstone

What are the characteristics of natural salt (NaCl) deposits? -deposited in layers -very soluble in water -can flow to form domes

All of these are characteristics of natural salt deposits.

Which site would most likely contain oil in the subsurface?

C, a permeable sandstone

Which of the following is a valid description of features within continental interiors?

The continental platform has nearly horizontal sedimentary rocks deposited on crystalline basement.

Why is there a basin associated with some thrust faults?

Thrust sheets depress the crust in front of the thrust.

Which of the following is NOT a setting in which regional mountain belts form? -subduction zone -upwelling of the mantle -the collision of India with Asia -continental collision -passive margin

passive margin

Why did the Great Barrier Reef in Australia grow upward, forming the largest organic structure on Earth?

sea level rose

Which of the following places would NOT be a good place to visit a reef?

shallow, clear waters off Iceland

A continental shelf along a passive margin is below sea level because...

the crust has been thinned by normal faulting.

Submarine canyons in the continental slope are eroded by...

turbidity currents

Which of the numbered features on this figure is a continental shelf?

1

Which of the numbered features on this figure is a continental slope?

2

The average thickness of continental crust is:

30-50 km

Which of these numbered features is a fold and thrust belt?

4

An accretionary prism is...

a wedge-shaped zone of faults, folds, and metamorphosed rocks formed along the upper parts of a subduction zone as material is scraped off

The process of adding a terrane to another landmass is called....

accretion

Oil that reaches the surface can form... -an oil seep -tar sands. -tar pits

all of these choices are correct

Once oil and gas are formed, they... -rise toward the surface. -are lighter than water. -flow most easily through permeable rocks, such as sandstone. -can be prevented from reaching the surface if they are trapped by impermeable layers

all of these choices are correct

What is the main cause of uplift during a continental collision?

an almost doubling of the thickness of continental crust

The image shows Stone Mountain in Georgia, a feature made of granite that was uncovered by erosion that removed the overlying and flanking softer rocks. What is the best name for this feature?

an erosional remnant

For a terrane to become attached to a continent, it typically...

enters a subduction zone, where it is scraped off the subducting plate and added to the continent.

A mountain or hill that remains when adjacent areas have eroded to lower levels is a(n)

erosional remnant

Regional elevation can be increased by...

heating the crust and mantle

The principle that regional elevations adjust to the types and thicknesses of rocks at depth is known as...

isostasy

Regional elevations on land are primarily controlled by...

the thickness of continental crust.

If you had this type of deformation of a region, it would...

thicken the crust and cause uplift.

If you erode material off of a region, it would...

thin the crust

If you had this type of deformation of a region, it would....

thin the crust and cause subsidence.