Geology Chapter 9

In which state would you NOT expect to find karst?

California

Rainwater becomes acidic as it dissolves limestone.

False

​_______________ is soil containing frozen groundwater.

Permafrost

_______________ clay is most involved with swelling soils.

Smectite

Sinkholes are formed as a result of the collapse of a limestone cavern.

True

Landslides due to the melting of permafrost ____.

are shallow and only affect a few meters as the thawed layer slides off the remaining permafrost

A sinkhole is most likely to form ____.

at the end of a dry season

​Land subsidence increases the hazard of ____.

flooding

Exposure of limestone rock creates an uneven and potholed surface called _______________.

karst

The effects of land subsidence due to groundwater extraction are generally ____.

permanent and irreversible

Swelling soils are typically due to ____.

smectite clay increasing in volume as it absorbs water

What creates caverns in limestone rock?

Acidic rainwater dissolves limestone rock, leaving empty caverns.

​In order to dissolve limestone, groundwater must be slightly _______________.

acidic

The damage due to swelling soils results in losses of ____ in the United States.

billions of dollars, primarily through damage to highways and streets,

Limestone consists of rock made from ____.

calcium carbonate

Clays play a role in land subsidence by ____.

collapsing into compact layers when dried, increasing subsidence

Thawing permafrost _______________.

increases climate change dangers by injecting warm water into the Arctic Ocean

In addition to limestone, evaporites like ____ and ____ can create underground cavities.

smectite; salt

A(n) _______________ hangs from the ceiling of a cavern.

stalactite

Land subsidence that results from petroleum mining ____.

can be mitigated by pumping fluid into the well

The decomposition of peat layers in soils ____.

can result in flooding in land drained for farming

Water and soil percolating through karst fissures can create a small depression through the process of _______________.

dissolution

​The uneven, potholed surface of karst is caused by ____.

erosion from ancient streambeds

The level to which _______________ rises in a well is the location of the water table.

groundwater

In order for limestone to collapse to form a major sinkhole, the ground above must be ____.

thick and rich in cohesive clay to allow a cavern to form