3.2 Weathering and rocks Flashcards Preview

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Flashcards in 3.2 Weathering and rocks Deck (24)
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1
Q

Biological weathering

A

Form of weathering caused by activities of living organisms. (Chemical and physical)

2
Q

Carboniferous limestone (karst)

A

Formed of remains of organic matter, mostly plants and shells.

3
Q

Why is limestone scenery unique?

A

It is hard but permeable.

It dissolves very slowly in acid water.

4
Q

Freeze-thaw

A

Form of physical weathering, common in mountains and glacial environments.

5
Q

Granite

A

Coarse-grained, intrusive, igneous rock, typically consisting of the mineral quartz, feldspar and mica.

6
Q

Joint

A

Vertical crack in a rock formed by compression. Weathering of joints in granite and limestone is responsible for the formation of swallow holes.

7
Q

Karst

A

Characteristic scenery of a carboniferous limestone region with underground streams.

8
Q

Mechanical (physical weathering)

A

Includes process like freeze-thaw and exfoliation or onion-skin.

9
Q

Scree

A

Angular sediment that collects at the foot of a mountain range or a cliff.

10
Q

Solution

A

Occurs on rocks like chalk and limestone that contain calcium carbonate. When dissolved in rain CO2 forms weak carbonic acid.

11
Q

Tor

A

Isolated mass of rock, often granite, left upstanding on a hilltop after the surrounding rock has been broken down and removed.

12
Q

Weathering

A

Process by which exposed rocks are broken down on the spot by the action of rain, frost, wind and other elements of weather.

13
Q

Salt crystallization

A

Causes decomposition of rocks by solution of salt.

14
Q

Exfoliation

A

When rocks heat up and cool down (contract) at nightime, stresses occur in outer layers casting the rock to peel.

15
Q

Aggresivity

A

Ability of water to de solve calcium carbonate

16
Q

Dolines

A

Large depressions formed by solution of limestone

17
Q

Uvaalas

A

Large depressions (30 m in diameter)

18
Q

Swallow holes (sinks)

A

Smaller depressions in the landscape

19
Q

Stalactites

A

Develop from the top of caves

20
Q

Stalagmites

A

Formed on the base of the cave

21
Q

Speleothems

A

Cave deposits formed by precipitation of calcium carbonate

22
Q

Granite

A

Igneous, crystalline rock.

23
Q

Watershed

A

Drainage basin divide

24
Q

Disintegration

A

Found in hot desert areas where there is a large diurnal temperature range