Flashcards in 3.2 Weathering and rocks Deck (24)
Form of weathering caused by activities of living organisms. (Chemical and physical)
Carboniferous limestone (karst)
Formed of remains of organic matter, mostly plants and shells.
Why is limestone scenery unique?
It is hard but permeable.
It dissolves very slowly in acid water.
Form of physical weathering, common in mountains and glacial environments.
Coarse-grained, intrusive, igneous rock, typically consisting of the mineral quartz, feldspar and mica.
Vertical crack in a rock formed by compression. Weathering of joints in granite and limestone is responsible for the formation of swallow holes.
Characteristic scenery of a carboniferous limestone region with underground streams.
Mechanical (physical weathering)
Includes process like freeze-thaw and exfoliation or onion-skin.
Angular sediment that collects at the foot of a mountain range or a cliff.
Occurs on rocks like chalk and limestone that contain calcium carbonate. When dissolved in rain CO2 forms weak carbonic acid.
Isolated mass of rock, often granite, left upstanding on a hilltop after the surrounding rock has been broken down and removed.
Process by which exposed rocks are broken down on the spot by the action of rain, frost, wind and other elements of weather.
Causes decomposition of rocks by solution of salt.
When rocks heat up and cool down (contract) at nightime, stresses occur in outer layers casting the rock to peel.
Ability of water to de solve calcium carbonate
Large depressions formed by solution of limestone
Large depressions (30 m in diameter)
Swallow holes (sinks)
Smaller depressions in the landscape
Develop from the top of caves
Formed on the base of the cave
Cave deposits formed by precipitation of calcium carbonate
Igneous, crystalline rock.
Drainage basin divide