文档介绍：HIGHER GEOGRAPHY LITHOSPHERE LIMESTONE SCENERY
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There are several types of limestone in Britain - this presentation will concentrate on Carboniferous Limestone and look at the Yorkshire Dales in particular.
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These limestones were formed from the fossilised remains of countless marine plants and animals, such as corals, which lived during the Carboniferous period, 345 - 280 million years ago.
These former sea beds were moved from the equator due to continental drift and forced upwards during the Hercynian orogeny or mountain building period, 280 - 230 million years ago.
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Britain during the Carboniferous.
Here, on the Great Barrier Reef off the Australian coast, is the world’s biggest expanse of coral reef.
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Brain coral, one of the main reef building species.
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The Dolomite mountains in the Alps - these 3000 metre peaks are made of limestone and were once the bed of the sea!
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Limestone - Chemical weathering
Limestone = Calcium Carbonate
Rainwater = Carbonic Acid
Carbonic Acid dissolves Calcium Carbonate
This is called CARBONATION, a type of solution weathering.
Or … H2O + CO2= H2CO3
CaCO3 + H2CO3 = Ca(HCO3)2
Calcium Carbonate Dilute Carbonic Acid Calcium Hydrogen Carbonate (Soluble)
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Carbonation / solution weathering also attacks buildings made from limestone
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This type of landscape is more correctly known as Glacio Karst - glacio because it has also been glaciated, and karst after an area in Slovenia, which gives its name to this kind of landscape.
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The dry, barren landscape of limestone country.
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