![]() Characteristics of carboniferous limestone landscapes Limestone is formed of calcium carbonate from the remains of sea creatures and corals on the seabed. There are different types of limestone in the UK:
As the weak carbonic acid in rainwater slowly dissolves carboniferous limestone via chemical weathering, especially as it is a pervious rock which means water flow is restricted to the bedding planes and joints, making them more vulnerable to weathering. At the surface: Limestone pavements are flat areas of limestone blocks called clints, which are separated by weathered joints called grikes. Swallow holes are weaknesses in the rock that have been weathered to form holes. Limestone gorges are steep sided gorges which are formed when a cavern underground collapses. Dry valleys are formed when a river which used to flow on the surface (due to the ground being frozen during an Ice Age or due to a higher water table) now flows underground. Resurgent rivers are rivers that emerge to the surface when the limestone is on top of impermeable rock. This BBC Bitesize video shows these processes: http://www.bbc.co.uk/education/clips/z3jfb9q Underground: Caverns form when water flows through joints in the rock or down swallow holes. Stalactites and stalagmites form in caverns when the dissolved minerals in the water solidify and build up. When they meet they form a pillar and when it flows as a sheet, a curtain builds up. This BBC Bitesize video demonstrates these processes: http://www.bbc.co.uk/education/clips/zjs8q6f Uses of carboniferous limestone landscapes Limestone is quarried for building stone and also used to make cement. Tourists visit limestone landscapes to see the distinctive features, such in the Yorkshire Dales, a case study which I'll look at in more detail in the Teaching Ideas section. Dairy farming and rearing livestock is common in limestone areas, as well as some arable farming, although the soil can be too alkaline. Sources: BBC (no date) Bitesize: GCSE Geography. Rock Landscapes Classroom Resources. [Accessed on 11/08/15) Available from: http://www.bbc.co.uk/education/topics/ztbd7ty/resources/3 Coordination Group Publications Ltd. (CGP) (2010) GCSE Geography: The Revision Guide. CGP.Waugh, D. and Bushell, T (2002) New Key Geaography for GCSE. Nelson Thrones, Cheltenham. p.52
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AuthorMy name is Heather and I am going to begin my SCITT course to train as a Geography teacher. ArchivesCategories
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