Sample:Geography - 2006 Q2 B - Landform Development

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Sample:Geography - 2006 Q2 B - Landform Development
Subject:	Geography
Paper	2006
Section	Landform Development
Question	Question 2 B
Level	H
By	User:Odhran

2006 Question 2 B - Landform Development

"With the aid of a labelled diagram, examine the processes that have led to the formation of any one Irish landform of your choice - excluding those shown in the above photograph."

30 Marks

Carboniferous limestone is a sedimentary rock. It is a stratified rock composed of calcium-carbonate (CaCO3). It was formed in warm tropical waters where marine creature remains accumulated, compacted and cemented. Carboniferous limestone can produce a distinctive landscape called Karst. An example is the Burren, Co. Clare. This landscape was created due to the chemical erosion of carboniferous limestone. Carbonation is the most significant process involved in the shaping of a limestone landscape. Carbon dioxide from the atmosphere or soil mixes with rainwater to form a weak carbonic acid (H2O + CO2 = H2CO3). This acid alters the insoluble calcium carbonate of limestone to soluble calcium bicarbonate which is then removed by solution (H2CO3 + CaCO3 = Ca(HCO3)2).This process creates distinct features like limestone pavements. Joints or fissures in the limestone become enlarged by carbonation. They are widened and deepened to form grikes. The flat-topped residual blocks separating the grikes are called clints. Solution holes called karrens may form on the pavement. Other distinct features found in this landscape are swallow holes, dolines, caves, stalactites and stalagmites.

26/30 marks + 4/30 for a diagram with labelled features