Theory question 204
Earth Movements and Vulcanicity(a) With the aid of diagrams, describe one mode of formation of a block mountain. (b) In what four ways are mountains of economic importance?
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(a) Tension (or compression) in the crust produces two parallel faults; either the land between the faults is pushed up, or the land on both sides sinks, leaving the middle block standing high as a block mountain (horst) with steep fault-scarp sides and a flat top; e.g. Vosges, Black Forest, Ruwenzori, Usambara. Diagrams showing the faults, the arrows of movement and the raised block.
(b) Source of minerals; tourism and recreation (mountaineering, cool resorts); hydro-electric power from fast rivers; source of rivers; grazing (transhumance); forests and timber; relief rainfall on windward slopes; climatic barriers and defence; cool climate for crops such as tea and temperate vegetables.
Draw before-and-after diagrams.