The Formation Of Granite Tors

The formation of granite tors for gcse geography 9 1.

The formation of granite tors. The formation of tors on dartmoor. Most commonly granites but also schists dacites dolerites ignimbrites coarse sandstones and others. There is often evidence of spheroidal weathering of the squared joint blocks. This feature is not available right now.

It has a high drainage density due to the impermeable nature of the granite. Weathering and tor formation. Weathering of the dartmoor granite began almost as soon as it had solidified. The processes resulting in the formation of the dartmoor tors started about 280 million years ago as the granite forming dartmoor cooled and solidified from molten rock at a.

Tors are mostly less than 5 meters 16 ft high. It is a flat topped moorland. Over time the material above the batholith was weathered and removed by rivers and glaciers. Many hypotheses have been proposed to explain their origin and this remains a topic of discussion among geologists and geomorphologists and physical geographers.

Tors are seldom more than 15 metres 50 feet high and often occur as residues at the summits of inselbergs and at the highest points of pediments. Tor exposed rock mass of jointed and broken blocks. Kit mikayi a celebrated tor near kisumu kenya. During daytime rocks are expose to the baking sun they expand due to the increase in temperature.

Tors usually overlie unaltered bedrock and are thought to be formed either by freeze thaw weathering or by groundwater weathering before exposure. At night due to radiate cooling effect the rocks are cooled rapidly and they contract. Greissen formation occurred in places such as at hemerdon where hydrothermal fluids decomposed the feldspars replacing them with muscovite whilst also depositing metalliferous mineralised veins and stockworks. The granite seen on dartmoor originated as a granite batholith under the surface of the earth.

Please try again later. A batholith is an area of molten rock that has cooled very slowly within the crust creating a rock with large crystals.