EduR7 Shap Granite

3D Model

77×59×58mm

Devonian (397Ma)

Cumbria, England

Granite is an igneous rock with the same silica-rich composition as rhyolite, but with much larger crystals visible without a microscope as it often forms when magma cools slowly under the surface of the earth, giving the crystals time to grow. Such silica-rich rocks are typically formed from melting of the crust. This granite near Scotland was formed when the continent Laurentia with most of Scotland, and Gondwana with most of England, collided in the late Silurian event known as the Caledonian Orogeny. The collision pushed the continental crust upwards to form tall mountains which trapped heat in the crust under them, melting it and hence forming this granite.

This granite is notable for its large crystals, known as phenocrysts, of orthoclase feldspar, which is why this granite is commonly used as a building and decorative stone. Such differences in size could be caused by different periods of cooling at different rates.

See: EduR604 Metamorphosed Granite