What Is Onion-skin Weathering?

Onion Skin Weathering is basically a form of Weathering. Another name for Onion-Skin Weathering is Thermal Expansion, insulation weathering, exfoliation, thermal shock etc.

This kind of weathering occurs in areas with large diurnal temperature range such as a dessert. Since the temperature is high in the day and low at night, the rocks heat up and expand during the day and cool and contracts by night. The outer layers of rock experience stress this way, which in turn causes peeling off of outer layer of rocks.

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There are all different types of minerals witch expand and contract at different rates, this causes the rock to peel away at different rates, it is known as differential mineral expansion.