In desert environment the moisture in form of dew creates cycle of hydration and dehydration of minerals which ultimately weakens the rock fractures for insolation weathering. Deserts have little soil because moisture is so low and the rate of chemical weathering is slow. Recall that chemical weathering is responsible for the formation of soils Bedrock commonly occurs at the surface. Mechanical weathering, also called physical weathering and dis-aggregation, causes rocks to crumble. Water, in either liquid or solid form, is often a key agent of mechanical weathering. For instance, liquid water can seep into cracks and crevices in rock.