rocks weather at different rates and in different ways. Rocks may be more or less susceptible to weathering because of such things as composition or induration, the hardening of a rock through processes like increased temperature of formation, pressure of formation or cementation of particles by precipitated minerals. Sheet erosion, detachment of soil particles by raindrop impact and their removal downslope by water flowing overland as a sheet instead of in definite channels or rills. A more or less uniform layer of fine particles is removed from the entire surface of an area, sometimes resulting in an extensive ...

Mechanical Weathering. Exfoliation: Rock breaks apart in layers that are parallel to the earth's surface; as rock is uncovered, it expands (due to the lower confining pressure) resulting in exfoliation.