What is silicate weathering?
The chemical breakdown of certain silicate minerals into other minerals as a result of the influence of different factors within the general weathering process such as a) water b) oxygen and c) temperature. Certain silicate minerals weather easier than others; potassium feldspar breaks down relatively easily to the clay, kaolinite. This becomes easier however, where the temperatures, especially temperatures of water interacting with the silicate minerals, are high as happens in much of Africa. In Africa, the top most 20 metres of the rock profile often consists of SAPROLITE which are largely secondary clays and iron oxides as a result of silicate weathering. Certain silicate minerals, especially quartz and tourmaline do NOT breakdown but remain in there original form and often get incorporated into a later generation of sedimentary rocks. Feldspars, which would normally breakdown as a result of silicate weathering, can sometimes be preserved and incorporated in later sedimentary rocks
