Kaolinite mud happens in plenitude in soils that have shaped from the substance enduring of rocks in hot, sodden atmospheres—for instance in tropical rainforest regions. Looking at soils along an inclination towards dynamically cooler or drier atmospheres, the extent of kaolinite diminishes, while the extent of other mud minerals, for example, illite (in cooler atmospheres) or smectite (in drier atmospheres) increments. Such climatically-related contrasts in mud mineral substance are frequently used to construe changes in atmospheres in the geographical past, where antiquated soils have been covered and protected.