Tropical deep weathering involves the intensive chemical weathering of the minerals in a rock over a long period of time. The minerals are converted to new forms which may be soluble, and can be removed in solution (analogous to karst); or may be softer, such as clay minerals, or crumbly, such as residual sand grains, and can be washed out of the rock by flowing water, a process called piping.
Strictly speaking the solutional process and resulting features are classed as "silicate karst" (or parakarst) and the mechanical erosion via the piping process is classed as a form of pseudokarst. But both processes tend to occur together and the general term "laterite karst" is therefore useful.
The resulting landforms vary from broad, shallow dolines (up to 2km across) through a variety of meso-scale features such as solution pipes and pinnacles to smaller-scale vughs and breccias. As well as solution and removal of material, hard indurated bands, called "duricrusts" form in the upper part of the weathering profile. These are named according to the composition of the hard cementing material: ferricrete (Fe), silcrete (Si), calcrete (Ca), bauxite (Al). Laterite is another name for ferricrete, but the term is also used in a broad sense for the whole weathering profile.
Caves typically occur in the softer weathered material beneath the duricrusts, which provide a hard roof. Solution and piping removes the softer material to form small caves, some of which can be complex mazes (e.g. Lefroy & Lake, 1972)