Define etchplanation and explain the formation?

Etchplanation involves 2 processes namely deep weathering followed by exhumation. Deep weathering refers to rapid chemical weathering and this causes rock paricles to further disintegrate into even smaller particles. This occurs when rainwater enters cracks and crevices in rocks thus exposing the rock to greater surface area of weathering. This process of deep weathering occurs during the warm pliocene period and results in a deep layer of weather materials. Exhumation or removal of weathered materials happens during periglacial times due to flash floods or solifluction. Hence, this can expose the basal surface of weathering ( the limit to weathering- from completely weathered rocks in the upper layers to unjointed basal suface). Outcrop in the basal surface that is exposed in the surface is formed as inselberg. In places whereby there are orthogonal joints, tors may be formed after repeated process of etchplanation. This will exposed corestones that are more resistant to weathering due to more spacious jointing that stack on top of one another to form heaps of boulders 4-20m high. Spheroidal weathering may occur on the side of the corestones (form of exfoliation) resulting in the rounded nature of the core stone.