The process is known as Pedogenesis. Erosion and siltation are two of the mechanisms that contribute to pedogenesis.

Yes, and this process is called pedogenesis.

Pedogenesis.

Evolution of chordates is based on pedogenetic theory i.e. primitive chordate ancestor evolved from echinoderm by pedogenesis .

Yes, by series of processes that gradually breaks it down and disintegrates its parts into regoliths and soil. This process of soil formation is known as "Pedogenesis".