Avertical cross section of soil extending from the surface to the deepest extent of plant root activity or to the regolith and bedrock is known as

A vertical cross section of soil extending from the surface to the deepest extent of plant root activity or to the regolith and bedrock is known as soil profile. This profile is the vertical section of the soil that is exposed by a soilpit. It is composed of a series of horizons, or layers of soil stacked on top of one another like layers of a cake. 

Answer collision and mountain formation;