these processes do not allow for strict analysis as topofunctions because of the extensive variation in climate, vegetation, parent materials, and land surface age at different elevations on a mountainside. (Retallack 2001) Parent Material The rock or sediment associated with a soil's development is referred to as its parent material; it's the starting point for the process of soil formation. During early formation, soils are not so different from their parent materials. With time however, soils will contain less and less features of their original parent material, until eventually taking on an identity all of their own. In order to make an accurate assessment of the amount of soil formation that has occurred, the parent material must be known to establish a base line, or starting point in the soil's formation. In most instances, parent material is independent of soil formation. The formation of igneous rocks and metamorphic rocks occur in locations and by processes removed from the surface of the Earth. These sediments are often the parent material for soils and are derived from soils, but the degree of sedimentary sorting and distribution varies so widely that these are also considered to be independent of soils. Very few parent materials associated with soils are entirely uniform in their composition or structure. Frequently, there is some degree of irregularity including foliation, veining, jointing, or layering that in some cases helps with soil formation, and in other cases hampers it. For example, some sedimentary layering promotes the formation of soil such as a silty cover on bedrock, or a sandy cover on a clayey alluvium layer. In both of these cases, a friable surface material has been established by nonpedogenic instances. Other instances of sedimentary surface cementation, or fine interbedded sequences of clay and sand, could be considered to be not conducive to the formation of a soil. Nonuniform parent materials may be difficult to find in soils and paleosols, although deviations from normally found minerals could lend clues to the original parent material. If grains of primary materials are not found in the parent material, it can be inferred that later additions occurred. For example, quartz is not found in basaltic phonolite, and olivine is not found in granite. The role of parent material is best understood from studies of soils that formed under similar conditions on different parent materials or lithosequences (differing soil profile characteristics because of differing parent