The Evolution of the Profile Paradigm in the History of Pedology and Quaternary Geology: Concepts and Applications

Abstract

This study proposes a unified profile paradigm through the introduction of the pedo-weathering profile (PWP) concept. The pedo-weathering profile demands a re-examination of the pedological subsolum region; a region that has been studied closely by Quaternary geologists. The PWP subsolum contains a C horizon concept of more precisely defined scope than that traditionally used in pedology. In the traditional sense the interval between the solum and bedrock is designated as the C, whether pedogenically modified or not. In the PWP, the C horizon is limited to the part of the traditional C that is pedogenically altered. That part of the subsolum unaltered by pedogenic processes and not having the hardness of bedrock (R) is redefined here as the D horizon. These subsolum horizons exist worldwide in all terranes where fresh geologic materials are exposed at the earth surface and become modified by pedogenic processes; they are the evidence for land surfaces throughout the geologic record. The PWP concept should be useful in disciplines that, in reality, have overlapping interests with pedology.