Rates of Holocene Soil Formation in South-Central Arizona

Establishment of chronology is essential to historical sciences like geology and archaeology. In geology, it is the starting point for understanding biological and landscape evolution. In archaeology, it is the framework for attaining the more important goal of understanding cultural change through time. One of the tools geologists and archaeologists use to assess chronology is stratigraphy. Both specialists employ the principle of superposition to define a relative chronology based on vertical stratigraphic relationships, i.e., in undisturbed strata, younger deposits overlie older deposits. Determining the relative ages of landforms is more problematic, because seldom is it possible to trace strata between non-contemporaneous surfaces. Consequently, geologists and archaeologists have turned to soils to help assess relative ages of landforms and associated cultural deposits (Birkeland, 1984; Holliday, 1990) In most situations, soils provide relative chronologies for landforms and cultural deposits. If, however, soils of different age are independently dated over a given area, then calibrated ages (Colman et aI., 1987) can be derived for landforms and cultural deposits based on soil development.Documents in the AZGS Document Repository collection are made available by the Arizona Geological Survey (AZGS) and the University Libraries at the University of Arizona. For more information about items in this collection, please contact azgs-info@email.arizona.edu