Soil is a valuable medium when investigating the past-- from understanding rates of development, landform evolution, to the construction of various predictive models. Landforms and sediments provide insight into depositional environments and soil morphology indicates pedogenic change within those landforms. The rate at which pedogenesis occurs has been quantitatively measured by use of eight soil properties (clay films, texture + wet consistence, rubification (hue and chroma), structure, dry consistence, moist consistence, color value, and pH) to better understand landform type, soil development, as well as the archaeology of the Upper Klamath River Canyon.
Soils within the Upper Klamath River Canyon consist of colluvium and Quaternary alluvium, which have been forming over the last 2.59 million years. Archaeological sites in the region are much younger than that and are expected to be found on landforms adjacent to the river channel. Currently the Klamath River chronology is incomplete with little-to-no information covering the Early and Middle Archaic Periods; conversely most archaeological information comes from the most recent period--the Late Archaic.
In order to better understand the history of the canyon, landforms and depositional environments were identified and soil development was quantitatively measured by use of a soil development index and horizon index. A total of 21 soil pits, located on 21 alluvial terraces, within five terrace complexes, in a five-mile segment of the Upper Klamath River Canyon were recorded. Results indicate that overtime soil properties tend to change in a linear progression and older terraces are higher in elevation from the current river channel. Use of soil development indices have proven useful in demonstrating soil development within a group of terraces as well as by showing pedogenic development within a single soil profile through the quantification of soil morphological characteristics.