Soil data release of U.S. Geological Survey Bulletin 1590, collected across the Western United States between 1975 and 1983

Early studies of soil formation highlighted several key factors that together determine the degree of soil pedogenesis, which include climate, organisms (including vegetation), topography, and parent material (Jenny H.; 1941; Factors of Soil Formation, a System of Quantitative Pedology; https://doi.org/10.2134/agronj1941.00021962003300090016x). A soil chronosequence is defined as a series of soils in which all soil-forming factors except time are similar, where time is represented by soil or landform age. In 1978, the late Denis Marchand launched a project to identify, sample, and analyze soil profiles from seven soil chronosequences in the Western United States. The resulting datasets were compiled as part of a series of reports titled "Soil Chronosequences in the Western United States". This compilation of chronosequences included soils developed on a variety of landforms including alluvial fans, fluvial terraces, glacial moraines, and marine terraces. The estimated age of these soils was based on a variety of chronological dating tools specific to each chronosequence and values range from modern-aged samples to samples that are three hundred thousand years old. At the time preceding this work, it was becoming clear from the marine record that the variations in climate and terrestrial processes were extensive with a paucity of numerical dating techniques applicable to the geologic record. The ubiquitous nature of soils made this project of critical importance to a better understanding of terrestrial processes. These data were originally published in analog form by individual authors in the U.S. Geological Survey Bulletin 1590 series, which was edited by J.W. Harden. Here, data from the original bulletin series including location, land cover, horizon depths, field morphology, color, texture, particle size, bulk density, organic carbon, pH, cation exchange capacity, dithionite extractable iron, major element abundance, trace element abundance, inorganic carbon content, and mineralogy, are compiled together as a single dataset in digital form. In addition, we have also compiled scanned field notes and site photographs that are associated with these publications. The original samples that were collected and analyzed associated with this dataset for the Colorado, Cowlitz, Kane Fans, Merced, Rock Creek, and Ventura chronosequences have been archived via the U.S. Geological Survey Soil Sample Archive (https://doi.org/10.5066/P90KTZW4).