Geochemical evidence of anthropogenic activity in western Mesoamerica since the Classic Period

Sediments of the La Colorada Lake provided evidence of anthropogenic perturbations in western part of the Mesoamerica over the last 2000 years. Comparison of chemical compositions of these sediments and sediments from a nearby reference site, containing both natural and perturbed deposits, suggested that erosion of the felsic rocks occurred under humid conditions during the terminal Formative Period (100 BCE–100 CE) and it caused natural sedimentation in the lacustrine basin. Deposition of sediments sourced from mixed provenances (felsic and mafic rocks) increased since the Classic Period (>100 CE). Enhancement in anthropogenic activities related to agricultural practices of the Classic and Epiclassic Periods triggered transportation of sediments from the nearby as well as long-distance sources. Farming activities and organic waste discharge of the Industrial Period (1600–2017 CE) caused the enrichment of P and Ca.