A paleosol from the Middle Holocene with traces of occupation in the middle basin of the Magdalena River, Colombia

Abstract

We present the genetic evaluation of a paleosol formed during the Northgrippian period, which presents traces of human occupation evidenced by  carved  lithic  materials. The analysis unit is located in the south of the middle basin of the Magdalena River valley in Colombia, in the municipality of La Dorada, Caldas, a place where the archaeological paleoenvironmental reconstruction program is being developed by the Geoarchaeology Research Group GIGA of the University of Caldas. Taking into account the different paleoenvironmental, paleoclimatic, geomorphological and geological phenomena, we proposed to develop  hypotheses about the soil formation processes of the archaeological site, understood as an activity area, in the paleosurface in which the pedogenetic process that gave rise to the paleosol developed. Based on the results of physical and chemical analyses, such as pH values, organic  matter accumulation and base concentrations of the last two soil sequences and the paleosol obtained by atomic absorption, a correlative table of the study area has been developed. This table was used to make a spatial projection that showcases the specific pedogenetic processes that formed the pedostratigraphic sequences, whether or not associated with human occupation. The results indicate that the environmental stability conditions of the sedimentary deposits of the valley floor were complex but suitable for both pedogenesis and human occupation and had a similar impact on the pedogenic processes.