The Use of Innovative Techniques to Decodify Early Anthropic Activity in the Sonoran Desert (NW Mexico)

the Altithermal period (7500–4500 years BP). During the EAP, agricultural societies cultivated corn
and constructed canals for irrigation; however, searching for the sites of this period and reconstruction
of the ancient activities surrounding them meets difficulties and requires the development of
geoarchaeological indicators. The present study aims to identify anthropic processes from three
paleosols in the arid Northwest Mexico using physical, micromorphological and biogeochemistry
characteristics. In addition, the physical and biogeochemical variables were analysed by redundancy
analysis. Results show that the combination of physical, micromorphological-micromorphometric and
biogeochemistry analyses are an accurate indicator of agriculture during the Early Agriculture Period
(4500 years BP); additionally, the soil organic P (Po
) fraction extracted by HCl (HCl-Po
) is also a good
indicator of soil changes induced by human fire management. The integrated analyses of these methods
thus had a higher potential for determining the human activities effect on paleosols from the Late
Holocene.