Geoarchaeological interpretations of the formation and environment of Samaca H-8, Ica Valley, south coast Peru (c. AD 900–1550)

Abstract

Today the Lower Ica Valley (Peru) exhibits evidence of environmental degradation, strong activity of deposition and erosion processes through modifying agents such as water and wind. All of this is the product of a long process of environmental transformation both during and since pre-Columbian times. Archaeological remains present in this valley evidence a long and important pre-Columbian cultural trajectory. We provide a case study of the geoarchaeology of the Samaca H-8 archaeological site that was founded sometime towards the end of the Middle Horizon (c. AD 900-1000) and consolidated its development during the Late Intermediate period (AD 1000-1400). This work contemplates the analysis of soils and sediments using micromorphology, geochemical-geophysical analyzes and radiocarbon dating. The results reveal that the construction and first occupation of Samaca H-8 (or at least the eastern part of the site), during the transition from the Middle Horizon period to the Late Intermediate Period, was marked by environmental dynamics and drastic landscape change toward more arid conditions. Recurrent deposition of windblown materials took place, perhaps due to a lack of protection offered by riparian dry forest cover. The Samaca H-8 site was established under these environmental conditions around AD 900.