An Isotopic Perspective of the Alero El Puesto 1 Zooarchaeology: Environmental Changes, Extinct Fauna and the First Human Occupations of Southern Patagonia

Abstract

The aim of this chapter is to characterize the isotopic paleoecology of the end of the Pleistocene and the Pleistocene-Holocene transition in the Central Plateau of Santa Cruz province, Argentina. δ13C and δ15N analysis of extinct fauna and guanaco recovered in the Alero El Puesto 1 site, Piedra Museo locality is presented. The samples analyzed correspond to the latest Pleistocene, the Pleistocene-Holocene Transition and the Middle Holocene. The δ13C records little variation over time, with means differing in 0.2‰ between periods; with values indicated an association with environments belonging to C3 photosynthetic pathways vegetation. On the contrary, δ15N values of the AEP-1 zooarchaeological record show greater variation, associated with the diversity of species analyzed for this period: Hippidion saldiasi, Mylodontidae, Lama gracilis and Lama guanicoe. The guanacos (Lama guanicoe) of the Pleistocene-Holocene Transition and Middle Holocene record a similar mean for δ13C, but there is a statistically significant difference in the δ15N, with higher values during the Middle Holocene. These δ15N variations would be a reflection of environmental changes occurring in the Central Plateau during this period.