Stable isotopes (&13C and &18O) and trace elements (Mn and Sr) as paleoenvironmental indicators in archaeological freshwater bivalves (Diplodon chilensis) in North Patagonia, Argentina

ALBERTO PEREZ; DANIEL BATRES; IARA ROCCHETTA; MARIA ROSA EPPIS; MARIA LAURA BIANCHI; CARLOS LUQUET

Environmental Archaeology

Maney Publishing

Año: 2012

1461-4103

Stable isotopes of oxygen and carbon (18O and 13C) and the trace elements, manganese and strontium were analyzed in shell fragments of the freshwater bivalve Diplodon chilensis, recovered from the archaeological site Parque Diana Cave, near Meliquina Lake, Neuquén Province, Argentina, as a tool for paleoenvironmental reconstruction. The results reflect temporal temperature and primary productivity variations in the aquatic environment from 2370 to 580 years BP. The older occupations (lower component) reflect exploratory movements of hunter gatherer groups from the eastern steppe. Stable isotopes and trace elements suggest that this was a cold period, which was probably more severe in the steppe. For the middle component (contemporary to the medieval climatic anomaly), high temperature and primary productivity could be inferred from the obtained data. The observed recurrent occupation of this site by human groups coming from the west of the Andes range was probably favored by such environmental conditions. At the beginning of the upper component, while favorable conditions could be inferred from stable isotopes, the occupation of this site by the same groups recorded in the middle component became permanent. The more developed adaptation to the environment, related to permanent settlement made possible to this group to remain in this site during the cold period indicated by stable isotopes data for the second half of this component.