Environmental instability in western Tinogasta (Catamarca) during the Mid-Holocene and its relation to the regional cultural development

The survey of natural profiles comprising thin interspersed volcanic and peat banks along different ecological zones and altitudinal levels in western Tinogasta (Catamarca Province, Argentina) provides an insight into the natural environmental conditions for the past human activities in these areas. The geological analysis integrated to the archaeological data allows the proposal of climatic fluctuations, explosive volcanism and, probably recurrent, seismic activity influencing the low and null occupation intensity of the highlands and lowlands, respectively, during the Mid-Holocene (8000–4000 BP). These conditions generated unstable environments that prevented the continuous and sustained occupation of the ecological zone of the Chaschuil Valley highlands (3500–4000 m asl), and hindered the occupation of the lowlands in the mesothermal valleys of the Fiambalá region (1400–2400 m asl). The products of explosive volcanism caused changes in topography which, along with other factors, had different impacts on the productive populations occupying the region since the first century AD.