Geoarchaeological results on the Northern Peruvian coast: environmental changes and societal responses in the Sechura Desert during the last two millennia.

We present here recent results of a geoarchaeological study on the Northern coast of Peru. Concerning the scientificcontext, excavation of new or already known archaeological sites in the Sechura Desert, since 2012, revealed thehigh potential of the area to reconstruct Human-Environment interactions during the last two millennia at least. Thepresent geographical setting with an arid and unoccupied coast contrasts with the past activities, as fishing and preparedfish trade, of prehispanic societies which have occupied the coast of the desert. These populations used somenatural resources which are not available anymore nowadays (water, fish, mollusks, wood). A pluridisciplinaryapproach associating geomorphological, palaeoenvironmental and geoscientific methods, allows to reconstruct thepast middles and landscapes in the vicinity of the archaeological sites. Deposits from the filling of the costal depressionof Las Salinas closed by a sand bar and from a shore area at the Nunura’s bay have been investigated interms of sedimentary facies, of mollusc isotopic geochemistry, of ostracod identification and of radiocarbon datings.Results show the variability of the environments during the studied period and further during the Holocene,in terms of climate, landscapes or shoreline position, with e.g. succession of several lagoons in the Las Salinasdepression. These data are obviously cross-studied with archaeological and archaeozoological data from excavationswhich confirm and supply environmental scenarios. Through this research, we aim to characterize the originsof environmental changes in this singular region of the world, between palaeoclimatic trends, ENSO events andgeomorphological dynamics, and to determine the responses of societies to these latters, in space and time.