The geoarchaeology, chronology and environment of Lusakert-1, a Late Middle Palaeolithic rockshelter (Kotayk Province, Armenia)

Lusakert-1 (LKT-1) is a key site in any discussion of the Palaeolithic of the Armenian Highlands. This is in large part because of a long-running campaign of excavation in the 1970–1980s which recovered an obsidian artefact assemblage that was then interpreted as spanning the Lower–Upper Palaeolithic. Our reinvestigation in 2008–2012 revealed evidence of occupation in the interior of the LKT-1 rockshelter comprising spreads of ash, obsidian artefacts and human-modified bone. Deposits inside the rockshelter interdigitate with alluvial sediments deposited in a now-abandoned meander of the river Hrazdan demonstrating that occupation took place at the floodplain edge. Artefacts are typologically Middle Palaeolithic, and based on refits and inferences made from micromorphological and lithostratigraphical observation, are preserved in a near in situ state in the rockshelter interior. Artefacts recovered from alluvial strata on the rockshelter exterior are, however, in a secondary context. In addition to stone tool production and use, and the laying of fires, the butchery of wild goat and wild ass is also documented. These activities likely took place seasonally given that evidence of the use of the site by owls - raptors that avoid humans - is found through much of the rockshelter stratigraphy. Radiocarbon and luminescence dating indicate that the rockshelter sequence accumulated in the 65–34 ka interval, i.e. during Marine Isotope Stage 3. Indeed, micromorphological and stable isotopes of n-alkanes demonstrate changes between the warm-humid and cool-dry climates that characterise MIS 3 in the region. Nevertheless, stable isotope data, vertebrate remains, and wood charcoal suggest that grassland vegetation dominated throughout, albeit that arboreal vegetation is associated with deposits accumulating during humid phases. LKT-1 offers a unique and detailed perspective on hominin behaviour and palaeoenvironments in the Armenian Highlands prior to the Upper Palaeolithic and serves as a valuable comparison to the growing Middle Palaeolithic record of the broader region.