English

Abstract

In recent years, substantial evidence for the early human occupation of the Caucasus during the Quaternary (the last 2.58 million years) has emerged in the literature. The importance of this region for early hominin migration cannot be underestimated. Finds of Homo erectus (thought to be the first hominin to leave Africa), found close to the Georgian village of Dmanisi (see figure 1, over the page) and associated with volcanic deposits with age estimates of around 1.7–1.8 million years, have ignited debates around the topic of ‘the first Eurasians’ (Gabunia et al. 2000). Within Turkey, the oldest known hominin locality is that of Kocabas, in the Buyuk Menderes valley in western Anatolia, where fragments of a cranium, tentatively attributed to Homo erectus, have been found in travertine deposits dated to around 490–510 thousand years (Kappelman et al. 2008). However, earlier hominins are known to have occupied Turkey, as evidenced by finds of Lower Palaeolithic artefacts (Harmankaya, Tanindi 1996), but their chronology is often poorly constrained and the region generally remains poorly understood in terms of hominin dispersal. This three-year pilot project is designed to help initiate renewed efforts to investigate the record of hominin occupation and migration in Turkey. Specifically, we will investigate the environmental changes which provide the context for early hominin occupation in northeastern Turkey by exploiting the palaeoenvironmental archives contained within sedimentary records. Our study area, the upper catchment of the Kura river, spans the Turkish-Georgian border and lies within 100km of the hominin site of Dmanisi (see the maps over the page), and thus there is every reason to believe that hominins would have been present in the area, early in the Quaternary. The Kura river rises in northeastern Turkey and traverses the Lesser Caucasus mountain range, passing the TurkishGeorgian border en route, and ultimately flows through the Transcaucasus depression, through Georgia and on into Azerbaijan where it debouches into the Caspian Sea (see figure 1). The catchment spans a highly active tectonic zone. The mountain ranges of the Caucasus testify to the largescale continental collision (compressional tectonics) and uplift of the Arabian and Eurasian plates which started in the Oligocene (~ 34–23 million years ago) and continued into the Miocene (~ 23–5 million years ago). However, since the Middle Pliocene (~ the last four million years) the Lesser Caucasus and much of the east Anatolian plateau have been subjected to an extensional tectonic regime dominated by strike-slip faulting which has been accompanied by extensive alkali volcanism (Kocyigit et al. 2001). These transform motions have created a series of pull-apart basins which have subsequently filled with sediment (figure 2). More recently, some of these basins have experienced uplift, with active inversion of the basin fill sequences, forcing rivers to incise through their thick sedimentary fills, in response to the uplift. The Kura river, in our Turkish field area, traverses the still deepening (subsiding) Ardahan Basin, but also flows across areas where extensive river terrace sequences have formed in response to localised uplift (for example along the southern edges of the Hanak Basin). The development of this river system is complicated further by extensive localised faulting (normal and oblique, see figure 3), which often offsets river terraces, and the frequent incursion of basaltic lava flows into the developing valley floors from nearby eruption centres. C L I M AT E A N D I T S H I S T O R I C A L & C U R R E N T I M PA C T