RAPID EPIPALEOLITHIC RESPONSE TO SHORT-TERM EOLIAN-FLUVIAL PALEOENVIRONMENTAL CHANGES ALONG THE MARGINS OF THE NORTHWESTERN NEGEV DUNEFIELD, ISRAEL

Archaeological investigations along central Nahal Sekher on the eastern edge of Israel's northwestern Negev Desert dunefield revealed prehistoric campsites from the Epipaleolithic period, mainly from the Natufian culture which are dated to the end of the Pleistocene. The current research is aimed at understanding better the motivation behind the density of these campsites through geomorphological study of the Natufian campsite of Nahal Sekher VI. Fluvial and eolian environs of this site were analyzed by integrating field mapping, stratigraphic sections, sedimentological analysis and optically stimulated luminescence (OSL) ages.

Residual sequences of diagnostic low-energy fluvial fine-grained deposits (LFFDs), often associated with a more humid paleoclimate, were identified within the sections of the drainage system of central Nahal Sekher. It is suggested that these have been deposited in standing to slow-moving water bodies caused by encroaching sand that reached the region and probably intermittently blocked the course of central Nahal Sekher only between the Late Pleistocene and early Holocene. LFFD sections representing both shoreline and mid-water deposits were found to resemble the descriptions of ephemeral event-layers of hyper-concentrated flow into nearby modern man-made ever-emptying dryland-type reservoirs. The shoreline facies that thin out into the sands adjacent to the Nahal Sekher VI site affiliates the site among others to the ancient water bodies. The finds point to a rapid but temporary response to a 'window' of short-term and improved local environmental conditions that explain the concentration of Epipaleolithic sites along the Negev dunefield fringe.