PALEOECOLOGY AND PALEOSALINITY OF SOME PLEISTOCENE LACUSTRINE STRATA IN NORTHERN ISRAEL: ACHEULIAN CULTURE, TRACE ELEMENTS AND STABLE ISOTOPES OF OSTRACODE VALVES

The Acheulian archaeological site Gesher Benot Ya'acov is located along the shoreline of a Pleistocene lake within the Jordan Rift Valley, Israel, in the northern part of the African-Rift System (33° 00' 30"N, 35° 37' 30"E). The 30 m sequence contains abundant ostracodes and lithic assemblages that are accurately dated based on the occurrence of the Matuyama-Brunhes geomagnetic polarity chron boundary (780 Ka) within the section. Ostracode distributions indicate a freshwater-oligohaline environment of deposition for the lower part of the section and oligohaline to mesohaline water in the upper part. In addition, the Sr/Ca and Mg/Ca ratios and the C and O isotopes of the ostracode shells (Candona neglecta) exhibit three geochemical zones supporting the paleoecological biozonation. They reflect a cooler period for the lower part of the sequence, changing into a warmer climate at the Matayuma-Brunhes boundary and upward. A further gradual temperature increase in the uppermost interval caused the retraction and desiccation of this lake. The cyclical sedimentary section yields a rich assemblage of well-preserved organic remains consisting of wood, seeds, fruit and pollen as well as lithic artifacts and vertebrate fossil remains. These remains are indicative of: (1) hominid activities in the region, and (2) an early movement of hominid technologies out of Africa via the "Levantine Corridor" around 780 Ka. The shores of the lake represent a unique ecological environment, with repetitive Paleolithic habitations along the margins that provided a supportive living mode for the Acheulian hominid.