Geo-chronological context of the open-air Acheulian site at Nahal Hesi, northwestern Negev, Israel Y. Zaidner a, b, * , N. Porat c , E. Zilberman c , G. Herzlinger a, d , A. Almogi-Labin c , J. Roskin e, f, g a Institute of Archaeology, The Hebrew University of Jerusalem, Jerusalem 91905 Israel b Zinman Institute of Archaeology, University of Haifa, Haifa, Mount Carmel 31905 Israel c Geological Survey of Israel, Jerusalem 95501 Israel d The Jack, Joseph and Morton Mandel School for Advanced Studies in the Humanities, The Hebrew University of Jerusalem, Israel e Department of Maritime Civilizations, Charney School of Marine Studies and The Leon Recanati Institute for Maritime Studies (RIMS), University of Haifa, Israel f Department of Marine GeoSciences, Charney School of Marine Studies, University of Haifa, Israel g School of Sciences, Achva Academic College, Israel article info Article history: Received 7 February 2017 Received in revised form 29 July 2017 Accepted 8 August 2017 Available online xxx abstract The open-air site of Nahal Hesi, located on northwestern Negev desert fringe of Israel, is one of the few primary-context late Acheulian localities in the Levant. Late Acheulian sites in the Levant rarely provide faunal assemblages and radiometric ages, leaving large gaps in our knowledge of the Lower Paleolithic palaeoenvironment, ecology, subsistence and chronology. Here we present a new geo-chronological study conducted at the Nahal Hesi site. The major objectives were to describe the geological and archaeological stratigraphy, assign a numerical age to the Acheulian artifact-bearing deposit by TT-OSL and pIR-IR 290 dating, and reconstruct the local palaeoenvironment during the human occupation at the site. Geological and microfaunal observations suggest that late Acheulian hominins at Nahal Hesi exploited marshy environments. The limited spatial and vertical extent of the artifact-bearing deposit and the presence of artifacts only in context of marsh-like sediments, highlight the utilization of short-lived water bodies by the hominins. The combined TT-OSL and pIR-IR 290 methods provide an average age of 430 ± 35 ka for the studied marsh-like deposits. The study indicates that the Middle Pleistocene in the area of the Nahal Hesi site is characterized by lengthy cycles of deposition and erosion of fine-grained sediments associated with the semi-arid Nahal Shiqma drainage system. Marshy sediments could be the result of full or partial blockage of the Shiqma system, probably by coastal dune ridges, that led to formation of standing water bodies during the Middle Pleistocene. © 2017 Elsevier Ltd and INQUA. All rights reserved. 1. Introduction The site of Nahal Hesi is located along the desert fringe between the northwestern Negev desert and the southern coastal plain of Israel, on the eastern bank of Nahal Shiqma (Wadi el-Hesi), five meters above the Shiqma riverbed (Fig. 1). The site is situated 500 m east of the archaeological site of Tell el-Hesi (Dahlberg and O'Connell, 1989). It is an open-air Acheulian locality that was excavated by David Gilead in 1971 and 1973. The lithic and faunal assemblages were studied only recently (Yeshurun et al., 2011; Zaidner, 2014). Because most of the documentation was lost, we lack direct data on the depositional context and mode of collection of lithics and faunal remains. Yet, lithic pieces were probably collected quite meticulously during excavation as suggested by the presence of microdebris. The analysis of the lithic assemblage in- dicates in situ knapping activities and complex pattern of exploi- tation of raw materials. Use of limestone is one of the major features of the lithic industry of Nahal Hesi and it is rare phe- nomenon in the Levant, occurring only at the Early Pleistocene and * Corresponding author. Institute of Archaeology, The Hebrew University of Je- rusalem, Jerusalem 91905 Israel. E-mail address: yzaidner@research.haifa.ac.il (Y. Zaidner). Contents lists available at ScienceDirect Quaternary International journal homepage: www.elsevier.com/locate/quaint http://dx.doi.org/10.1016/j.quaint.2017.08.023 1040-6182/© 2017 Elsevier Ltd and INQUA. All rights reserved. Quaternary International xxx (2017) 1e14 Please cite this article in press as: Zaidner, Y., et al., Geo-chronological context of the open-air Acheulian site at Nahal Hesi, northwestern Negev, Israel, Quaternary International (2017), http://dx.doi.org/10.1016/j.quaint.2017.08.023