Paleoanthropologically significant South African sea caves dated to 1.1e 1.0 million years using a combination of UePb, TT-OSL and palaeomagnetism Robyn Pickering a, * , Zenobia Jacobs b , Andy I.R. Herries c , Panagiotis Karkanas d , Miryam Bar-Matthews e , Jon D. Woodhead a , Peter Kappen f , Erich Fisher g , Curtis W. Marean g a School of Earth Sciences, University of Melbourne, McCoy Building, Cnr Swanston and Elgin Streets, Parkville, Melbourne, Victoria 3010, Australia b Centre for Archaeological Science, School of Earth and Environmental Sciences, University of Wollongong, New South Wales 2522, Australia c Australian Archaeomagnetism Laboratory, Department of Archaeology, Environment and Community Planning, Faculty of Humanities and Social Sciences, La Trobe University, Victoria 3086, Australia d Ephoreia of PalaeoanthropologyeSpeleology of Southern Greece, Ministry of Culture, Greece e Geological Survey of Israel, 30 Malchei Israel St., Jerusalem 95501, Israel f Department of Physics, Faculty of Science, Technology and Engineering, La Trobe University, Victoria 3086, Australia g Institute of Human Origins, School of Human Evolution and Social Change, PO Box 872402, Arizona State University, Tempe, AZ 85287-2402, USA article info Article history: Received 27 September 2012 Received in revised form 20 December 2012 Accepted 22 December 2012 Available online Keywords: Geochronology UePb dating TT-OSL dating Palaeomagnetism Pinnacle Point South African cave deposits abstract Deposits in sea caves found along the southern coastline of South Africa have produced a rich and detailed archaeological record of early modern humans. There is, however, little evidence for coastal cave deposits and human occupation older than MIS5e (w120 ka). Based on the correlation of four different chronological methods we present evidence for remnant cave deposits of 1.1e1.0 Ma from the quartzite sea cliff of Pinnacle Point, near Mossel Bay. Initial uraniumethorium ages at isotopic equilibrium indi- cated an age of >500 ka for two flowstone layers, confirmed by uraniumelead dating of these flowstones from 1.099  0.012 to 1.047  0.011 Ma. TT-OSL (thermally transferred optically stimulated lumines- cence) provides an age of 1.02  0.088 Ma for the sand grains imbedded in the tufa underlying the flowstone and 0.720  0.066 to 0.665  0.056 for the overlying beach sediments, producing an internally consistent age sequence centring on 1.0e1.1 Ma. The normal palaeomagnetic signal of the younger section of the flowstone is interpreted to represent the Jaramillo between 1.07 and 0.99 Ma. There is a clear hiatus in the middle of this flowstone, leading us to interpret the lower normal signal as the Punaruu event at w1.115e1.1051 Ma. Together these four techniques point to an age of 1.1e1.0 Ma for these cave deposits at Pinnacle Point, far older than anticipated. The persistent presence of these 1.1 e1.0 Ma deposits means that the enigmatic lack of Earlier Stone Age (Acheulean) artefacts in the sea caves along this coastal region can no longer be explained entirely by the age of the caves or through removal of sediments by previous sea level highstands. We believe that these and other coastal caves from this region, if located high enough above sea level, may contain deposits of great antiquity, which could provide outstanding records of climate, environment, sea level change, and human occupation back into the early to middle Pleistocene. Ó 2013 Elsevier Ltd. All rights reserved. 1. Introduction Sea caves and rockshelters along the west and south coasts of South Africa provide some of the richest archaeological records of early modern humans worldwide. The quartzitic coastal cliffs of Pinnacle Point (PP), near the town of Mossel Bay on the south coast of South Africa (Fig. 1), contain a series of caves and rockshelters, formed as a result of previous high sea-levels stands (Marean et al., 2007). These caves and rockshelters contain rich anthropogenic sediments, as well as ancient dune and beachrock deposits and cave carbonate layers, both pure speleothem and impure tufa deposits. The younger deposits at PP have been the subject of much recent investigation (Marean et al., 2007; Brown et al., 2009; Bar- Matthews et al., 2010; Matthews et al., 2011), during which a number of cave sites were shown to contain deposits older than the 500 ka limit of UeTh dating. This was initially surprising as * Corresponding author. Tel.: þ61 (0)3 8344 6531; fax: þ61 (0)3 8344 7761. E-mail addresses: robynpickering79@gmail.com, r.pickering@unimelb.edu.au, rpi@unimelb.edu.au (R. Pickering). Contents lists available at SciVerse ScienceDirect Quaternary Science Reviews journal homepage: www.elsevier.com/locate/quascirev 0277-3791/$ e see front matter Ó 2013 Elsevier Ltd. All rights reserved. http://dx.doi.org/10.1016/j.quascirev.2012.12.016 Quaternary Science Reviews 65 (2013) 39e52