Eustatic control of late Quaternary sea-level change in the Arabian/Persian Gulf Thomas Stevens a, ⁎, Matthew J. Jestico a , Graham Evans b,1 , Anthony Kirkham c a Centre for Quaternary Research, Department of Geography, Royal Holloway University of London, Egham, Surrey TW20 0EX, UK b Ocean and Earth Science, National Oceanographic Centre, Southampton University, Southampton S014 3ZH, UK c Sedimentology and Reservoir Development Ltd, Pen-yr-Allt, Village Road, Nannerch, Mold, Flintshire CH7 5RD, UK abstract article info Article history: Received 29 June 2013 Available online xxxx Keywords: Arabian Gulf Persian Gulf OSL Luminescence Sea level Quaternary Accurate sea-level reconstruction is critical in understanding the drivers of coastal evolution. Inliers of shallow marine limestone and aeolianite are exposed as zeugen (carbonate-capped erosional remnants) on the southern coast of the Arabian/Persian Gulf. These have generally been accepted as evidence of a eustatically driven, last- interglacial relative sea-level highstand preceded by a penultimate glacial-age lowstand. Instead, recent optically stimulated luminescence (OSL) dating suggests a last glacial age for these deposits, requiring N 100 m of uplift since the last glacial maximum in order to keep pace with eustatic sea-level rise and implying the need for a wholesale revision of tectonic, stratigraphic and sea-level histories of the Gulf. These two hypotheses have radically different implications for regional neotectonics and land–sea distribution histories. Here we test these hypotheses using OSL dating of the zeugen formations. These new ages are remarkably consistent with earlier interpretations of the formations being last interglacial or older in age, showing that tectonic movements are negligible and eustatic sea-level variations are responsible for local sea-level changes in the Gulf. The cause of the large age differences between recent studies is unclear, although it appears related to large differences in the measured accumulated dose in different OSL samples. © 2014 University of Washington. Published by Elsevier Inc. All rights reserved. Introduction, geologic and stratigraphic setting Previously prevailing sea-level history of the Arabian/Persian Gulf Relative sea level in the Arabian/Persian Gulf (Fig. 1) during the Quaternary has generally been considered as controlled eustatically under relatively stable tectonic conditions, with a fall of 110–125 m and the exposure of the entire sea bed of the Gulf during the last glacial maximum (Kassler, 1973; Lambeck, 1996). This classic interpretation has been based largely on the apparent stratigraphic position and depositional interpretation of the Fuwayrit and Ghayathi Formations (Figs. 2 and 3) and deflated Holocene beach ridges that are exposed along the southern edge of the Gulf. As part of the above interpretation it was considered that during the global low sea levels of the middle and early Pleistocene glaciations (N 250 ka), an aeolian dune field of quartzose dune sand (later to be- come the Ghayathi Formation; Figs. 2 and 3) was transported from the northwest by the palaeo-Shamal wind and covered the present site of the U.A.E. At about 250–200 ka, sea level rose during an interglacial period and transgressed onto the Arabian Peninsula, resulting in car- bonate deposition including the development of coral reefs (Evans et al., 2002; Evans and Kirkham, 2005). Subsequent regression led to these deposits being covered by carbonate-rich aeolian dune sands de- rived from the adjacent exposed shelf. These sands extended inland so that the aeolian dunes in proximity to the coast became almost entirely composed of CaCO 3 (later to become known as ‘Miliolite’, and consid- ered to be a carbonate variant of the Ghayathi Formation). The penulti- mate sea-level rise (ca. 125 ka) resulted in deposition of shallow water intertidal carbonates (later to become the Fuwayrit Formation) above the Miliolite. Global sea level fell again during the last glaciation to 110–125 m below present-day level at ca. 18 ka (Whitehouse and Bradley, 2013). The succeeding and latest (Holocene) transgression climaxed at a height of approximately 1–2 m above present-day sea level ca. 6 ka, well below the height of many outcrops of the Fuwayrit Formation that capped the zeugen, and was accompanied by continued deflation due to drowning of the aeolian source area. As a result, carbon- ate aeolian dunes and their capping of marine sediment near the coast were cannabalised by the wind to leave merely remnants that form cores of the barrier islands and zeugen scattered in the lagoons and across the coastal sabkha (Fig. 3). The flat coastal sabkha surface there- fore expanded landwards along its innermost reaches due to deflation (Kirkham, 1998a,b; Evans and Kirkham, 2005). At its climax, the Holocene transgression flooded areas which now form the outer parts of the coastal sabkha. Its approximate limits are Quaternary Research xxx (2014) xxx–xxx ⁎ Corresponding author. E-mail address: thomas.stevens@rhul.ac.uk (T. Stevens). 1 Formerly Department of Geology, Imperial College London, SW7 2AZ, UK. YQRES-03544; No. of pages: 10; 4C: http://dx.doi.org/10.1016/j.yqres.2014.03.002 0033-5894/© 2014 University of Washington. Published by Elsevier Inc. All rights reserved. Contents lists available at ScienceDirect Quaternary Research journal homepage: www.elsevier.com/locate/yqres Please cite this article as: Stevens, T., et al., Eustatic control of late Quaternary sea-level change in the Arabian/Persian Gulf, Quaternary Research (2014), http://dx.doi.org/10.1016/j.yqres.2014.03.002