Preliminary ages from cosmogenic nuclide burial dating of stratigraphy in the Megalopolis basin

Abstract

The Megalopolis Basin, an intra-mountain depression in the Central Peloponnese (Greece), consists of Pliocene–Pleistocene lacustrine and fluvial sediments. The Choremi Formation, which contains several archaeological sites of interest (e.g., Panagopoulou et al., 2018), dates to the Early and Middle Pleistocene (van Vugt et al., 2000). However, numerical dating of Middle Pleistocene lacustrine and fluvial sediments is challenging (Rixhon et al., 2017). Commonly used dating methods have a limited age range (e.g., 14C dating) or are restricted due to a paucity of datable material (e.g., teeth). An intensively studied and numerically dated archaeological site in the Megalopolis Basin is Marathousa-1 (Fig. 1). Relative correlations of Marathousa-1 put the sedimentary deposits into glacial Marine Isotope Stages (MIS). Possible scenarios from relative correlations suggest sediment deposition during MIS16 (Van Vugt et al., 2000) as well as MIS14, or possibly MIS12 (Okuda et al., 2002; Tourloukis et al., 2018). Numerical age dating of the sediment with pIRIR on K-Feldspar reflects a deposition during MIS12 (Jacobs et al., 2018), although these samples are near, or at, a saturation of this technique and could represent minimum ages. In contrast, a cervid molar from the artifact- and fossil-bearing unit dated with ESR indicates a deposition age during MIS13 and a maximum age during MIS16 (Blackwell et al., 2018). Neither relative nor numerical dating give a conclusive answer of the depositional age for archaeological findings at the Marathousa-1 site.