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Luminescence chronology of alluvial and aeolian sands from the Island of Lopud, Croatia

The extension of Pleistocene alluvial and aeolian sediments along the eastern Adriatic coast and on the islands documents terrestrial environments during a time period of the lowest sea-level stand of the Adriatic Sea. On the southeasternmost Adriatic island of Lopud such deposits were studied along two lateral sections showing alluvial and aeolian sands intercalated with breccia lenses and a tephra interlayer. Alluvial deposits are represented mostly by recycled aeolian sands, accumulated by tractional sheet flows in a small-scale alluvial plain during a relatively long-lasting humid phase. Aeolian sands were probably deposited by sand sheet migration under the influence of the NNE wind during a more arid and relatively windy phase. Sporadically occurring breccia lenses composed of limestone fragments of the Cretaceous basement are the result of occasional high sediment concentration flows, and deposition in shallow stream channels(Kovačić et al., 2018). The reworked and pedogenically altered tephra belongs to the high-K calc-alcaline and shoshonite series having a trachyte-trachydacite composition indicating the Campanian Province in Southern Italy as the most probable source area (Kovačić et al., 2018). This suggests the influence of a southern wind during the humid phase of the Pleistocene. The luminescence dating method was applied to these deposits to establish their chronological framework. Both quartz and feldspar grains were tested and measured to obtain most reliable ages. While the OSL very likely implies to the maximum dating limits and shows problematic dose recovery test results, the pRIR290 ages can be correlated to the OIS4 and OIS5. The results imply that during that time the Island of Lopud in the south Adriatic was part of the mainland exposed to significant fluvial activity of the palaeo-Neretva river and its tributaries. Kovačić, M., Pavelić, D., Vlahović, I., Marković, F., Wacha, L., Kampić, Š., Rončević, S., Drempetić, D., 2018. Pleistocene alluvial and aeolian deposits with tephra on the island of Lopud (eastern mid-Adriatic, Croatia): Provenance, wind regime, and climate controls. Quaternary International 494, 92–104. doi:10.1016/j.quaint.2017.11.054

aeolian-alluvial sands, Lopud, OSL/IRSL, tephra

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