engleski

The Chronology of Quaternary Sediments along the Eastern Adriatic Coast

Pleistocene climate was marked by repeated glacial-interglacial cycles. During the last ice age much of northern Europe was glaciated as were the Mediterranean mountains (HUGHES et al., 2010) ; overlain by a thick ice cover which played an important role in glacial grinding and producing of voluminous fine grained clastic material. At the same time in the periglacial environment, south of the ice margin, large (braided-) river systems that carried large volumes of suspended and bedload material from the glacial meltwater and paraglacial processes, formed, as a consequence, vast floodplains exposed to strong wind activity. The North Adriatic Sea is a relatively shallow basin with depths up to 120 m and during the Late Pleistocene regression it was a wide alluvial plain. The relative sea- level dropped about 100-120 m and the shoreline was situated about 250 km south of its present- day position (SIKORA et al., 2014) resulting in terrestrial sedimentary environments in the North Adriatic basin and most of the recent coast and islands. Evidences of such environmental conditions can be recognized in sediment archives found along the Adriatic coast and on the islands. To fully understand these evidences it is mandatory to establish a reliable chronological framework of the exposed sediments. The most appropriate methods available for dating of sediments are the optically stimulated and infrared luminescence dating methods (OSL and IRSL ; respectively). In recent years numerous data were obtained from alluvial-eolian and eolian sediments from the Adriatic area. The results show that there was an intensive alluvial influence during the end of the Penultimate Glacial and the older parts of the Last Glacial period which is evidenced by coarser sediments, like breccia intercalations in eolian sand on the island of Hvar (WACHA et al., 2016 ; PAVELIĆ et al., 2011, 2014) or Lopud (KOVAČIĆ et al., 2018). During the Last Glacial period intensive wind activity and aridity as well as the sea-level drop of about 120 m below todays level, influenced the mass accumulation of dust which formed loess (e.g. WACHA et al., 2011, 2018 ; ZHANG et al., 2018). During the Last Glacial sand dunes were formed, too (e.g. Vis Island ; WACHA et al., 2019 ; PAVELIĆ et al., 2014). Furthermore, Pleistocene coastal, marine and terrestrial sediments are also recorded at higher elevations, e.g. between 30 and 60 m a.s.l. on the island of Krk (MARJANAC et al., 1992) which could either be a climbing dune form or an evidence of active tectonics in the northern Adriatic area. As part of an ongoing research, IRSL and OSL data will be presented with the purpose to unravel the stratigraphy and chronology of Quaternary sediments in the eastern Adriatic area and to reconstruct the dynamic and changing environment during the end of the Penultimate and Last Glacial periods.

OSL and IRSL dating, Adriatic coast and islands, chronology, stratigraphy

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