engleski

The Chronology and Provenance of Pleistocene coarse-grained Sands on Krk Island (northern Adriatic Sea, Croatia)

The Krk Island is the second-largest Adriatic island located in the Kvarner Bay in the northern Adriatic Sea. During the Pleistocene sea-level low stands the island was part of the mainland and was influenced by terrestrial and fluvial sedimentary processes. The River Po and its tributaries flowed towards the Jabuka depression in the central Adriatic during most of the Pleistocene forming an alluvial plain, while rivers Rječina and Dubračina were major sediment carriers in the area of the Kvarner Bay and the Vinodol Channel, respectively, which probably formed karst lakes at the time. Evidence of the Late Pleistocene – Holocene sea-level changes and coastal neotectonics occur extensively along the Eastern Adriatic coastline. For example, on the island of Krk, based on submerged speleothems a long-term regional tectonic uplift during the last 80 ka was presumed. Furthermore, Pleistocene coastal, marine and terrestrial sediments are also recorded at higher elevations, e.g. between 30 and 60 m a.s.l. In addition, glacial activities during the Pleistocene are evidenced in the form of glacigenic coarse-grained sediments on some locations on Krk. As part of the ongoing study, Quaternary sediments on Krk Island are investigated in more detail on two locations in order to establish their chronological framework. The luminescence dating method will be applied to present the timing of the deposition of the investigated sediments. Furthermore, detailed mineralogical and sedimentological analyses are performed to describe and understand their depositional mechanism and to determine their provenance. The first results imply a relatively short transport as seen from the shape of the sand and gravel grains. This is also evidenced by the mineralogical composition of the deposits indicating mainly to carbonate rocks of the basement exposed in the vicinity of the investigated profiles (e.g. Cretaceous limestones and dolomites and Eocene foraminifera limestones). The siliciclastic content in the sands implies that Eocene flysch probably also contributed significantly as sediment source. (This research is financed by the Croatian Science Foundation (HRZZ), Project IP-2016-06-1854.)

luminescence dating, provenance, Krk Island

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