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Recent sediments of Makirina bay (northern Dalmatia, Croatia): their origin viewed through a multidisciplinary approach

As a consequence of sea-level rise during the Holocene, the Albian-Cenomanian dolomitic basement of the Makirina depression was inundated by the sea ingression at approximately 4500 y B.P. The morphology of the land and the depositional basin geometry, as well as the balanced relationship between the ongoing Holocene sea-level rise and the sedimentation rate, enabled formation of an up to the present persisting restricted, shallow marine (< 1m) environment. Makirina Bay represents a stressed environment with seawater temperatures varying during the year from 0-35 oC and fluctuating salinities caused by seasonally enhanced evaporation, continous freshwater supply through small capacity submarine springs associated with the coastal karst area and temporary surface runoff episodes. These environmental conditions have been conducive to high primary production of organic matter resulting in formation of overall organic-rich deposits which contain up to 5 wt% of organic carbon of the total sediment. During approximately 4500 years, up to 3.5 m of sediments were deposited indicating a relatively high sedimentation rate estimated at 0.75 m/1000 y in the northern central part of the Bay. The sediments have been deposited mostly as weakly sorted

recent sediments ; geological setting ; sedimentology ; mineralogy ; geochemistry ; O and C stable isotopes ; palynology ; depositional environmental ; Makirina Bay ; Northern Dalmatia ; Croatia

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