Middle Miocene (Upper Badenian/Sarmatian) Palaeoecology and Evolution of the Environments in the Area of Medvednica Mt. (North Croatia)

摘要

In the area of Medvednica Mt., the Upper Badenian and Sarmatian deposits are divided into four facies associations: (A) deposits of a small carbonate platform represented by breccia, conglomerates, biocalcirudites, biocalcarenites and biocalclutites; (B) open-sea deposits composed of marls with intercalations of clay; (C) nearshore deposits of reduced salinity composed of conglomerates, sandstones, biocalcarenites, biocalcirudites and biocalclutites, and (D) lagoonal deposits represented by spongitic calclutites with clay, marl and sand intercalations. Deposits of these facies associations contain numerous and very diverse fossil species with very different palaeoecological characteristics, from shallow- and deeper-water normal marine to shallow- and deeper-water environment of reduced salinity, even of fresh-water. The transition from Late Badenian to Sarmatian deposition was characterized by three different unconformities and one conformity. Unconformities are located between different lithologies reflecting an amount of uplifting and erosion at the end of the Badenian. The occurrence of an angular unconformity suggests the influence of local tectonics. The Middle Miocene deposition shows different local variations but generally fits with the evolution of Central Paratethys and the Pannonian Basin System.