Alveolinas From the Bunić Section (Lika, Croatia)

Abstract

The Bunić section of Palaeogene carbonates is exposed in a tectonicwindow through the Dinaric tectonic units in the Kozjak valleyin the central part of the Lika region (Croatia). The Lower Eocenelimestones in this section yielded Alveolina histrica septentrionalis and A. rakoveci. These two species characterize a particular facies ofshallow water deposits during Middle to Late Cuisian times, asobserved at Golež and Voz on the north-western margin of the Adriaticand also at Lištica and Hrgud in Herzegovina. This is in contrastto Alveolina assemblages of the same age composed of A. levantina,Periloculina dalmatina, Coskinolina liburnica which characterize theshallow transgressive deposits of the coastal and insularregions inparticular at the Pićan and Benkovac sections.The Bunic Alveolina assemblage indicates that the limestones inthe tectonic window formed part of the sedimentary realm representingthe north - eastern margin of the Adriatic platform. This also supportsHerak's tectonic model by distinguishing two tectonically superimposedcarbonate platforms, the Dinaricum and the Adriaticum separated by an interplatform basin called the Epiadriaticum.