Lower Oligocene non-geniculate coralline red algal (Corallinales, Rhodophyta) assemblage from Poljšica pri Podnartu (Upper Carniola, Slovenia)

Abstract

The Lower Oligocene Gornji Grad beds from Polj{ica pri Podnartu consist of marly limestone, mudstone, several layers of limestones and two layers of sandstones, and were deposited on a mixed carbonate-siliciclastic ramp.Especially the limestones contain rich fossil fauna and non-geniculate coralline red algae. These were systematicallycollected from four horizons and researched in thin sections under an optical microscope. Genera Lithoporella,Neogoniolithon, Spongites, Lithothamnion, Mesophyllum and Spongites were recognized. Surface area for each genus was calculated and the differences in the coralline assemblages in the four horizons were analysed. Thecorallines originate from two source areas: sandy-muddy bottom of a shallow marine environment, and small coral bioherms with its encrusters.

Keywords

• coralline red algae
• Lower Oligocene
• Gornji Grad beds
• palaeoecology
• Podnart
• Slovenia