Palaeogene sediments (Mechit Formation) near Panagyurishte and Strelcha (Sredna gora Mts.)

Abstract

The newly-introduced Mechit Formation is a continental (fluvial) sequence of conglomerates and sandstones with occasional clays and coalefied plant debris. The pebbles derived from pre-Alpine basement rocks (gneisses, amphibolites, granites, pegmatites) and Upper Cretaceous (Coniacian – Campanian) sedimentary, volcanic and intrusive rocks and ores. The formation is more than 570 m thick. It covers with unconformable depositional contact Maastrichtian flysch and older Cretaceous and pre-Cretaceous rocks, and forms denudation pockets and neptunian clastic dykes in the pre-Cretaceous basement. On the basis of taxa from the Normapolles group, the formation is referred to uppermost Maastrichtian - Danian. The new data point at the existence of a considerably eroded relief of the Late Cretaceous Srednogorie orogen already in late Maastrichtian time, and of a fluvial system draining the region towards North and East - into the then existing narrow sea gulf from the Emine flysch trough.