Mohorje Formation, Southern Slovenia

Abstract

In this paper a variegated and pretty heterogeneous development of the Carnian stratigraphic sequence with volcaniclastic rocks, we denominated as Mohorje Formation, has been researched and described. The new formation is subdivided in four members, namely: Boštetje Member, Borovnik Member, Rupe Member and Selo at Rob Member. In addition, the primary Carnian volcanism in the Rute Region has been examined in detail. The volcaniclastic succession (Borovnik Member) lies concordantly upon the black platy and bedded bituminous limestones with Carnian lamellibranchs. Transgressivelly over them and without visible signs of erosive or angle discordance repose typical red Carnian clastic rocks - dolomitic marlstones, quartz and jasper sandstones, conglomeratic sandstones and fine-grained breccioconglomerates, among which red dolomitic marlstones predominate. The Mohorje Formation lies concordantly upon the medium-grey to very light grey, nearly white, massive or thick-bedded, more or less dolomitized Diplopora Limestones of Cordevolian age conformably underlying Norian Main Dolomite with gastropods and megalodons.