Facies and Olistolith occurrence in Barremian and Aptian sediments of Dobri Do zone of Stara Planina

Facijalne karakteristike i pojava olistolita u sedimentima baremskog i aptskog kata Dobrodolske zone na Staroj planini

Abstract

Lower Cretaceous formation of Dobri Do zone of Stara Planina are of a composite type, with particularly great facies diversity in Barremian and Aptian stages. A rapid and sharp succession of many different facies in a small area without any visible pattern is notable in parts of the zone. These could not have been a result of tectonic events alone, which much deformed the rocks, but an occurrence of submarine slides when Barremian and Aptian deposits were formed. There are grounds to conclude the olistolithic character for some blocks of Urgonian limestones in clastic sediments of the uppermost Aptian.