engleski

Oligocene-Miocene Jelar breccia

The Jelar Breccia covers a large area of the W and SW slopes of Velebit Mt., more than 2 km wide, stretching for more than 100 km. It is in contact with Upper Jurassic limestones, partly disconformably and partly faulted, and the first outcrops of underlying deposits are Neocomian age. The Jelar Breccia is massive carbonate breccia composed of various, mostly angular to subangular, weakly sorted rock clasts, mostly clast-supported, containing variable amounts of fine-grained calcareous matrix. Clast size is very variable, from several mm to boulders several dm in diameter, but the most comon grains are 2-10 cm in diameter.Intense tectonic were a major prerequisite for the significant mechanical desintegration of the source rocks essential during formation of this tectonostratigraphic unit. The age of Jelar Breccia formation cannot be determined from its matix, witch contains no fossil remains, but can be estimated as Late Eocene to Oligocene/Miocene on the basis of clast composition, superpositional relationships, and the age of the maximum tectonic activity in the area.

Jelar Breccia, Oligocene-Miocene, tectonostratigraphic unit, Velebit Mt. Croatia

nije evidentirano