Structure of Mt. Blegoš between the Inner and the Outer Dinarides

Abstract

The boundary between the Inner and the Outer Dinarides in the sense of Buser (1987b) west of the Zagreb lineament is predominantly of overthrust character. The Inner Dinarides are ovethrusted on the Outer Dinarides. Mt. Blegoš, situated in the Outer Dinarides west of Ljubljana, on the boundary with the Inner Dinarides, consists of horses that were formed during overthrusting of the Outer Dinarides from the direction of the Dinaric carbonate platform towards the Adriatic platform, i.e. in the present sense from northeast to southwest, probably during the Upper Eocene. After Sarmatian time these horses were first folded and then rotated around the W-E axis owing to the overthrusting of the Inner Dinarides and Southern Alps from north towards south on the Outer Dinarides. The footwall nappe plane along which the Inner Dinarides in the Blegoš area were overthrusted southwards on the Outer Dinarides is besides the footwall nappe plane of the Southern Alps the most important nappe line south of the Periadriatic lineament. In the area from Ljubljana basin to Tolmin this boundary is clearly expressed, whereas westwards and eastwards it has not been uniformly defined. Along the considered footwall nappe plain the Outer Dinarides were clearly rotated towards the Inner Dinarides and the Southern Alps for 30° to 45°, and thrusted under them.