engleski

Provenance of Cretaceous clastic sediments from the Western Dinarides of Croatia

The provenance of Cretaceous synorogenic clastic formations of the W Dinarides, Croatia, was studied using sandstone composition, heavy mineral chemistry and zircon fission track dating. The clastics occur in isolated exposures in the uplifted basement units of Medvednica, Ivanščica, Žumberak and Samobor Mts. near Zagreb. In the Early Cretaceous the ophiolitic source area was predominantly composed of harzburgite peridotites and associated cumulate rocks which developed in a supra-subduction zone setting. Similarities with neighboring areas suggest that a rather extensive harzburgitic ophiolite belt extended along the margin of Adria during the Early Cretaceous, and its exposed remnants persisted through the Cretaceous. Exposed continental fragments which underwent thermal overprint related to the subduction of the Dinarides in the late Jurassic, and were exhumed in the earliest Cretaceous, shed zircons and other continental derived detritus onto the margin of Adria in the Early Cretaceous. In the Maastrichtian the detritus which was supplied to the basins in the western Dinarides derived from the erosion of rapidly exhumed basement units which had undergone Eo-alpine metamorphism in the western Dinarides, or from the Eastern Alps and/or Tisza. The studied sediments record tectonic events which can be correlated with regional events affecting both the Alps to the north and the central Dinaride region to the south.

Cretaceous; Clastics; Western Dinarides; Provenance; Whole rock geochemistry; Heavy mineral chemistry; Zircon Fission Track

nije evidentirano