The Middle and Upper Permian Deposits in Gorski Kotar: Facts and Misconceptions

Abstract

The frequent occurrence of sandstones and other coarse-grainedsedimentary rocks in Gorski Kotar indicates molasse type sedimentationas a consequence of the intensive erosion of all uplifted terrain ina tectonically active area. The indirect assumptions indicate that theage of the Gorski Kotar Palaeozoic complex, with the exception of alimited occurrence of Carboniferous clastic rocks, corresponds to theclastic Trogkofel beds. i.e. to Middle Permian. The absence of UpperPermian carbonate deposition in Gorski kotar indicates an interruptionin sedimentation at the Permo-Triassic boundary, and a possiblehiatus in the Upper Permian. In previous studies it was concluded thatthere is a continuous transition from the Permian (developed as theGroeden clastic facies) to the Lower Triassic shallow marine sedimentaryrocks, although no such transitions occur in either the neighbouringareas (Velebit, Slovenia) nor in thc wider Southern Alps. Thecontinuous transition exists only in the carbonatc successions (UpperPermian dolomite in the Velebit region and the Bellerophone formationin the Alps).