Famennian-Tournaisian neptunian dykes and their conodont fauna from Dalnia in the Holy Cross Mts

Abstract

Neptunian dykes containing a unique fossil assemblage were found in the Upper Devonian limestones of a reef-complex on the Dalnia Hill in the Holy Cross Mts. Fissures of the tectonic origin were opened and filled under subaqueous conditions. The conodont fauna they contain indicates that a repeated filling and re-opening of the fissures took place in the Famennian and Tournaisian. The filling of a main dyke and ,the fauna it contains correspond to a condensed sequence deposited on a submarine rule. The reconstructed outline of the area of a condensed sedimentation ,in the Famennian and Tournaisian approximately coincides with the outline of a dead Frasnian table reef. The trace of facial boundaries in the Upper Devonian and Tournaisian is to a considerable degree determined by a block-faulting simultaneous with the sedimentation. The facies pattern here presented seems to exert a 'certain influence on later, post-Carboniferous tectonics. The paleontological part of the present paper inc1udesa systematic description of 29 conodont species, mostly Tournaisian ones, which have not so far been described from the Lower Carboniferous of the Holy Cross Mts.