Archive
Article
Geologica Carpathica, 1996, vol. 47, no. 4
SERPENTINITIC SANDSTONES FROM THE SAMBRON-KAMENICA ZONE IN EASTERN SLOVAKIA: EVIDENCE OF DEPOSITION IN A TERTIARY COLLISIONAL BELT
Abstract
The specific type of sediments, which arise in subduction complexes are serpentinitic sandstones. Their material originates from disintegrated ophiolite series. The first occurrences of serpentinitic sandstones in the Western Carpathians have been recorded from the Peri-Klippen area in Eastern Slovakia (Sambron-Kamenica Zone). They occur within the Upper Oligocene flysch formations. The sequence is notable for its thin-rhythmic character and the constant thickness of the sandstone ? claystone intervals ("zebra"-type flysch). The proportions Q25F8L67 express the average modal composition of the sandstones. The high content of detrital serpentinites and glassy clasts (Lv = 62%) causes a prevalence of unstable lithic components. The interstitial material of sandstones corresponds mainly to pseudomatrix (originating from the breakdown of lithic grains), recrystallized during diagenesis into orthomatrix and/or epimatrix. In diagrams for determining the provenance of arenites, the projection points of serpentinitic sandstones are concentrated in the field of magmatic-arc related sandstones (Dickinson et al. 1983) or oceanic-arc related sandstones (Valloni 1985). The preservation of fragile clasts of serpentinite points to deposition from a diluted turbidite suspension. In dense flows with a high dispersive pressure caused by grain collisions the serpentinites should be almost destroyed. Accumulation of these clasts could also occur as a result of hydrodynamic separation, with the lighter grains of serpentinite reaching a higher level of the currents, which carries them to deeper parts of the basin.The occurrence of serpentinitic sandstones in the Sambron-Kamenica flysch deposits indicates a suture zone of the Tertiary collision occurring on the contact of the Central Carpathian Paleogene and the Klippen Belt. The flysch formations of the Sambron-Kamenica Zone are sediments of perisutural basins, which, to the north were connected with trench-type flysch deposits in the Magura Unit.
Pages:
227 - 238
Published online:
0. 0. 1996