Provenance Of Albian To Cenomanian Exotics-Bearing Turbidites In The Western Carpathians: A Heavy Mineral Analysis

Throughout the Cretaceous, Tethyan oce anic branches gradually closed, and various ophiolites became obducted and eroded. Their remnants, however, pro vide an abundance of exotic clasts of unknown origin. Sandstone samples from the oldest, Albian exotics-bearing strata of the Pieniny Klippen Belt and Cen tral Western Carpathians were analysed for heavy minerals. These samples were dominated by a high con tent of chrome-spi nels, zircon, tourmaline, apatite and rutile. Titanite, kyanite, monazite, epidote, sillimanite and staurolite were much less abundant. Garnet was generally also rare; however, it was locally common, as were blue amphiboles, pyroxenes and kyanite. The spinels found in the sam ples were predominantly derived from harzburgites (supra-subduction peridotites and volcanic rocks). The blue amphiboles represented glaucophanes to ferroglaucophanes, and were derived from HP/LT metabasites. Pyroxenes (enstatite, less commonly augite and diopside) most likely came from coeval volcanics. Most of the tourmalines were derived from metasedimentary rocks and lo cally from granitoids. Furthermore, some have a complex zonation with two phases of tourmaline, or tour maline intergrown with quartz. These were likely de rived from ophiolitic sources. The results from our analysis indicate a dom inance of ophiolites and older sediments with local input of continen tal crust metamor phic rocks. A result ing palaeogeographic reconstruction involves secondary doubling of the Neotethys suture zone and its lateral shift north of the Central Western Carpathians, which formed a common source for exotics in the Pieniny Klippen Belt and the Cen tral Western Carpathians.