Pages: 251 - 264
Abstract: The possibility of localizing the source area for the Lower Triassic (Scythian) quartzites and sandstones (Luzna Fm.) was checked. Cross-bedding measurements show the transport from the Carpathian foreland, from the NW and N (the same as in the Eastern Alps). The source area could be in the eastern part of the Bohemian Massif (now subducted under the Carpathians), or in the Armorican Massif, if the supposed large left-lateral shift of the Central Western Carpathians took place. The sedimentary environment can be characterized as fluvial braidplain of ephemeral sandy-pebbly streams with intervals of eolian transport. Rare intercalations of psephitic clasts contain only the most resistent rocks: vein quartz, quartz porphyries (rhyolites) with their pyroclastics, rare intermediary volcanites, postvolcanic products as jaspers and hematitic quartzites, graphitic metaquartzites, radiolarian lydites, silicified wood of Dadoxylon sp., limnosilicites with pollen grains and a single silicite with ostracods. Various tourmalinitic rocks are the most promising for the identification of the provenance area.
Keywords: Western Carpathians, Lower Triassic, paleogeography, braided rivers, pebble analysis, tourmalinitesDownload PDF document