TY - JOUR A1 - Hroch,T. A1 - Rajchl,M. A1 - Kraft,P. A1 - Rapprich,V. T1 - Sedimentary record of subaerial volcanic activity in the basal Ordovician shoal-marine deposits: the Trenice Formation of the Prague Basin, Bohemian Massif, Czech Republic JF - Bulletin of Geosciences JA - Bull. Geosci. Y1 - 2012 VL - 87 IS - 2 SP - 359 EP - 372 CY - Prague PB - Czech Geological Survey SN - 1803-1943 (online), 1802-6222 (print) AV - Free KW - Prague Basin KW - shoal-marine sediments KW - volcaniclastics KW - Ordovician AB - The basal Ordovician Trenice Formation represents an initial unit of the preserved infill of the Prague Basin. Volcanic admixture in sediments preserved in the south-western part of the basin suggests subaerial volcanic activity during the deposition of the Trenice Formation. Three principal lithofacies associations were defined within sedimentary record of the Trenice Formation based on petrography and observed sedimentary structures: i) graded conglomerates, ii) lithic sandstones and iii) volcanigenic deposits. The studied sediments were mostly deposited as subtidal sand dunes, locally interbedded with volcaniclastic rocks. They are considered deposits of a marine lower shoreface influenced by ebb-tide currents. Volcaniclastic intercalations are interpreted as deposits of debris flows and turbidity currents that redeposited volcaniclastic material derived from subaerial Krivoklat-Rokycany and Strasice volcanic complexes. ER -