Evolution of geochemistry and depositional settings of Early Palaeozoic siliciclastics of the Barrandian (Teplá-Barrandian Unit, Bohemian Massif, Czech Republic)

Abstract

Cambrian and Ordovician-Middle Devonian sequences of two successive Early Palaeozoic basins of the Barrandian unconformably overlie Cadomian basement in the Bohemian Massif NW interior (Teplµ-Barrandian unit) which is the easternmost peri-Gondwanan remnant within the Variscides. Correlation of stratigraphy and geochemistry of the Early Palaeozoic siliciclastic rocks elucidated sediment provenances. Sandstones of the Middle Cambrian Příbram-Jince Basin were derived from a Cadomian Neoproterozoic island arc. The source area of the Ordovician shallow-marine siliciclastics of the successor Prague Basin is a dissected Cadomian orogen. Late Cambrian acid volcanics of the Barrandian and Cambrian (meta)granitoids emplaced in the W part of the Teplµ-Barrandian Cadomian basement are also discernible in these sediments. Old sedimentary component increased during the Ordovician. Early Llandovery siliciclastic rocks show characteristics of an abruptly weakened supply of terrigenous material and an elevated proportion of synsedimentary basic volcanics as a result of Silurian transgression. Emsian siliciclastics (intercalated in the Late Silurian to Early Devonian limestone suite) presumably comprise an addition of coeval basic/ultrabasic volcaniclastics. Middle Devonian flysch-like siliciclastics indicate reappearance of Cadomian source near the Barrandian during early Variscan convergences of Armorican microplates that preceeded accretion of the Teplµ-Barrandian unit within the Bohemian Massif terrane mosaic.

Stratigraphic correlation potential of magnetic susceptibility and gamma-ray spectrometric variations in calciturbiditic facies (Silurian-Devonian boundary, Prague Synclinorium, Czech Republic)

“…1). They consist of marine sediments (mostly shales and limestones; Chlupáč et al 1998) and submarine volcanic rocks (basic volcanics and coeval basic/ultrabasic volcaniclastics ;Fiala 1970;Patočka & Štorch 2004). Prague Synclinorium was interpreted as located on the northern margins of Gondwana during the S-D interval with affinities to Armorica (e.g.…”

The birth of the Rheic Ocean — Early Palaeozoic subsidence patterns and subsequent tectonic plate scenarios

“…Related extensional faults were discussed by Zulauf et al (1997), and the deposition of Cambrian epicontinental sediments was accompanied by contemporaneous rifting (Liñan and Quesada, 1990) and volcanic activity (Extebarria et al, 2006). Robardet et al (1994), Patoĉka and Storch (2004), and Silva and Pereira (2004) discussed the presence of marine to intra-cratonic basins, long rivers recycling the products of erosion of the cratonic areas (Zeh et al, 2001). The resulting sediments and their chemical composition recorded the increasing erosion of pre-existing crust with a considerable geochemical homogeneity of the shaly components .…”

“…6; Julivert and Duran, 1990;alkaline volcanics, Gil Ibarguchi et al, 1990), in the Prague-basin (Barrandian) of the Bohemian Massif (Patoĉka and Storch, 2004), in Sardinia (flood basalts, Stampfli et al, 2002), and in Iran (flood basalts of up to 500 m thick extending over 1000 km of the margin; Bagheri and Stampfli, 2008). In the Eastern Alps (7, Fig.…”

“…In addition, at the northern limit of the Central Iberian domain, Silurian extensional faults strongly influenced the distribution of Silurian sediments (Martínez Catalán et al, 1992, 2004). (Robardet et al, 1994); 2: Julivert and Duran, 1990;Gil Ibarguchi et al, 1990); 3: Sardinia ; 4: S. Black Forest (Vaida et al, 2004); 5: Barrandian (Chlupaĉ et al, 1998;Patoĉka and Storch, 2004); 6: Carnic Alps (Schönlaub, 1993); 7: Graz Palaeozoic (Fritz and Neubauer, 1988). AM -Armorican Massif; BM -Moldanubian part of the Bohemian Massif; Ca -Cantabrian Zone; CIb -Central Iberia (Saupé, 1973;Diez Balda, 1986, Gutierrez Marco et al, 1990Martínez Catalán et al, 1992;Silva and Pereira 2004); MC -French Massif Central; Ms -Meseta (Piqué, 1989); OM -Ossa Morena Zone; Py -Pyrenees; SxSaxothuringian (Linnemann et al, 2003); WL -Westasturian Leonese Zone.…”

Nomenclature of Cambrian lithostratigraphy of the Skryje-Týřovice Basin

“…Lower Palaeozoic development of the Teplá-Barrandian unit, e.g. the Příbram-Jince and Skryje-Týřovice basins (both entirely Cambrian) and Prague Basin (Ordovician to Devonian) was summarized by Patočka & Štorch (2004) and Fatka & Mergl (2009).…”