caa a22 4500 477064523 CHVBK 20180405111409.0 cr unu---uuuuu 170330e19960601xx s 000 0 eng 10.1007/BF02422233 doi (NATIONALLICENCE)springer-10.1007/BF02422233 Epigenetic dolomitization of the Přaídolí formation (Upper Silurian), the Barrandian basin, Czech Republic: implications for burial history of Lower Paleozoic strata [Elektronische Daten] [V. Suchý, I. Rozkošný, K. Žák, J. Franců] Stratabound epigenetic dolomite occurs in carbonate facies of the Barrandian basin (Silurian and Devonian), Czech Republic. The most intense dolomitization is developed in bioclastic calcarenites within the transition between micritic limestone and shaledominated Přídolí and Lochkov formations deposited on a carbonate slope. Medium-crystalline (100-400 µm), inclusion-rich, xenotopic matrix dolomite (δ 18O=−4.64 to −3.40‰ PDB;δ 13C=+1.05 to +1.85‰ PDB) which selectively replaced most of the bioclastic precursor is volumetrically the most important dolomite type. Coarse crystalline saddle dolomite (δ 18O=−8.04 to −5.14‰ PDB;δ 18C=+0.49 to +1.49 PDB) which precipitated in fractures and vugs within the matrix dolomite represents a later diagenetic dolomitization event. In some vugs, saddle dolomite coprecipitated with petroleum inclusion-rich authigenic quartz crystals and minor sulfides which, in turn, were post-dated by semisolid asphaltic bitumen. The interpretation of the dolomitization remains equivocal. Massive xenotopic dolomite, although generally characteristic of a deeper burial setting, may have been formed by a recrystallization of an earlier, possibly shallow burial dolomite. Deeper burial recrystallization by reactive basinal pore fluids that presumably migrated through the more permeable upper portion of the Přídolí sequence appears as a viable explanation for this dolomitization overprint. Saddle dolomite cement of the matrix dolomite is interpreted as the last dolomitization event that occurred during deep burial at the depth of the oil window zone. The presence of saddle dolomite, the fluid inclusion composition of associated quartz crystals, and vitrinite paleogeothermometry of adjacent sediments imply diagenetic burial temperatures as high as 160°C. Although high geothermal gradients in the past or the involvement of hydrothermally influenced basinal fluids can account for these elevated temperatures, burial heating beneath approximately 3-km-thick sedimentary overburden of presumably post-Givetian strata, no longer preserved in the basin, appears to be the most likely interpretation. This interpretaion may imply that the magnitude of post-Variscan erosion in the Barrandian area was substantially greater than previously thought. Springer-Verlag GmbH & Co KG, 1996 Dolomitization nationallicence Burial diagenesis nationallicence Oil window nationallicence Saddle dolomite nationallicence Barrandian basin nationallicence Bohemian massif nationallicence Vitrinite reflectance nationallicence Fluid inclusions nationallicence Illite crystallinity nationallicence Thermal history nationallicence Suchý V. Mineralogisch-Petrographishes Institut der Universität Basel, CH-4056, Basel, Switzerland aut Rozkošný I. Department of Petrology, Charles University, Albertov 6, 128 43, Praha, Czech Republic aut Žák K. Czech Geological Survey, Malostranské nám. 19, 118 21, Praha 1, Czech Republic aut Franců J. Department of Geology, University of Missouri, Columbia, 101 Geological Sciences Bld., 65211, Columbia, Missouri, USA aut Geologische Rundschau Springer-Verlag 85/2(1996-06-01), 264-277 0016-7835 85:2<264 1996 85 531 https://doi.org/10.1007/BF02422233 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/BF02422233 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Suchý V. Mineralogisch-Petrographishes Institut der Universität Basel, CH-4056, Basel, Switzerland aut NATIONALLICENCE 700 1- Rozkošný I. Department of Petrology, Charles University, Albertov 6, 128 43, Praha, Czech Republic aut NATIONALLICENCE 700 1- Žák K. Czech Geological Survey, Malostranské nám. 19, 118 21, Praha 1, Czech Republic aut NATIONALLICENCE 700 1- Franců J. Department of Geology, University of Missouri, Columbia, 101 Geological Sciences Bld., 65211, Columbia, Missouri, USA aut NATIONALLICENCE 773 0- Geologische Rundschau Springer-Verlag 85/2(1996-06-01), 264-277 0016-7835 85:2<264 1996 85 531 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer