Dispersed organic matter from Silurian shales of the Barrandian Basin, Czech Republic: optical properties, chemical composition and thermal maturity

Diagenesis to very low-grade metamorphism in lower Palaeozoic sediments: A case study from deep borehole Tobolka 1, the Barrandian Basin, Czech Republic

“…Previous studies have already documented that the Silurian strata experienced diagenetic transformations and paleotemperatures in the range of 90-180°C (Suchý and Rozkošný, 1996;Suchý et al, 2002). Various scenarios concerning the palaeothermal and tectonic evolution of the basin involving several stages of burial heating punctuated by episodes of uplift, hydrocarbon migration, tectonic thrusting and exhumation have been discussed by Francu et al (1998) and Glasmacher et al (2002).…”

Oil-bearing inclusions in vein quartz and calcite and, bitumens in veins: Testament to multiple phases of hydrocarbon migration in the Barrandian basin (lower Palaeozoic), Czech Republic

“…1). Indirect geological evidence exists to show that these intrusions were emplaced at a shallow depth (w100-200 m) below the seabed, when the enclosing shale was still soft and water-saturated Such y et al, 2004). The adjacent sediments which were partly affected by heat from the intrusions, are black, calcareous, graptolite shales that form the upper part of the Liteň Formation and the lower part of the overlying Kopanina Formation (late Wenlock to early Ludlow).…”

“…Solid and liquid bitumen occurrences were noted in fossil moulds and diagenetic concretions, but many other finds were reported from tectonic fractures cutting through various sedimentary and volcanic rocks (Bořick y, 1873; see also Dubansk y et al, 1990 and the references therein). More recently, bituminous impregnations found in tectonic fractures have led to renewed debate about the petroliferous potential of the basin (Šimá nek and Cílek, 1969;Brunnerová et al, 1975;Rozkošn y et al, 1994;Such y et al, 2002b). In other recent studies from the region, hydrocarbon inclusions hosted in vein minerals were described, indicating primary and secondary oil migration (Dobeš et al, 1997;Grimmer et al, 2002;Such y et al, 2002a).…”

Source rock characteristics and biostratigraphy of the Lower Silurian (Telychian) organic-rich shales at Akyaka, central Taurus region, Turkey

“…Graptolite reflectance as an alternative to vitrinite reflectance has been evaluated by numerous studies (Kurylowicz et al, 1976;Goodarzi, 1984Goodarzi, , 1985Norford, 1987, 1989;Bustin et al, 1989;Link et al, 1990;Cole, 1994;Suchy et al, 2002) in assessing the level of thermal maturity in Ordovician and Silurian strata because of the absence of higher-plant remains in pre-Devonian age sedimentary units. Correlation between the reflectance of pyrobitumen, vitrinite, graptolite and amorphous organic matter has been documented in Bertrand and Heroux (1987), Goodarzi and Norford (1989), Bertrand, 1990;Yang andHesse (1993), Cole, (1994), and Geintzis et al (1996).…”