Thermal history of the lower Carboniferous Culm Basin in the Nízký Jeseník Mts. (NE Bohemian Massif, Czech Republic and Poland)

Abstract

Raman microspectroscopy of organic matter, vitrinite reflectance and fluid inclusion data were used to reconstruct the thermal history in the lower Carboniferous accretionary prism of the Culm Basin in the Nízký Jeseník Mts. (NE Bohemian Massif). The model involves the Variscan (mid-late Carboniferous) burial diagenesis, which was overprinted by a post-Variscan, probably Permian and/or early Mesozoic, thermal pulse(s) in its central and western parts. The latter may have been related to advective heat transport and the circulation of hot fluids. In the siliciclastic rocks of the Culm Basin, the maximum palaeotemperatures varied from~200 ± 30°C in the E (in the Hradec-Kyjovice Formation) to~350 ± 30°C in the NW (in the Andìlská Hora Formation).

Acta Geologica Polonica

“…The rock samples were cut perpendicular to the bedding and from these rock pieces standard polished slides were prepared for vitrinite reflectance measurements (R' max -mean apparent maximum reflectance, R' min -mean apparent minimum reflectance and VR omean random vitrinite reflectance) and laser Raman spectroscopy. In the case of the highly disordered low-grade OM which occurs within the diagenetic zone such type of sample can be used efficiently (Rahl et al 2005;Kouketsu et al 2014;Wilkins et al 2014Wilkins et al , 2015Lünsdorf 2016;Botor et al 2017a;Henry et al 2019;Zhang and Li 2019). However, in highordered OM (particularly in graphite) several authors have shown that the polishing of a sample could cause a change in the Raman record (e.g., Katagiri et al 1988;Wopenka and Pasteris 1993).…”

“…In the past few decades, the development of optics (including lasers) and computing has influenced progress in the Raman spectroscopy technique which allows for detailed study of OM and their thermal transformation (e.g., Beyssac et al 2002aBeyssac et al , b, 2003aJehlička et al 2003;Rahl et al 2005;Aoya et al 2010;Kouketsu et al 2014;Lünsdorf et al 2014;Lünsdorf 2016;Wilkins et al 2014Wilkins et al , 2015Botor et al 2017a;Henry et al 2018Henry et al , 2019Zhang and Li 2019). The Raman spectrum of OM is composed of firstorder (1000-1800 cm -1 ) and second-order (2500-3350 cm -1 ) regions (e.g., Pasteris and Wopenka 1991;Beyssac et al 2002a).…”

“…The thermal history of the Sudetes, NE Bohemian Massif (Text-fig. 1), is still a matter of debate, particularly due to the poorly preserved post-Variscan sedimentary record (e.g., Maluski et al 1995;Migoń and Danišík 2012;Danišík et al 2012;Sobczyk et al 2015;Botor et al 2017aBotor et al , b, 2019. Particularly, in the Intra-Sudetic Basin (ISB) magmatic bodies are widely known (e.g., Awdankiewicz et al 1999aAwdankiewicz et al , b 2004Ulrych et al 2011) and these represent a possible source of heat that could have directly influenced the thermal maturity of organic matter (e.g., Kwiecińska et al 1992;Adamczyk et al 2018).…”