Burial and thermal history of the Intra-Sudetic Basin (SW Poland) constrained by 1-D maturity modelling - implications for coalification and natural gas generation

 

Authors: Botor D

Published in: Bulletin of Geosciences, volume 95, issue 4; pages: 497 - 514; Received 30 January 2020; Accepted in revised form 28 July 2020; Online 18 October 2020

Keywords: Variscides, Bohemian Massif, Carboniferous, maturity modelling, coalification, vitrinite reflectance,

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Abstract

Kinetic maturity modelling was performed using publicly available vitrinite reflectance data, for nine well sections in the Intra-Sudetic Basin (NE part of the Bohemian Massif) in order to reconstruct its burial and thermal history. The modelling results indicate that the Carboniferous strata reached maximum palaeotemperatures of c. 100-260 °C in the latest Carboniferous to early Permian. The Carboniferous-Permian magmatic activity must have contributed to high heat flow (c. 90-150 mW/m2 during the late Palaeozoic), adding to the effect of sedimentary burial (to a total depth c. 3-6 km in the early Permian), and caused the coalification of organic matter (c. 0.6-4.5% of vitrinite reflectance), and finally natural gas generation. Major hydrocarbon products were dominated by methane. The second phase of temperature rise occurred due to mainly Late Cretaceous sedimentary burial, but it had no effect on the maturation of the Carboniferous organic matter.