Assessment of thermal evolution of Paleozoic successions of the Holy Cross Mountains (Poland). (February 2017)

• Record Type: Journal Article
• Authors: Schito, A.; Corrado, S.; Trolese, M.; Aldega, L.; Caricchi, C.; Cirilli, S.; Grigo, D.; Guedes, A.; Romano, C.; Spina, A.; Valentim, B.
• Is Part Of: Marine and petroleum geology. Volume 80(2017)
• Page Start: 112
• Page End: 132
• Publication Date: 2017-02
• Subjects: Paleozoic source rocks -- Thermal maturity -- Vitrinite and organoclast reflectance -- Clay mineralogy -- Raman spectroscopy -- Palynomorph darkness index -- Holy Cross Mountains; Submarine geology -- Periodicals; Petroleum -- Geology -- Periodicals; Géologie sous-marine -- Périodiques; Pétrole -- Géologie -- Périodiques; Petroleum -- Geology; Submarine geology; Periodicals; Electronic journals; 551.468
• DOI: 10.1016/j.marpetgeo.2016.11.016
• Languages: English
• ISSNs: 0264-8172

Abstract

Abstract: Poland is considered the most prospective country for shale gas production in Europe. Hydrocarbon generation/expulsion scenarios, drawn in the latest intensive exploration phases, tend to overestimate maturation levels when compared with brand new data acquired after recent drillings. We tested an integrated workflow to correlate published and original thermal maturity datasets for the Paleozoic to Jurassic successions cropping out in the Holy Cross Mountains. These successions, when preserved in subsurface, host the major source rocks in the area. The application of the workflow allowed us to highlight the burial and thermal evolutionary scenarios of the two tectono-stratigraphic blocks of the Holy Cross Mountains (Łysogòry and Kielce blocks) and to propose this approach as a tool for reducing levels of uncertainty in thermal maturity assessment of Paleozoic successions worldwide. In particular, published datasets including colour alteration indexes of Paleozoic microfossils (conodont, acritarchs) and vitrinite and graptolite reflectance data, show differences in levels of thermal maturity for the Łysogòry (mid mature to overmature) and Kielce (immature to late mature) blocks. Original data, derived from optical analysis, pyrolysis, and Raman spectroscopy on kerogen, and X-Ray diffraction on fine-grained sediments, mostly confirm and integrate published data distribution. 1D thermal models, constrained by these data, show burial and exhumation events of different magnitude, during the Late Cretaceous, for the Łysogòry (maximum burial depths of 9 km) and Kielce (burial depths of 6 km) blocks that have been related to the Holy Cross Fault polyphase activity. In the end, Palynomorph Darkness Index and Raman spectroscopy on kerogen, for Llandoverian and Cambrian rocks, turned out to be promising tools for assessing thermal maturity of Paleozoic organic facies devoid of vitrinite macerals. Highlights: We used an integrated approach to assess thermal maturity of Paleozoic successions. Data were used to calibrate two thermal models in the Holy Cross Mountains. A new thermal and burial evolution of the area has been proposed. New and old dataset were used to build thermal maturity maps at different ages. Coupling maps and pyrolysis we define the potential of source rocks in the area.