Jurassic-to-Miocene Evolution of the Polish and Ukrainian Carpathian Foreland Based on Geological and Geophysical Data and Analogue Modeling

Krzywiec, Piotr¹, Jacek Gutowski¹, Igor Popadyuk², Hemin A. Koyi³, Zbigniew Zlonkiewicz⁴, Piotr Gliniak⁵, Igor Gubych², Kazimierz Madej⁶, Irena Matyjasik⁷, Barbara Olszewska⁸, Tatiana Syrota², Andrzej Urbaniec⁵, Grzegorz Wróbel¹ (1) Polish Geological Institute, Warsaw, Poland (2) Ukrainian Geological Institute, Lviv, Ukraine;.(3) Uppsala University, Uppsala, Sweden (4) Polish Geological Institute, Kielce, Poland;.(5) Polish Oil & Gas Company, Krakow, Poland (6) Polish Oil & Gas Company, Jaslo, Poland (7) Oil & Gas Institute, Krakow, Poland (8) Polish Geological Institute, Kraków, Poland

    Seismic and well data combined with results of analogue models are used to unfold the Mesozoic evolution of the epicontinental basin of SE Poland and W Ukraine. During Jurassic to Early Cretaceous subsidence, siliciclastic and carbonate sediments were formed, includ­ing Oxfordian-Beriassian carbonate organic buildups forming hydrocarbon reservoirs. The formation of the carbonate buildups was controlled by syn-depositional basement normal / transtensional faulting. Tithonian - Beriassian pelagic black bituminous shales deposited in front of the bioherm-reef belt form source rock. In Late Cretaceous main basement fault zones were inverted due to the Alpine - Carpathian collision. The Nida Trough, located in front of the orogenic belt, was inverted in latest Maastrichtian or Palaeogene. Along the NE edge of the Mid-Polish Trough, due to buttressing effect exterted by the East European Craton, inversion has been initiated already in Late(?) Turonian, with its peak during Campanian – Maastrichtian and post-Maastrichtian times. As a result of Miocene thrusting within the Carpathians, the epicontinental basin was covered by the Miocene sediments of the Carpathian foredeep and/or by the Carpathian nappes. Miocene foredeep evaporites and Upper Cretaceous marls act as hydrocarbon seal. During the Miocene, basement fault zones have been partly reactivated in transtensional regime. This extension has enhanced HC prospectivity in selected areas by juxtaposing source and reservoir rocks. Mesozoic fault geometry and depocenter migration was imaged in a series of analogue models, which sug­gest complex rotation of basement microplates related to changes in extension / compres­sion directions combined with strike-slip movements.