Seismic geomorphology of the karstified Upper Jurassic-Lower Cretaceous carbonate succession in the Carpathian Foredeep area, Poland

Abstract

Characterization of subsurface reservoirs composed of soluble rock formations is commonly challenged by the presence of structures forming irregularly distributed, multi-scale inhomogeneities originating from karstification and karst degradation. Although the majority of paleokarst features occur at sub-seismic scales, seismic data interpretation can provide information on type and spatial distribution of meso-scale karst features. Integrating these with other data sources and a genetic understanding of karst formation provides a means to decipher former karst systems and their extent and potential impact on subsurface reservoirs. In turn this offers the potential for improved reservoir characterization and reducing exploration- and production-risks. The present work investigates the Upper Jurassic–Lower Cretaceous carbonate succession located in the Polish sector of the Carpathian Foredeep. From the Early Cretaceous to Middle Miocene, the stratigraphic record reveals that the region experienced two prolonged episodes of subaerial exposure, highlighting the potential for extensive overprinting of these formations by karst during these events. Using conventional 3D seismic data, supplemented by wireline logs, numerous karst-related features can be identified and mapped. Detailed structural, stratigraphic, and geomorphological analysis suggest that karst development was controlled by lithological and tectonic factors, as well as relative sea level change. The results are synthesized into a conceptual model for regional karst evolution and its impact on the Upper Jurassic–Lower Cretaceous carbonate succession in the Carpathian Foredeep. Our study demonstrates the utility of applying an integrated workflow when characterizing paleokarst systems in geologically complex, carbonate successions.