Thermal Maturity of the Magura Nad Dukla Nappes (Outer Carpathian, Poland) - Data from Vitrinite Reflectance and Illite-s

The aim of the present studies was to evaluate thermal maturity of internal nappes in the Polish segment of the Outer Carpathians using independent methodologies. Studies were performed on twenty one claystone samples collected from natural exposures The age of sampled rocks ranges from Late Cretaceous to Oligocene. Reflectance of vitrinite (Rₒm%) was used as organic indicator of thermal maturity. Standard deviation values were calculated for all measurements. Smectite to illite transformation in mixed-layer illite-smectite (I-S) were used as inorganic indicator. For all samples maximum paleotemperatures were estimated. The random reflectance of vitrinitic organic matter varies between 0.205 and 1.13% and calculated paleotemperatures vary between 55 and 170 °C. The analysed rocks contain 7-40 %S in I-S. The paleotemperatures according to inorganic indicator varies between 111 and 193°C and generally is always higher than those achieved using organic indicator. The results of presented studies can be used in petroleum prediction as well as for verification of present ideas on thermal structure of the Outer Carpathians.