Comparative petrography and organic geochemistry of different types of organic matter occurring in the Outer Carpathians rocks

Organic-matter vitrinite reflectance variability in the Outer Carpathians, Poland: relationship to tectonic evolution

The Grajcarek Unit of the Pieniny Klippen Belt (PKB), at the boundary between the Central (Inner) and Outer Carpathians, resulted from the convergence of the ALCAPA (the Alps–Carpathians–Pannonia) block and European plate. The strongly deformed slices of the Grajcarek Unit consist of Jurassic–Cretaceous sedimentary rocks associated with Late Cretaceous–Middle Palaeocene synorogenic wild-flysch, and sedimentary breccias with olistoliths. Maximum burial temperatures and burial depths were estimated based on vitrinite reflectance data. The vitrinite reflectance values were wide scattered through the Grajcarek sedimentary succession, especially in the flysch formations. This is attributed mainly to the depositional effects that affected the vitrinite evolution. The determined maximum burial temperatures were interpreted due to the regional compression controlled by tectonic burial coeval with thrusting and strike-slip faulting. The regional vitrinite reflectance variations might estimate cumulative displacement around the NNW–SSE and oriented the strike-slip Dunajec fault, which is a continuation of the deep fracture Kraków–Myszków fault zone.

The Zembrzyce Beds were studied to interpret the environments and facies in the western part of the Siary Subunit. New sedimentological data were obtained for the reconstruction of the depositional architecture of the Zembrzyce Beds. Based on detailed facies analysis, 9 facies and 4 facies associations were recognized. The facies associations represent different architectural elements of a submarine fan, such as: termination of distributary channel with transition to depositional lobe (distal part of mid-fan/outer fan sub-deposystem), lobes and distal lobes (outer fan sub-deposystem). According to the classification of Reading & Richards (1994) the fan deposystem can be classified as mud/sand-rich ramp. This system consists of several elongated lobes that formed synchronously, migrated laterally, and then retreated or decayed. The depositional system was supplied from the north and north-east. The inner-fan sub-deposystem was not detected. The sediments were deposited by high- and low-density turbidity currents and hyper-concentrated density flows sensu Mulder & Alexander (2001) with participation of the depositional background processes (pelagic settling). The sedimentary conditions of the Zembrzyce Beds during the Late Eocene were controlled by tectonic movements, the progress of the subduction and the global sea level changes.