Palaeogeographic evolution of the Pieniny Klippen Basin using stratigraphic and palaeomagnetic data from the Veliky Kamenets section (Carpathians, Ukraine)

Abstract

A 40-m-thick carbonate succession of the Bajocian to Berriasian age from the Veliky Kamenets quarry (Novoselica area, Pieniny Klippen Belt, Ukraine) resembles both the Czorsztyn and Niedzica successions of the Pieniny Klippen Belt, traditionally considered ridge slope-related deposits. A total of 176 individually oriented cores, collected from the bottom to the top of the sequence with sampling density dependent on inferred sedimentation rates, show multicomponent remanent magnetization with magnetite as a main magnetic carrier. Thermal demagnetization revealed two main components of natural remanent magnetization (NRM). A low-blocking temperature component S of normal polarity is considered of posttectonic, probably thermoviscous, origin due to overheating by Neogene volcanics. A stable, high-blocking temperature NRM component P shows dual-polarity distribution and is considered primary. It was possible to recognize 23 polarity zones that have been correlated with a biostratigraphic scale. Since two significant sedimentary gaps occur at 422 and 860 cm (the main hiatus—MS) from the base, the latter comprising the Middle Callovian/Early Oxfordian time span (6–8 Ma), an obtained pattern of magnetic reversals presented in this study cannot be considered complete. A palaeolatitude of 41±5° is calculated for the mid-Jurassic part below MS, similar to that expected for the European Craton at the Kamenets locality. The mid-Oxfordian limestone, directly overlying the MS, has palaeolatitudes around 28±6°. This implies a relatively fast opening of the oceanic domain to the north from the Kamenets block. This conclusion, combined with similarity of the Kamenets sequence to ridge-related sediments of the Pieniny Klippen Belt, makes it possible to speculate on the existence of the Kamenets Ridge (a new term), a structure of uncertain, although possible, structural links to the Czorsztyn Ridge. Palaeomagnetic declinations suggest 100° counterclockwise rotation of the whole section before the Neogene.