WYKSZTAŁCENIE, STRATYGRAFIA I ŚRODOWISKA DEPOZYCJI UTWORÓW POGRANICZA BADENU I SARMATU Z SW OTOCZENIA GÓR ŚWIĘTOKRZYSKICH – PROFILE OTWORÓW BADAWCZYCH BUSKO (MŁYNY) PIG-1 i KAZIMIERZA WIELKA (DONOSY) PIG-1

Abstract

CHARACTERISTICS, STRATIGRAPHY AND DEPOSITIONAL ENVIRONMENTS OF THE BADENIAN–SARMATIAN TRANSITION DEPOSITS FROM THE SW MARGIN OF THE HOLY CROSS MOUNTAINS – THE PROFILES OF THE BUSKO (MŁYNY) PIG-1 AND KAZIMIERZA WIELKA (DONOSY) PIG-1 BOREHOLESAbstract. Results of sedimentological and petrological studies of drill cores from two boreholes drilled in the northern part of the Carpathian Foredeep by the Polish Geological Institute in 2009–2010, accompanied by the complex palaeontological, geochemical-petrographic, isotopic, mineralogical and palaeomagnetic analyses have enabled to characterize the development and depositional history of the Upper Neogene deposits. The Upper Neogene series consists of monotonous clastics (mainly siltstones, claystones and marls) of Upper Badenian and Lower Sarmatian age. The Badenian–Sarmatian transition is a continuous succession without any lithological expression. The well sections represent the more nearshore (Busko (Młyny) PIG-1) and the more offshore (Kazimierza Wielka (Donosy) PIG-1) zones of the Neogene marine basin of the Carpathian Foredeep. A distinct geochemistry change is recorded later in the Kazimierza Wielka (Donosy) PIG-1 section than in the Busko (Młyny) PIG-1 section, there it took place a little bit earlier than the noticed change in the foraminiferal assemblages from the Badenian to the Sarmatian type. Anyway, the new fauna (bivalves and nannoplankton), associated with the Sarmatian transgression, occurred in the sections earlier than the general geochemical transformation of the basin. All observed faunal and geochemical changes took place in a deep-marine environment, with a calm deposition from suspension, before the episodes of turbidite activity. Two of numerous tuffite interbeds have been regionally correlated and the upper one is located above the registered normal (C5AAn) to reversed (C5Ar.3r) polarity change (Kazimierza Wielka (Donosy) PIG-1), dated at 12.8 ±0.1 Ma.