MAŁŻE Z OSADÓW ŚRODKOWEGO MIOCENU ZAPADLISKA PRZEDKARPACKIEGO: OTWORY WIERTNICZE BUSKO (MŁYNY) PIG-1 I KAZIMIERZA WIELKA (DONOSY) PIG-1 – STRATYGRAFIA I TAKSONOMIA

Abstract

MIDDLE MIOCENE BIVALVES FROM THE CARPATHIAN FOREDEEP BASIN: THE BUSKO (MŁYNY) PIG-1 AND KAZIMIERZA WIELKA (DONOSY) PIG-1 BOREHOLES – STRATIGRAPHY AND TAXONOMY

Abstract. The study is based on the fossil material derived from cores drilled in 2010 in the western part of the Carpathian Foredeep Basin. The deposits overlying the gypsum level, represented mainly by mudstones and clays of the Machów Fm., are less than 200m thick in this part of the Carpathian Foredeep. In total, 56 samples were investigated: 32 samples from the Busko (Młyny) PIG-1 drilling core 200 m long; and 24 samples from the Kazimierza Wielka (Donosy) PIG-1 drilling core, 191m long. Twelve bivalve species have been identified, namely: Nucula (Nucula) nucleus (Linnaeus, 1758), Lentipecten corneus denudatus (Reuss, 1867), Delectopecten vitreus (Gmelin, 1791), Inaequicostata cf. politioanei (Jekelius, 1944), Obsoletiforma vindobonensis (Laskarew, 1903), Plicatiforma pseudoplicata (Friedberg, 1934), Ervilia podolica (Eichwald, 1830), Ervilia trigonula Sokolov, 1899, Abra (Syndosmya) reflexa (Eichwald, 1830), Macoma (Psammacoma) elliptica (Brocchi, 1814), Corbula (Varicorbula) cf. gibba (Olivi, 1792) and Cuspidaria rostrata (Spengler, 1793). Stratigraphic ranges of bivalve species as well as descriptions of rare or stratigraphically important species have been presented. The bivalves define the Badenian/Sarmatian boundary within the depth range 109.10–127.70 m in the Busko (Młyny) PIG-1 borehole, and within the depth range 150.80–162.80 m in the Kazimierza Wielka (Donosy) PIG-1 borehole. Specifically, the scallop Delectopecten vitreus (Gmelin, 1791) defines the base of the Machów Fm. as the Late Badenian, while the species Abra (Syndosmya) reflexa (Eichwald, 1830) enables to specify the age of the uppermost part of the Machów Fm. as the Early Sarmatian.