Sediments of Bisnik Cave (Poland): Lithology and stratigraphy of the Middle Palaeolithic site

摘要

Bisnik Cave is an important Palaeolithic site located in the Krakow-Czestochowa Upland. The cave fill is a complex well-stratified sequence composed of 35 layers/sublayers interrupted by number of hiatuses and ranging from Pliocene till modern times. Fifteen Middle Palaeolithic horizons, some of them among the oldest in Poland, represent the most important part of the sequence from an archaeological point of view. The sedimentary sequences in particular parts of the cave have been studied for more than 20 years to investigate the chronostratigraphy and palaeoenvironment. The recent multi-proxy study is based on the application of new methods for the site: analysis of sedimentary and post-sedimentary structures, and weathering stage of limestone rubble and fossil bones, pollen analysis, molecular biomarkers, palaeomagnetic analysis and radiometric dating. Results indicated a more intensive role of re-working and re-deposition in the cave. Older sediments were transported into some stratigraphic horizons from sources within the cave itself as well as from outside, including palaeontological and archaeological materials. Some the detected layers therefore represent a mix derived from different sources. A record of two interglacials (Eemian Interglacial, MIS 5e and Penultimate Interglacial, MIS 7) was established in layers Nos. 15-14-13a-13 and 19a-19, respectively. Middle-Upper Pleistocene sedimentary units were identified with MIS 3-MIS 7/8, instead of previous interpretation to MIS 4-MIS 9. The age of the basal vario-colored complex, previously interpreted mostly as pre-Pleistocene, was newly correlated with MIS 7/8 and Early Pleistocene/Pliocene.