Plejstoceńskie deformacje tektoniczne w Szaflarach na Podhalu

Abstract

Pleistocene tectonic deformations at Szaflary, West Carpathians, Poland Unconsolidated Pleistocene sediments at Szaflary, West Carpathians, Poland (Figs. 1—3), show tectonic tilt to the south of the order of 10 degrees. The Pleistocene succession at Szaflary includes four stratigraphie units (Figs. 3—5, Tab. 1): 1) regolith (0.1—3 m), correlated with the Donau-Günz Interglacjal, filling karst holes and depressions in the underlying Jurassic limestone; 2) reworked regolith (0.05—0.5 m) and lower gravel (up to 1.4 m), correlated with the Günz Glaciation (fluvial or fluvioglacial material); 3) banded clay (lacustrine, finely laminated sediment with pollen spectrum indicating a warm climatic phase of interglacial character), correlated with the Günz-Mindel Interglacial; 4) upper gravel (1—8), representing fluvioglacial cover correlated with the Mindel Glaciation (see Birkenmajer & Stuchlik, 1975). The whole profile of Pleistocene sediments (layers 1—4) shows deformations due to loading and compaction, and due to sediment creep related to tectonic tilting. Deformations due to loading are visible best at the contact of the upper gravel with the underlying plastic sediments (Fig. 4A). Deformations caused by sediment creep related to tectonic tilting, are pronounced best in plastic layers underlying the Mindel fluvioglacial cover (Figs. 4B, 5A, B). The tectonic tilt of the whole Pleistocene profile was caused by differential movements of the Jurassic-Gretaceous klippe and its Pleistocene cover along a steep breccia-filled fault separating the Czorsztyn unit and the Magura unit of the Pieniny Klippen Belt at Szaflary (Figs. 6, 7). This fault represents part of a major dislocation zone along the northern border of the Klippen Belt, formed already during the Lower Miocene (Savian) orogenic movements. Evidences of vertical displacements along this dislocation zone during the Miocene, Pliocene and Pleistocene to Holocene times are known from the eastern part of the Klippen Belt of Poland (see Birkenmajer, 1970, 1971). The tectonic deformations of Pleistocene cover at Szaflary, involving also the Mindel fluvioglacial deposits, are thus younger than the Mindel Glaciation. They took place, most probably, during the Mindel-Riss Interglacial, as neither the Riss nor Würm fluvioglacial covers of the nearest vicinity show any trace of comparable deformations (Fig. 8).