Middle Pleistocene sedimentation and palaeogeography of the Dzierżoniów basin, Sudetic Foreland, Southwestern Poland
Abstract
Środkopleistoceńska sedymentacja i ewolucja paleogeograficzna Kotliny Dzierżoniowskiej na Przedgórzu Sudeckim, południowo-zachodnia Polska
The Dzierżoniów Basin contains deposits of three glacial stages: older Elsterian, younger Elsterian and older Saalian (Odranian). The first and the last are represented by tills and thin, discontinuous proglacial (transgressive) deposits. Younger Elsterian represents both transgressive glaciofluvial/glaciolacustrine deposits and a till, as well as deglaciation suite. The latter is represented by extensive glaciolacustrine suite, formed in the ice-contact lake, and series of glaciofluvial deposits. Glacial palaeotransport was from northwest during both Elsterian stadials. During Odranian, two ice lobes occurred, one flowing from north and the second one from northeast. Holsteinian fluvial series occur directly on younger Elsterian deglaciation suites. They represent gravelly or sandy-gravelly sequences deposited by braided rivers. Holsteinian age is inferred from geological position. No pollen data are available. Elsterian and Holsteinian deposits have been tectonically shifted and slighty deformed. The amplitude of tectonic movements is ca 30 - 40 m. Age of the tectonic movements is, most probably, post-Odranian. Younger Saalian (Wartanian) and Upper Pleistocene sequences are represented mainly by fluvial deposits (valleys) and loess or slope deposits (uplands). Deep valleys were formed during the Odranian/Wartanian interstadial, possibly because of increased uplift and regional tectonic movements.
The Dzierżoniów Basin contains deposits of three glacial stages: older Elsterian, younger Elsterian and older Saalian (Odranian). The first and the last are represented by tills and thin, discontinuous proglacial (transgressive) deposits. Younger Elsterian represents both transgressive glaciofluvial/glaciolacustrine deposits and a till, as well as deglaciation suite. The latter is represented by extensive glaciolacustrine suite, formed in the ice-contact lake, and series of glaciofluvial deposits. Glacial palaeotransport was from northwest during both Elsterian stadials. During Odranian, two ice lobes occurred, one flowing from north and the second one from northeast. Holsteinian fluvial series occur directly on younger Elsterian deglaciation suites. They represent gravelly or sandy-gravelly sequences deposited by braided rivers. Holsteinian age is inferred from geological position. No pollen data are available. Elsterian and Holsteinian deposits have been tectonically shifted and slighty deformed. The amplitude of tectonic movements is ca 30 - 40 m. Age of the tectonic movements is, most probably, post-Odranian. Younger Saalian (Wartanian) and Upper Pleistocene sequences are represented mainly by fluvial deposits (valleys) and loess or slope deposits (uplands). Deep valleys were formed during the Odranian/Wartanian interstadial, possibly because of increased uplift and regional tectonic movements.