Über eine interessante Froststruktur im episodisch-solifluidal bewegten Boden während der Würmeiszeit
Abstract. A frost-kettle is described as situated in the eastern part of the town of Bielefeld and reaching about 3 m into green and red marl, which had been moved episodically during the Würm glaciation. The frost-kettle was filled with yellow sand and glacial rubble as well as 4 layers of brown sand with small particles of clay (2.5 cm thick), inserted at regular intervals into the yellow sand. The brown layers showed a frost-upheaval of 5.5 cm in the centre due to hydration in a cold stadium of the last glaciation. While the yellow sand was washed into the cleft during the summer thawing periods, the clay particles of the brown layers consisting of weathered marl were blown into it after the soil had been dried. As loess-loam lies above a stone-layer showing no frost-dynamic modifications, the frost-kettle must have been formed during the second phase of the Würm glaciation, i. e. the high-glacial period.