Periglaziäre, polygonal-verzweigte rinnenförmige Bildungen und glazitektonische Strukturen in Saale-Till am Elbe-Urstomtalrand bei Wedel (Schleswig-Holstein)

Abstract

Remarkable polygenetical structures were observed at a refinery rehabilitation site in Wedel/Holstein. The polygonal shaped, channel-like structures are incised in mid-Saalian clayey, chalk-rich till. They are symmetrically semicircular shaped and filled with calcareous, silty sands that can be interpreted as sandy reworked till with aeolian components. The width reaches from approx. 0.3 to 1.5 metres, the depth up to approx. 0.8 metres. Horizontal cracks up to more than 10 meters in lengths, occurring as narrow belts of sand with reddish colour, are often centrally aligned in the channel-like structures. The present-day red colour is not natural but related to pollution. These belts reach down to the bottom of the channel like structures. At the lower site of the channel-like structures glacitectonic fissures with a width up to a few centimetres were to be traced into a depth of several metres to the basis of the excavat ion. The genesis of the channel-like structures is discussed. e. g. a possible relation with the pre-existing glacitectonic joints resp. the expected periglacial paleohydrogeological setting.