Middle-Pleniglacial soil formation (MIS 3) in the Upper Rhine Graben

In the southern End of the Rhine Graben near Basel (Switzerland), an up to 3 m thick stratigraphy of loess deposits and palaeosols was investigated in a construction pit. Field studies in combination with sedimentology, micromorphology and OSL-dating provided insights on the processes of loess deposition, formation of cambisols (brown earth) and periglacial phenomena around 45 (±5.7) ka. A succession of tundra soils on loess preserving locally foliated organic material can be attributed to the time period between 30.8 (±3.7) ka and 29.4 (±3.4) ka. Furthermore the basal deposit of weathered loess yielded an OSL age which dates back to the Eemian interglacial or the very begining of the last glaciation.

The outcrop of Basel-Schäublinstrasse provided further information to the ongoing studies on loess deposits, regional landscape evolution and environmental conditions during the late Pleistocene in the southern part of the Upper Rhine Plain.