Luminescence dating of ice‐marginal deposits in northern G ermany: evidence for repeated glaciations during the M iddle P leistocene ( MIS 12 to MIS 6)

The exact number, extent and chronology of the M iddle P leistocene E lsterian and S aalian glaciations in northern C entral E urope are still controversial. This study presents new luminescence data from M iddle P leistocene ice‐marginal deposits in northern G ermany, giving evidence for repeated glaciations during the M iddle P leistocene ( MIS 12 to MIS 6). The study area is located in the L eine valley south of the N orth G erman L owlands. The data set includes digital elevation models, high‐resolution shear wave seismic profiles, outcrop and borehole data integrated into a 3D subsurface model to reconstruct the bedrock relief surface. For numerical age determination, we performed luminescence dating on 12 ice‐marginal and two fluvial samples. Luminescence ages of ice‐marginal deposits point to at least two ice advances during MIS 12 and MIS 10 with ages ranging from 461±34 to 421±25 ka and from 376±27 to 337±21 ka. The bedrock relief model and different generations of striations indicate that the older ice advance came from the north and the younger one from the northeast. During rapid ice‐margin retreat, subglacial overdeepenings were filled with glaciolacustrine deposits, partly rich in re‐worked Tertiary lignite and amber. During MIS 8 and MIS 6, the study area may have been affected by two ice advances. Luminescence ages of glaciolacustrine delta deposits point to a deposition during MIS 8 or early MIS 6, and late MIS 6 (250±20 to 161±10 ka). The maximum extent of both the E lsterian ( MIS 12 and MIS 10) and S aalian glaciations ( MIS 8? and MIS 6) approximately reached the same position in the Leine valley and was probably controlled by the formation of deep proglacial lakes in front of the ice sheets, preventing a further southward advance.