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Simulation of the shorelines of glacial Lake Peipsi in Eastern Estonia during the Late Weichselian

Rosentau A., Hang T., Miidel A.

Geological Quarterly

2004

Vol. 48, No 4

299--307

Digital reconstruction of the evolution of glacial Lake Peipsi, Eastern Estonia, was based on a geographic information system (GIS) method that removed isostatically deformed palaeowater planes fromthe current digital terrain model. A reconstruction of the proglacial water levels was performed with respect to geomorphological correlation of river terraces, raised shorelines and eroded surfaces of various aqueoglacial landforms. The configuration of shorelines, main outlets and water depths of glacial Lake Peipsi, corresponding to the Otepää, Piirissaar, Kaiu and Pandivere–Neva stades during the deglaciation of the Lake Peipsi depression, was simulated. The two approaches used, reflecting the geomorphological correlation of Raukas and Rähni (1969) and Hang (2001), are discussed.

Late Saalian (Wartanian) glacial palaeogeography and formation of end moraines at the northern slope of Silesian Rampart, Southwestern Poland

Krzyszkowski D., Łabno A.

Annales Societatis Geologorum Poloniae

2002

Vol. 72, No 1

67-87

There is evidence, hitherto often denied, for the ice marginal features, including the end moraine hills along the Silesian Rampart, SW Poland. These end moraines are attributed to the regional advance of the Wartanian ice sheet into its maximum position, which is also marked by subglacial till bed. The end moraine hills are located on the northern slopes of the Silesian Rampart and they are very rare, partly due to subsequent erosion, but mainly due to conditions not favourable for a remarkable proglacial accumulation. The Wartanian end moraines of southwestern Poland possess several features that suggest that they are end moraines with dominant waterlain, stratified sediments. They are interpreted as alluvial fans, where the ice margin is represented by a 'scarp'. They have semi-conical form, often plano-convex geometry and an average distal slope of 2-25°. These fans are equivalent to sheetflow-dominated or 'humid' alluvial fans in non-glacial environments. Sedimentary sequences of the end moraines consist mainly of coarse-grained material, with boulders up to 1.8 m in diameter, with typical sediments of 'proximal fan' with a highly pulsatory water discharge. The formation of the end moraine followed the formation of a proglacial lake and strong erosion after its drainage. The end moraine was formed during oscillation of the ice margin that resulted in local glaciotectonic deformation of the end moraine fan sediments (push) and a set of parallel hills, with successive younger alluvial fans (retreat).