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LATE SAALIAN (WARTANIAN) GLACIAL PALAEOGEOGRAPHY AND FORMATION OF END MORAINES AT THE NORTHERN SLOPES OF SILESIAN RAMPART, SOUTHWESTERN POLAND Dariusz KRZYSZKOWSKI (1) & Andrzej £ABNO
(2) Krzyszkowski, D. & £abno, A., 2002. Late Saalian (Wartanian)
glacial palaeogeography and formation of end moraines at the northern
slopes of Silesian Rampart, Southwestern Poland. Annales Societatis
Geologorum Poloniae, 72: 67-87. Key words: proglacial environment, end moraines, ice-marginal sediments and processes, landscape evolution, Late Saalian, SW Poland. |
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| Abstract: 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). |
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