Volume 16 (2010): Issue 2 (June 2010)

An atypical lithological development of outwash deposits in the Carpathians Foreland (S Poland) shows lower and middle parts of the sedimentary succession that are characterized by sinuous palaeochannels. This channel facies consists of laterally accreted sands derived from side bars. The sedimentary environment was a proglacial system of anabranching channels, presumably of anastomosed type. The outwash channel pattern was most probably controlled by the raising base level of the fluvial system. Both proglacial and extraglacial waters were dammed by a sandur within a small upland valley. Aggradation and progradation of the glaciofluvial deposits resulted in progressive rising of the dammed lake level. The low hydraulic gradient of the outwash streams resulted in a sinuous planform as well as a low-energy style of deposition. Afterwards, the rising lake water was drained off through a low watershed and the entire valley became filled with outwash sediments. The bedrock morphology thus became buried and a typical unconfined sandur with a braided channel network developed during the last phase of the glaciomarginal sedimentation (upper part of the sedimentary succession under study).

The depositional conditions of kame terraces in a mountain valley were analysed sedimentologically and petrologically through a series of kame terraces in the Rudawy Janowickie mountains. The kame terraces comprise five lithofacies associations. Lithofacies association GRt, Sp originates from deposition in the high-energy, deep gravel-bed channel of a braided river. Lithofacies association GC represents a washed out glacial till. Probably a thin layer of till was washed out by sandy braided rivers (Sp). The fourth association (Fh, Fm) indicates a shallow and quite small glaciomarginal lake. The last association (GRt, GRp) indicates the return of deposition in a sandy-bed braided channel. The petrography of the Janowice Wiekie pit and measurements of cross-stratified beds indicate a palaeocurrent direction from N to S. The Janowice Wielkie sedimentary succession accumulated most probably during the Saalian (Odranian, Saale I, Drenthe) as the first phase of ice-sheet melting, because the kame terrace under study is the highest one, 25-27 m above the Bóbr river level. The deposits under study are dominated by local components. The proglacial streams flowed along the margin of the ice sheet and deposited the kame terrace. The majority of the sedimentary succession was deposited in a confined braided-river system in quite deep channels.