The Valley-Fill Deposits of the Kłodnica River (Southern Poland): Environmental Drivers of Facies Changes from the Late Vistulian Through the Holocene

Abstract

Lithological analyses and radiocarbon dating were used to elucidate the patterns and controls of Late Quaternary valley floor development of the Kłodnica River, the Upper Odra Basin. The research results were discussed with data obtained from valleys of rivers draining piedmont basins and highlands of southern Poland. In consequence, five stages of morpho-sedimentary evolution of the Kłodnica valley were distinguished. In the Late Vistulian a large-scale deposition of channel alluvium took place in the conditions of high river discharges. This sedimentary style probably still existed in the Early Pre-Boreal as long as open grass communities survived in the Kłodnica catchment. The next phase, in the Late Pre-Boreal and Boreal, is characterized by a significant increase in accumulation rate of biochemical facies.. The considerable restriction of minerogenic deposition was connected with widespread of forest and gradual limitation of the river discharges. The third stage began at the decline of the Boreal and was defined by decrease of accumulation rate or even biogenic accumulation break. Synchronously, periodic increases of fluvial activity were noticed in the form of cutoffs of meander loops and overbank deposition in oxbows. The beginning of the fourth period took place not earlier than in the Early Sub-Boreal. This stage was distinguished by renewed peat growth/increase in biochemical accumulation rate and periodic increase in alluviation, generally taking place in the conditions of low channel-forming flows. The latest phase (from the Middle SubAtlantic till now) is characterized by common initiation of slope deposition and a rapid increase in fluvial sedimentation, especially overbank and tributary fan facies. An increase in minerogenic deposition occurred in response to human impact, which became more significant from the Roman Period and occurred on a large scale from the early Middle Ages. Older settlement phases, including intense settlement from the Hallstatt Period, were not clearly recorded in the Kłodnica valley fill.

The organic and mineral matter contents in deposits infilling floodplain basins: Holocene alluviation record from the Kłodnica and Osobłoga river valleys, southern Poland

“…4c) composed of low-cohesion sediment were produced by the mixed-load channel system. Under influence of Mid-and Late-Holocene conditions, the river formed a smaller and very sinuous channel with more stable banks (Wójcicki and Nita, 2004;Wójcicki, 2010). Along the lower reach of the Osobłoga Valley, two Pleistocene terraces with traces of braided paleochannels as well as the Late GlacialHolocene floodplain can be observed (Fig.…”

Anthropogenic causes of wetland loss and degradation in the lower Kłodnica valley (southern Poland)

“…Nevertheless, the main cause of the total fossilisation of the fen was an increase in sedimentation rate associated with soil erosion. Similar factors determined the development of fossil mire at the Bany site where the covering of peat by sandy-silty slope deposits was initiated approximately 540±60 14 C yrs BP (WÓJCICKI, 2010).…”

“…The formation of wetlands in the Kłodnica valley was mainly the result of the favourable pattern of the geomorphological and lithological factors. The latter include the presence of poorly permeable sediments: Miocene clays in the distal zone (KOTLICKI & KOTLICKA, 1980) and Late Holocene overbank sediments in the proximal zone of the floodplain (WÓJCICKI, 2010). The conversion of dry land to wetland depends strongly on geomorphological factors: primarily the formation of floodplain depressions (oxbow lakes, flood basins) and obstruction of the outflow in the progradation zones of alluvial fans.…”

Authigenic and allogenic organic remains as an indicator of geomorphological process activity within the floodplain environment: two case studies from Racibórz Basin, southern Poland

“…These fragments of the valley floors were originally formed by a sinuous river from the Late Vistulian to the middle Holocene. As a result, what predominate in the distal zone of the Kłodnica and Osobło-ga valleys are sand-bed meandering rivers, featuring lateral bars built of up to 3 m upward-fining (from gravelly sand to silty sand) alluvial series (Wójcicki 2006(Wójcicki , 2010. In the second order, a large area within the distal floodplain is occupied by organic plains developed in former oxbow lakes.…”

“…The flood sediments (fine sand to sandy mud) are usually poorly sorted, normally graded and massive or rhythmically stratified. They commonly consist of organic-rich layers with organic detritus and charcoal (Wójcicki 2006(Wójcicki , 2010. According to this scheme, the oxbow at the Steblów 2 site is filled with mineral-organic sediments ( …”