Geneza i zasięg vistuliańskiego zespołu terasowego Odry-Osobłogi pod Krapkowicami

Abstract

The system of morphological levels occurs on the slopes of the Odra and Osobłoga valleys in the vicinity of Krapkowice, southern Poland. Their genesis, range and age have been the subject of lively scientific discussion since the 1930s. Geomorphological analysis confirmed the fluvial origin of these flats. The use of LIDAR data allowed for precise height determination and revision of the range of indivi-dual river terraces, which rise above the valley bottom to a height of about 166 m a.s.l. (more or less 6 m above the Osobłoga/Odra channel), 168 m a.s.l. (8 m), 172 m a.s.l. (12 m), 174 m a.s.l. (14 m) and 181 m a.s.l. (21 m) res-pectively. The dating of sediments building the terrace elevated to 172 m a.s.l. using the OSL-SAR method gave a result of 87.7 ± 5.7 ka (GdTL-2820) indicating that it originated from the last cold stage of the Pleistocene. The ter-race surface was shaped by a sand-gravel braided river, which has developed on the substratum of the alluvium do-cumenting the period of intense valley-floor aggradation.