Wiek bezwzględny aluwiów niektórych rzek Dolnego Śląska

Abstract

CARBON-14 DATINGS OF ALLUVIA OF SOME LOWER SILESIA RIVERS Summary The age of the youngest accumulation forms of the river valleys from the Lower Silesia has received a remarkable attention in recent literature. The debate primarily concerned the age of the upper valley- bottom terraces (flood plains). The terraces are built of gravels; their upper surface is sometimes fairly wide and situated up to 6-7 m above the river water level. The deposits forming such terraces often bear tree trunks, mostly oak trunks, down to the depth of 10 m. An attempt was made to determine the age of •these macrofossils by the use of Carbon-14 method. Age measurements were carried out in the Carbon-14 Laboratory of the Institute of Physics of the Silesian Polytechnic Institute at Gliwice, under the supervision of Prof. Dr. W. Mościcki. Carbon-14 dates show that the age of the wood found in the deposits of upper valley-bottom terrace ranges from 7300 years to 1450 years. B. P., i.e. up to the times of initiation of land cultivation in the area of the Lower Silesia. In those times the accumulation processes predominated in the area. The datings show that geological section through Nysa Kłodzka river valley (Fig. 4) is, in general, typical of all the larger river valleys of the Lower Silesia. This section is generally similar to that of the Odra river valley, presented by S. Szczepankiewicz (1959, 1968).