RADIOCARBON DATING OF HOLOCENE SEDIMENTS - FLOOD EVENTS AND EVOLUTIONOF THE LABE (ELBE) RIVER IN CENTRAL BOHEMIA (CZECH-REPUBLIC)

We studied the structure and development of the Holocene floodplain of the Labe (Elbe) River by radiocarbon dating sections of the upper and middle courses of the river. We focused on geomorphological and sedim entological conditions, mineralogy and the chemical composition of sed iments. We established the stratigraphy of the Holocene deposits of th e floodplain. The results of our investigation of fluvial sediments im ply that several abrupt changes in temperature and precipitation occur red during the Holocene. These changes led to intervals of hydrologica l disequilibrium, which caused the formation of two Holocene terraces and a contemporaneous floodplain. The lower terrace was flooded and co vered with sediments upon which the recent floodplain formed. During t he Holocene, there were four periods during which large tree trunks we re deposited in the fluvial sediments, indicating periods of extensive flooding. The supposition that these events were of more global scale is supported by the results of investigations made on the Holocene fl oodplains of other regions.