PALEOCLIMATE RECORDS OF THE HOLOCENE INFERRED FROM PROGLACIAL LAKE BOTTOM SEDIMENTS OF EAST SIBERIA

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The pebble fines contribution into radiation environment of the river Yenisei floodplain in an influence zone of the Krasnoyarsk mining and chemical combine (KMCC)

The results of investigation of radioactive contamination of the river Yenisei bed pebbles in an influence zone of the KMCC (especially in its near-field part) are presented in this work. It is demonstrated, that pebbles can contain up to 30 % of the total amount of γ-emitting technogenic radionuclides (TRN) in the places with overlying soils. In addition, river bed pebbles, situated in permanently washing riverside sections of islands and banks, can contain significant amount of TRN too. These facts considerably increase an estimation of TRN reserves in the Yenisei floodplain. Without the contribution of the river bed pebbles the fraction of TRN, accumulated in the underlying and tow path pebbles in the near and far-field influence zones of the KMCC, can reach 7,9% for 137Cs, 5,8% for 152Eu, 5,6% for 154Eu and <3% for 60Co of their total amount

Uranium and its decay products in radioactive anomalies of oxidized brown coals (western part of Kansko-Achinsk brown coal basin)

Vertical distribution of uranium and its decay products (226Ra and 210Pb) in the uppermost layers of the oxidised brown coals was studied for some deposits and natural outcrops of the Western part of the Kansko-Achinsk brown-coal basin. Abnormal accumulation of the mentioned radioactive elements is observed in all studied sites. Several types of radioactive anomalies are differed by the ratio of activities of 238U and 226Ra: 1) Equilibrium; 2) Radium; 3) Uranium. The depletion of 210Pb in the radioactive horizons of some sites indicates an active emanation of 222Rn in the underlying coal layers. Uranium besides the form sorbed on coal is presented in poral solutions. It says about its potential mobility and is confirmed experimentally. Radium is actively absorbed by the plants growing on radioactive coals

PALEOCLIMATE RECORDS OF THE HOLOCENE INFERRED FROM PROGLACIAL LAKE BOTTOM SEDIMENTS OF EAST SIBERIA

118-11