The functional significance of petrographic and mineralogical composition of alluvial soil in distribution and migration of radionuclides in river basins
The main goal of the study was to study the role of particle size, petrographic and mineralogical composition of alluvial soils in Cs-137 fixation and to reveal its regional specificity by comparison of samples collected in floodplains of two rivers draining geochemically different areas Soil sample...
| Main Authors: | , , , |
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| Format: | Dataset |
| Language: | Russian |
| Published: |
Theoretical and Applied Ecology
2017
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| Subjects: | |
| Online Access: | https://dx.doi.org/10.25750/1995-4301-2017-2-071-077 http://envjournal.ru/ari/v2017/v2/17213.pdf |
| Summary: | The main goal of the study was to study the role of particle size, petrographic and mineralogical composition of alluvial soils in Cs-137 fixation and to reveal its regional specificity by comparison of samples collected in floodplains of two rivers draining geochemically different areas Soil samples were taken in the period of 1999–2000 from soil pits located in riverside and island floodplain areas of the river Iput’ (Bryansk region) and Yenisey (Krasnoyarsk region) after field gamma-spectrometry along landscape cross-sections. Silt and clay mineralogy was performed for selected specimens with a considerably higher Cs-137 activity. Field gamma-spectrometry was performed by the CORAD device developed in Kurchatov Institute. Laboratory measurements of Cs-137 activity were carried out by a Canberra gamma-spectrometer with an HP-Ge detector. Soil fine fractions were separated using Gorbunov technique (1971), mineralogical composition of fines was determined with an X-ray diffractometer (Carl-Zeiss Jena). A comparative analysis of radiocesium distribution in alluvial soils performed in the studied regions confirmed that its fixation in soils is defined mainly by sorption processes controlled by granulometric and mineral composition of soil fractions. It is shown that samples taken from the Iput’ river basin belong to mica-smectite petro-mineralogical category while specimens collected in the Yenisey river basin appertain to chlorite-vermiculite category. The finding corresponds to difference in composition of the parent rocks and their weathering. This may lead to different character and rate of the long-term secondary processes of radiocesium redistribution in the soil-water system after the contamination event that should be accounted of in radioecological monitoring of geochemically different areas. |
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