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- Author or Editor: L. Schuch x
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Abstract
Soil samples from Paraná State, Brazil, were collected in 1991 and compared with others collected at the same location in March 1977 and at the end of 1983. Pedological analyses were practiced on these samples and137Cs and232Th,226Ra and40K activities were determined by gammaray spectrometry. A latitude dependence of137Cs was found as well. It was impossible to determine the137Cs contribution from Chernobyl nuclear accident because of low fallout and intense leaching, erosion and re-suspension in soils of regions with high annual precipitation. Natural radionuclides did not show such effects.
Abstract
Various types of soil samples were collected in the southern part of Brazil, with depth intervals of 5 cm, down to 50 cm, using a specially designed sampler. Pedological analysis of these soils were performed. Nuclear activities of137Cs (expressed in Bq m–2) and radioactive natural element (226Ra,228Ra and40K) concentrations were determined by low background gamma-ray spectrometry.137Cs concentrations were correlated with radioactive natural element concentrations and pedological, climatological and geographic parameters related to the soil samples collected.
Abstract
Sediments from the Admiralty Bay, King George Island, Antarctica, were investigated by 57Fe Mössbauer spectroscopy, X-ray diffractometry, and radiometry. Quartz, feldspar, chlorite, calcite, dolomite, mica, kaolinite, hematite and magnetite were identified as constituent minerals in the sediment samples. The phase composition and the iron distribution among the crystallographic sites of iron-bearing minerals (silicates, magnetite and hematite) of samples from different location have been derived from the complex Mössbauer spectra. At different locations sediments had significant characteristic differences in the mineral composition, in the iron distribution among the crystallographic site of silicates, and in the specific radioactivity of Cs radionuclides. These results indicate differences in the rock formation and alteration by the sediments in this maritime part of Antarctica. There is a much higher amount of iron oxides in the sediments from south part of the geological fault across the Admiralty Bay than in the north part. This can be associated with much more alteration in the rocks in the south part compared to the northern one. This finding can contribute to the question of the history of the formation and alteration of volcanic rocks in the border of Antarctica.
