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Fallout 137Cs and natural 40K as tracers of topsoil development during slope processes – a case study from the Daugai environs, Southern Lithuania

Bauziene I., Mazeika J., Skuratovic Z.

Geochronometria

2013

Vol. 40, no. 2

126--133

Investigations of soil erosion by 137Cs method brings uncertainties of different nature. The estimation of the 137Cs local inventory is associated with problems of data comparison and instrumen-tal errors. In order to avoid systematic errors, the rate of soil erosion determined by the 137Cs method is compared with the values obtained for other radioactive elements. Soil parameters must be regard-ed too. The aim of the work was to test the character of 137Cs and 40K distribution in the topsoil verti-cal section for determination erosion-accumulation type and ratio in different time spans. The topsoil thickened by different types of erosion-accumulation processes was sampled at a 2-3 cm interval. Soil samples were analysed by means of scintillation gamma spectrometry. The relationship between 137Cs and 40K inventories was weakest in the topsoil formed by mixing of soil material during the installa-tion of artificial drains. Based on climatic characteristics, variations of theoretical soil accumulation rate in the last 50 years were calculated for the topsoil accumulated predominantly by water erosion. 40K and 137Cs correlation in the bottom of vertical section of topsoil or arable horizon are closest and this section may be used as a complementary parameter determining the local inventory value

The basis of the study of the age of the Holocene diluvium on loess areas of Polish Highlands

Bluszcz A., Poręba G. J., Śnieszko Z.

Geochronometria

2007

Vol. 28

61-66

Large part of slope sediments (pediment) which are the effect of water induced soil erosion in the loess areas of Polish Uplands, has a close relationship with pre-historical, historical and "present" agricultural activity. The sediments accumulated in different periods are often separated by fossil soils. These soils are correlated with the periods of relinquishment of agricultural land use in a given area. A precise dating of the cycles of fossil soil formation is practically impossible. Therefore it is important to gain a possibility to establish the age of sediments between old fossil soils corresponding with the phases of soil erosion. The organic material in the floor or roof of deposits permitting a 14C dating is very seldom. This is why attempts were made to use the OSL method to date mineral parts of slope sediments. In connection with pedological and sedimentological methods, the OSL method makes it possible to give some information about the age of pre-historical and historical phases of intensive soil erosion. In order to date sediments accumulated during the last 50 years, the method based on measurement of 137Cs isotope in products of soil erosion is used. This paper shows some examples of the application of 14C, OSL and 137Cs methods in some selected research sites. In each case there is a discussion of limitations of the methods used.