Anomalous radioactivity level and high concentrations of heavy minerals in Lemme area, South-West Estonia

Raukas, Anto; Koch, Rein; Jüriado, Krista; Järvelill, Johanna-Iisebel

doi:10.5200/baltica.2014.27.19

Cited by 6 publications

(4 citation statements)

References 25 publications

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“…The activity concentration of U-238 in the sample was calculated using a gamma line of Th-234 (63.3 keV) and gamma lines of the Ra-226 daughter nuclides Pb-214 and Bi-214, under the assumption that U-238 is in secular equilibrium with the daughter nuclide of Ra-226. This is consistent with how it was considered in previous studies in the Lemme area coastal sands in southwestern Estonia (Koch, 2006;Raukas et al, 2014). The activity concentration of Th-232 in the sample was determined using the gamma lines of Th-232 daughter nuclides as Ac-228, Bi-212, Pb-212 and Tl-208.…”

Section: Methodssupporting

confidence: 87%

“…Elevated concentrations of heavy minerals have been identified in different parts of the Estonian coast (Järvelill et al, 2015). Due to complicated cross-shore and alongshore migration of sedimentary material in the coastal zone, enrichment of heavy minerals, including zircon, monazite and other radioactive minerals, has occurred, for example in the Lemme area of southwestern Estonia (Raukas et al, 2014).…”

Section: Introductionmentioning

confidence: 99%

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Hazardous radioactivity levels and heavy mineral concentrations in beach sediments of Lake Peipsi, northeastern Estonia

et al. 2018

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The present study discusses results of heavy mineral analyses and radioactivity of beach sediments of Lake Peipsi. Such analyses are commonly done globally, but had not yet been conducted for the fourth largest lake in Europe. The average heavy mineral content in Lake Peipsi beach sediments along the northern and western coast is higher than usual for Estonian coastal and Quaternary sediments. Concomitantly, elevated radioactivity levels have been measured in several places, with the highest concentrations observed at Alajõe (1885.5 Bq/kg), which is over five times more than the recommended limit. The aim of the present study is to find sites with higher radioactivity levels, because the northern coast of Lake Peipsi is a well-known recreational area.

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Section: Methodssupporting

confidence: 87%

Section: Introductionmentioning

confidence: 99%

Hazardous radioactivity levels and heavy mineral concentrations in beach sediments of Lake Peipsi, northeastern Estonia

et al. 2018

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“…A high content of these minerals (2.5 %) was found also in one sample from the Rae 1 site. The high content of zircon in the Lemmeoja area has caused high levels of radioactivity there (Raukas et al, 2014).…”

Section: Mineralogymentioning

confidence: 99%

Accumulation of heavy minerals in the eastern coast of the Gulf of Riga, south-western Estonia

Järvelill¹,

Kleesment²,

Raukas³

2015

Bull. Geol. Soc. Finland

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The Baltic Sea is characterised by tectonic conditions that cause its northern parts to lift and southern parts to sink. Our study area (eastern coast of the Gulf of Riga) has been rather stable for a long time. During transgressive phases in the course of the sea's invasion to the coast intensive mechanical and mineralogical differentiation of the sediments took place, causing the separation of heavy minerals. The largest concentrations of heavy minerals were found in transgressive sediments of the Litorina Sea. Their concentration was especially high in the Lemmeoja site (in some layers up to 83.7 % of the sediment). The goal of our research was to study the heavy mineral content and composition in different age sediments of the area and to find regularities in the accumulation processes through time. To achieve our aim we collected samples from 16 sites between Pärnu and Ikla in south-western Estonia. The heavy mineral content in the whole investigated area is high, amounting on average to about 5 %. The deposits of transgressive phases of the Baltic Sea are more reworked than those of the regressive phases and contain more heavy minerals. Our investigation of initial rocks allows to conclude that garnets and zircon originated mainly from the Devonian sandstones of the Aruküla and Narva regional stages, amphiboles and pyroxenes mainly from Quaternary deposits.Keywords (GeoRef Thesaurus, AGI): transgression, sea-level changes, heavy minerals, Baltic Sea, Gulf of Riga * Corresponding author e-mail: iisebel@hotmail.com AbstractAccumulation of heavy minerals in the eastern coast of the Gulf of Riga, south-western Estonia

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“…During the last decade an abundant new factual material (about 480 observation points) was collected by ourselves (Petersell et al, 2006;Petersell et al, 2008;Jüriado & Petersell, 2010;Jüriado et al, 2012;Raukas et al, 2014) and added to our new map, compiled by M. Shtokalenko, under the supervision of V. Petersell.…”

Section: Introductionmentioning

confidence: 99%

Quaternary deposits and weathered bedrock material as a source of dangerous radon emissions in Estonia

et al. 2015

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The risk of dangerous radon emissions in Estonia is high, being among the highest in Europe. In almost 33 per cent of Estonian land area, the content of radon in soil-contained air exceeds the safe limit for unrestricted construction (50 kBq/m 3 ). In such high radon-risk areas the concentration of radon in soil-contained air ranges from 50 to 400 kBq/m 3 , in a few cases reaching up to 2,100 kBq/m 3 exceeding the permitted level for residential areas. The situation is particularly serious in the northernmost part of the country, where uranium-rich graptolite argillite (Dictyonema shale) and the Obolus phosphorite are close to ground surface and their particles are constituent parts of Quaternary deposits. Radon emissions from bedrock have been investigated in detail, but to date Quaternary strata as a source of radon emissions are poorly studied. According to our measurements the highest concentrations of radon are related to tills containing clasts and fines of graptolite argillite and phosphorite. Glacial deposits include also granitoidal material, containing U, Th and K, which have been transported by glaciers from the outcrop areas of crystalline basement rocks in Finland and the Gulf of Finland. Due to weathering, outwash and repeated redeposition other genetic types are poorer in radioactive elements and they are weaker sources of radon.

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Anomalous radioactivity level and high concentrations of heavy minerals in Lemme area, South-West Estonia

Cited by 6 publications

References 25 publications

Hazardous radioactivity levels and heavy mineral concentrations in beach sediments of Lake Peipsi, northeastern Estonia

Hazardous radioactivity levels and heavy mineral concentrations in beach sediments of Lake Peipsi, northeastern Estonia

Accumulation of heavy minerals in the eastern coast of the Gulf of Riga, south-western Estonia

Quaternary deposits and weathered bedrock material as a source of dangerous radon emissions in Estonia

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