Abstract
Results of 253 gamma spectrometric analyses of radon daughters in soil and bedrocks of the King George Island (West Antarctica) are presented. Measured values range from 0.1 to 58.4 Bq/kg, and from 4.9 to 75.5 Bq/kg for 214Bi and 208Tl respectively, but most measurements fall in the lower part of this range due to predominantly basaltic character of the geological basement. Obtained gamma spectrometric data correspond well to very low soil gas radon content measured by means of Kodak LR115 being below 454 Bqm-3. Low soil gas radon content and characteristic type of architecture is responsible for low indoor radon activity in Arctowski Station being as low as 10- 15 Bqm-3. The highest 105 Bqm-3 indoor Rn activity has been measured in the greenhouse bungalow of the station. This increased value was probably connected with the presence of about 1000 kg of imported soil material in the greenhouse room of the bungalow. Local zones of increased uranium and thorium content, discovered as a result of radiometric mapping, can potentaily influence atmospheric radon used for meteorological interpretation.
Highlights
The area under investigation is a part of the Shetland microplate which originated at the subducting Pacific margin of Gondwana and contains Cretaceous-Early Miocene island arc extrusives and intrusives (Birkenmajer et al, 1991)
Oceanic basalts are normally of low uranium and thorium content. and atmospheric radon activity is extremly low over ocean
Obtained results indicate that King George Island area is of extremely low Rn potential due to low uranium and thorium content and low emanation coefficient of the chemically unweathered bedrock material
Summary
The area under investigation (fig. 1) is a part of the Shetland microplate which originated at the subducting Pacific margin of Gondwana and contains Cretaceous-Early Miocene island arc extrusives (mainly basalts and andesites) and intrusives (gabros, diorites, monzonites) (Birkenmajer et al, 1991). Oceanic basalts are normally of low uranium and thorium content. Even within oceanic islands, magmatic differentiates of andesitic and granodioritic character and hydrothermal zones occur. They can be enriched in uranium and thorium making them a significant local source of radon emmanation. This possibility should be taken into account in the case of any meteorological interpretation. A pioneering paper on radon activity in the King George Island Area published by Evangelista, Pereira (2002) did not contain elements of radiometric mapping, in spite of the consolidated geophysical experience of both authors probably because of logistic problems. 0.661 cps/% 0.067 cps/ppm 0.025 cps/ppm author by means of a portable gammaspectrometer GR-320
Sign-in/Register to view highlights & summary 
Published Version (
Free)
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call