Přirozená radioaktivita hornin ve střední části velkolomu Mokrá
| Title in English | Natural radioactivity of rocks in the central part of the Mokrá quarry |
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| Authors | |
| Year of publication | 2013 |
| Type | Article in Proceedings |
| Citation | |
| Keywords | Moravian Karst; limestones; calciturbidites; natural radioactivity |
| Description | Concentrations of potassium, uranium and thorium were determined by using a field gamma–ray spectrometer GS–256 and a laboratory gamma–ray spectrometer SG–1000 LAB in carbonate rocks of Macocha Fm. and Líšeň Fm. (limestones and calciturbidites) extracted in a central part of the Mokrá quarry in the Moravian Karst. The concentrations of the elements were converted to the mass activity of 226Ra equivalent (am) in order to express gamma–ray activity of the studied rocks. Very low natural radioactivity of platform carbonates of the Macocha Fm. (only 12 Bq.kg-1 on average) is caused by low contents of K, U and Th. Similarly low mass activity values were found in nodular limestones (so–called Křtiny Lmst.) of the Líšeň Fm. (25 Bq.kg-1 on average). Slightly increased contents of potassium, uranium and thorium are in calciturbidites belonging to the Líšeň Fm.: in contrast to limestone beds with low natural radioactivity (37 Bq.kg-1 on average), siliciclastic beds of calciturbidites show increased mass activities in the range from 60 to 368 Bq.kg-1 (146 Bq.kg-1 on average). |