Accumulation of Uranium in Granitic Soils Overlying the Mourne Mountains, County Down, Northern Ireland

Abstract

Accumulation of uranium is correlated with a number of major elements, classical soil properties, mineralogy, and chemical weathering index of podzolic soils from the Mourne Mountains, Northern Ireland. Degree of enrichment of this element in the organic, amorphous, and crystalline fractions has also been investigated. Results show a relationship between the concentration of this element and the pedogenetic processes of podzolic soil formation. Soils formed over the different types of granite (G2–G5) show U to be evenly distributed between the three fractions analyzed. Results from one site (Rocky River), a weathered relict of the Tertiary period, show higher levels of organic carbon and oxyhydroxides and also the associated mineral gibbsite [Al(OH)3]. Higher concentrations of these constituents correlate with a significant accumulation of U in the soil. Results strongly indicate that this anomalous accumulation of U is a direct consequence of chemical weathering and pedological processes with the formation of clay and associated minerals.