Uranium and Selected Trace Elements in Granites from the Caledonides of East Greenland

Agnete Steenfelt
Geological Survey of Greenland, Øster Voldgade 10, DK-1350 København K, Denmark

Abstract: The Caledonian fold belt of East Greenland contains calc-alkaline granite (sensu lato) intrusions with ages ranging from c.2000 Ma to c.350 Ma. The Proterozoic granites have low U contents and the pre-Devonian Caledonian granites contents of U corresponding to the clarke value for U in granites. Some aspects of the geochemistry of U are discussed using U-K/Rb, U-Sr, U-Zr, and U-Th diagrams. Secondary enrichment and mineralization occurs in fractured and hydrothermally altered granites and rhyolites situated in or near a major NNE fault zone. The U is associated with iron oxides or hydrocarbons. It is suggested that the source of the mineralization was Devonian acid magma, which also acted as a heat source for circulating hydrothermal fluids.

Mineralogical Magazine; June 1982 v. 46; no. 339; p. 201-210; DOI: 10.1180/minmag.1982.046.339.06
© 1982, The Mineralogical Society
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