Uranium and thorium geochemistry in the ferriferous rocks of Gimol'sk series (Karel a)

Investigation results of regularities of uranium and thorium distribution in rocks of Gimol'sk series of iron-ore region (Northern Kareliya) are presented. Conclusions are made on premetamorphic and ferriferous-carbonate nature of ore substance of the considered ferriferous formation. The content of natural radioelements in rocks of ferriferous formation of Gimol'sk series on the whole is almost 4 times lower than on the average for earth crust (0.7x10-4% U and 2.6x10-4% Th, Th/U=3.7). From radiogeochemical point of view ferriferous quartzites are the poorest among metamorphized sedimentary rocks