Download PDF

PETROGRAPHIC FEATURES OF GRANITOIDS AND MINERALS-CONCENTRATORS OF RADIOACTIVE AND RARE EARTH ELEMENTS OF THE OB-ZAISAN FOLDED REGION

V. P. Sukhorukov 1,3, D. A. Novikov 1,2, A. F. Sukhorukova 1,2, A. A. Maksimova 1,2, N. I. Yandola 1,2

1 Novosibirsk State University, Novosibirsk, Russia; 2 A.A.Trofimuk Institute of Petroleum Geology and Geophysics SB RAS, Novosibirsk, Russia; 3 V.S.Sobolev Institute of Geology and Mineralogy SB RAS, Novosibirsk, Russia

The paper presents data on the mineralogical, petrographic and geochemical features of granitoids of the Ob-Zaisan folded region. Two complexes such as Priobsky and Barlaksky are considered. The first one is represented by medium and acidic rocks of the moderately alkali-type. The rocks are enriched with light REE to the greatest extent, and are also characterized by generally low uranium content (mainly 1–3 g/t), the thorium content is mainly 1–16 g/t. The U/Th ratio in these rocks mainly varies in a narrow range from 0.1 to 0.5 and does not exceed 1. The second one is composed of granites of normal and moderately alkali-type. The Barlaksky complex rocks have comparable values of light and heavy REE contents. The rocks are characterized by a sharply increased content of uranium (10–30 g/t) and thorium (up to 35–40 g/t). The ratio of uranium to thorium is mainly 0.1–0.7.

Keywords: granitoids, accessory minerals, rare earth elements, uranium, thorium, Ob-Zaisan folded region, West Siberia.

DOI 10.20403/2078-0575-2024-2-86-99

​ ​​​​​​