Petrology and age of granitoids of the Aturkol Massif, Gorny Altai: Contribution in the problem of formation of intraplate granitoids

作者：Kruk N N^*; Gavryushkina O A; Rudnev S N; Shokalsky S P; Vasyukova E A; Kotov A B; Sal'nikova E B; Travin A V; Kovach V P; Kruk E A

来源：Petrology, 2017, 25(3): 318-337.

DOI：10.1134/S086959111703002X

Geological, mineralogical, petrographic, geochemical, and geochronological data are reported for granitoids of the Aturkol Massif (Gorny Altai). It is shown that it was formed in within-plate setting in the Early Triassic, nearly simultaneously with flood basalts of the Kuznetsk Basin and alkalic basite and lampropyre dike swarms in the western Altai-Sayan Fold Region. At the same time, the mineralogical-petrographic, geochemical, and isotope characteristics of the considered granitoids are close to those of I-type granites. Intraplate signatures (elevated HFSE and REE) are recognized only in the least silicic rocks (granosyenites). Obtained data suggest mantle-crustal nature of the granitoids. They were formed by mixing of lamprophyre magmas with high pressure (> 10 kbar) crustal melts derived from a mixed source consisting mainly of N-MORB-type metabasites with insignificant admixture of high-Ti basalts and metasedimentary rocks. The contribution of mantle component in the granitoids was insignificant (< 20%). Proposed petrogenetic mechanism can provide the formation of large volumes of granitoid magmas with "crustal" geochemical and isotope signatures in an intraplate setting.

• 出版日期2017-5