Инд. авторы:	Samsonov A.V., Postnikov V.V., Spiridonov V.A., Larionova Y.O., Larionov A.N., Travin A.V., Postnikova O.V., Solovyeva N.V., Sabirov I.A., Spiridonov I.V.
Заглавие:	Neoarchean Granitoids in the Western Part of the Tunguska Superterrane, Basement of the Siberian Platform: Geochronology, Petrology, and Tectonic Significance
Библ. ссылка:	Samsonov A.V., Postnikov V.V., Spiridonov V.A., Larionova Y.O., Larionov A.N., Travin A.V., Postnikova O.V., Solovyeva N.V., Sabirov I.A., Spiridonov I.V. Neoarchean Granitoids in the Western Part of the Tunguska Superterrane, Basement of the Siberian Platform: Geochronology, Petrology, and Tectonic Significance // Petrology. - 2021. - Vol.29. - Iss. 5. - P.449-474. - ISSN 0869-5911. - EISSN 1556-2085.
Внешние системы:	DOI: 10.1134/S0869591121050064; WoS: 000695843000001;
Реферат:	eng: The paper presents data on the granitoids of the Yurubchen massif, which make up the basement of the Kamov arch, Baikit uplift in the western part of the Tunguska superterrane of the Siberian craton. Rocks of the massif were recovered by drillholes from depths of 1.8-2.0 km and occupy an area of at least 400 km(2). The U-Pb (SHRIMP) zircon age, geochemistry, and isotopic features of rocks of the Yurubchen massif indicate that it comprises granitoids of two groups, which are coeval but spatially separated from one another and differ in petrogenetic characteristics. The granodiorites (2562 +/- 16 Ma) have epsilon(Nd)(T) = + 0.9 to +2.1, contain high LREE concentrations, show highly fractionated HREE patterns (Gd-N/Yb-N = 3.4-6.2), which could be formed via partial melting of an enriched mafic source with a short crustal history at a depth of at least 45 km, in equilibrium with garnet-bearing residue. In contrast to the granodiorites, the sodic and potassic leucogranites (2563 +/- 10 and 2563 +/- 18 Ma, respectively) with epsilon(Nd)(T) from -0.3 to -1.7 and less fractionated HREE patterns (Gd-N/Yb-N = 1.7-2.3) could be produced by melting a crustal source at shallower depths. Isotopic data on the rock-forming and accessory minerals point to ca. 2.40 Ga (Rb-Sr and Sm-Nd mineral isochrones) and ca. 1.87 Ga (Ar-Ar, biotite) episodes in the postmagmatic history of the Yurubchen massif. The synchronous generation of petrogenetically different granodiorites and leucogranites may be explained by postcollisional lithosphere extension at ca. 2.56 Ga, which resulted in the melting of heterogeneous crustal material of different age at various depths. The closure of the Rb-Sr and Sm-Nd systems at ca. 2.40 Ga was probably related to the termination of the evolution of the Neoarchean collisional orogen and the cooling of the Yurubchen massif to a temperature of ca. 400 degrees C at a depth of 7-10 km. The later episode at ca. 1.87 Ga could be related to the tectonic exhumation of the Archean rocks in the western Tunguska superterrane during the development of the Paleoproterozoic Angara belt. In terms of the stabilization of the Archean continental crust, which was marked by ca. 2.56 Ga postcollisional granitoids, the Tunguska superterrane is younger than the terranes attributed to the Archaean Vaalbara and Superia supercratons but is comparable to crustal blocks in the Slavia supercraton and, perhaps, is a tectonic fragment of this youngest Neoarchean continent.
Ключевые слова:	PB; ROCKS; AGE; SM-ND; LU-HF; GREENSTONE BELTS; PERIDOTITE XENOLITHS; TRACE-ELEMENT; NORTH CHINA CRATON; geochronology and tectonic setting of granitoids; petrology; Early Precambrian; Tunguska superterrane; Siberian craton; basement of ancient platforms; EVOLUTION;
Издано:	2021
Физ. характеристика:	с.449-474