Mineralogy, geochemistry and conditions of formation Permian-Triassic intraplate granitoids of Sinyushenskiy Massif (Gorny Altai)

• Main Authors: N. N. Kruk, O. A. Gavrushkina, C. G. Shokalskiy, A. V. Travin
• Format: Article
• Language: English
• Published: A.N. Zavaritsky Institute of Geology and Geochemistry 2016-04-01
• Series: Литосфера
• Subjects: внутриплитные гранитоиды; геохимия; геохронология; петрогенезис; горный алтай; intraplate granitoids; geochemistry; geochronology; petrogenesis; gorny altay
• Online Access: https://www.lithosphere.ru/jour/article/view/14
• ISSN: 1681-9004; 2500-302X

The data on geological settings, ages, special features of mineralogy and composition of Sinyushensky Massif granitoids the in north-west part of the Gorny Altay region. The age of the Sinyushensky Massif rocks is 248 ± 0.7 Ma (Ar-Ar dating by biotite). This massif belongs to Permo-Triassic Siberian large igneous province. Sinyushensky Massif granit-leucogranites are drastically different from typical intra-plate A-type granitoids. They correspond to S-type granitoids by mineralogy and petrochemical characteristics, and are characterised by the increased fluorine and LILE concentrations. Nd isotopic composition corresponds to that of the metasedimentary rocks of the north-west Altay’s upper crust. The formation of Sinyushensky Massif granitoids melts was the consequence of continental crust rocks melting. The enrichment by LILE and Ce-group REE associates with the influence of deep fluids caused selective melting of mica and accessory minerals.