Инд. авторы:	Kiseleva O.N., Airiyants E.V., Belyanin D.K., Zhmodik S.M., Ashchepkov I.V., Kovalev S.A.
Заглавие:	Multistage Magmatism in Ophiolites and Associated Metavolcanites of the Ulan-Sar'dag Melange (East Sayan, Russia)
Библ. ссылка:	Kiseleva O.N., Airiyants E.V., Belyanin D.K., Zhmodik S.M., Ashchepkov I.V., Kovalev S.A. Multistage Magmatism in Ophiolites and Associated Metavolcanites of the Ulan-Sar'dag Melange (East Sayan, Russia) // MINERALS. - 2020. - Vol.10. - Iss. 12. - Art.1077.
Внешние системы:	DOI: 10.3390/min10121077; WoS: 000602383600001;
Реферат:	eng: We present new whole-rock major and trace element, mineral chemistry, and U-Pb isotope data for the Ulan-Sar'dag melange, including different lithostratigraphic units: Ophiolitic, mafic rocks and metavolcanites. The Ulan-Sar'dag melange comprises of a seafloor and island-arc system of remnants of the Paleo-Asian Ocean. Detailed studies on the magmatic rocks led to the discovery of a rock association that possesses differing geochemical signatures within the studied area. The Ulan-Sar'dag melange includes blocks of mantle peridotite, podiform chromitite, cumulate rocks, deep-water siliceous chert, and metavolcanic rocks of the Ilchir suite. The ophiolitic unit shows overturned pseudostratigraphy. The nappe of mantle tectonites is thrusted over the volcanic-sedimentary sequence of the Ilchir suite. The metavolcanic series consist of basic, intermediate, and alkaline rocks. The mantle peridotite and cumulate rocks formed in a supra-subduction zone environment. The mafic and metavolcanic rocks belong to the following geochemical types: (1) Ensimatic island-arc boninites; (2) island-arc calc-alkaline andesitic basalts, andesites, and dacites; (3) tholeiitic basalts of mid-ocean ridges; and (4) oceanic island basalts. U-Pb dating of zircons from the trachyandesite, belonging to the second geochemical type, yielded a date of 833 +/- 4 Ma which is interpreted as the crystallization age during mature island-arc and intra-arc rifting stages. The possible influence of later plume magmatic-hydrothermal activities led to the appearance of moderately alkaline igneous rocks (monzogabbro, trachybasalt, trachyandesite, subalkaline gabbro, and metasomatized peridotites) with a significant subduction geochemical fingerprint.
Ключевые слова:	SUBDUCTION; BREAK-UP; TRACE-ELEMENT; SOUTHERN SIBERIA; NORTHERN MONGOLIA; MANTLE PERIDOTITES; PGE MINERALIZATION; U-PB; VOLCANIC-ROCKS; plume magmatic-hydrothermal activity; subduction; geochemistry; volcanic rocks; ophiolite; EVOLUTION;
Издано:	2020
Физ. характеристика:	1077