Инд. авторы:	Berzina A.P., Lepekhina E.N., Berzina A.N., Gimon V.O.
Заглавие:	Zircons of igneous rocks at the Erdenetuin-Obo porphyry Cu-Mo deposit (Mongolia): U-Pb dating and petrological implications
Библ. ссылка:	Berzina A.P., Lepekhina E.N., Berzina A.N., Gimon V.O. Zircons of igneous rocks at the Erdenetuin-Obo porphyry Cu-Mo deposit (Mongolia): U-Pb dating and petrological implications // Doklady Earth Sciences. - 2012. - Vol.442. - Iss. 2. - P.249-255. - ISSN 1028-334X. - EISSN 1531-8354.
Внешние системы:	DOI: 10.1134/S1028334X12010059; SCOPUS: 2-s2.0-84861180917;
Реферат:	eng: The Erdenetuin-Obo porphyry Cu-Mo deposit was formed at the final stage of development of magmatic activity occasionally manifested in the Late Permian-Early Triassic in the period of at least 40 Ma. Early plutonic (host) and late ore-bearing porphyry intrusive complexes were formed in that period. The plutonic complex is multiphase, while the porphyry complex is polyrhythmical and multiphase within rhythms. The obtained data on the U-Pb isotopic composition (SHRIMP II) of zircons from unaltered rocks of the ore field are discussed: gabbro, diorite, and granodiorite of the plutonic complex and granodiorite-porphyry I and II of the first and second rhythms of the ore-bearing complex, respectively. Zircons of different age levels and genotypes were identified in the course of performed investigations. Gabbro are dominated by postmagmatic (superimposed) zircons with the datings of 239-225 Ma. The age of xenogenic zircon brought out from the basement rocks is estimated at 1146 ± 11 Ma. Zircons occur as magmatic and postmagmatic (superimposed) minerals dated 252-247, 244-233 Ma in diorite and 244-242, 239-224 Ma in granodiorite. The ages of postmagmatic zircons from diorite are partially overlapped by datings of magmatic zircons from granodiorite and granodiorite-porphyry. In the porphyry complex, the datings of magmatic zircons are 240-234 and 222-220 Ma in granodiorite-porphyries I and II, respectively. There are also inherited zircons with datings coinciding with those of magmatic zircons from precursor intrusive rocks. Datings of such zircons are 249-241 and 257-231 Ma for granodiorite-porphyries I and II, respectively. As a whole, zircon datings in all studied igneous rocks forming a virtually uninterrupted range in the period of 257-220 Ma allow us to suggest the relation of the ore magmatic system to the long-living constantly active deep source occasionally delivering melt to the upper levels. © Pleiades Publishing, Ltd., 2012.
Ключевые слова:	Granodiorite; Intrusive rocks; Isotopic composition; Magmatic activity; Mongolia; Ore fields; Ore-magmatic system; Triassic; U-Pb dating; Geochronology; Igneous rocks; Lead; Molybdenum deposits; Zircon; Ores; copper; diorite; gabbro; granodiorite; igneous rock; molybdenum; ore deposit; Permian-Triassic boundary; porphyry; uranium-lead dating; Decapoda (Crustacea); Mongolia; zircon; Deep sources; Basement rocks;
Издано:	2012
Физ. характеристика:	с.249-255