U-Pb zircon and titanite ages from granulites of the Koraput area - Evidence for Columbia, Rodinia and Gondwana from the Eastern Ghats Province, India

被引:14
|
作者
Nanda, Jagatbikas [1 ]
Gupta, Saibal [1 ]
Hacker, Bradley [2 ]
机构
[1] Indian Inst Technol, Dept Geol & Geophys, Kharagpur 721302, W Bengal, India
[2] Univ Calif Santa Barbara, Earth Sci, Santa Barbara, CA 93106 USA
关键词
Eastern Ghats Province; Columbia; LA-MC-ICP-MS geochronology; U-Pb zircon; U-Pb titanite; Jeypore Province; ALKALINE MAGMATISM; TRACE-ELEMENT; MOBILE BELT; MESOPROTEROZOIC SUPERCONTINENT; GEOLOGICAL EVOLUTION; SOUTHEASTERN MARGIN; DEFORMATION HISTORY; ONGOLE DOMAIN; BASTAR CRATON; BREAK-UP;
D O I
10.1016/j.precamres.2018.06.013
中图分类号
P [天文学、地球科学];
学科分类号
07 ;
摘要
The Eastern Ghats Province (EGP) of India, characterized by similar to 1 Ga granulite metamorphism (Ml), collided with the Archaean Indian craton in either Grenvillian (similar to 1 Ga) or Pan-African (similar to 0.6-0.5 Ga) time. At similar to 850 Ma, the Koraput Alkaline Complex (KAC) intruded into M-1 EGP granulites, and was metamorphosed during a second granulite event (M-2) in the EGP. U Pb zircon dates from gneisses in Koraput yield magmatic ages similar to 1500 Ma, with overgrowths at 1100-900 Ma and 800-700 Ma. Cratonic zircons from the EGP contact zone have Archaean 2.8-2.6 Ga cores with overgrowths at similar to 700 Ma. Titanites from a calc-silicate gneiss within the EGP define a U-Pb isochron around 700 Ma, whereas titanites from nepheline syenites within the KAC yielded a range of dates from 622 to 520 Ma. The c. 1500 Ma age in the EGP either implies Columbia break-up or proximity to a Columbia margin. The similar to 700 Ma age is interpreted as the age of M-2 granulite metamorphism that followed intracontinental thrusting of the EGP over similar to 2.8 Ga granulites of the Jeypore Province. The similar to 520 Ma titanite ages are correlated with final juxtaposition of the EGP-Jeypore Province amalgam with the Indian craton during Gondwana formation.
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页码:394 / 413
页数:20
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