India-Antarctica-Australia-Laurentia connection in the Paleoproterozoic-Mesoproterozoic revisited: Evidence from new zircon U-Pb and monazite chemical age data from the Eastern Ghats Belt, India

We present zircon and monazite U-Pb data from ultrahigh-temperature (UHT) metamorphosed orthogneisses and paragneisses collected from key areas of the Eastern Ghats Belt, India. The results show contrasting tectono-thermal histories in different isotopic domains of the Eastern Ghats Belt that were identified by previous workers. Of particular importance is the discovery of a ca. 1760 Ma event (concordia age) in the southern domain 1A, which is interpreted to be the age of an early UHT metamorphism event. This was followed by a second granulite-facies metamorphism event and partial melting at ca. 1600 Ma. This domain was presumably cratonized with India at around 1600 Ma. The record of the ca. 1760-1600 Ma events in domain 1A of the Eastern Ghats Belt allows-us to speculate on modeling the Paleoproterozoic-Mesoproterozoic transcontinental correlation. The accretionary orogenic processes in the supercontinent Columbia-encompassed Australia, Antarctica, Laurentia, and parts of India. The central part of Eastern Ghats Belt (isotopic domain 2), on the other hand, contains zircons showing inherited ages of ca. 1880-1700 Ma, with a concordant age group of ca. 1760 Ma. Moderately to strongly discordant ages in the time span of ca. 16001100 Ma in domain 2 are interpreted to be mixing ages as a result of strong overprint of a ca. 1030-900 Ma tectonothermal event(s) that affected this domain. An early UHT metamorphism event in this domain is inferred to have occurred at ca. 1030-990 Ma chemical dating of included monazite grains). Zircon records the most pervasive tectonothermal event in this domain at ca. 980-900 Ma, which is correlative with the Rayner orogeny in East Antarctica as a part of the formation of Rodinia.