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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

Sankar Bose, Daniel J. Dunkley, Somnath Dasgupta, Kaushik Das and Makoto Arima
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
Geological Society of America Bulletin (September 2011) 123 (9-10): 2031-2049

Abstract

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 tectonothermal 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. 1600-1100 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.


ISSN: 0016-7606
EISSN: 1943-2674
Coden: BUGMAF
Serial Title: Geological Society of America Bulletin
Serial Volume: 123
Serial Issue: 9-10
Title: 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
Affiliation: Presidency University, Department of Geology, Calcutta, India
Pages: 2031-2049
Published: 201109
Text Language: English
Publisher: Geological Society of America (GSA), Boulder, CO, United States
References: 103
Accession Number: 2011-071104
Categories: StratigraphyGeochronology
Document Type: Serial
Bibliographic Level: Analytic
Annotation: With GSA Data Repository Item 2011137
Illustration Description: illus. incl. 1 table, geol. sketch map
N16°00'00" - N21°00'00", E80°00'00" - E87°00'00"
Secondary Affiliation: National Institute of Polar Research, JPN, JapanIndian Institute of Science Education and Research, IND, IndiaBengal Engineering and Science University, IND, IndiaYokohama National University, JPN, Japan
Country of Publication: United States
Secondary Affiliation: GeoRef, Copyright 2017, American Geosciences Institute. Reference includes data from GeoScienceWorld, Alexandria, VA, United States. Reference includes data supplied by the Geological Society of America, Boulder, CO, United States
Update Code: 201139
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