Archaean gold mineralization synchronous with late cratonization of the Western Dharwar Craton, India: 2.52 Ga U–Pb ages of hydrothermal monazite and xenotime in gold deposits

New zircon U–Pb ages for a felsic volcanic rock (2,588 ± 10 Ma) and an intrusive granite (≥2,555 ± 6 Ma) in the Gadag greenstone belt in the Western Dharwar Craton, southern India, are similar to dates for equivalent rocks in the Eastern Dharwar Craton and indicates docking of the two cratons prior...

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Main Authors: Sarma, D., Fletcher, Ian, Rasmussen, Birger, McNaughton, Neal, Mohan, M., Groves, D.
Format: Journal Article
Published: Springer 2011
Subjects:
Online Access:http://hdl.handle.net/20.500.11937/42053
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author Sarma, D.
Fletcher, Ian
Rasmussen, Birger
McNaughton, Neal
Mohan, M.
Groves, D.
author_facet Sarma, D.
Fletcher, Ian
Rasmussen, Birger
McNaughton, Neal
Mohan, M.
Groves, D.
author_sort Sarma, D.
building Curtin Institutional Repository
collection Online Access
description New zircon U–Pb ages for a felsic volcanic rock (2,588 ± 10 Ma) and an intrusive granite (≥2,555 ± 6 Ma) in the Gadag greenstone belt in the Western Dharwar Craton, southern India, are similar to dates for equivalent rocks in the Eastern Dharwar Craton and indicates docking of the two cratons prior to this time. The zircons in the intrusive granite are strongly overprinted, and coexisting titanites yielded two different age populations: the dominant group gives an age of 2,566 ± 7 Ma, interpreted as the emplacement age, whereas the minor group gives an age of 2,516 ± 10 Ma, reflecting a hydrothermal overprint. In situ U–Pb dating of monazite and xenotime in gold reefs of the Gadag (2,522 ± 6 Ma) and Ajjanahalli (2,520 ± 9 Ma) gold deposits reveal a previously undated episode of gold mineralization at 2.52 Ga, substantially younger than the 2.55 Ga Hutti deposit in the eastern Dharwar Craton. The new dates confirm that both the younger greenstone belts and lode gold mineralization in the Dharwar Craton are about 100–120 My, younger than in other well-dated Archaean cratons. Although gold mineralization across the craton postdates most of the magmatic activity and metamorphism at upper crustal levels, widespread thermal reworking of the lower-middle crust, involving partial melting, metamorphism, and lower crustal granitoid intrusion, occurred concurrently with gold mineralization.It is likely that the large-scale hydrothermal fluid flow that produced widespread gold deposition was also part of this tectono-thermal event during the final stages of cratonization of the Dharwar Craton in southern India.
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spelling curtin-20.500.11937-420532017-09-13T16:09:21Z Archaean gold mineralization synchronous with late cratonization of the Western Dharwar Craton, India: 2.52 Ga U–Pb ages of hydrothermal monazite and xenotime in gold deposits Sarma, D. Fletcher, Ian Rasmussen, Birger McNaughton, Neal Mohan, M. Groves, D. Gold – Dharwar craton – Monazite – Xenotime – Archaean – SHRIMP New zircon U–Pb ages for a felsic volcanic rock (2,588 ± 10 Ma) and an intrusive granite (≥2,555 ± 6 Ma) in the Gadag greenstone belt in the Western Dharwar Craton, southern India, are similar to dates for equivalent rocks in the Eastern Dharwar Craton and indicates docking of the two cratons prior to this time. The zircons in the intrusive granite are strongly overprinted, and coexisting titanites yielded two different age populations: the dominant group gives an age of 2,566 ± 7 Ma, interpreted as the emplacement age, whereas the minor group gives an age of 2,516 ± 10 Ma, reflecting a hydrothermal overprint. In situ U–Pb dating of monazite and xenotime in gold reefs of the Gadag (2,522 ± 6 Ma) and Ajjanahalli (2,520 ± 9 Ma) gold deposits reveal a previously undated episode of gold mineralization at 2.52 Ga, substantially younger than the 2.55 Ga Hutti deposit in the eastern Dharwar Craton. The new dates confirm that both the younger greenstone belts and lode gold mineralization in the Dharwar Craton are about 100–120 My, younger than in other well-dated Archaean cratons. Although gold mineralization across the craton postdates most of the magmatic activity and metamorphism at upper crustal levels, widespread thermal reworking of the lower-middle crust, involving partial melting, metamorphism, and lower crustal granitoid intrusion, occurred concurrently with gold mineralization.It is likely that the large-scale hydrothermal fluid flow that produced widespread gold deposition was also part of this tectono-thermal event during the final stages of cratonization of the Dharwar Craton in southern India. 2011 Journal Article http://hdl.handle.net/20.500.11937/42053 10.1007/s00126-010-0326-3 Springer restricted
spellingShingle Gold – Dharwar craton – Monazite – Xenotime – Archaean – SHRIMP
Sarma, D.
Fletcher, Ian
Rasmussen, Birger
McNaughton, Neal
Mohan, M.
Groves, D.
Archaean gold mineralization synchronous with late cratonization of the Western Dharwar Craton, India: 2.52 Ga U–Pb ages of hydrothermal monazite and xenotime in gold deposits
title Archaean gold mineralization synchronous with late cratonization of the Western Dharwar Craton, India: 2.52 Ga U–Pb ages of hydrothermal monazite and xenotime in gold deposits
title_full Archaean gold mineralization synchronous with late cratonization of the Western Dharwar Craton, India: 2.52 Ga U–Pb ages of hydrothermal monazite and xenotime in gold deposits
title_fullStr Archaean gold mineralization synchronous with late cratonization of the Western Dharwar Craton, India: 2.52 Ga U–Pb ages of hydrothermal monazite and xenotime in gold deposits
title_full_unstemmed Archaean gold mineralization synchronous with late cratonization of the Western Dharwar Craton, India: 2.52 Ga U–Pb ages of hydrothermal monazite and xenotime in gold deposits
title_short Archaean gold mineralization synchronous with late cratonization of the Western Dharwar Craton, India: 2.52 Ga U–Pb ages of hydrothermal monazite and xenotime in gold deposits
title_sort archaean gold mineralization synchronous with late cratonization of the western dharwar craton, india: 2.52 ga u–pb ages of hydrothermal monazite and xenotime in gold deposits
topic Gold – Dharwar craton – Monazite – Xenotime – Archaean – SHRIMP
url http://hdl.handle.net/20.500.11937/42053