Constraints on the Tectonic Setting of the Andaman Ophiolites, Bay of Bengal, India, from SHRIMP U-Pb Zircon Geochronology of Plagiogranite
The Andaman ophiolites are well exposed in the Andaman group of islands, which is part of the Sunda-Burmesedouble-chain arc system in the Bay of Bengal, India. Plagiogranites occurring on the eastern margin of the southernpart of South Andaman Island appear as interstitial vermicular and micrographi...
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| Format: | Journal Article |
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University of Chicago
2010
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| Online Access: | http://hdl.handle.net/20.500.11937/5000 |
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| author | Sarma, D Jafri, S. Fletcher, Ian McNaughton, Neal |
| author_facet | Sarma, D Jafri, S. Fletcher, Ian McNaughton, Neal |
| author_sort | Sarma, D |
| building | Curtin Institutional Repository |
| collection | Online Access |
| description | The Andaman ophiolites are well exposed in the Andaman group of islands, which is part of the Sunda-Burmesedouble-chain arc system in the Bay of Bengal, India. Plagiogranites occurring on the eastern margin of the southernpart of South Andaman Island appear as interstitial vermicular and micrographic intergrowths of quartz and plagioclase.They are tonalitic to trondhjemitic in composition, and their Rb, Yb, Ta, and Y abundances are characteristicof a volcanic-arc affinity. Sensitive high-resolution ion microprobe U-Pb dating of zircons from a plagiogranite withinthe Andaman ophiolite has yielded a weighted mean 206Pb/238U age of 93.61.3 Ma, interpreted as the age of itscrystallization. The subduction-related plagiogranite has intruded a gabbro unit of the Andaman ophiolites as wellas extrusives of the East Coast Volcanics at this time. Since the Andaman ophiolitic rocks predate the plagiogranite,they cannot have been generated in the currently active Late Miocene Andaman-Java subduction zone and were mostlikely obducted onto the leading edge of the Eurasian continent at an earlier phase of subduction activity during earlyCretaceous time. |
| first_indexed | 2025-11-14T06:05:11Z |
| format | Journal Article |
| id | curtin-20.500.11937-5000 |
| institution | Curtin University Malaysia |
| institution_category | Local University |
| last_indexed | 2025-11-14T06:05:11Z |
| publishDate | 2010 |
| publisher | University of Chicago |
| recordtype | eprints |
| repository_type | Digital Repository |
| spelling | curtin-20.500.11937-50002017-09-13T16:06:09Z Constraints on the Tectonic Setting of the Andaman Ophiolites, Bay of Bengal, India, from SHRIMP U-Pb Zircon Geochronology of Plagiogranite Sarma, D Jafri, S. Fletcher, Ian McNaughton, Neal Rocks Arc Subduction Petrogenesis Emplacement History Geochemistry Stratigraphy Naga Hills Belt Complex The Andaman ophiolites are well exposed in the Andaman group of islands, which is part of the Sunda-Burmesedouble-chain arc system in the Bay of Bengal, India. Plagiogranites occurring on the eastern margin of the southernpart of South Andaman Island appear as interstitial vermicular and micrographic intergrowths of quartz and plagioclase.They are tonalitic to trondhjemitic in composition, and their Rb, Yb, Ta, and Y abundances are characteristicof a volcanic-arc affinity. Sensitive high-resolution ion microprobe U-Pb dating of zircons from a plagiogranite withinthe Andaman ophiolite has yielded a weighted mean 206Pb/238U age of 93.61.3 Ma, interpreted as the age of itscrystallization. The subduction-related plagiogranite has intruded a gabbro unit of the Andaman ophiolites as wellas extrusives of the East Coast Volcanics at this time. Since the Andaman ophiolitic rocks predate the plagiogranite,they cannot have been generated in the currently active Late Miocene Andaman-Java subduction zone and were mostlikely obducted onto the leading edge of the Eurasian continent at an earlier phase of subduction activity during earlyCretaceous time. 2010 Journal Article http://hdl.handle.net/20.500.11937/5000 10.1086/656354 University of Chicago fulltext |
| spellingShingle | Rocks Arc Subduction Petrogenesis Emplacement History Geochemistry Stratigraphy Naga Hills Belt Complex Sarma, D Jafri, S. Fletcher, Ian McNaughton, Neal Constraints on the Tectonic Setting of the Andaman Ophiolites, Bay of Bengal, India, from SHRIMP U-Pb Zircon Geochronology of Plagiogranite |
| title | Constraints on the Tectonic Setting of the Andaman Ophiolites, Bay of Bengal, India, from SHRIMP U-Pb Zircon Geochronology of Plagiogranite |
| title_full | Constraints on the Tectonic Setting of the Andaman Ophiolites, Bay of Bengal, India, from SHRIMP U-Pb Zircon Geochronology of Plagiogranite |
| title_fullStr | Constraints on the Tectonic Setting of the Andaman Ophiolites, Bay of Bengal, India, from SHRIMP U-Pb Zircon Geochronology of Plagiogranite |
| title_full_unstemmed | Constraints on the Tectonic Setting of the Andaman Ophiolites, Bay of Bengal, India, from SHRIMP U-Pb Zircon Geochronology of Plagiogranite |
| title_short | Constraints on the Tectonic Setting of the Andaman Ophiolites, Bay of Bengal, India, from SHRIMP U-Pb Zircon Geochronology of Plagiogranite |
| title_sort | constraints on the tectonic setting of the andaman ophiolites, bay of bengal, india, from shrimp u-pb zircon geochronology of plagiogranite |
| topic | Rocks Arc Subduction Petrogenesis Emplacement History Geochemistry Stratigraphy Naga Hills Belt Complex |
| url | http://hdl.handle.net/20.500.11937/5000 |