Journal article
The Burmese Jade Mines belt: origins of jadeitites, serpentinites and ophiolitic peridotites and gabbros
- Abstract:
- Ophiolitic peridotites in Myanmar (Burma) occur along three major tectonic zones: the Kaleymyo–Nagaland suture along the Indo-Burman Ranges, the Jade Mines belt and the Tagaung–Mytkyina belt. These belts all show harzburgite–lherzolite–dunite peridotites, but the Hpakan-Taw Maw region (Jade Mines belt) also hosts jadeitites, including pure jadeite, mawsitsit (Cr-rich jadeite) kosmochlore (Cr-rich clinopyroxene) and albitite. Jadeitites with high Na and Al contents require either very unusual Al-rich, Si-poor protoliths or extensive fluid metasomatism, or both. The Hpakan jadeitites formed by Na-, Al- (and Si-) metasomatic alteration of pyroxenite–wehrlite intrusions into harzburgite–dunite from widespread fluid alteration. The fluids could have been derived from a mid-Jurassic intermediate pressure subduction event during ophiolite formation and emplacement. In the Lake Indawgyi area, normal ophiolitic peridotites, including harzburgite and dunite with pyroxenite veins, have not been jadeitized. Gabbros related to the Jade Mines ophiolite gave a U–Pb zircon age of 169.71 ± 1.3 Ma (MSWD 2.2), a similar timing to the Myitkyina ophiolite (173 Ma) to the east, suggesting that the ophiolite belts were originally continuous. The jade ‘boulders’ in the Uru conglomerate beds at Hpakan have also resulted from normal in situ serpentinization weathering processes, followed by limited fluvial mass transport processes along the Uru River.
- Publication status:
- Published
- Peer review status:
- Peer reviewed
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(Preview, Version of record, pdf, 11.7MB, Terms of use)
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- Publisher copy:
- 10.1144/jgs2023-004
Authors
- Publisher:
- Geological Society of London
- Journal:
- Journal of the Geological Society More from this journal
- Volume:
- 180
- Issue:
- 4
- Article number:
- jgs2023-004
- Publication date:
- 2023-05-24
- Acceptance date:
- 2023-05-18
- DOI:
- EISSN:
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2041-479X
- ISSN:
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0016-7649
- Language:
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English
- Keywords:
- Pubs id:
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1345471
- Local pid:
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pubs:1345471
- Deposit date:
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2023-07-03
Terms of use
- Copyright holder:
- Searle et al.
- Copyright date:
- 2023
- Rights statement:
- © 2023 The Author(s). Published by The Geological Society of London. This is an Open Access article distributed under the terms of the Creative Commons Attribution 4.0 License (http://creativecommons.org/licenses/by/4.0/).
- Licence:
- CC Attribution (CC BY)
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