The Burmese Jade Mines belt: origins of jadeitites, serpentinites and ophiolitic peridotites and gabbros
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 be...
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| Format: | Journal article |
| Language: | English |
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Geological Society of London
2023
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| _version_ | 1797110754519810048 |
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| author | Searle, MP Palin, RM Gardiner, NJ Htun, K Wade, J |
| author_facet | Searle, MP Palin, RM Gardiner, NJ Htun, K Wade, J |
| author_sort | Searle, MP |
| collection | OXFORD |
| description | 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. |
| first_indexed | 2024-03-07T07:59:17Z |
| format | Journal article |
| id | oxford-uuid:9b0e127b-61fa-4fd8-8e4a-fcd4d6e603a2 |
| institution | University of Oxford |
| language | English |
| last_indexed | 2024-03-07T07:59:17Z |
| publishDate | 2023 |
| publisher | Geological Society of London |
| record_format | dspace |
| spelling | oxford-uuid:9b0e127b-61fa-4fd8-8e4a-fcd4d6e603a22023-09-12T11:44:47ZThe Burmese Jade Mines belt: origins of jadeitites, serpentinites and ophiolitic peridotites and gabbrosJournal articlehttp://purl.org/coar/resource_type/c_dcae04bcuuid:9b0e127b-61fa-4fd8-8e4a-fcd4d6e603a2EnglishSymplectic ElementsGeological Society of London2023Searle, MPPalin, RMGardiner, NJHtun, KWade, JOphiolitic 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. |
| spellingShingle | Searle, MP Palin, RM Gardiner, NJ Htun, K Wade, J The Burmese Jade Mines belt: origins of jadeitites, serpentinites and ophiolitic peridotites and gabbros |
| title | The Burmese Jade Mines belt: origins of jadeitites, serpentinites and ophiolitic peridotites and gabbros |
| title_full | The Burmese Jade Mines belt: origins of jadeitites, serpentinites and ophiolitic peridotites and gabbros |
| title_fullStr | The Burmese Jade Mines belt: origins of jadeitites, serpentinites and ophiolitic peridotites and gabbros |
| title_full_unstemmed | The Burmese Jade Mines belt: origins of jadeitites, serpentinites and ophiolitic peridotites and gabbros |
| title_short | The Burmese Jade Mines belt: origins of jadeitites, serpentinites and ophiolitic peridotites and gabbros |
| title_sort | burmese jade mines belt origins of jadeitites serpentinites and ophiolitic peridotites and gabbros |
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