Zircon xenocrysts from cenozoic alkaline basalts of the ratanakiri volcanic province (Cambodia), southeast asia—trace element geochemistry, O-Hf isotopic composition, U-PB and (U-TH)/he geochronology—revelations into the underlying lithospheric mantle
Zircon xenocrysts from alkali basalts in Ratanakiri Province, Cambodia represent a unique low-Hf zircon within a 12,000 km long Indo-Pacific megacryst zone. Colorless, yellow, brown, and red crystals ({100}, {101}, subordinate {211}, {1103}), with hopper growth and corrosion features range up to 20...
| Main Authors: | , , , , , |
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| Format: | Journal Article |
| Language: | English |
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MDPI
2018
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| Online Access: | http://purl.org/au-research/grants/arc/DP160102427 http://hdl.handle.net/20.500.11937/90786 |
| _version_ | 1848765427736379392 |
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| author | Piilonen, P.C. Sutherland, F.L. Danišík, M. Poirier, G. Valley, J.W. Rowe, R. |
| author_facet | Piilonen, P.C. Sutherland, F.L. Danišík, M. Poirier, G. Valley, J.W. Rowe, R. |
| author_sort | Piilonen, P.C. |
| building | Curtin Institutional Repository |
| collection | Online Access |
| description | Zircon xenocrysts from alkali basalts in Ratanakiri Province, Cambodia represent a unique low-Hf zircon within a 12,000 km long Indo-Pacific megacryst zone. Colorless, yellow, brown, and red crystals ({100}, {101}, subordinate {211}, {1103}), with hopper growth and corrosion features range up to 20 cm in size. Zircon chemistry indicates juvenile, Zr-saturated, mantle-derived alkaline melt (Hf 0.6–0.7 wt %, Y <0.2 wt %, U + Th + REE (Rare-Earth Elements) < 600 ppm, Zr/Hf 66–92, Eu/Eu*N ~1, positive Ce/Ce*N, HREE (Heavy REE) enrichment). Incompatible element depletion with increasing Yb/SmN from core to rim at ~ constant Hf suggests single stage growth. Ti-in-zircon temperatures (~570–740 _C) are lower than predicted by crystal morphology (800–900 _C) and decrease from core to rim (DT = 10–50 _C). The _18O values (4.88 to 5.01‰ VSMOW (Vienna Standard Mean Ocean Water)) are relatively low for xenocrysts from the zircon Indo-Pacific zone (ZIP). The176Hf/177Hf values (+εHf 4.5–10.2) give TDepleted Mantle model source ages of 260–462 Ma and TCrustal ages of 391–754 ma. The source magmas reflect variably depleted lithospheric mantle with little supracrustal input. Zircon U-Pb (0.88–1.56 Ma) and (U-Th)/He (0.86–1.02 Ma) ages are older than host basalt ages (~0.7 Ma), which suggests limited residence before transport. Zircon genesis suggests Zr-saturated, Al-undersaturated, carbonatitic-influenced, low-degree partial melting (<1%) of peridotitic mantle at ~60 km beneath the Indochina terrane. |
| first_indexed | 2025-11-14T11:35:05Z |
| format | Journal Article |
| id | curtin-20.500.11937-90786 |
| institution | Curtin University Malaysia |
| institution_category | Local University |
| language | English |
| last_indexed | 2025-11-14T11:35:05Z |
| publishDate | 2018 |
| publisher | MDPI |
| recordtype | eprints |
| repository_type | Digital Repository |
| spelling | curtin-20.500.11937-907862023-04-19T07:26:14Z Zircon xenocrysts from cenozoic alkaline basalts of the ratanakiri volcanic province (Cambodia), southeast asia—trace element geochemistry, O-Hf isotopic composition, U-PB and (U-TH)/he geochronology—revelations into the underlying lithospheric mantle Piilonen, P.C. Sutherland, F.L. Danišík, M. Poirier, G. Valley, J.W. Rowe, R. Science & Technology Physical Sciences Geochemistry & Geophysics Mineralogy Mining & Mineral Processing zircon xenocryst alkali basalt Ratanakiri Volcanic Province trace elements O-isotopes and Hf-isotopes U-Pb (U-Th)/He IGNEOUS ALBITITE DIKES CARBONATITE METASOMATISM OXYGEN ISOTOPES OROGENIC LHERZOLITES FELDSPAR XENOCRYSTS WESTERN PYRENEES HIGH-PRECISION FISSION-TRACK RED ZIRCON SAPPHIRE Zircon xenocrysts from alkali basalts in Ratanakiri Province, Cambodia represent a unique low-Hf zircon within a 12,000 km long Indo-Pacific megacryst zone. Colorless, yellow, brown, and red crystals ({100}, {101}, subordinate {211}, {1103}), with hopper growth and corrosion features range up to 20 cm in size. Zircon chemistry indicates juvenile, Zr-saturated, mantle-derived alkaline melt (Hf 0.6–0.7 wt %, Y <0.2 wt %, U + Th + REE (Rare-Earth Elements) < 600 ppm, Zr/Hf 66–92, Eu/Eu*N ~1, positive Ce/Ce*N, HREE (Heavy REE) enrichment). Incompatible element depletion with increasing Yb/SmN from core to rim at ~ constant Hf suggests single stage growth. Ti-in-zircon temperatures (~570–740 _C) are lower than predicted by crystal morphology (800–900 _C) and decrease from core to rim (DT = 10–50 _C). The _18O values (4.88 to 5.01‰ VSMOW (Vienna Standard Mean Ocean Water)) are relatively low for xenocrysts from the zircon Indo-Pacific zone (ZIP). The176Hf/177Hf values (+εHf 4.5–10.2) give TDepleted Mantle model source ages of 260–462 Ma and TCrustal ages of 391–754 ma. The source magmas reflect variably depleted lithospheric mantle with little supracrustal input. Zircon U-Pb (0.88–1.56 Ma) and (U-Th)/He (0.86–1.02 Ma) ages are older than host basalt ages (~0.7 Ma), which suggests limited residence before transport. Zircon genesis suggests Zr-saturated, Al-undersaturated, carbonatitic-influenced, low-degree partial melting (<1%) of peridotitic mantle at ~60 km beneath the Indochina terrane. 2018 Journal Article http://hdl.handle.net/20.500.11937/90786 10.3390/min8120556 English http://purl.org/au-research/grants/arc/DP160102427 http://creativecommons.org/licenses/by/4.0/ MDPI fulltext |
| spellingShingle | Science & Technology Physical Sciences Geochemistry & Geophysics Mineralogy Mining & Mineral Processing zircon xenocryst alkali basalt Ratanakiri Volcanic Province trace elements O-isotopes and Hf-isotopes U-Pb (U-Th)/He IGNEOUS ALBITITE DIKES CARBONATITE METASOMATISM OXYGEN ISOTOPES OROGENIC LHERZOLITES FELDSPAR XENOCRYSTS WESTERN PYRENEES HIGH-PRECISION FISSION-TRACK RED ZIRCON SAPPHIRE Piilonen, P.C. Sutherland, F.L. Danišík, M. Poirier, G. Valley, J.W. Rowe, R. Zircon xenocrysts from cenozoic alkaline basalts of the ratanakiri volcanic province (Cambodia), southeast asia—trace element geochemistry, O-Hf isotopic composition, U-PB and (U-TH)/he geochronology—revelations into the underlying lithospheric mantle |
| title | Zircon xenocrysts from cenozoic alkaline basalts of the ratanakiri volcanic province (Cambodia), southeast asia—trace element geochemistry, O-Hf isotopic composition, U-PB and (U-TH)/he geochronology—revelations into the underlying lithospheric mantle |
| title_full | Zircon xenocrysts from cenozoic alkaline basalts of the ratanakiri volcanic province (Cambodia), southeast asia—trace element geochemistry, O-Hf isotopic composition, U-PB and (U-TH)/he geochronology—revelations into the underlying lithospheric mantle |
| title_fullStr | Zircon xenocrysts from cenozoic alkaline basalts of the ratanakiri volcanic province (Cambodia), southeast asia—trace element geochemistry, O-Hf isotopic composition, U-PB and (U-TH)/he geochronology—revelations into the underlying lithospheric mantle |
| title_full_unstemmed | Zircon xenocrysts from cenozoic alkaline basalts of the ratanakiri volcanic province (Cambodia), southeast asia—trace element geochemistry, O-Hf isotopic composition, U-PB and (U-TH)/he geochronology—revelations into the underlying lithospheric mantle |
| title_short | Zircon xenocrysts from cenozoic alkaline basalts of the ratanakiri volcanic province (Cambodia), southeast asia—trace element geochemistry, O-Hf isotopic composition, U-PB and (U-TH)/he geochronology—revelations into the underlying lithospheric mantle |
| title_sort | zircon xenocrysts from cenozoic alkaline basalts of the ratanakiri volcanic province (cambodia), southeast asia—trace element geochemistry, o-hf isotopic composition, u-pb and (u-th)/he geochronology—revelations into the underlying lithospheric mantle |
| topic | Science & Technology Physical Sciences Geochemistry & Geophysics Mineralogy Mining & Mineral Processing zircon xenocryst alkali basalt Ratanakiri Volcanic Province trace elements O-isotopes and Hf-isotopes U-Pb (U-Th)/He IGNEOUS ALBITITE DIKES CARBONATITE METASOMATISM OXYGEN ISOTOPES OROGENIC LHERZOLITES FELDSPAR XENOCRYSTS WESTERN PYRENEES HIGH-PRECISION FISSION-TRACK RED ZIRCON SAPPHIRE |
| url | http://purl.org/au-research/grants/arc/DP160102427 http://hdl.handle.net/20.500.11937/90786 |