Petrogenesis of isotopically enriched Quaternary magma with adakitic affinity associated with subduction of old lithosphere beneath central Myanmar
Abstract We present a model for the petrogenesis of magma with adakitic affinity in an old subduction zone, which does not involve slab melting and is constrained by new geochronological and geochemical data for Mt. Popa, the largest of three Quaternary volcanoes in central Myanmar (Popa, Monywa and...
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Nature Portfolio
2022-02-01
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| Series: | Scientific Reports |
| Online Access: | https://doi.org/10.1038/s41598-022-07097-4 |
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| author | Takashi Sano Kenichiro Tani Shigekazu Yoneda Hla Min Thaung Htike Zin Maung Maung Thein Osamu Ishizuka Nao Kusuhashi Reiko T. Kono Masanaru Takai Chris E. Conway |
| author_facet | Takashi Sano Kenichiro Tani Shigekazu Yoneda Hla Min Thaung Htike Zin Maung Maung Thein Osamu Ishizuka Nao Kusuhashi Reiko T. Kono Masanaru Takai Chris E. Conway |
| author_sort | Takashi Sano |
| collection | DOAJ |
| description | Abstract We present a model for the petrogenesis of magma with adakitic affinity in an old subduction zone, which does not involve slab melting and is constrained by new geochronological and geochemical data for Mt. Popa, the largest of three Quaternary volcanoes in central Myanmar (Popa, Monywa and Singu). The edifice is composed of Popa Plateau (0.8–0.6 Ma) with high-K rocks and a stratovolcano (< 0.33 Ma) predominantly composed of medium-K rocks with adakitic affinity (Mg# 45–63, Sr/Y > 40). The distinct K contents indicate that the adakitic magmas cannot be derived from Popa high-K rocks, but they share trace-element signatures and Sr–Nd isotope ratios with medium-K basalts from Monywa volcano. Our estimation of water contents in Popa magma reveals that primary magma for medium-K basalts was generated by partial melting of wedge mantle with normal potential temperature (TP 1330–1340 °C) under wet conditions (H2O 0.25–0.54 wt%). Its melting was probably induced by asthenospheric upwelling that is recognized by tomographic images. Mafic adakitic magma (Mg# ~ 63, Sr/Y ~ 64) was derived from the medium-K basaltic magma in fractional crystallization of a garnet-bearing assemblage at high pressure, and felsic adakitic rocks (Mg# ~ 45, Sr/Y ~ 50) were produced by assimilation-fractional crystallization processes at mid-crustal depths. |
| first_indexed | 2024-12-20T17:40:07Z |
| format | Article |
| id | doaj.art-dee7bf2e46bc46a194a23581a004a8e8 |
| institution | Directory Open Access Journal |
| issn | 2045-2322 |
| language | English |
| last_indexed | 2024-12-20T17:40:07Z |
| publishDate | 2022-02-01 |
| publisher | Nature Portfolio |
| record_format | Article |
| series | Scientific Reports |
| spelling | doaj.art-dee7bf2e46bc46a194a23581a004a8e82022-12-21T19:31:07ZengNature PortfolioScientific Reports2045-23222022-02-0112111110.1038/s41598-022-07097-4Petrogenesis of isotopically enriched Quaternary magma with adakitic affinity associated with subduction of old lithosphere beneath central MyanmarTakashi Sano0Kenichiro Tani1Shigekazu Yoneda2Hla Min3Thaung Htike4Zin Maung Maung Thein5Osamu Ishizuka6Nao Kusuhashi7Reiko T. Kono8Masanaru Takai9Chris E. Conway10Department of Geology and Paleontology, National Museum of Nature and ScienceDepartment of Geology and Paleontology, National Museum of Nature and ScienceDepartment of Science and Engineering, National Museum of Nature and ScienceDepartment of Geology, Meiktila UniversityPro-Rector, University of MagwayDepartment of Geology, University of MandalayResearch Institute of Earthquake and Volcano Geology, AISTFaculty of Science, Ehime UniversityFaculty of Letters, Keio UniversityPrimate Research Institute, Kyoto UniversityResearch Institute of Earthquake and Volcano Geology, AISTAbstract We present a model for the petrogenesis of magma with adakitic affinity in an old subduction zone, which does not involve slab melting and is constrained by new geochronological and geochemical data for Mt. Popa, the largest of three Quaternary volcanoes in central Myanmar (Popa, Monywa and Singu). The edifice is composed of Popa Plateau (0.8–0.6 Ma) with high-K rocks and a stratovolcano (< 0.33 Ma) predominantly composed of medium-K rocks with adakitic affinity (Mg# 45–63, Sr/Y > 40). The distinct K contents indicate that the adakitic magmas cannot be derived from Popa high-K rocks, but they share trace-element signatures and Sr–Nd isotope ratios with medium-K basalts from Monywa volcano. Our estimation of water contents in Popa magma reveals that primary magma for medium-K basalts was generated by partial melting of wedge mantle with normal potential temperature (TP 1330–1340 °C) under wet conditions (H2O 0.25–0.54 wt%). Its melting was probably induced by asthenospheric upwelling that is recognized by tomographic images. Mafic adakitic magma (Mg# ~ 63, Sr/Y ~ 64) was derived from the medium-K basaltic magma in fractional crystallization of a garnet-bearing assemblage at high pressure, and felsic adakitic rocks (Mg# ~ 45, Sr/Y ~ 50) were produced by assimilation-fractional crystallization processes at mid-crustal depths.https://doi.org/10.1038/s41598-022-07097-4 |
| spellingShingle | Takashi Sano Kenichiro Tani Shigekazu Yoneda Hla Min Thaung Htike Zin Maung Maung Thein Osamu Ishizuka Nao Kusuhashi Reiko T. Kono Masanaru Takai Chris E. Conway Petrogenesis of isotopically enriched Quaternary magma with adakitic affinity associated with subduction of old lithosphere beneath central Myanmar Scientific Reports |
| title | Petrogenesis of isotopically enriched Quaternary magma with adakitic affinity associated with subduction of old lithosphere beneath central Myanmar |
| title_full | Petrogenesis of isotopically enriched Quaternary magma with adakitic affinity associated with subduction of old lithosphere beneath central Myanmar |
| title_fullStr | Petrogenesis of isotopically enriched Quaternary magma with adakitic affinity associated with subduction of old lithosphere beneath central Myanmar |
| title_full_unstemmed | Petrogenesis of isotopically enriched Quaternary magma with adakitic affinity associated with subduction of old lithosphere beneath central Myanmar |
| title_short | Petrogenesis of isotopically enriched Quaternary magma with adakitic affinity associated with subduction of old lithosphere beneath central Myanmar |
| title_sort | petrogenesis of isotopically enriched quaternary magma with adakitic affinity associated with subduction of old lithosphere beneath central myanmar |
| url | https://doi.org/10.1038/s41598-022-07097-4 |
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