Cross‐Orogen Granite Migration as an Indicator of Slab Rollback Along Eastern Gondwana
Abstract Slab rollback during subduction plays a key role in controlling continental growth at convergent plate boundaries. The dynamics of currently subducting slabs can be precisely constrained using geophysical techniques. In contrast, ancient episodes of slab rollback can be difficult to constra...
| Main Authors: | , , , , , , |
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| Format: | Article |
| Language: | English |
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Wiley
2023-06-01
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| Series: | Geochemistry, Geophysics, Geosystems |
| Subjects: | |
| Online Access: | https://doi.org/10.1029/2023GC010895 |
| _version_ | 1797638031985868800 |
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| author | Qing Zhang Solomon Buckman Ross N. Mitchell Allen P. Nutman Xian‐Hua Li Vickie C. Bennett Courtney Beer |
| author_facet | Qing Zhang Solomon Buckman Ross N. Mitchell Allen P. Nutman Xian‐Hua Li Vickie C. Bennett Courtney Beer |
| author_sort | Qing Zhang |
| collection | DOAJ |
| description | Abstract Slab rollback during subduction plays a key role in controlling continental growth at convergent plate boundaries. The dynamics of currently subducting slabs can be precisely constrained using geophysical techniques. In contrast, ancient episodes of slab rollback can be difficult to constrain, yet are critical to unlocking the tectonic evolution of long‐lived orogens such as the Phanerozoic Australian Tasmanides of eastern Gondwana. Recognition of ancient slab rollback relies on the identification of the progressive migration of magmatic arcs. Here, we investigate the timing and isotopic variation of ∼90 km of the trans‐orogen migration of the Carboniferous Bathurst Batholith as a potential indicator of slab rollback. U–Pb–Hf isotopes, combined with a regional zircon Hf isotope data set, suggest that the eastward migration of the batholith over ∼18 Myr, from 340.1 to 322.4 Ma, records a maximum slab steepening rate of ∼0.6–1.2° Myr−1 in a relatively stable trench setting. These results provide a magmatic record of Carboniferous slab rollback and establish a missing link between the long‐lived Lachlan and New England orogens of the eastern Gondwanan Tasmanides. |
| first_indexed | 2024-03-11T12:57:51Z |
| format | Article |
| id | doaj.art-bcbaa8c9ec9240d0acb0aaa24eeb6b74 |
| institution | Directory Open Access Journal |
| issn | 1525-2027 |
| language | English |
| last_indexed | 2024-03-11T12:57:51Z |
| publishDate | 2023-06-01 |
| publisher | Wiley |
| record_format | Article |
| series | Geochemistry, Geophysics, Geosystems |
| spelling | doaj.art-bcbaa8c9ec9240d0acb0aaa24eeb6b742023-11-03T16:56:13ZengWileyGeochemistry, Geophysics, Geosystems1525-20272023-06-01246n/an/a10.1029/2023GC010895Cross‐Orogen Granite Migration as an Indicator of Slab Rollback Along Eastern GondwanaQing Zhang0Solomon Buckman1Ross N. Mitchell2Allen P. Nutman3Xian‐Hua Li4Vickie C. Bennett5Courtney Beer6State Key Laboratory of Lithospheric Evolution Institute of Geology and Geophysics Chinese Academy of Sciences Beijing ChinaSchool of Earth, Atmospheric and Life Sciences University of Wollongong Wollongong NSW AustraliaState Key Laboratory of Lithospheric Evolution Institute of Geology and Geophysics Chinese Academy of Sciences Beijing ChinaSchool of Earth, Atmospheric and Life Sciences University of Wollongong Wollongong NSW AustraliaState Key Laboratory of Lithospheric Evolution Institute of Geology and Geophysics Chinese Academy of Sciences Beijing ChinaResearch School of Earth Sciences Australian National University Canberra ACT AustraliaSchool of Earth, Atmospheric and Life Sciences University of Wollongong Wollongong NSW AustraliaAbstract Slab rollback during subduction plays a key role in controlling continental growth at convergent plate boundaries. The dynamics of currently subducting slabs can be precisely constrained using geophysical techniques. In contrast, ancient episodes of slab rollback can be difficult to constrain, yet are critical to unlocking the tectonic evolution of long‐lived orogens such as the Phanerozoic Australian Tasmanides of eastern Gondwana. Recognition of ancient slab rollback relies on the identification of the progressive migration of magmatic arcs. Here, we investigate the timing and isotopic variation of ∼90 km of the trans‐orogen migration of the Carboniferous Bathurst Batholith as a potential indicator of slab rollback. U–Pb–Hf isotopes, combined with a regional zircon Hf isotope data set, suggest that the eastward migration of the batholith over ∼18 Myr, from 340.1 to 322.4 Ma, records a maximum slab steepening rate of ∼0.6–1.2° Myr−1 in a relatively stable trench setting. These results provide a magmatic record of Carboniferous slab rollback and establish a missing link between the long‐lived Lachlan and New England orogens of the eastern Gondwanan Tasmanides.https://doi.org/10.1029/2023GC010895slab rollbacktrans‐orogengraniteHf isotopesAustralian Tasmanideseastern Gondwana |
| spellingShingle | Qing Zhang Solomon Buckman Ross N. Mitchell Allen P. Nutman Xian‐Hua Li Vickie C. Bennett Courtney Beer Cross‐Orogen Granite Migration as an Indicator of Slab Rollback Along Eastern Gondwana Geochemistry, Geophysics, Geosystems slab rollback trans‐orogen granite Hf isotopes Australian Tasmanides eastern Gondwana |
| title | Cross‐Orogen Granite Migration as an Indicator of Slab Rollback Along Eastern Gondwana |
| title_full | Cross‐Orogen Granite Migration as an Indicator of Slab Rollback Along Eastern Gondwana |
| title_fullStr | Cross‐Orogen Granite Migration as an Indicator of Slab Rollback Along Eastern Gondwana |
| title_full_unstemmed | Cross‐Orogen Granite Migration as an Indicator of Slab Rollback Along Eastern Gondwana |
| title_short | Cross‐Orogen Granite Migration as an Indicator of Slab Rollback Along Eastern Gondwana |
| title_sort | cross orogen granite migration as an indicator of slab rollback along eastern gondwana |
| topic | slab rollback trans‐orogen granite Hf isotopes Australian Tasmanides eastern Gondwana |
| url | https://doi.org/10.1029/2023GC010895 |
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