Eocene north–south trending dikes in central Tibet: New constraints on the timing of east–west extension with implications for early plateau uplift?
East–west extension has been a prominent feature of Cenozoic tectonics in central-southern Tibet, and the onset of this extension has been interpreted as indicating the surface uplift of the Tibetan Plateau to a critical level. Previous studies suggested that extension started in the Neogene between...
| Main Authors: | , , , , , , , , , , , , |
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| Format: | Journal Article |
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Elsevier Science BV
2010
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| Online Access: | http://hdl.handle.net/20.500.11937/22666 |
| _version_ | 1848750933550301184 |
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| author | Wang, Qiang Wyman, D. Li, Zheng-Xiang Sun, W. Chung, S. Vasconcelos, P. Zhang, Q. Dong, H. Yu, Y. Pearson, N. Qiu, H. Zhu, T. Feng, X. |
| author_facet | Wang, Qiang Wyman, D. Li, Zheng-Xiang Sun, W. Chung, S. Vasconcelos, P. Zhang, Q. Dong, H. Yu, Y. Pearson, N. Qiu, H. Zhu, T. Feng, X. |
| author_sort | Wang, Qiang |
| building | Curtin Institutional Repository |
| collection | Online Access |
| description | East–west extension has been a prominent feature of Cenozoic tectonics in central-southern Tibet, and the onset of this extension has been interpreted as indicating the surface uplift of the Tibetan Plateau to a critical level. Previous studies suggested that extension started in the Neogene between 18–13 Ma and 8 Ma, based on dating results from north–south trending normal faults, grabens or rifts, and dikes. We report here the discovery of widespread north–south trending diabase and andesitic porphyry dikes in and around the Shuang Hu graben, central Tibet, where crustal extension has previously been argued to start from 13.5 Ma based on mineral ages from graben-bounding faults. Our results show that dikes in this area were mainly formed in the Eocene (47–38 Ma). Geochemical and Nd–Sr isotopic data suggest that the diabase dikes originated from partial melting of an enriched lithospheric mantle source metasomatized by melts from subducted continental crust, and the andesitic porphyry dikes were probably derived from interactions between the subducted continental crust-derived melts and the mantle. Given that north–south trending Eocene dikes are found widely dispersed in central Tibet, we argue that the onset of east–west extension, and likely regional uplift of the Tibetan Plateau, began much earlier than previously thought. Our study implies that a large part of the Tibetan Plateau had already attained near-maximum elevation in the Eocene and is consistent with recent investigations regarding the Middle–Late Eocene (47–34 Ma) initiation of aridification in Asia, evidence from contemporary global oceanic O–Sr isotope curves and temperatures, and the carbon cycle. |
| first_indexed | 2025-11-14T07:44:42Z |
| format | Journal Article |
| id | curtin-20.500.11937-22666 |
| institution | Curtin University Malaysia |
| institution_category | Local University |
| last_indexed | 2025-11-14T07:44:42Z |
| publishDate | 2010 |
| publisher | Elsevier Science BV |
| recordtype | eprints |
| repository_type | Digital Repository |
| spelling | curtin-20.500.11937-226662017-09-13T13:57:44Z Eocene north–south trending dikes in central Tibet: New constraints on the timing of east–west extension with implications for early plateau uplift? Wang, Qiang Wyman, D. Li, Zheng-Xiang Sun, W. Chung, S. Vasconcelos, P. Zhang, Q. Dong, H. Yu, Y. Pearson, N. Qiu, H. Zhu, T. Feng, X. extension dikes global climate change Tibet crustal flow uplift East–west extension has been a prominent feature of Cenozoic tectonics in central-southern Tibet, and the onset of this extension has been interpreted as indicating the surface uplift of the Tibetan Plateau to a critical level. Previous studies suggested that extension started in the Neogene between 18–13 Ma and 8 Ma, based on dating results from north–south trending normal faults, grabens or rifts, and dikes. We report here the discovery of widespread north–south trending diabase and andesitic porphyry dikes in and around the Shuang Hu graben, central Tibet, where crustal extension has previously been argued to start from 13.5 Ma based on mineral ages from graben-bounding faults. Our results show that dikes in this area were mainly formed in the Eocene (47–38 Ma). Geochemical and Nd–Sr isotopic data suggest that the diabase dikes originated from partial melting of an enriched lithospheric mantle source metasomatized by melts from subducted continental crust, and the andesitic porphyry dikes were probably derived from interactions between the subducted continental crust-derived melts and the mantle. Given that north–south trending Eocene dikes are found widely dispersed in central Tibet, we argue that the onset of east–west extension, and likely regional uplift of the Tibetan Plateau, began much earlier than previously thought. Our study implies that a large part of the Tibetan Plateau had already attained near-maximum elevation in the Eocene and is consistent with recent investigations regarding the Middle–Late Eocene (47–34 Ma) initiation of aridification in Asia, evidence from contemporary global oceanic O–Sr isotope curves and temperatures, and the carbon cycle. 2010 Journal Article http://hdl.handle.net/20.500.11937/22666 10.1016/j.epsl.2010.07.046 Elsevier Science BV restricted |
| spellingShingle | extension dikes global climate change Tibet crustal flow uplift Wang, Qiang Wyman, D. Li, Zheng-Xiang Sun, W. Chung, S. Vasconcelos, P. Zhang, Q. Dong, H. Yu, Y. Pearson, N. Qiu, H. Zhu, T. Feng, X. Eocene north–south trending dikes in central Tibet: New constraints on the timing of east–west extension with implications for early plateau uplift? |
| title | Eocene north–south trending dikes in central Tibet: New constraints on the timing of east–west extension with implications for early plateau uplift? |
| title_full | Eocene north–south trending dikes in central Tibet: New constraints on the timing of east–west extension with implications for early plateau uplift? |
| title_fullStr | Eocene north–south trending dikes in central Tibet: New constraints on the timing of east–west extension with implications for early plateau uplift? |
| title_full_unstemmed | Eocene north–south trending dikes in central Tibet: New constraints on the timing of east–west extension with implications for early plateau uplift? |
| title_short | Eocene north–south trending dikes in central Tibet: New constraints on the timing of east–west extension with implications for early plateau uplift? |
| title_sort | eocene north–south trending dikes in central tibet: new constraints on the timing of east–west extension with implications for early plateau uplift? |
| topic | extension dikes global climate change Tibet crustal flow uplift |
| url | http://hdl.handle.net/20.500.11937/22666 |