Assessing the Activity of Eastern Himalayan Extensional Structures: Evidence from Low-Temperature Thermochronology of Granitic Rocks from Yadong
The east–west-trending South Tibetan Detachment System (STDS) and north–south-trending rifts (NSTRs) are the two main types of extensional structures that have developed within the Tibetan Plateau during continent–continent collision since the early Cenozoic. They have played significant roles in th...
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MDPI AG
2024-01-01
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| author | Tiankun Xu Yalin Li Finlay M. Stuart Zining Ma Wenjun Bi Yongyong Jia Bo Yang |
| author_facet | Tiankun Xu Yalin Li Finlay M. Stuart Zining Ma Wenjun Bi Yongyong Jia Bo Yang |
| author_sort | Tiankun Xu |
| collection | DOAJ |
| description | The east–west-trending South Tibetan Detachment System (STDS) and north–south-trending rifts (NSTRs) are the two main types of extensional structures that have developed within the Tibetan Plateau during continent–continent collision since the early Cenozoic. They have played significant roles in the evolution of the plateau, but it is unclear how they are related genetically. In the Yadong area of the eastern Himalaya, the NSTRs cross-cut the STDS. Apatite and zircon fission track ages of a leucogranite pluton in the footwall of the two extensional faults can be used to reconstruct the cooling and exhumation history and thereby constrain the activity of extensional structures. The new AFT ages range from 10.96 ± 0.70 to 5.68 ± 0.37 Ma, and the ZFT age is 13.57 ± 0.61 Ma. Track length distributions are unimodal, albeit negatively skewed, with standard deviations between 1.4 and 2.1 µm and mean track lengths between 11.6 and 13.4 µm. In conjunction with previously published datasets, the thermal history of the region is best explained by three distinct pulses of exhumation in the last 16 Ma. The first pulse (16–12 Ma) records a brittle slip on the STDS. The two subsequent pulses are attributed to the movement on the Yadong normal fault. The normal fault initiated at ~12 Ma and experienced a pulse of accelerated exhumation between 6.2 and 4.7 Ma, probably reflecting the occurrence of two distinct phases of fault activity within the NSTRs, which were primarily instigated by slab tear of the subducting Indian plate. |
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| last_indexed | 2024-03-08T10:39:39Z |
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| series | Minerals |
| spelling | doaj.art-b7d896c3bc764bef8345432e1c34deb12024-01-26T17:52:29ZengMDPI AGMinerals2075-163X2024-01-011416610.3390/min14010066Assessing the Activity of Eastern Himalayan Extensional Structures: Evidence from Low-Temperature Thermochronology of Granitic Rocks from YadongTiankun Xu0Yalin Li1Finlay M. Stuart2Zining Ma3Wenjun Bi4Yongyong Jia5Bo Yang6School of Earth Sciences and Resources, China University of Geosciences, Beijing 100083, ChinaSchool of Earth Sciences and Resources, China University of Geosciences, Beijing 100083, ChinaScottish Universities Environmental Research Centre (SUERC), Rankine Avenue, East Kilbride G75 0QF, UKSchool of Earth Sciences and Resources, China University of Geosciences, Beijing 100083, ChinaDepartment of Earth Sciences and Engineering, Taiyuan University of Technology, Taiyuan 030024, ChinaSchool of Earth Sciences and Resources, China University of Geosciences, Beijing 100083, ChinaSchool of Earth Sciences and Resources, China University of Geosciences, Beijing 100083, ChinaThe east–west-trending South Tibetan Detachment System (STDS) and north–south-trending rifts (NSTRs) are the two main types of extensional structures that have developed within the Tibetan Plateau during continent–continent collision since the early Cenozoic. They have played significant roles in the evolution of the plateau, but it is unclear how they are related genetically. In the Yadong area of the eastern Himalaya, the NSTRs cross-cut the STDS. Apatite and zircon fission track ages of a leucogranite pluton in the footwall of the two extensional faults can be used to reconstruct the cooling and exhumation history and thereby constrain the activity of extensional structures. The new AFT ages range from 10.96 ± 0.70 to 5.68 ± 0.37 Ma, and the ZFT age is 13.57 ± 0.61 Ma. Track length distributions are unimodal, albeit negatively skewed, with standard deviations between 1.4 and 2.1 µm and mean track lengths between 11.6 and 13.4 µm. In conjunction with previously published datasets, the thermal history of the region is best explained by three distinct pulses of exhumation in the last 16 Ma. The first pulse (16–12 Ma) records a brittle slip on the STDS. The two subsequent pulses are attributed to the movement on the Yadong normal fault. The normal fault initiated at ~12 Ma and experienced a pulse of accelerated exhumation between 6.2 and 4.7 Ma, probably reflecting the occurrence of two distinct phases of fault activity within the NSTRs, which were primarily instigated by slab tear of the subducting Indian plate.https://www.mdpi.com/2075-163X/14/1/66southern Tibetlow-temperature thermochronologypecubeextensional structureexhumationYadong region |
| spellingShingle | Tiankun Xu Yalin Li Finlay M. Stuart Zining Ma Wenjun Bi Yongyong Jia Bo Yang Assessing the Activity of Eastern Himalayan Extensional Structures: Evidence from Low-Temperature Thermochronology of Granitic Rocks from Yadong Minerals southern Tibet low-temperature thermochronology pecube extensional structure exhumation Yadong region |
| title | Assessing the Activity of Eastern Himalayan Extensional Structures: Evidence from Low-Temperature Thermochronology of Granitic Rocks from Yadong |
| title_full | Assessing the Activity of Eastern Himalayan Extensional Structures: Evidence from Low-Temperature Thermochronology of Granitic Rocks from Yadong |
| title_fullStr | Assessing the Activity of Eastern Himalayan Extensional Structures: Evidence from Low-Temperature Thermochronology of Granitic Rocks from Yadong |
| title_full_unstemmed | Assessing the Activity of Eastern Himalayan Extensional Structures: Evidence from Low-Temperature Thermochronology of Granitic Rocks from Yadong |
| title_short | Assessing the Activity of Eastern Himalayan Extensional Structures: Evidence from Low-Temperature Thermochronology of Granitic Rocks from Yadong |
| title_sort | assessing the activity of eastern himalayan extensional structures evidence from low temperature thermochronology of granitic rocks from yadong |
| topic | southern Tibet low-temperature thermochronology pecube extensional structure exhumation Yadong region |
| url | https://www.mdpi.com/2075-163X/14/1/66 |
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