Petrogenesis and tectonic implications of Late-Triassic high eNd(t)-eHf(t) granites in the Ailaoshan tectonic zone (SW China)
High eNd(t)-eHf(t) granites are robust evidence for crustal growth. In this paper we report results of petrologic, geochronological and geochemical investigations on the Huashiban granites from the Ailaoshan tectonic zone in western Yunnan (SW China). Zircon grains separated from the two samples (10...
| Main Authors: | , , , , , |
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| Format: | Journal Article |
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Science China Press
2014
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| Online Access: | http://hdl.handle.net/20.500.11937/41350 |
| _version_ | 1848756121252134912 |
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| author | Liu, H. Wang, Y. Fan, W. Zi, Jianwei Cai, Y. Yang, G. |
| author_facet | Liu, H. Wang, Y. Fan, W. Zi, Jianwei Cai, Y. Yang, G. |
| author_sort | Liu, H. |
| building | Curtin Institutional Repository |
| collection | Online Access |
| description | High eNd(t)-eHf(t) granites are robust evidence for crustal growth. In this paper we report results of petrologic, geochronological and geochemical investigations on the Huashiban granites from the Ailaoshan tectonic zone in western Yunnan (SW China). Zircon grains separated from the two samples (10HH-119A and 10HH-120A) yield the weighted mean 206Pb/238U ages of 229.9 ± 2.0 Ma and 229.3 ± 2.3 Ma, respectively, interpreted as the crystallization ages of the granites. Based on our results, in combination with the existing U-Pb geochronological data for the Ailaoshan metamorphic rocks, we propose that the Ailaoshan Group might be a rock complex composed of the Mesoproterozoic, Neoproterozoic, Hercynian, Indosinian and Himalayan components, rather than a part of the crystalline basement of the Yangtze block. The zircon grains show highly depleted Lu-Hf isotope compositions, with positive ? Hf(t) values ranging from 8.4 to 13.1. The Huashiban granites have high SiO2 (72.66 wt%–73.70 wt%), low Mg# (0.28–0.34) with A/CNK=1.01–1.05, and can be classified as peralumious high-K calc-alkaline I-type granites. A synthesis of these data indicates that the Ailaoshan tectonic zone had evolved into a post-collisional setting by the Late-Triassic (229 Ma). Genesis of the Huashiban high ? Nd(t)-? Hf(t) granites involved into two processes: (1) underplating of the sub-arc mantle into the lower crust, and (2) remelting of the juvenile crustal materials in response to the upwelling of the asthenospheric mantle in the post-collisional setting. |
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| format | Journal Article |
| id | curtin-20.500.11937-41350 |
| institution | Curtin University Malaysia |
| institution_category | Local University |
| last_indexed | 2025-11-14T09:07:10Z |
| publishDate | 2014 |
| publisher | Science China Press |
| recordtype | eprints |
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| spelling | curtin-20.500.11937-413502017-09-13T14:09:29Z Petrogenesis and tectonic implications of Late-Triassic high eNd(t)-eHf(t) granites in the Ailaoshan tectonic zone (SW China) Liu, H. Wang, Y. Fan, W. Zi, Jianwei Cai, Y. Yang, G. High eNd(t)-eHf(t) granites are robust evidence for crustal growth. In this paper we report results of petrologic, geochronological and geochemical investigations on the Huashiban granites from the Ailaoshan tectonic zone in western Yunnan (SW China). Zircon grains separated from the two samples (10HH-119A and 10HH-120A) yield the weighted mean 206Pb/238U ages of 229.9 ± 2.0 Ma and 229.3 ± 2.3 Ma, respectively, interpreted as the crystallization ages of the granites. Based on our results, in combination with the existing U-Pb geochronological data for the Ailaoshan metamorphic rocks, we propose that the Ailaoshan Group might be a rock complex composed of the Mesoproterozoic, Neoproterozoic, Hercynian, Indosinian and Himalayan components, rather than a part of the crystalline basement of the Yangtze block. The zircon grains show highly depleted Lu-Hf isotope compositions, with positive ? Hf(t) values ranging from 8.4 to 13.1. The Huashiban granites have high SiO2 (72.66 wt%–73.70 wt%), low Mg# (0.28–0.34) with A/CNK=1.01–1.05, and can be classified as peralumious high-K calc-alkaline I-type granites. A synthesis of these data indicates that the Ailaoshan tectonic zone had evolved into a post-collisional setting by the Late-Triassic (229 Ma). Genesis of the Huashiban high ? Nd(t)-? Hf(t) granites involved into two processes: (1) underplating of the sub-arc mantle into the lower crust, and (2) remelting of the juvenile crustal materials in response to the upwelling of the asthenospheric mantle in the post-collisional setting. 2014 Journal Article http://hdl.handle.net/20.500.11937/41350 10.1007/s11430-014-4854-z Science China Press restricted |
| spellingShingle | Liu, H. Wang, Y. Fan, W. Zi, Jianwei Cai, Y. Yang, G. Petrogenesis and tectonic implications of Late-Triassic high eNd(t)-eHf(t) granites in the Ailaoshan tectonic zone (SW China) |
| title | Petrogenesis and tectonic implications of Late-Triassic high eNd(t)-eHf(t) granites in the Ailaoshan tectonic zone (SW China) |
| title_full | Petrogenesis and tectonic implications of Late-Triassic high eNd(t)-eHf(t) granites in the Ailaoshan tectonic zone (SW China) |
| title_fullStr | Petrogenesis and tectonic implications of Late-Triassic high eNd(t)-eHf(t) granites in the Ailaoshan tectonic zone (SW China) |
| title_full_unstemmed | Petrogenesis and tectonic implications of Late-Triassic high eNd(t)-eHf(t) granites in the Ailaoshan tectonic zone (SW China) |
| title_short | Petrogenesis and tectonic implications of Late-Triassic high eNd(t)-eHf(t) granites in the Ailaoshan tectonic zone (SW China) |
| title_sort | petrogenesis and tectonic implications of late-triassic high end(t)-ehf(t) granites in the ailaoshan tectonic zone (sw china) |
| url | http://hdl.handle.net/20.500.11937/41350 |