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Pliocene-Quaternary crustal melting in central and northern Tibet and insights into crustal flow.

ABSTRACT: There is considerable controversy over the nature of geophysically recognized low-velocity-high-conductivity zones (LV-HCZs) within the Tibetan crust, and their role in models for the development of the Tibetan Plateau. Here we report petrological and geochemical data on magmas erupted 4.7-0.3 Myr ago in central and northern Tibet, demonstrating that they were generated by partial melting of crustal rocks at temperatures of 700-1,050?°C and pressures of 0.5-1.5?GPa. Thus Pliocene-Quaternary melting of crustal rocks occurred at depths of 15-50?km in areas where the LV-HCZs have been recognized. This provides new petrological evidence that the LV-HCZs are sources of partial melt. It is inferred that crustal melting played a key role in triggering crustal weakening and outward crustal flow in the expansion of the Tibetan Plateau.

SUBMITTER: Wang Q

PROVIDER: S-EPMC4912662 | biostudies-literature | 2016 Jun

REPOSITORIES: biostudies-literature

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Pliocene-Quaternary crustal melting in central and northern Tibet and insights into crustal flow.

Wang Qiang Q Hawkesworth Chris J CJ Wyman Derek D Chung Sun-Lin SL Wu Fu-Yuan FY Li Xian-Hua XH Li Zheng-Xiang ZX Gou Guo-Ning GN Zhang Xiu-Zheng XZ Tang Gong-Jian GJ Dan Wei W Ma Lin L Dong Yan-Hui YH

Nature communications 20160616

There is considerable controversy over the nature of geophysically recognized low-velocity-high-conductivity zones (LV-HCZs) within the Tibetan crust, and their role in models for the development of the Tibetan Plateau. Here we report petrological and geochemical data on magmas erupted 4.7-0.3 Myr ago in central and northern Tibet, demonstrating that they were generated by partial melting of crustal rocks at temperatures of 700-1,050 °C and pressures of 0.5-1.5 GPa. Thus Pliocene-Quaternary melt ...[more]

PMID: 27307135

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