Petrogenesis and geological significance of the Late Carboniferous granites from Gangou, Central Tianshan Mountains, Xinjiang

FENG Guang-ying; YANG Jing-sui; LIU Fei; NIU Xiao-lu; GAO Jian

doi:10.12029/gc20160505

2016 Vol. 43, No. 5

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Article navigation > Geology in China > 2016 > (5): 1545-1557

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FENG Guang-ying, YANG Jing-sui, LIU Fei, NIU Xiao-lu, GAO Jian. Petrogenesis and geological significance of the Late Carboniferous granites from Gangou, Central Tianshan Mountains, Xinjiang[J]. Geology in China, 2016, (5): 1545-1557. doi: 10.12029/gc20160505

Citation:

FENG Guang-ying, YANG Jing-sui, LIU Fei, NIU Xiao-lu, GAO Jian. Petrogenesis and geological significance of the Late Carboniferous granites from Gangou, Central Tianshan Mountains, Xinjiang[J]. Geology in China, 2016, (5): 1545-1557. doi: 10.12029/gc20160505

Petrogenesis and geological significance of the Late Carboniferous granites from Gangou, Central Tianshan Mountains, Xinjiang

1.
CARMA, Institute of Geology, Chinese Academy of Geological Sciences, Beijing 100037, China
2.
Kunming University of Science and Technology, Kunming 650504, Yunnan, China

Received Date: 27 March 2016

Revised Date: 17 May 2016

Publish Date: 24 October 2016

Abstract

Abstract

Granitoid plutons are widespread in Gangou of Central Tianshan orogen. Previous studies of the augen granite and the fine-grained granite from north Gangou revealed that their SHRIMP U-Pb dating ages were 428 Ma and 361-368 Ma, respectively. Comparatively, zircon LA-ICP-MS U-Pb dating of the south granitoid pluton in this study yielded the 206Pb/238U age of 301±1.0 Ma. Major and trace elements show that the granites belong to high-K calc-alkaline series, and their σ=2.67-3.22. In addition, they are enriched in LREE, Rb, K, Th, La, Zr and Hf, and depleted in Ba, Sr, Nb, Ta, P and Ti. They show a transitional features from I-type to A-type. Compared with the Silurian-Devonian granites, late-Carboniferous granits are characterized by lower ISr values (0.704771-0.705451), higher εNd(t) (2.14-2.51) and younger TDM2 (861-891 Ma), suggesting that more new depleted mantel-derived materials contributed to the generation of the granites during post orogen. It is therefore held that the petrogenesis of the late-Carboniferous granites was related to the underplating of the mantle-derived magmas. This study also provides new evidence for Phanerozoic vertical continental crustal growth in the Central Asian orogenic belt.
- Gangou /
- late Carboniferous /
- granites /
- mantle-derived magma underplating /
- crustal growth