Structural characteristics of the Wanghushan ductile shear zone in northwestern Inner Mongolia and its geological significance

被引：0
|
作者：
Wang W. [1 ]
Lei C. [1 ]
Li G. [2 ]
Li W. [1 ]
Ding H. [1 ]
Ma J. [1 ]
Yan Z. [1 ]
机构：
[1] Hohhot Natural Resources Comprehensive Survey Center, China Geological Survey, Inner Mongolia, Hohhot
[2] College of Earth Sciences, Jilin University, Jilin, Changchun
来源：
Dizhi Xuebao/Acta Geologica Sinica | 2023年 / 97卷 / 07期
关键词：
Alxa; Central Asian Orogenic Belt; ductile shear; Late Carboniferous-Early Permian; zircon U-Pb dating;
D O I：
10.19762/j.cnki.dizhixuebao.2023103
中图分类号：
学科分类号：
摘要：
The Wanghushan ductile shear zone (WHSSZ) is located in the Yagan fault zone in Southernmost Central Asian Orogenic Belt (CAOB). In this study, we applied structural, microstructural and Ar/ Ar thermochronology, and U-Pb zircon geochronology to constrain the tectonic evolution of WHSSZ, and discussed its relations with subduction/collision dynamics in the Central Asian Orogenic Belt (CAOB). The WHSSZ is a nearly E-W striking ductile strike-slip shear zone, and various kinematic indicators indicate dextral shearing. The dynamic recrystallization characteristics of quartz and plagioclase indicate that the dextral ductile shearing belt is a high greenschist facies to low amphibolite facies dynamical metamorphism belt and the deformation temperature is approximately 400 - 500°C. LA-ICP-MS U-Pb dating were conducted on zircons from the mylonitized diorite, granite dikes, and undeformed syenogranite The weighted mean ages of diorite and syntectonic granitic vein are 331. 3 + 5. 7 Ma and 304. 8 + 2. 3 Ma. The crystallization ages of syntectonic mylonitized granite dikes and undeformed syenogranite are 308. 9 + 2. 0 Ma and 288. 4 + 1. 3 Ma, suggesting that the dextral shearing took place after 331 Ma and before 288 Ma. Ar- Ar plateau age of muscovite and biotite samples from metamorphic-deformed rocks of the WHSSZ range from 253 Ma to 237 Ma, which are consistent with the age of the Triassic magmatic rocks intrusive in the WHSSZ, and should be the record of that magmatic thermal event. We infer that the WHSSZ should be the direct record of the assembly of the middle segment of the southern CAOB during Late Carboniferous to Early Permian, and probably ended in Late Early Permian. © 2023 Geological Society of China. All rights reserved.
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页码：2141 / 2156
页数：15
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共 51 条
  • [1] Badarch G, Cunningham W D, Windley B F., A new terrane subdivision for Mongolia: Implications for the Phanerozoic crustal growth of Central Asia, Journal of Asian Earth Sciences, 21, 1, pp. 87-110, (2002)
  • [2] Cai Zhihui, Xu Zhiqin, He Bizhu, Wang Ruirui, Age and tectonic evolution of ductile shear zones in the eastern Tianshan-Beishan orogenic belt, Acta Petrologica Sinica, 28, 6, pp. 1875-1895, (2012)
  • [3] Charvet J, Shu Liangshu, Laurent-Charvet S., Paleozoic structural and geodynamic evolution of eastern Tianshan (NW China): Welding of the Tarim and Junggar plates, Episodes, 30, pp. 162-186, (2007)
  • [4] Chen Gongzheng, Wu Guang, Li Tiegang, Liu Ruilin, Li Ruihua, Li Yinglei, Yang Fei, Mineralization of the Daolundaba Cu-W-Sn deposit in the southern Great Xing'an Range: Constraints from zircon and monazite U-Pb and sericite 40Ar-39Ar ages, Acta Petrologica Sinica, 37, 3, pp. 865-885, (2021)
  • [5] Diaz-Azpiroz M, Brune S, Leever K A, Fernandez C, Czeck D M., Tectonics of oblique plate boundary systems, Tectonophysics, 693, pp. 165-170, (2016)
  • [6] Didenko A N, Li Yongfei, Peskov A Y, Shouliang Sun, Karetnikov A S, Zhou Yongheng, Closure of the Solonker basin: Paleomagnetism of the Linxi and Xingfuzhilu Formations (Inner Mongolia, China), Russian Journal of Pacific Geology, 10, 5, pp. 317-336, (2016)
  • [7] Edel J B, Schulmann K, Hanzl P, Lexa O., Palaeomagnetic and structural constraints on 90°anticlockwise rotation in SW Mongolia during the Permo-Triassic: implications for Altaid oroclinal bending. Preliminary palaeomagnetic results, Journal of Asian Earth Sciences, 94, 2014, pp. 157-171, (2014)
  • [8] Eizenhofer P R, Guochun Zhao, Solonker Suture in East Asia and its bearing on the final closure of the eastern segment of the Palaeo-Asian Ocean, Earth-Science Reviews, 186, pp. 153-172, (2018)
  • [9] Harrison T M., Diffusion of 40Ar in biotite: Temperature and compositional effects, Geochimica et Cosmochimica Acta, 49, pp. 2461-2468, (1981)
  • [10] Jahn B M., The Central Asian Orogenic Belt and growth of the continental crust in the Phanerozoic, Geological Society, London, Special Publications, 226, 1, pp. 73-100, (2004)
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