Magmatic response to arc-arc amalgamation: insights from latest Paleozoic igneous rocks from the Gangou section of the Eastern Tianshan
Magmatic response to arc-arc amalgamation: insights from latest Paleozoic igneous rocks from the Gangou section of the Eastern Tianshan
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弧弧拼合的岩浆响应：东天山甘沟段最新古生代火成岩的见解
DOI：
10.1016/j.gr.2022.04.018
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发表时间：
2022
影响因子：
6.1
通讯作者：
D. Graham Pearson
中科院分区：
文献类型：
--
作者：
Xiangsong Wang;Min Sun;Pengfei Li;Keda Cai;Guochun Zhao;Xiaoping Xia;Xijun Liu;Zhenglin Li;Yan Luo;D. Graham Pearson
·在中国天山甘沟段识别出两期岩浆作用。·晚石炭世和二叠纪岩浆作用记录了构造转换。·石炭系中段岩石为地幔楔熔融产物。·二叠纪岩浆岩显示出与软流圈地幔上涌的成因联系。古亚洲洋新元古代至中生代的消亡形成了多个弧系，它们的岩浆演化对理解中亚造山带的弧弧融合作用具有重要意义。本文报道了东天山甘沟段与剪切带有关的晚古生代岩浆岩的全岩地球化学资料和锆石U-Pb、Lu-Hf同位素原位同步结果，以约束其成因和弧弧拼合过程。分别获得了晚石炭世闪长岩和中二叠世安山岩的∼307 Ma和∼270 Ma的锆石U-Pb年龄。这些岩石具有较高的镁含量(分别为∼65和∼47)，富含大离子亲石元素(LILEs)，亏损高场强元素(HFSE)，亏损锆石εHf(T)值(+12.1~+18.1)，表明其起源于亏损地幔的部分熔融和不同程度的分异。此外，我们的结果还提供了中二叠世花岗斑岩的∼276 Ma锆石U-Pb年龄和晚二叠世辉绿岩的∼256 Ma锆石U-Pb年龄。花岗斑岩与A2型花岗岩具有相似的地球化学特征，即高K2O+Na2O，FeOT/MgO，Ga/Al，低CaO，Sr，Ba值。它们具有较高的锆石εHf(T)(+9.0~+13.7)值，表明它们可能来自年轻的下地壳。辉绿岩显示轻稀土元素(LREE)的亏损，类似于正常的大洋中脊玄武岩。这些岩石具有亏损的锆石Hf同位素组成(εHf(T)=+8 9~+15 8)，表明它们可能来自亏损地幔的部分熔融。东天山地区已有的地球化学资料表明，剪切带上的二叠纪镁铁质岩具有较高的Nb/La和较低的Ba/La比值。这些对比特征表明，石炭纪镁铁质岩起源于交代地幔楔体，而二叠纪镁铁质岩可能起源于亏损的地幔，并增加了富集型软流圈成分。二叠纪A型花岗岩类的高锆石饱和温度(主要为&800℃)和同时代镁铁质岩石的不同岩浆来源也暗示了软流圈上涌的可能性。因此，我们认为晚石炭世岩浆岩可能是北天山大洋板块俯冲作用的产物，而二叠纪岩浆岩的时空演化可能是与弧弧拼合有关的大规模右行走滑构造作用的结果。
• Two stages of magmatism are identified in the Gangou section of the Chinese Tianshan. • The Late Carboniferous and Permian magmatism recorded tectonic transition. • The Carboniferous intermediate rocks were derived from melting of mantle wedge. • The Permian magmatic rocks show a genetic link with upwelling of asthenosphere mantle. Multiple arc systems were developed in response to Neoproterozoic to Mesozoic consumption of the Paleo-Asian Ocean and their magmatic evolution is crucial for understanding the arc-arc amalgamation in the Central Asian Orogenic Belt. Here, we report whole-rock geochemical data as well as simultaneous in situ zircon U-Pb and Lu-Hf isotope results for the late Paleozoic magmatic rocks associated with the shear zones in the Gangou section of the Eastern Tianshan to constrain their petrogenesis and arc-arc amalgamation processes. We obtained ∼307 Ma and ∼270 Ma zircon U-Pb ages for the Late Carboniferous diorites and Middle Permian andesites, respectively. These rocks have high Mg (∼65 and ∼47, respectively) values, and are enriched in large ion lithophile elements (LILEs) and depleted in high field strength elements (HFSEs), with depleted zircon ε Hf (t) values (+12.1 to +18.1), suggesting an origin from partial melting of the depleted mantle with various degree of differentiation. Furthermore, our results also provided ∼276 Ma zircon U-Pb ages for the Middle Permian granitic porphyries and ∼256 Ma zircon U-Pb ages for the Late Permian diabase rocks. The granitic porphyries are geochemically similar to A 2 -type granites, i.e., high K 2 O + Na 2 O, FeO T /MgO, Ga/Al and low CaO, Sr and Ba. They have high zircon ε Hf (t) (+9.0 to +13.7) values, indicating a possible derivation from juvenile lower crust. The diabase rocks show depletion of light rare earth elements (LREEs), resembling normal mid-ocean ridge basalt. These rocks have depleted zircon Hf isotopic compositions (ε Hf (t) = +8.9 to +15.8), demonstrating a possible derivation from partial melting of the depleted mantle. The available geochemical data from the Eastern Tianshan show that the Permian mafic rocks along the shear zones possess higher Nb/La and lower Ba/La ratios than their counterparts in the Carboniferous. These contrasting features imply that the Carboniferous mafic rocks originated from a metasomatic mantle wedge, while the Permian mafic rocks were likely derived from the depleted mantle with addition of enriched asthenosphere components. The high zircon saturation temperatures (mostly > 800 °C) of the Permian A-type granitoids and diverse magma sources of coeval mafic rocks also imply possible asthenosphere upwelling. Therefore, we propose that the Late Carboniferous magmatic rocks were likely resulted from subduction of the North Tianshan oceanic plate, while the spatial and temporal evolution of the Permian magmatic rocks were probably attributed to large-scale dextral transcurrent tectonics associated with arc-arc amalgamation.
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影响因子：
1.5
作者：
Bo Wang;M. Faure;Dominique Cluzel;L. Shu;J. Charvet;S. Meffre;Q. Ma
通讯作者：
Bo Wang;M. Faure;Dominique Cluzel;L. Shu;J. Charvet;S. Meffre;Q. Ma
影响因子：
2.6
作者：
B. Su;K. Qin;P. Sakyi;Dongmei Tang;Ping Liu;S. Malaviarachchi;Qing-Hua Xiao;He Sun
通讯作者：
B. Su;K. Qin;P. Sakyi;Dongmei Tang;Ping Liu;S. Malaviarachchi;Qing-Hua Xiao;He Sun
中亚造山带二叠纪黄山西硫化矿镁铁-超镁铁岩体的岩石成因及成矿作用
影响因子：
3.5
作者：
Mao, Ya-Jing;Qin, Ke-Zhang;Li, Chusi;Xue, Sheng-Chao;Ripley, Edward M.
通讯作者：
Ripley, Edward M.
DOI：
10.1146/annurev-earth-060614-105254
发表时间：
2015-06
影响因子：
14.9
作者：
W. Xiao;B. Windley;S. Sun;Jiliang Li;Baochun Huang;Chunming Han;C. Yuan;Minjia Sun;Hanlin Chen-Hanli
通讯作者：
W. Xiao;B. Windley;S. Sun;Jiliang Li;Baochun Huang;Chunming Han;C. Yuan;Minjia Sun;Hanlin Chen-Hanli
影响因子：
6.1
作者：
Weifeng Zhang;Huayong Chen;Jinsheng Han;Liandang Zhao;Jianhan Huang;Juntao Yang;Xuelu Yan
通讯作者：
Weifeng Zhang;Huayong Chen;Jinsheng Han;Liandang Zhao;Jianhan Huang;Juntao Yang;Xuelu Yan