Kinematics and age constraints of deformation in a Late Carboniferous accretionary complex in Western Junggar, NW China

Ji'en ZHANG; Wenjiao XIAO; Chunming HAN; Songjian AO; Chao YUAN; Min SUN; Hongyan GENG; Guochun ZHAO; Qianqian GUO; Chong MA

doi:10.1016/j.gr.2010.10.003

Kinematics and age constraints of deformation in a Late Carboniferous accretionary complex in Western Junggar, NW China

Ji'en ZHANG, Wenjiao XIAO^*, Chunming HAN, Songjian AO, Chao YUAN, Min SUN, Hongyan GENG, Guochun ZHAO, Qianqian GUO, Chong MA

^*Corresponding author for this work

Research output: Journal Publications › Journal Article (refereed) › peer-review

178 Citations (Scopus)

Abstract

The Karamay area, situated in the eastern part of Western Junggar, Southern Altaids, contains an ophiolitic mélange with ultramafic rocks, gabbro, basalt, chert and limestone, which show typical block-in-matrix structures, and coherent turbidites and tuffs. These lithological associations are interpreted as incoherent and coherent series formed in an accretionary complex. On the basis of detailed field mapping and analyses of the asymmetry of imbricate thrusts, duplexes, tilted structures, shear band cleavages, and the NW-verging inclined to overturned folds, we conclude that the overall movement in the accretionary complex was top-to-the-NW. The youngest tuff involved in the deformation contains detrital zircons that have a U-Pb age (LA-MC ICP-MS) of 308±7Ma. ^³⁹Ar-⁴⁰Ar resistance furnace step-heating of amphibole separates from a diorite dike, which cuts the folded and imbricated rocks in the accretionary prism, yielded a plateau age of 307±2Ma. Consequently, the age of the deformation in the prism is tightly constrained at 307-308Ma, implying that the deformation occurred in an extremely short time-span during SE-ward subduction. Combined contemporaneous occurrence of Baogutu adakite, high-Mg, Sr-enriched and Y-poor dioritic dikes, Miaoergou charnockite, and Maliya mafic rocks, we further suggest the accretionary complex was cut by near-trench volcanic rocks and plutons possibly due to interaction with a spreading ridge.

Original language	English
Pages (from-to)	958-974
Number of pages	17
Journal	Gondwana Research
Volume	19
Issue number	4
Early online date	17 Oct 2010
DOIs	https://doi.org/10.1016/j.gr.2010.10.003
Publication status	Published - Jun 2011
Externally published	Yes

Bibliographical note

We thank Jiliang Li, Jinyi Li, Yue Zhao, Lifei Zhang, Jinjiang Zhang, Zhaojie Guo, Baofu Han, Tianfeng Wan, Yadong Zheng and Fei Wang for useful discussions and suggestions on this manuscript. We acknowledge Drs. Liangjun Yu, Qigui Mao, and Peng Xu for field assistance and Liekun Yang for argon–argon analytic procedure. Brian F. Windley, Timothy M. Kusky and Cameron Quinn critically read earlier versions of the manuscript. We sincerely appreciate K. de Jong, an anonymous reviewer, and the editor for their critical and constructive comments.

Funding

Funds from the Chinese State 973 Program ( 2007CB411307 ) the Innovative Program of the Chinese Academy of Sciences ( KZCX2-YW-Q04-08 ), and the Natural Science Foundation of China Projects ( 40725009 and 40523003 ) are gratefully acknowledged.

Keywords

Accretionary complex
Coheret unit
Melange
Southern Altaids
West Junggar

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10.1016/j.gr.2010.10.003

Cite this

@article{2ff5a98f9fe24a5fbfed73b8e7433edd,

title = "Kinematics and age constraints of deformation in a Late Carboniferous accretionary complex in Western Junggar, NW China",

abstract = "The Karamay area, situated in the eastern part of Western Junggar, Southern Altaids, contains an ophiolitic m{\'e}lange with ultramafic rocks, gabbro, basalt, chert and limestone, which show typical block-in-matrix structures, and coherent turbidites and tuffs. These lithological associations are interpreted as incoherent and coherent series formed in an accretionary complex. On the basis of detailed field mapping and analyses of the asymmetry of imbricate thrusts, duplexes, tilted structures, shear band cleavages, and the NW-verging inclined to overturned folds, we conclude that the overall movement in the accretionary complex was top-to-the-NW. The youngest tuff involved in the deformation contains detrital zircons that have a U-Pb age (LA-MC ICP-MS) of 308±7Ma. 39Ar-40Ar resistance furnace step-heating of amphibole separates from a diorite dike, which cuts the folded and imbricated rocks in the accretionary prism, yielded a plateau age of 307±2Ma. Consequently, the age of the deformation in the prism is tightly constrained at 307-308Ma, implying that the deformation occurred in an extremely short time-span during SE-ward subduction. Combined contemporaneous occurrence of Baogutu adakite, high-Mg, Sr-enriched and Y-poor dioritic dikes, Miaoergou charnockite, and Maliya mafic rocks, we further suggest the accretionary complex was cut by near-trench volcanic rocks and plutons possibly due to interaction with a spreading ridge.",

keywords = "Accretionary complex, Coheret unit, Melange, Southern Altaids, West Junggar",

author = "Ji'en ZHANG and Wenjiao XIAO and Chunming HAN and Songjian AO and Chao YUAN and Min SUN and Hongyan GENG and Guochun ZHAO and Qianqian GUO and Chong MA",

note = "We thank Jiliang Li, Jinyi Li, Yue Zhao, Lifei Zhang, Jinjiang Zhang, Zhaojie Guo, Baofu Han, Tianfeng Wan, Yadong Zheng and Fei Wang for useful discussions and suggestions on this manuscript. We acknowledge Drs. Liangjun Yu, Qigui Mao, and Peng Xu for field assistance and Liekun Yang for argon–argon analytic procedure. Brian F. Windley, Timothy M. Kusky and Cameron Quinn critically read earlier versions of the manuscript. We sincerely appreciate K. de Jong, an anonymous reviewer, and the editor for their critical and constructive comments.",

year = "2011",

month = jun,

doi = "10.1016/j.gr.2010.10.003",

language = "English",

volume = "19",

pages = "958--974",

journal = "Gondwana Research",

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T1 - Kinematics and age constraints of deformation in a Late Carboniferous accretionary complex in Western Junggar, NW China

AU - ZHANG, Ji'en

AU - XIAO, Wenjiao

AU - HAN, Chunming

AU - AO, Songjian

AU - YUAN, Chao

AU - SUN, Min

AU - GENG, Hongyan

AU - ZHAO, Guochun

AU - GUO, Qianqian

AU - MA, Chong

N1 - We thank Jiliang Li, Jinyi Li, Yue Zhao, Lifei Zhang, Jinjiang Zhang, Zhaojie Guo, Baofu Han, Tianfeng Wan, Yadong Zheng and Fei Wang for useful discussions and suggestions on this manuscript. We acknowledge Drs. Liangjun Yu, Qigui Mao, and Peng Xu for field assistance and Liekun Yang for argon–argon analytic procedure. Brian F. Windley, Timothy M. Kusky and Cameron Quinn critically read earlier versions of the manuscript. We sincerely appreciate K. de Jong, an anonymous reviewer, and the editor for their critical and constructive comments.

PY - 2011/6

Y1 - 2011/6

N2 - The Karamay area, situated in the eastern part of Western Junggar, Southern Altaids, contains an ophiolitic mélange with ultramafic rocks, gabbro, basalt, chert and limestone, which show typical block-in-matrix structures, and coherent turbidites and tuffs. These lithological associations are interpreted as incoherent and coherent series formed in an accretionary complex. On the basis of detailed field mapping and analyses of the asymmetry of imbricate thrusts, duplexes, tilted structures, shear band cleavages, and the NW-verging inclined to overturned folds, we conclude that the overall movement in the accretionary complex was top-to-the-NW. The youngest tuff involved in the deformation contains detrital zircons that have a U-Pb age (LA-MC ICP-MS) of 308±7Ma. 39Ar-40Ar resistance furnace step-heating of amphibole separates from a diorite dike, which cuts the folded and imbricated rocks in the accretionary prism, yielded a plateau age of 307±2Ma. Consequently, the age of the deformation in the prism is tightly constrained at 307-308Ma, implying that the deformation occurred in an extremely short time-span during SE-ward subduction. Combined contemporaneous occurrence of Baogutu adakite, high-Mg, Sr-enriched and Y-poor dioritic dikes, Miaoergou charnockite, and Maliya mafic rocks, we further suggest the accretionary complex was cut by near-trench volcanic rocks and plutons possibly due to interaction with a spreading ridge.

AB - The Karamay area, situated in the eastern part of Western Junggar, Southern Altaids, contains an ophiolitic mélange with ultramafic rocks, gabbro, basalt, chert and limestone, which show typical block-in-matrix structures, and coherent turbidites and tuffs. These lithological associations are interpreted as incoherent and coherent series formed in an accretionary complex. On the basis of detailed field mapping and analyses of the asymmetry of imbricate thrusts, duplexes, tilted structures, shear band cleavages, and the NW-verging inclined to overturned folds, we conclude that the overall movement in the accretionary complex was top-to-the-NW. The youngest tuff involved in the deformation contains detrital zircons that have a U-Pb age (LA-MC ICP-MS) of 308±7Ma. 39Ar-40Ar resistance furnace step-heating of amphibole separates from a diorite dike, which cuts the folded and imbricated rocks in the accretionary prism, yielded a plateau age of 307±2Ma. Consequently, the age of the deformation in the prism is tightly constrained at 307-308Ma, implying that the deformation occurred in an extremely short time-span during SE-ward subduction. Combined contemporaneous occurrence of Baogutu adakite, high-Mg, Sr-enriched and Y-poor dioritic dikes, Miaoergou charnockite, and Maliya mafic rocks, we further suggest the accretionary complex was cut by near-trench volcanic rocks and plutons possibly due to interaction with a spreading ridge.

KW - Accretionary complex

KW - Coheret unit

KW - Melange

KW - Southern Altaids

KW - West Junggar

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U2 - 10.1016/j.gr.2010.10.003

DO - 10.1016/j.gr.2010.10.003

M3 - Journal Article (refereed)

AN - SCOPUS:79954632194

SN - 1342-937X

VL - 19

SP - 958

EP - 974

JO - Gondwana Research

JF - Gondwana Research

IS - 4

ER -

Kinematics and age constraints of deformation in a Late Carboniferous accretionary complex in Western Junggar, NW China

Abstract

Bibliographical note

Funding

Keywords

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