Mylonitized peridotites of Songshugou in the Qinling orogen, central China: A fragment of fossil oceanic lithosphere mantle
文献类型：期刊论文
| 作者 | Yu, Hong1; Zhang, Hong-Fu1,2; Santosh, M.3,4 |
| 刊名 | GONDWANA RESEARCH
 |
| 出版日期 | 2017-12-01 |
| 卷号 | 52页码:1-17 |
| 关键词 | Mylonitized Peridotites Ductile Shear Deformation Melt/fluid Circulation Fossil Oceanic Lithosphere Songshugou |
| ISSN号 | 1342-937X |
| DOI | 10.1016/j.gr.2017.08.007 |
| 文献子类 | Article |
| 英文摘要 | The Songshugou mylonitized peridotites within the Qinling Group metamorphic rocks in Central China are distributed in the northern part of the Shang-Dan Suture Zone (SDSZ) and contain abundant dunites and harzburgites. The dunites were intensely deformed and mylonitized converting the coarse-grained type to medium- and fine-grained types which contain prominent lenticular structure and relict olivine (Ol) porphyroclasts. Mineralogical and geochemical compositions suggest that the protoliths of the mylonitized peridotites were coarse-grained peridotites of lithospheric mantle origin. The harzburgites occur as enclaves within mylonitic peridotites in the form of lenses or veins. The orthopyroxenes in harzburgites were formed at the expense of Ol and have similar compositions to those of metasomatized harzburgites, characterized by low Al2O3, CaO and Cr2O3 contents. The harzburgites exhibit the gently U-type REE patterns with enriched incompatible elements (Rb, Ba, Sr, Zr and Hf), suggesting the metasomatic origin. The obvious ductile deformation of the large porphyroclastic orthopyroxene (Opx) suggests that the metasomatism occurred before the deformation. Ductile shearing deformation is indicated by the small fold structures and net-style ductile shearing zones within the Songshugou peridotite massif. The process is also result in the alignment of elongated Ol grains from initially coarse-granular via porphyroclastic to fine-granular texture. The relatively low Fo olivine, together with high Al2O3, and CaO contents and the abnormally low total PGE abundance in the fine-grained dunites suggest the ingress of melt/fluid during the mylonitization. The presences of significant amount of amphibole in the peridotites indicate the ingress of hydrous fluids. In general, the Songshugou peridotites have similar compositional characteristics with peridotites of Oman and Troodos ophiolites which are fragments of oceanic lithosphere mantle. One coarse-grained dunite has a T-RD age of 875 Ma. Additionally two stages Paleozoic T-RD ages are obtained from medium-grained and fine-grained dunites (491 Ma and 550 Ma; 446 Ma and 476 Ma). The broadly coeval nature of mylonitization with progressive metamorphism of surrounding amphibolites suggested that the Songshugou peridotites were generated before the early Paleozoic deformation. Our data, combined with the previous work on the surrounding HP/UHP metamorphic rocks, demonstrate that the Songshugou mylonitized peridotites represent fragments of the Neoproterozoic fossil oceanic lithospheric mantle that experienced extensive deformation during the Early Paleozoic subduction processes. (C) 2017 International Association for Gondwana Research. Published by Elsevier B.V. All rights reserved. |
| WOS关键词 | NORTHERN OMAN OPHIOLITE ; TECTONIC EVOLUTION ; SHEAR ZONES ; ULTRAMAFIC ROCKS ; SERPENTINITE MYLONITES ; HARZBURGITE XENOLITHS ; STRAIN LOCALIZATION ; ELEMENT ABUNDANCES ; CHROMITE DEPOSITS ; UPWELLING MANTLE |
| WOS研究方向 | Geology |
| 语种 | 英语 |
| WOS记录号 | WOS:000416498500001 |
| 出版者 | ELSEVIER SCIENCE BV |
| 资助机构 | Natural Science Foundation of China(91414301) ; Natural Science Foundation of China(91414301) ; Program for Changjiang Scholars and Innovative Research Team in University(IRT1281) ; Program for Changjiang Scholars and Innovative Research Team in University(IRT1281) ; Young Scientist Fund of NSFC(41603037) ; Young Scientist Fund of NSFC(41603037) ; Natural Science Foundation of China(91414301) ; Natural Science Foundation of China(91414301) ; Program for Changjiang Scholars and Innovative Research Team in University(IRT1281) ; Program for Changjiang Scholars and Innovative Research Team in University(IRT1281) ; Young Scientist Fund of NSFC(41603037) ; Young Scientist Fund of NSFC(41603037) ; Natural Science Foundation of China(91414301) ; Natural Science Foundation of China(91414301) ; Program for Changjiang Scholars and Innovative Research Team in University(IRT1281) ; Program for Changjiang Scholars and Innovative Research Team in University(IRT1281) ; Young Scientist Fund of NSFC(41603037) ; Young Scientist Fund of NSFC(41603037) ; Natural Science Foundation of China(91414301) ; Natural Science Foundation of China(91414301) ; Program for Changjiang Scholars and Innovative Research Team in University(IRT1281) ; Program for Changjiang Scholars and Innovative Research Team in University(IRT1281) ; Young Scientist Fund of NSFC(41603037) ; Young Scientist Fund of NSFC(41603037) |
| 源URL | [http://ir.iggcas.ac.cn/handle/132A11/82110]  |
| 专题 | 中国科学院地质与地球物理研究所 |
| 通讯作者 | Yu, Hong |
| 作者单位 | 1.Chinese Acad Sci, State Key Lab Lithospher Evolut, Inst Geol & Geophys, POB 9825, Beijing 100029, Peoples R China 2.Northwest Univ, State Key Lab Continental Dynam, Dept Geol, Xian 710069, Shaanxi, Peoples R China 3.Univ Adelaide, Dept Earth Sci, Adelaide, SA 5005, Australia 4.China Univ Geosci, Sch Earth Sci & Resources, Beijing, Peoples R China |
| 推荐引用方式 GB/T 7714 | Yu, Hong,Zhang, Hong-Fu,Santosh, M.. Mylonitized peridotites of Songshugou in the Qinling orogen, central China: A fragment of fossil oceanic lithosphere mantle[J]. GONDWANA RESEARCH,2017,52:1-17. |
| APA | Yu, Hong,Zhang, Hong-Fu,&Santosh, M..(2017).Mylonitized peridotites of Songshugou in the Qinling orogen, central China: A fragment of fossil oceanic lithosphere mantle.GONDWANA RESEARCH,52,1-17. |
| MLA | Yu, Hong,et al."Mylonitized peridotites of Songshugou in the Qinling orogen, central China: A fragment of fossil oceanic lithosphere mantle".GONDWANA RESEARCH 52(2017):1-17. |
入库方式： OAI收割
来源：地质与地球物理研究所
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