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Trachytic Rock and Associated Fenitization in the Bayan Obo Ore Deposit,Inner Mongolia,China:Evidence for Magmatic-Hydrothermal Mineralization Related to a Carbonatitic Complex

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Acta Geologica Sinica(English Edition) 2000年第2期74卷 148-153页

作者： YUAN Zhongxin BAI Ge zhang zongqing Institute of Mineral Deposits Chinese Academy of Geological Sciences26 Baiwanzhuang Rd.Beijing 100037 Institute of Geology Chinese Academy of Geological Sciences 26 Baiwanzhuang Rd.Beijing 100037

Trachytic rock and its altered rock—fenite—in the Bayan Obo ore district, Inner Mongolia, China, were referred to as slate or feldspar rock before, and identified by the authors for the first time (in 1992). In the paper the mineral assemblages, structures and textures and petrochemical compositions of the rocks, as well as the electron microprobe analysis of feldspars in the rocks are described. The Sm-Nd isochron age of the trachytic rock is 1096 ± 56 Ma, with INd=0.51100±4 (2 s?) and ?Nd(t)= ?4.4 ± 0.7. Alterations of the trachytic rock, including microclinization, riebeckitization, aegirinization and biotitization, and accompanied rare element and REE mineralizations are discussed. Based on the occurrence of the trachytic rock and associated fenitization it is deduced that the Bayan Obo Fe-Nb-REE ore deposit is genetically related to magmatic-hydrothermal activity of an alkali carbonatite complex.

关键词： trachytic rock fenitization Bayan Obo

Isotope chronological trace of granite gravel in Hefei Basin

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Chinese Science Bulletin 2001年第20期46卷 1716-1722页

作者： LIU Shaofeng zhang Guowei zhang zongqing SU Shangguo China University of Geosciences Beijing 100083China Northwest University Xi’an 710069China Institute of Geology Chinese Academy of Geological SciencesBeijing 100037China

The discovery of granite gravel in Hefei Jurassic backland basin, which came from the Dabie Shan or North Huaiyang, has a great significance for probing into uplift and exhumation of the Dabie orogenic belt. Litho-chemical and isotope chronological analyses on the granite gravel in the Sanjianpu Formation and the Fenghuangtai Formation in Jinzhai County prove that post-orogenic granite was developed in the major provenance of the Hefei Basin; that is, Dabie Shan or North Huaiyang. Discordant lower intersection point age of zircon U-Pb of granite gravel is about 214 Ma, and 40Ar/39Ar age of muscovite about 196 Ma, K-Ar age of K-spar about 181 Ma. The former is the diagenetic age of the sample, and the latter two represent the sealed ages of muscovite and K-spar respectively. The age of sedimentary rocks in which a lot of granite gravels appear in the sedimentary section may represent the newest age of the exhumation of the granite body, so we assume that the age is 166 Ma. Therefore, we calculated the

关键词： Hefei Basin gravel provenance isotope chronological trace.

Geochronology of the Hannan intrusive complex to adjoin the Qinling orogen and its rapid cooling reason

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Chinese Science Bulletin 2001年第8期46卷 685-689页

作者： zhang zongqing zhang Guowei TANG Suohan zhang Qiaoda WANG Jinhui Institute of Geology Chinese Academy of GeosciencesBeijing 100037China Department of Geology Northwest UniversityXi’an 710069China

The geochronological works for the Hannan intrusive complex, cosisting of the gabbro-quartz dio-rite-plagiogranite bodies, in the north border of the Yangtze craton block, adjoining the Qinling orogen, are reported, because its age and genesis are of great importance to research of the tectonic evalutional history for the Qinling orogen and of the rifted processes for the Late Proterozoic supercontinent Rodinia. A good isochron of t=(837±26) Ma (2σ), corresponding to INd=0.51165±2(2σ), εNd(t)=+1.9, MSWD1.02, was difined by the Nd isotopic analytical results for the 21 whole-rock samples from the varied lithological complex bodies, but for the Rb-Sr isotopic aralytical data there is no isochron. The 40Ar/39Ar plateau age of the biotite, sorted from plagiogranites, is (796±20) Ma(2σ), and yet for the Rb-Sr isotopic data of the plagiogranite whole-rock samples (WR) and the sorted biotite (Bio), plagioclase (Plag) and apatite (Apt) mineral samples from the plagiogranitewhole-rock samples, an

关键词： isotopic geochronology Hannan intrusive complex Qinling orogen China.

H infinity Control for Sandwiched Maglev Stage with Dynamic Damping

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Journal of Beijing Institute of Technology 2019年第2期28卷 218-225页

作者： Ningran Song Shuyuan Ma zongqing zhang Shansi zhang Changmeng Liu School of Mechanical Engineering Beijing Institute of Technology

An H infinity(H∞)controller for a sandwiched maglev positioning stage is *** maglev positioning stage has a special structure:a sandwiched maglev stage,consisting of repulsive linear motors and attractive linear motors,which have better levitation *** on the sandwiched maglev stage are analyzed and *** positioning controller is designed based on the feedback linearized model with a dynamic damping *** design of the H infinity controller for stage positioning is derived as a series of linear matrix inequalities(LMIs)which are efficiently solved in *** proposed controller and its effectiveness is demonstrated compared to PID method.

关键词： sandwiched structure positioning stage maglev technology H infinity(H∞)control

Nd isotopic disequilibrium between minerals and Rb-Sr age of the secondary phengite in eclogite from the Yangkou area,Qingdao,eastern China

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Chinese Science Bulletin 2001年第3期46卷 252-255页

作者： LI Shuguang SUN Weidong zhang zongqing LI Qiuli Chemical Geodynamics Laboratory Department of Earth and Space SciencesUniversity of Science and Technology of ChinaHefei 230026China Institute of Geology Chinese Academy of Geological SciencesBeijing 100037China

There are two generations of white micas in retrograded coesite-bearing eclogite from the Yangkou area near Qingdao, eastern China. The secondary phengite developed along the folliations in eclogite is the majority of the white micas. Nd and Sr isotopic disequilibriums between garnet and retrograded omphacite as well as secondary phengite have been observed. Consequently, the Rb-Sr ages ((193±4) Ma-(195±4) Ma) given by the tie lines of the secondary phengite + garnet or whole rock may predate the formation time of the phengite. The Rb-Sr age of (183±4) Ma given by the secondary phengite + retrograde omphacite is much closer to the formation time of the phengite indicating the retrograde age of eclogite instead of a cooling age of eclogite at 500℃.

关键词： eclogite Nd isotopic disequilibrium Rb-Sr dating Su-Lu UHPM belt.

Geochronology and geochemistry of the Heihe mafic pillow lavas in the Qinling Mountains,China

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Science China Earth Sciences 2001年第6期44卷 517-524页

作者： zhang zongqing zhang Guowei TANG Suohan WANG Jinhui Institute of Geology Chinese Academy of GeosciencesBeijing 100037China Department of Geology Northwest UniversityXi'an 710069China Institute of GeologyChinese Academy of GeosciencesBeijing 100037China

The Qinling Mountains in central China are the joint orogenic zone between the Sino-Korean(or North China)and the Yangtze craton *** age and genesis of the Danfeng mafic volcanics in the north of the Shangzhou-Danfeng fault zone,*** main suture zone in the Qinling orogenic belt,have been controverted for a long time because their age is closely related to the converged time of two *** ages and the geochemical data of the Heihe pillow lavas for the Danfeng mafic volcanics in the Heihe River area in the Qinling orogen are reported in this *** obtained isochron age by the Sm-Nd isotopic data of the 13 whole-rock samples for the mafic pillow lavas is 963±130(2σ)Ma,corresponding to I_(nd)=0.51173±16(2σ),ε_(Nd)(T)=+6.6,***,the Rb-Sr isotopic analytical results for the same samples as the Sm-Nd whole-rock ones are *** the Sm-Nd isotopic systems were interfered during the later geological functions,the Sm-Nd isochron age for the whole-rock sample(Q9511WR)and the mineral phenocrystal sam-ples:amphiboles(Hb)and plagioclases(Plag)presents the better uncertainty,whereas isochron ages of 930 Ma and 437 Ma are given if the WR-Plag and WR-Hb are calculated respectively,and their Rb-Sr isochron age is 268±47(2σ)Ma,I_(sr)=0.70475±11(2σ),*** major and trace elements for the lavas show that they were formed in the quasi-N-MORB setting.

关键词： age Danfeng mafic volcanics Qinling orogen

Age of Anzishan granulites in the Mianxian-Lueyang suture zone of Qingling orogen:With a discussion of the timing of final assembly of Yangtze and North China craton blocks

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Chinese Science Bulletin 2002年第22期47卷 1925-1930页

作者： zhang zongqing zhang Guowei TANG SuohaiV XU Jifeng YANG Yongcheng WANG Jinhui Institute of Geology Chinese Academy of GeosciencesBeijing 100037China Department of Geology Northwest UniversityXi’an 710069China Guangzhou Institute of Geochemistry Chinese Academy of SciencesGuangzhou 510640China Shaanxi Institute of Regional Geology and Mineral Resources Xian-yang 712000China

Many granulite blocks have been recently dis-covered in the Anzishan area, Mianxian County, ShaanxiProvince, in the central segment of the Manxian-Lueyangsuturc zone. Sm-Nd isochron and 40 Ar39 Ar ages of mineralsamples of granulites from this area are reported in the *** granulite mineral samples give a Sm-Nd isochron age oft=(206 ± 55) Ma (2σ), with INd = 0.51302±7(2σ) and MSWD =1.6, and a biotite 40Ar/39 Ar plateau age of (199.7±l.7) Ma(2σ). The formation and uplift of the granulites were relatedto subduction of the Yangtze block beneath the SouthQinling microcontinent and their collision and the finalamalgamation of the Yangtze and Sino-Korean craton blocksin the Indosinian, and their age is consistent with or close tothose of the Dabie ultrahigh-pressure and high-pressuremetamorphic rocks, so have great tectonic significance.

关键词： isotope geochronology granulite Qinling orogen.

SHRIMP Zircon U-Pb Dating of Gabbro and Granite from the Huashan Ophiolite,Qinling Orogenic Belt,China: Neoproterozoic Suture on the Northern Margin of the Yangtze Craton

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Acta Geologica Sinica(English Edition) 2007年第2期81卷 239-243页

作者： SHI Yuruo LIU Dunyi zhang zongqing MIAO Laicheng zhang Fuqin XUE Hongmei Beijing SHRIMP Center Institute of Geology Chinese Academy of Geological Sciences Beijing 100037 Institute of Geology and Geophysics Chinese Academy of Sciences Beijing 100029 No. 4 Geological Team Xinjiang Bureau of Geology and Mineral Resources Altay Xinjiang 836500

The recently identified Huashan ophiolitic mélange was considered as the eastern part of the Mianlüe suture in the Qinling orogenic belt. SHRIMP zircon U-Pb geochronology on gabbro from the Huashan ophiolite and granite intruding basic volcanic rocks indicates crystallization ages of 947±14 Ma and 876±17 Ma respectively. These ages do not support a recently proposed Hercynian Huashan Ocean, but rather favor that a Neoproterozoic suture assemblage （ophiolite） is incorporated into the younger （Phanerozoic） Qinling orogenic belt.

关键词： SHRIMP Neoproterozoic Ophiolite Huashan Mianlüe Suture Qinling

Zircon U-Pb and geochemical analyses for leucocratic intrusive rocks in pillow lavas in the Danfeng Group,north Qinling Mountains,China

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Science China Earth Sciences 2008年第2期51卷 249-262页

作者： Yan QuanRen Chen JunLu Wang ZongQi Yan Zhen Wang Tao Li QiuGen zhang zongqing Jiang ChunFa Institute of Geology Chinese Academy of Geological Sciences (CAGS) Beijing 100037 China Beijing SHRIMP Center CAGS Beijing 100037 China Xi’an Institute of Geology and Mineral Resources China Geological Survey Xi’an 710054 China

Field observation showed that there are many irregular leucocratic intrusive rocks in pillow lavas in the Danfeng Group in the Xiaowangjian area, north Qinling orogenic belt. Photomicrographs indicated that the protol... 详细信息

关键词： Danfeng Group pillow lava leucocratic intrusive rock geochemistry and isotope SHRIMP U-Pb dating