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Petrogenesis and significance of early Yanshanian syenite-granite complex in eastern Nanling Range

Science china Earth Sciences 2005年第7期48卷 912-924页

作者： CHEN Peirong1, ZHOU Xinmin1, ZHANG Wenlan1, LI Huimin2, FAN Chunfang1, SUN Tao1, CHEN Weifeng1 & ZHANG Min1 1. State Key Laboratory of mineral Deposits Research, Department of Earth Sciences, Nanjing University, Nanjing 210093. china 2. tianjin Institute of {3. and mineral resources, china Geological Survey, tianjin 3.0170, china State Key Laboratory of mineral Deposits Research Department of Earth Sciences Nanjing University Nanjing 210093 China tianjin Institute of geology and mineral {3. China Geological Survey Tianjin 300170 China

In the eastern Nanling Range there exists the early Yanshanian syenite-granite assemblage. A representative example is the Pitou-Tabei complex composed of the Tabei syenite pluton and the Pitou syenogranite pluton in southern Jiangxi Province. U-Pb zircon dating yields ages of 188.6±2.2 Ma for the Tabei pluton and 186.3.1.1 Ma for the Pitou pluton. The Tabei syenite is characterized by relatively low SiO2 content (62.4.% - 68.75%), high alkalis (K2O+Na2O = 10.56%-11.96%), low percent K2O/Na2O ratios (0.56-0.93., metaluminous fea- ture (A/CNK = 0.80-1.00), enrichment in LILE (Rb, Ba, K) and HFSE (Th, U, Nb, Ta, Zr, and so on), weakly negative to positive Eu anomalies (δ Eu = 0.63.1.82), relatively low (87Sr/86Sr)i (0.704.2-0.7054.0}, and relatively high ε Nd(t) (3.14.3.52). The Pitou syenogranite is charac- terized by high silicon content (SiO2 = 71.06%-76.28%), relatively low alkalis (K2O+Na2O = 8.10%-9.80%), high percent K2O/Na2O ratios (1.22-1.94., metaluminous feature (A/CNK = 0.94.1.07), enrichment in Rb, Th (U), K, depletion in Ba, Nb, Ta, Sr, P , Zr, Ti, high ΣREE (av- eraging 4.1.03.μg/g), strong negative Eu anomalies (δ Eu = 0.27-0.3.), relatively high (87Sr/86Sr)i (0.70805-0.70912), and relatively low ε Nd( t ) (?5.3.-?6.29). The Tabei syenite and Pitou syenogranite both have the characteristics of A-type granites. The former is considered to be from the asthenosphere mantle, and the latter was the product of the crust-mantle mixture. They both were probably formed in a rifting setting.

关键词： syenite-granite assemblage single zircon U-Pb age rifting environment Nanling Range.

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Precambrian Geochronology, Chronotectonic Framework and Model of Chronocrustal Structure of the Zhongtiao Mountains

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Acta Geologica Sinica(English Edition) 1992年第1期66卷 23-37页

作者： Sun Dazhong Li Huimin Lin Yuanxian Zhou Huifang Zhao Fengqing Tang Min tianjin Institute of geology and mineral {3., Chinese Academy of Geological Sciences, tianjin Fei Zhenbi tianjin Institute of geology and mineral {3. Chinese Academy of Geological Sciences Tianjin

The Zhongtiao Mountains, a typical exposure area of Precambrian rocks, are a concentration area of vari-ous types of copper deposit. The rocks were dated using several dating methods. Based on the age data ob-tained by means of three methods, several aspects are dealt with: (1) the dating results obtained by differentmethods and their geological implications have been compared; (2) a chronotectonic framework has been con-structed by means of these reliable ages, which indicates that the ages of the rocks of the Proterozoic mobilebelt fall in a time span of 24.0 to 2000 Ma during which global magmatic records are lacking and reflects theages of important events in the mobile belt; (3. according to the ages of inherited zircons, neodymium modelage of the depleted mantle sources (T_(DM)) and geochemical and geological data, a model of Precambrianchronocrustal structure has been constructed, representing a typical for the North china craton.

关键词： Precambrian Geochronology Chronotectonic Framework and Model of Chronocrustal Structure of the Zhongtiao Mountains

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Zircon geochronology and geochemistry of mafic xenoliths from Liaoning kimberlites:Track the early evolution of the lower crust,North china Craton

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Science china Earth Sciences 2004年第11期47卷 961-972页

作者： ZHENG Jianping1,YU Chunmei1,LU Fengxiang1 & LI Huimin2 1.Faculty of Earth Sciences,china University of Geosciences,Wuhan 4.1}074.china 2.tianjin Institute of {3. and mineral resources,tianjin 3.0170,china 1. Faculty of Earth Sciences China University of Geosciences 430074 Wuhan China 2. tianjin Institute of geology and mineral {3. 300170 Tianjin China

Mafic xenoliths from Paleozoic Fuxian kimberlites (Liaoning Province) mainly in- clude garnet granulite, with minor pyroxene amphibolite, meta-gabbro and pyroxene syenite. The SiO2 contents of the xenoliths are from 4..3.wt% to 4..9 wt%. The granulites are mainly coarse-medium grained and reasonably with well-developed granoblastic (mostly polygonal) texture, contain the assemblage of garnet + plagioclase + pyroxene + K-feldspar ±phlogopite. The mineral assemblage of the amphibolites is plagioclase + pyroxene + amphibole ±K-feldspar, with the equilibrium temperature and pressure conditions of 74.—821℃ and 0.76—0.88 GPa. The granulites are regarded as derivation from the lower crust depth (more than 29 km), below the amphibolites. Garnet granulites compositionally correspond to sub-alkalic basalt, and have wide ranges of Ni abundance (13.—84. ppm), and Nb/Y (0.12—1.85), Nb/U (3.51—53.86) and Ta/U (0.3.—2.4.). The amphibolite and the syenite correspond to alkalic basalt. The Fuxian ma- fic xenoliths are regarded as the metamorphic product of the underplated magmas (including fractional crystallization or not) experienced the contamination with the pre-existed crustal com- ponents, and partly effected by kimberlitic magmas. The concordant ages of zircons for the gab- bro (2610—2580 Ma) and the near-concordant upper intercept ages of zircons for the garnet granulite and pyroxene amphibolite (2578—253. Ma) indicate that they are currently known as the oldest deep-seated xenoliths from the lower crust of the North china Craton. These ages recorded the formation of the united Eastern Block of the North china Craton, That is, Neoar- chean (2.6—2.5 Ga) is an important continental crustal growth period of the North china Craton. The lower intercept age of the garnet granulite (1853.Ma) recorded an important tectonic thermal event in Paleoproterozoic. This event was probably related to collision of the East and West block, and resulted in the final assembly of the North china

关键词： mafic xenolith, petrochemistry, zircon geochronology, petrogenesis, lower crustal evolution, North china Craton.

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The Palaeomagnetic Study of the mineralizationAge of Gold Deposits in the Xiong' ershan Area,Henan Province

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Acta Geologica Sinica(English Edition) 1996年第1期70卷 74-86页

作者： Wang Guanfu, Chen Zhihong, Ding Shiying and Ren Fugentianjin Institute of geology and mineral {3., tianjin, china tianjin Institute of geology and mineral {3. Tianjin China

Based on palaeomagnetic studies of the Precambrian gold deposits in the Xiong'ershan area, Henan Province, the authors infer that the ore-forming processes of the Beiling alteration-type gold ore deposit and the Dianfang breccia-type gold ore deposit started in the Proterozoic, and was superimposed by later mineralization, whereas the mineralization age of the Jiguanshan quartz- vein type gold ore deposit is Yanshanian.

关键词： Xiong' ershan area Precambrian palaeomagmatism gold deposits mineralization age

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A Simulated Test of Algal Influence of Formation and Deposition of Phosphates

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Acta Geologica Sinica(English Edition) 1991年第4期65卷 417-426页

作者： Liu Zhili Liu Xuexian Fan Yigong Zhu Shixin Department of Biology, Nanjing University tianjin Institute of geology and mineral {3.,Chinese Academy of Geological Sciences Department of Biology Nan jing University China

This paper deals with a simulated test of biogenic mineralization made with a blue-green alga species,Spirulina platensix. The data in the experiment were recorded by a computerized surveying system. The influ-ence of algae on the accumulation of phosphorus by changing their microenvironment to promote the forma-tion and deposition of phosphate was studied. The results show that the pH value of cultural liquor rose up to 10 and the redox potential (Eh) may dropby 100-200 mV during the algal logarithmic growth stage, and the cultrual liquor was changed into a mediumwith a weakly reducing condition. At the end of the logarithmic growth stage white deposits of Na_2Ca(CO_3._2·5H_2O and Ca_2Mg (PO_4._2·2H_2O were formed on the floor of cultural containers. The test presented a wduableevidence for the theory of biogenic mineralization.

关键词： In A Simulated Test of Algal Influence of Formation and Deposition of Phosphates Test

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Isotopic Geochronological Evidence for the Caledonian Xiongdian Eclogite in the Northwestern Dabie Mountains,china

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Acta Geologica Sinica(English Edition) 1997年第4期71卷 455-465页

作者： Jian PingYichang Institute of geology and mineral resources. CAGS, Yichang City,Hubei Province 4.3.03.ang Weiran{3. University of Geosciences, Wuhan, HubeiLi Zhichang Yichang Institute of geology and mineral resources, CAGS, Yichang, HubeiZhou Huifang tianjin Instutite of geology and mineral resources, CAGS, tianjin Zhu Xiling Yichang Institute of geology and mineral resources CAGS Yichang City Hubei Province 443003 china University of Geosciences Wuhan Hubei Yichang Institute of geology and mineral resources CAGS Yichang Hubei tianjin Instutite of geology and mineral {3. CAGS Tianjin [?]Jian Ping Born in October 1964 graduated from the china University of Geosciences with a master's degree in geochemistry. Mainly engaged in geochronology he is now an associated research professor of the Yichang Institute of Geology and Mineral Resources CAGS and is studying for a doctorate at the China University of Geosciences.

A typical HP/MT (high pressure/medium temperature) eclogite from Xiongdian, northwestern Dabie Mountains, has been geochronologically studied using the single-zircon U-Pb, 4.Ar-3.Ar and Sm-Nd methods. Prismatic zircons occurring as inclusions within garnets define a minimum crystallization age of 3.9.5±1.6 Ma. 4.Ar-3.Ar dating on amphibole gives a plateau *** 3.9.2 ± 4.Ma, which is interpreted as a retrogression age of amphibolite facies. This integrated study enables us to conclude that the age of high-pressure metamorphism is older than 3.9.5 ± 1.6 Ma, suggesting Caledonian collision between the North china and Yangtze plates. Round zircon within the aggregate of quartz and muscovite gives a concordant age of 3.1± 2 Ma, reflecting a later retrogression event. An age profile of post-eclogite metamorphism is documented, including amphibolite facies metamorphism at 3.9.2 Ma shortly after eclogitization and later retrogressive metamorphism at 3.1 Ma. Sm-Nd mineral isochron of garnet+omphacite gives an unreasonable age of 54. ± 23.Ma. which is quite older than that of prismatic zircon and may be attributed to isotopic disturbance by retrogression.

关键词： Caledonian collision eclogites geochronlogy Northwestern Dabie area Xiongdian Henan

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DISCUSSION ON THE NAMING OF QUATERNARY TRANSGRESSIONS IN WEST-SOUTHERN COAST PLAIN OF BOHAI SEA

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Acta Oceanologica Sinica 1987年第1期6卷 104-115页

作者：王强李凤林李玉德高秀林 tianjin Institute of geology and mineral {3. tianjin geology and mineral resources Bureau Shandong Province Dezhou Department of Geography tianjin Teachers University

Based on micropalaeontological information of over 150 drill holes, this paper discusses the problem on the naming of Quaternary transgressions in the west-southern coast plain of Bohai Sea. We consider that palaeotide and sedimentation have a great influence on the distribution of micropalaeontological fossils. In view of the present technical level, it is necessary for transgression sequence to be established under the following conditions: full evidence of fossils; clear climate; and stable sedimentary beds. In establishing a transgression, its contents of time and phase concept must be proposed, and its biofacies, sedimentary facies and palaeoclimatology must be analysed synthetically.

关键词： DISCUSSION ON THE NAMING OF QUATERNARY TRANSGRESSIONS IN WEST-SOUTHERN COAST PLAIN OF BOHAI SEA

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PALYNOLOGICAL ASSEMBLAGES FROM THE ZHIDAN GROUP OF HUATING AND LONGXIAN REGION,SOUTHWESTERN PART OF ORDOS BASIN

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西北地质科学 1989年第25期 79-96页

作者： Zhang Zifu (Xi’an Institute of geology and mineral resources,CAGS)Miao Shujuan ({3. Institute of geology and mineral resources,CAGS)

The working area is distributed from the Huating County of Gansu Pro-vince to Longxian County of Shaanxi Province in the southwestern Ordos Ba-sin. The Zhidan Group in this area, a series of terrestrial sediments, may be subdivided into five formations as follows(from lower to upper): Yijun-Luohe,Huanhe-Huachi, Luohandong, Jingchuan and Fengshan Formations. All samples were coliected from 1

关键词：未定种图版 PALYNOLOGICAL ASSEMBLAGES FROM THE ZHIDAN GROUP OF HUATING AND LONGXIAN REGION,SOUTHWESTERN PART OF ORDOS BASIN 希指相似种近似种单沟鄂尔多斯盆地西南部罗汉松罗汉杉罗汉松属陇县地区西安地质矿产研究所金毛狗

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An approach to 3. NURBS modeling of complex fault network considering its historic tectonics

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Progress in Natural Science:Materials International 2006年第5期16卷 546-553页

作者： ZHONG Denghua, LIU Jie and LI Mingchao (School of Civil Engineering, tianjin University, tianjin 3.0072, china) School of Civil Engineering Tianjin University Tianjin 300072 China

Fault disposal is a research area that presents difficulties in 3. geological modeling and visualization. In this paper, we propose an integrated approach to reconstructing a complex fault network (CFN). Based on the non-uniform rational B-spline (NURBS) techniques, fault surface was constructed, reflecting the regulation of its spatial tendency, and correlative surfaces were enclosed to form a fault body model. Based on these models and considering their historic tectonics, a method was put forward to settle the 3. modeling problem when the intersection of two faults in CFN induced the change of their relative positions. First, according to the relationships of intersection obtained from geological interpretation, we introduced the topological sort to determine the order of fault body construction and rebuilt fault bodies in terms of the order; then, with the disposal method of two intersectant faults in 3. modeling and applying the Boolean operation, we investigated the characteristic of faults at the intersectant part. An example of its application in hydropower engineering project was proposed. Its results show that this modeling approach can increase the computing efficiency while less computer memory is required, and it can also factually and objectively reproduce the CFN in the engineering region, which establishes a theoretical basis for 3. modeling and analysis of complex engineering {4..

关键词： fault network NURBS technique historic tectonics topological sort 3. modeling.

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Microfossils from the Wumishan Formation of the Jixian System in the Ming Tombs,Beijing,china

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Acta Geologica Sinica(English Edition) 1986年第4期 13-22+97-98页

作者： Zhang Pengyuan tianjin Institute of geology and mineral {3., Chinese Academy of Geological Sciences, tianjin Gu Shuqin Beoing Geological Survey, Beijing Bureau of geology and mineral {3., Beijing

Members Ⅰ-Ⅳ of the Wumishan Formation of the Jixian System are exposed respectively in Mt. Cuihua and Mt. Hushan in the Ming Tombs, Beijing. Black banded cherts which are extensively developed in this formation contain an abundance ofmicrofossils that are well preserved and variable in form. A study of thin sections shows that the microfossils include 10 genera, 12 species, 3.of. species, 2 indeterminate species and 1 unnamed form, of which 1 genus and 7 species are newly erected. The present assemblage is morphologically comparable to those from the Wumishan Formation in the Western Hills of Beijing, Jixian County of tianjin and Kuancheng of Hebei Province.

关键词： BW Microfossils from the Wumishan Formation of the Jixian System in the Ming Tombs,Beijing,china

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