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ESR and U-series ages of coral reef samples from shallow drill holes in the South china Sea

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Acta Oceanologica Sinica 1991年第3期10卷 423-431页

作者： Ye Yuguang, Gao Juncheng, He jie, Diao Shaobo, Liu Xinbo and Du Yajing institute of Marine geology, Ministry of geology and mineral resources, Qingdao, 266071, chinaNational institute of Metrology, Beijing, 100013, china institute of Marine geology Ministry of Geology & Mineral Resources Qingdao 266071 China.

The ages of coral reef samples from several shallow drill holes in the South china Sea are determined by ESR and U-series (230Th/234U) methods. The experimental results show ideal agreement between ESR and U-series ages and that the coral reefs were formed in the early Holocene. In the determination of natural total dose of coral reef by use of the additive dose method good results can be obtained by exponential fitting, no matter how the effect of dose saturation is. It was found that the ratio of the natural ESR signal intensity ( I0) to the ESR signal intensity at dose saturation ( Imax) of sample can reflect the significance of a irradiation efficiency-k value. Using the k value of sample determined by the formula given in this paper, the precision of ESR dating of marine carbonates can be improved.

关键词： Th ESR and U-series ages of coral reef samples from shallow drill holes in the South china Sea

STRATIGRAPHIC AND DEPOSITIONAL FILLING MODEL OF NORTH TARIM FORELAND BASIN SYSTEM

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地学前缘 2000年第S1期7卷 340-341页

作者： Wang Longzhang[WT5,5”BX](Chengdu institute of geology and mineral resources, CGSA, Chengdu 610082,china)

A stratigraphic and depositional filling modal of Triassic—Jurassic North Tarim foreland basin system is erected, through synthetic analysis of geological setting, depositional provenance, sequence stratigraphy, and quantitative tectonic stratigraphy. The result suggests that the major factors controlling formation and evolution of the system are oblique collision and convergence of different plates, and favorite hydrocarbon plays is *** geological setting analysis emphasizes the historical succession of the foreland basin system formation and evolution. The tectonic setting analysis sketchy outlines formation of the system and tectonic setting of its successive evolution. The sedimentary geology analysis reveals the uplift and subsidence of the basin basement a seesaw style movement.

关键词： foreland basin system filling model North Tarim Triassic and Jurassic

Discovery of submicron diamonds within kimberlite in Liaoning Province, china and its significance

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Chinese Science Bulletin 1997年第11期42卷 939-941页

作者： BAO Yanan, T. V. Dubuchick and T. D. Liabchekov1. Graduate School in Beijing, Chinese Mining University, Beijing 100083, china 2. Moscow resources institute of mineral Materials, Russia 3. resources institute of Deposit geology, Russian Academy of Sciences, Russia Graduate School in Beijing Chinese Mining University Beijing China Moscow resources institute of mineral Materials Russia resources institute of Deposit geology Russian Academy of Sciences Russia

ALTHOUGH a lot of research work on diamond mineralogy has already been done,the formationand development of diamond leave much to be *** have done some researches onthe diamond samples with obvious crystal-growing cha... 详细信息

关键词： submicron diamond lath-shape aggregative parent material.

The Genetic Types of Some Granite Intrusions Associated with Tin Polymetallic Deposits in the Nanling Region

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Acta Geologica Sinica(English Edition) 1988年第3期1卷 307-324页

作者： Liu Houqun Yang Shiyi Yichang institute of geology and mineral resources, CAGS, Yichang, Hubei Yichang institute of geology and mineral resources CAGS Yichang Hubei

Tin polymetallic deposits are the most important type of tin deposit in the Nanling region. Manyresearchers both at home and abroad consider this type of tin deposit to be the product of differentiation andevolution of granite magmas resulting from anatexis of continental crust and to be genetically related to thetransformation-type (S-type) granitoids. In this paper, on the basis of the geological settings, petrology, REEgeochemistry and strontium and oxygen isotopic compositions of 6 granite intrusions associaied with tinpolymetallic deposits in the Nanling region, the authors suggest that the ore-bearing granites of this type areprobably the products of differentiation and evolution of acid magmas resulting from 40-50‰ fractionalcrystallization of magmas formed by partial melting of the pre-existing intermediate-basic volcanic rocks ofmantle origin in the lower crust and a small amount of sialic material and belong to crust-mantle-derivedgranitoids (approaching I-type of B. W. Chappell and A.J.R. White, but being evidently different from theS-type granitoid related to W, Sn, Nb, Ta and REE deposits).

关键词： The Genetic Types of Some Granite Intrusions Associated with Tin Polymetallic Deposits in the Nanling Region

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

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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 geology and mineral resources, china Geological Survey, Tianjin 300170, china State Key Laboratory of mineral Deposits Research Department of Earth Sciences Nanjing University Nanjing 210093 China Tianjin institute of geology and mineral resources 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 (62.40% - 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 (0.70412-0.70543), 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 451.03 μg/g), strong negative Eu anomalies (δ Eu = 0.27-0.33), relatively high (87Sr/86Sr)i (0.70805-0.70912), and relatively low ε Nd( t ) (?5.35-?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.

Strongly peraluminous granites of Mesozoic in Eastern Nanling Range, southern china: Petrogenesis and implications for tectonics

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Science china Earth Sciences 2005年第2期48卷 165-174页

作者： SUN Tao, ZHOU Xinmin, CHEN Peirong, LI Huimin, ZHOU Hongying, WANG Zhicheng & SHEN Weizhou Department of Earth Sciences, Nanjing University, Nanjing 210093, china Tianjin institute of geology and mineral resources, china Geological Survey, Tianjin 300170, china Department of Earth Sciences Nanjing University Nanjing China Tianjin institute of geology and mineral resources China Geological Survey Tianjin China

The strongly peraluminous granites (SPGs) of Eastern Nanling Range (ENR) are a characteristic of all bearing highly aluminous minerals, such as muscovite±AI-rich biotite± tourmaline±garnet, and lack of cordierite. In respect of petrography, geochemistry, Nd isotope, and single grain zircon U-Pb dating, the representative granite bodies of them are studied. The research shows that these granites were emplaced in two stages, namely 228-225 Ma BP and J2-3 159-156 Ma BP, belonging to Indosinian and early Yanshanian periods, respectively, and they have low εNd(t) values (-10.6--11.1), high A/CNK, Rb/Sr ratios and tDM values (1887-1817 Ma), and REE's tetrad effect (TE1,3=1.13-1.34). In comparison with related geology, petrology and chronology of granites in adjacent regions, it is suggested that Indosinian SPGs of ENR formed in the circumstance of post-collisional extension 20 Ma after the major collision of Indosinian Movement (258-243 Ma BP) in Indo-china Peninsula, and early Yanshanian SPGs formed in the background of back-arc extension setting controlled by paleo-Pacific tectonic domain, and J1, the interval of two stages, is the interim from Tethyan to Pacific tectonic domains in South china. These SPGs have similar geological and geochemical characteristics, because they all crystallized from the magma of partial melting of early Proterozoic metasedimentary rocks when the thickened crust (≤50 km) became thinning, decompression, and transmitting of water.

关键词： Nanling Range, strongly peraluminous granite, petrogenesis of granite, South china.

Re-Os age for molybdenite from the Gangdese porphyry copper belt on Tibetan plateau: Implication for geody- namic setting and duration of the Cu mineralization

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Science china Earth Sciences 2004年第3期47卷 221-231页

作者： HOU Zengqian1, QU Xiaoming1, WANG Shuxian2, DU Andao2, GAO Yongfeng3 & HUANG Wei4 1. institute of mineral resources, Chinese Academy of Geological Sciences, Beijing 100037, china 2. National Center of Geoanalysis, Chinese Academy of Geological Sciences, Beijing 100037, china 3. Shijiazhuang College of Economy, Shijiazhuang 056000, china 4. Xizang Bureau of geology and mineral resources, Lhasa 850000, china institute of mineral resources Chinese Academy of Geological Sci. Beijing 100037 China National Center of Geoanalysis Chinese Academy of Geological Sci. Beijing 100037 China Shijiazhuang College of Economy Shijiazhuang 056000 China Xizang Bureau of Geol./mineral Rsrc. Lhasa 850000 China

The Gangdese porphyry copper belt consists of one large and five middle-small deposits in addition to dozens of ore-bearing porphyry bodies. The belt trends 350 km long along the EW-striking Gangdese batholith, and locally occurs as a string of beads extending about 50 km within the SN-trending rifting zones (grabens) on the Tibetan plateau. Monzonitic granite- porphyry and quartz monzonitic porphyry, as dominant host rocks, are shoshonitic and potassic calc-alkaline. Available dating data indicate that the ages of the shallow-level emplacement for these porphyries vary from 10 Ma to 18 Ma, which are identical to that of associated potassic calc-alkaline volcanic rocks (10—15 Ma) and mafic dykes (13—18 Ma). The timing and duration of Cu mineralization events are constrained by Re-Os ages for molybdenites from three porphyry copper deposits in the Gangdese porphyry copper belt. Five molybdenite samples from the Nanmu deposit yielded an 187Re-187Os isochron with a highly pre-cise age of (14.76?.22) Ma; six molybdenites from the Chongjiang deposit gave an isochron age of (14.04?.16) Ma. Re-Os model ages for two molybdenite samples from Lakang抏 deposit vary from 13.5 Ma to 13.6 Ma, which are basically identical to isochron ages mentioned above. All the thirteen samples from these three deposits yielded a linear array in the isochron diagram with a higher correlation coefficient of 0.99719 and an isochron age of (14.39?.22) Ma (1s error), suggesting an coeval event of the Cu mineralization and a shared source of ore materials for the Gangdese porphyry copper belt. Compared with the longer-lived felsic magmatic-hydrothermal system, the Cu mineralization is a relatively short event with duration of about 0.5 Ma, and usu-ally occurs in the later-stage of the complicate magmatic system. The emplacement age of the Gangdese porphyries indicates that they intruded after the rapid rising of the Gangdese Mountains at 21—23 Ma, and formed in a post-collision crustal ex-tension env

关键词： porphyry copper deposit, Re-Os age, Gangdese, Tibetan plateau.

^(207)Pb/^(206)Pb Zircon Dating of the Huangtuling Hypersthene-Garnet-Biotite Gneiss from the Dabie Mountains, Luotian County, Hubei Province, china: New Evidence for Early Precambrian Evolution

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Acta Geologica Sinica(English Edition) 1999年第1期73卷 78-83,127-128页

作者： JIAN Ping YANG Weiran and ZHANG Zichao institute of geology,CAGS,26 Baiwanzhuang Rd, Beijing 100037 china University of Geosciences, Wuhan, Hubei 430074 Yichang institute of geology and mineral resources, CAGS, Yichang, Hubei 443003 CAGS Inst Geol Beijing 100037 Peoples R China china Univ Geosci Wuhan 430074 Hubei Peoples R China CAGS Yichang Inst Geol & Mineral Resources Yichang 443003 Hubei Peoples R China

The Huangtuling hypersthene-garnet-biotite gneiss at Luotian County, Hubei Provine, is a typicalgranulite-facies rock of the Dabie Group Complex in the Dabie orogenic belt. Investigations on the morphology andoccurrence of zircons and their internal structures shown in the thin sections lead to the recognition of three types ofzircons, which are in good agreement with the types identified on the basis of morphology, colour and external fea-tures from the related zircon concentrates. The observation of zircons in the rock reveals that part of type 1 zirconsshow signs of a double-layered structure. The interval part existed in the protolith prior to the granulite-facies meta-morphism. Type 2, the prismatic zircons which mainly occur in garnet and hypersthene are metamorphic minerals ofthe granulite-facies metamorphism. Type 3, the round multifaceted zircons in felsic minerals and biotite, are proba-bly attributed to a later geological event related to migmatization. The ^(207)Pb/^(206)Pb zircon dating by direct evaporationon (thermal evaporation ion mass spectrometer) yields ages ranging from 2814 Ma to 1992 Ma. The age discrepancyamong these different zircon types is conspicuous. The yellow-brown(type 1) zircons give ages of 2814±29 Ma to2527±6 Ma, the prismatic euhedral zircons (type 2), 2456±7 Ma to 2254±4 Ma, and the round multifaceted zircons(type 3), 1992±10 Ma. The results are geologically interpreted in consideration of the complicated behaviours of zir-cons during Precambrian geological evolution of the Dabie area. (1) If the protolith of the gneiss is a sedimentaryrock, then type 1 zircons are clastic ones and the ages 2814±29 Ma and 2811±27 Ma may reflect the minimum age ofthe rocks of its source region. also the first geological event in the area. Sedimentation of the protolith occurred be-tween 2814 Ma and 2527 Ma, probably close to 2814 Ma. If the protolith is a volcanic rock, then the formation age ofthe supracrustal rocks of the Dabie Group Complex is

关键词： Dabie Mountains granulite facies Archaean multistage evolution zircon 207~Pb/206~Pb

A special intermediate-low temperature PGE-As-Co mineralization

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Chinese Science Bulletin 1999年第S2期44卷 42-44页

作者： WANG Jingbin, WANG Yuwang and WANG Lijuan Beijing institute of geology for mineral resources, china National Nonferrous Metal Industry Corporation, Beijing 100012 china Research Center of mineral resources Exploration, Chinese Academy of Sciences, Beijing 100101, china

THIS paper introduces a new type of platinum-group elements (PGE) mineralization formed under a special condition of intermediate to low temperature, i. e. Huanggang PGE-As-Co deposit related to cryptoex-plosive hornblendite, Inner Mongolia, of which the proven reserves of arsenic reached small size. 1 geology of mineral district Huanggang PGE-As-Co deposit, located at the margin of Huanggang Mesozoic volcanic basin in thesouthern part of Da Hinggan Range, was controlled by both Huanggang-Ganzhuermiao deep fracture andvolcanic apparatus. The volcanic apparatus in a protruding cupola land-form is about 0.25 km^2. It wasfilled with rhyolitic volcanic breccia, brecciated tuff, subvolcanic dacite porphyry and brecciated lava ofvolcanic neck facies. The host hornblendite, of which Rb-Sr isochron age (bulk rock) is (90.66 ±14.44) Ma, intruded into the apparatus in the form of irregular dike (figure 1).

关键词： intermediate-low temperature PGE-As-Co mineralization Inner Mongolia.