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Mineralization episode of porphyry copper deposits in the Jinshajiang-Red River mineralization belt: Re-Os dating

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Science China Earth Sciences 2005年第2期48卷 192-198页

作者： WANG Denghong, QU Wenjun, LI Zhiwei, YIN Hanlong4 & CHEN Yuchuan Institute of Mineral Resources, Chinese Academy of geological Sciences, Beijing 100037, China National Center of Rock and Mineral Analysis, Chinese Academy of geological Sciences, Beijing 100037, China Resource Assessment Center of Yunnan, Kunming 650011, China Institute of Geology and Geophysics, Chinese Academy of Sciences, Beijing 100101, China Chinese Academy of geological Sciences, Beijing 100037, China 1. Institute of Mineral Resources Chinese Academy of Geological Sciences 100037 Beijing China 2. National Center of Rock and Mineral Analysis Chinese Academy of Geological Sciences 100037 Beijing China 3. Resource Assessment Center of Yunnan 650011 Kunming China 4. Institute of Geology and Geophysics Chinese Academy of Sciences 100101 Beijing China 5. Chinese Academy of geological Sciences 100037 Beijing China

Re-Os isotopic dating for the molybdenites from the porphyry copper deposits of the Jinshajiang-Red River mineralization belt in Yunnan Province yields isochron ages of 33.9±1.1 Ma for the Machangqing deposit and 34.4±0.5 Ma for the Tongchang deposit. This result shows that both the Machangqing and the Tongchang porphyry Cu-Mo deposits from two different ore-fields formed simultaneously. This new data and the published Re-Os model ages of molybdenite (35.4 Ma, 35.9 Ma, 36.2 Ma) of the Yulong porphyry copper deposit in Tibet, which is located in the same Jinshajiang-Red River mineralization belt as the Machangqing deposit and the Tongchang deposit, suggest that these three Cenozoic porphyry copper deposits in the Jinshajiang-Red River mineralization belt were contemporary for their mineralization episode. That is to say, even their present locality is far away and nearly iso-distantly distributed, these three porphyry Cu(Mo) deposits belong to the same mineralization episode at the end of Eocene.

关键词： Re-Os isotopic dating, porphyry Cu deposits, Cenozoic, mineralization episode.

Geochemical Characteristics of Granitoids in the Eastern Sector of the Northern Tianshan Mountains in Xinjiang

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Acta Geologica Sinica(English Edition) 1990年第1期64卷 55-67页

作者： Wang Bixiang Li Zhaonai Zhao Guangzan Wang Fubao Zhang Shuizhe Fei Wenheng Institute of Geology, Chinese Academy of geological Sciences, Beijing Institute of Geology Chinese Academy of Geological Sciences Beijing

The granitioids in question are located in the geosynclinal fold belt of the Northern Tianshan Mountains.The magmas are intruded into a Carboniferous marine volcanic-sedimentary rock series. forming a contempo-raneous. intermediate-basic to acid. composite intrusion. With a whole-rock Rb-Sr isochron age of 315.7 Ma. itis considered to be of middle Heicynian age. The granitoids have a SiO_2 content of 48-78%, a calc-alkali indexof 60 and silica-alkali indices ρ=2.2-2.4 and σ=1.5-2. From basic to acid compositions, the total REE con-tent increases from 38 to 143 ppm. δEu ranges from 0.47 to 0.86 and the Eu anomalies are negative. Thenormalized curves of REE of various rock types are very similar. These coupled with the characteristics of traceelement geochemistry show that the intrusion is an island arc-continental margin, calc-alkaline one. Theδ^(18)O values range from 5.8 to 8.9‰ and the ^(87)Sr/^(86)Sr initial ratio is 0.705. The materials of the intrusion arecomposed of a mixture of the magmas at the top of the upper mantle and in the lower crust, This indicates thatthe rocks might be consanguineous. differentiated and evolved products and possess the characteristics of Ⅰtype granites.

关键词： Geochemical Characteristics of Granitoids in the Eastern Sector of the Northern Tianshan Mountains in Xinjiang

Discovery of low grade metamorphic volcanic rock sheets within UHP in Dabie Mts. and its implications

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Chinese Science Bulletin 1997年第14期42卷 1199-1203页

作者： DONG Shuwen, WANG Xiaofeng and HUANG Dezhi1. Chinese Academy of geological Sciences (CAGS), Beijing 100037, China 2. Institute of Geomechanics of CAGS, Beijing 100081 China 3. Anhui Institute of geological Sciences, Hefei 230001 Chinese Academy of geological Sciences (CAGS) Beijing 100037 China

THE ultrahigh-pressure metamorphic zone (UHP), outcropping in the central and southernDabie Mts. with an area of about 1000 km^2, may be the largest one in the world. The forma-tion and exhumation mechanism of the UHP rocks become a hot point in the study of continen-tal orogen. The first finding of the Shiqiao structural window, which is composed of low

关键词： ultrahigh-pressure metamorphic zone (UHP) low grade metamorphic rock sheets Dabie Mts.

A Further Research on the Precambrian-Cambrian Boundary at Meishucun Section of Jinning, Yunnan, China

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Acta Geologica Sinica(English Edition) 1992年第2期66卷 197-207页

作者： Luo Huilin Jiang Zhiwen Wu Xiche Ouyang Lin Song Xueliang Xue Xiaofeng Yunnan Institute of geological Sciences, Kunming, Yunnan Yunnan Institute of geological Sciences Kunming Yunnan

This paper gives a brief report on the latest results in litho-, bio-, and chrono-stratigraphy obtained fromthe authors' further research on the Meishucun section during 1987-1988. More attention was paid to the studyof the microtexture of Lapworthella and some new materials of trace fossils. Phycodes pendum Seilacher, animportant index for correlation, was also discovered in the Zhongyicun Member. In the Yu' anshan Membermany worms, medusas and arthropods of the Chengjiang fauna have been found by other workers. Asupplemental study was made on the fossil zones of the Meishucunian stage. Based on new isotopic data, theage of the Precambrian-Cambrian boundary should now be 597 Ma. It is further suggested that point 'B' re-mains as an optimum selection for defining the Precambrian-Cambrian boundary.

关键词： China A Further Research on the Precambrian-Cambrian Boundary at Meishucun Section of Jinning

A Preliminary Research on Skarns of Magmatic Origin

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Journal of Earth Science 1999年第1期18卷 58-61页

作者： Wu Yanchang Anhui Institute of geological Sciences, Hefei 230001

Skarns of magmatic origin, or magmatic skarns as called, are formed by crystallization of skarnic magma injecting into structural fissures. They occur in various rocks (rock formations), mainly in form of veins. Usually, they possess massive structure and cumulative texture. They mainly consist of calc silicate, without or with minor water bearing silicates. The typical minerals in it include alkali feldspar, calcite and anhydrite. Some silicate melt inclusions and high temperature, high salinity poly phase inclusions can be seen in the crystals of their host minerals. The particular members of the magmatic skarns are transitional skarn and skarnic pegmatite. The magmatic skarn and the congenetic alkali rich diorite usually collaborate in a conjugating and complementary manner. They probably are the products of calcic contamination, degassing, desilicification and separation in melt state of deep seated (high level magma chamber) alkali rich intermediate acid magma.

关键词： magmatic skarn magmatic skarn alkali intrusive pair the middle and lower reaches of Changjiang River.

Change monitoring of earth rotation parameter with Maglev gyroscope precessional torque

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中国有色金属学会会刊：英文版 2011年第S3期21卷 589-593页

作者： YANG Zhi-qiang, GONG Yun, SHI Zhen, LI Yun geological Engineering and Geomatics Institute, Chang’an University, Xi’an 710054, China geological Engineering and Geomatics Institute Chang'an University Xi'an 710054 China

Through analyzing the relationship between gyro dynamic torques produced by the changes of earth rotation parameters (ERP), a method of measuring the earth rotation parameters was proposed and explored by using gyroscope. The preliminary experiments were carried out using GAT Maglev Gyro Station (which is self-developed by China). Considering the measurement and expanding-application of the earth rotation parameters, some ideas and opinions about the structure design, measurement methods and data processing of gyro were proposed, and some outlook of the expanding-application of the gyroscope in geodetic and geophysical fields were done. The experimental results show that using the high-precision gyroscope to determine the changes of ERP is feasible, with the emergence of ultra-high precision gyro; it is possible for determining the earth rotation parameters by gyro in stead of by current complex space surveying technology.

关键词： Maglev gyroscope earth rotation parameters (ERP) precessional torque pole motion length of day

An Experimental Study on Three Quaternary Phases in the Fe-Sn-Sb-S System: Pb-Free Franckeite, Pb-Free Cylindrite and (Fe, Sb)-Ottemannite s.s.

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Acta Geologica Sinica(English Edition) 1988年第4期1卷 393-405页

作者： Li Jiuling Huang Jiashan Zhou Kezi Zhang Guilan Institute of Mineral Deposits, Chinese Academy of geological Sciences, Beijing Institute of Mineral Deposits Chinese Academy of Geological Sciences Beijing

Experimental studies on the two solid solutions franckeite s.s. and cylindrite s.s. yielded among others thePb-free endmembers of franckeite and cylindrite respectively. In these endmembers the lead content of the twomineral phases are completely substituted by bivalent tin. A third phase, ottemannite s.s. with （Fe. Sb）-bearingcompositions, was further identified in the Pb-free 4-component system Fe-Sn-Sb-S. Pb-free franckeite andcylindrite could only be synthesized as homogeneous phases at high temperatures. The ottemannite s.s. was ob-tained at 600℃ but an extensive existing range was also confirmed at temperatures below 500℃. The phase relations were discussed in the pseudoternary subsystem SnS-SnS2-FeSb2S4. The following se-quence of Pb-free phases and phase assemblages were observed under increasing Sn4+content at 600℃:herzenhergite （SnS）+franckeite, franckeite, franckeite+cylindrite, cylindrite, cylindrite+（Fe, Sb）-ottemannite.（Fe, Sb）-ottemannite. （Fe. Sb）-ottemannite+berndtite （SnS2）. The assemblage cylindrite+berndtite was identi-fied in synthetic systems involving Pb. The phase Fe. Sb-ottemannite s.s. appears to be stable only under Pb-de-ficient and high sulfur fugacity conditions.

关键词： Pb-Free Franckeite An Experimental Study on Three Quaternary Phases in the Fe-Sn-Sb-S System Ottemannite s.s Fe Sb Sn

Age Assignment of the Lycoptera- bearing Bed

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Acta Geologica Sinica(English Edition) 1994年第3期68卷 329-347页

作者： Li Peixian, Su Deying, Li Yougui and Yu JingxianInstitute of Geology, Chinese Academy of geological Sciences, Beijing Chinese Academy of geological Sciences Beijing

In the Yanliao area, the occurrence of the Nestoria-Keratestheria fauna and the Eoparacypris- Luanpingella-Darwinula assemblage in the Dabeigou Formation s.s., a Rb-Sr isochron age of 145.2 Ma for the Baiqi Formation and a complete stratigraphic sequence-all this proves that the Lycoptera-bearing bed overlies the Upper Jurassic. The Jehol fauna comprises the primitive Trigonioidids fauna, Eosestheria fauna, Lycoptera fauna et al., and their own laws of evolution expound that they belong to Cretaceous faunas. The associations of Eosestheria with Yanjiestheria, Lycoptera with Eosestheria, and Kuntulunia with Yanjiestheria as well as the occurrence of early angiosperms and sporo - pollen in the Fuxin Formation and its equivalents also demonstrate that the Lycoptera-bearing, bed should be assigned to the Cretaceous. The confirmation of the existence of Aucellina in the Jixi Group and the correlation of Trigonioidids and Cypridids with those in the equivalent strata of Japan and Western Europe have also been verified by corresponding marine strata. According to the magnetostratigraphic data from Zhejiang and Songliao, it has been preliminarily ascertained that M0 between the mixed polarity zone in the lower part and the normal polarity zone in the middle part of the Cretaceous is located in the upper member of the Huangjian Formation of the Jiande Group and the top member of the Denglouku Formation of the same group, and the isotopic age data of the Jehol and Jiande Groups show that the approximate geologic age of the Lycoptera bed is 135-122 Ma. These prove that the Lycoptera bed should be assigned to the Cretaceous.

关键词： Cretaceous Jurassic-Cretaceous boundary Lycoptera- bearing bed Jehol fauna

Cephalopods of the “Falang Formation” (Triassic) from Guanling and Zhenfeng Counties, Guizhou Province, China

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Acta Geologica Sinica(English Edition) 2003年第4期77卷 430-439页

作者： HAO Weicheng, SUN Yuanlin, JIANG Dayong, YANG Shouren and WANG Xinping geological Museum, Peking University, Beijing 100871 Peking Univ Geol Museum Beijing 100871 Peoples R China

The 'Falang Formation' of western Guizhou was previously called the 'Halobia Bed' and considered to be I .adinian in age. It was subdivided upward into the Zhuganpo, Laishike and Longchang members based on ammonites and the Trachyceras multitubertulatum Zone of the Longchang Member was put in the Lower Carnian. Here in the present paper, 4 genera and 9 species of ammonites and 1 nautiloid genus and species collected from the upper part of the 'Falang Formation' (i.e. the Wayao Formation used in this paper, equivalent to the Laishike Member from Guanling and Zhenfeng counties are described. The geological and geographical distribution of these cephalopods, as well as the co-existing conodonts, put the Wayao Formation to the late early Carnmian.

关键词： ammonites nautiloids 'Falang Formation' Carnian Triassic Guizhou China