检索结果-南通市图书馆

petrology,geochemistry and source characteristics of the Burpala alkaline massif,North Baikal

在线全文

学校读者我要写书评

暂无评论

Geoscience Frontiers 2017年第4期8卷 711-719页

作者： N.V.Vladykin I.A.Sotnikova vinogradov institute of geochemistry Siberian BranchRussian Academy of Sciences

The Burpala alkaline massif contains rocks with more than 50 minerals rich in Zr,Nb,Ti,Th,Be and rare earth elements（REE）.The rocks vary in composition from shonkinite,melanocratic syenite,nepheline and alkali syenites to alaskite and alkali granite and contain up to 10%LILE and HSFE,3.6%of REE and varying amounts of other trace elements（4%Zr,0.5%Y,0.5%Nb,0.5%Th and 0.1%U）.Geological and geochemical data suggest that all the rocks in the Burpala massif were derived from alkaline magma enriched in rare earth *** extreme products of magma fractionation are REE rich pegmatites,apatite-fiuorite bearing rocks and *** Sr and Nd isotope data suggest that the source of primary melt is enriched mantle（EM-Ⅱ）.We correlate the massif to mantle plume impact on the active margin of the Siberian continent.

关键词： Syenite pegmatite Rare metal and rare earths petrology geochemistry

Features of sampling stream sediments of large river valleys under cryolithogenesis conditions in the Balygychan-Sugoy trough,North-East of Russia

在线全文

学校读者我要写书评

暂无评论

Acta Geochimica 2024年第4期43卷 638-660页

作者： Artem S.Makshakov Raisa G.Kravtsova a.p.vinogradov institute of geochemistry Siberian Branch of the Russian Academy of SciencesFavorskiy Str 1AIrkutskRussia 664033

Comprehensive research has been implemented to raise the efficiency of the geochemical survey of stream sediments(SSs)that formed under the cryolithogenesis *** authors analysed the composition,structure and specific features of the formation of exogenous anomalous geochemical fields(AGFs)identified through SSs of large river valleys of IV *** our case,these were the valleys of Maly Ken,Ken and Tap *** rivers are located in the central and southern parts of the Balygychan-Sugoy trough enclosed in the Magadan region,North-East of *** authors proposed a new technique to sample loose alluvium of SSs in the large river valleys along the *** profiles were located across the *** AGFs of Au,Ag,pb,Zn,Sn,Bi,Mo and W were *** between elements have been *** elements are the main indicator elements of Au-Ag,Ag-pb,Sn-Ag,Mo-W and Sn-W mineralization occurring on the sites under *** results obtained were compared with the results of geochemical surveys of *** is concluded that the AGFs recognized along the profiles reflect the composition and structure of eroded and drained ore zones,uncover completely and precisely the pattern of element distribution in loose sediments of large water *** alluvium fractionpractical sense,as it concentrated numerous ore *** of this fraction in the river valleys of IV order does not cause any difficulty,for this kind of material is *** developed technique of alluvium sampling within large river valleys is efficient in searching for diverse mineralization at all stages of prognostic *** is applicable for geochemical survey of SSs performed at different scales both in the North-East of Russia,as well as other regions with similar climatic conditions,where the SSs are formed under the cryolithogenesis conditions.

关键词： Stream sediments Large river valleys Geochemical fields Mineralization Indicator elements Geochemical survey

Genesis of pyroxenite veins in supra-subduction zone peridotites:Evidence from petrography and mineral composition of Egiingol massif(Northern Mongolia)

在线全文

学校读者我要写书评

暂无评论

China Geology 2020年第2期3卷 299-313页

作者： Anas A.Karimov Marina A.Gornova Vasiliy A.Belyaev Aleksander Ya.Medvedev Nikolay V.Bryanskiy a.p.vinogradov institute of geochemistry Siberian Branch of Russian Academy of Sciences IrkutskFavorskogo str.1A 664033Russia

Swarms of orthopyroxenite and websterite veins are found within Egiingol residual SSZ peridotite massif of Dzhida terrain(Central Asian Orogenic Belt,Northern Mongolia).The process of Egiingol pyroxenite veins formation is investigated using new major and trace element analyses of pyroxenite minerals,calculations of closure temperatures and composition of equilibrium *** pyroxenites show abundant petrographic and geochemical evidence for replacement of the residual peridotite minerals by ortho-and clinopyroxene due to melt-rock *** of peridotite olivines are found in pyroxenites,Cr#of spinel increases from peridotites to pyroxenites,and compositions of ortho-and clinopyroxene change from peridotite to *** authors show that calculated equilibrium melts for investigated pyroxenites are very similar to compositions of boninite lavas from the Dzhida ***,formation of pyroxenite veins most likely resulted from percolation of boninite melts through the Egiingol *** veins formed at first,followed by websterite ***,the authors assume that pyroxenite veins represent the channels for boninitic melts migration in supra-subduction environment.

关键词： pyroxenite vein Boninite partial melting Melt-rock interaction Supra-subduction zone peridotite Egiingol massif Dzhida terrain Central Asian Orogenic Belt Northern Mongolia

Isotope geochemistry of the Dongchuan Copper Deposit, Yunnan, SW China: Stratigraphic Chronology and Application of Lead Isotopes in Geochemical Exploration

在线全文

学校读者我要写书评

暂无评论

Chinese Journal Of geochemistry 2002年第1期21卷 65-72页

作者：常向阳朱炳泉 Guangzhou institute of geochemistry Chinese Academy of Sciences Guangzhou China The State Key Lab. of Environmental geochemistry Institute of Geochemistry Guiyang China

In this paper the pb-pb isochron method was used to determine the isotopic ages of the Luoxue Formation dolomites (1716±56 Ma), the Heishan Formation carbonaceous slates (1607±128 Ma) of the middle sub-group of the Kunyang Group and the Dayingpan Formation carbonaceous slates (1258±70Ma) of the upper sub-group of the Kunyang Group. The age of the middle sub-group of the Kunyang Group is about 1800-1600 Ma, belonging to the Late paleo-proterozoic, and that of the Dayingpan Formation in the upper sub-group of the Kunyang Group is about 1200-1300 Ma, belonging to the Middle proterozoic. In addition, the pb isotope chemical exploration techniques were used to study systematically the pb isotopic compositions of rocks and ores across the No.14 vein in the middle segment of the No.1 pit of the Tangdan copper deposit and the result showed that the pb isotope V\-1 values are negatively correlated with the copper contents. It is the first trial to use the systematic section method to conduct pb isotope chemical exploration.

关键词：铜矿床同位素地球化学铅同位素云南指示同位素地层年代学调查

Isotopic geochemistry of Cadmium:A Review

在线全文

学校读者我要写书评

暂无评论

Acta Geologica Sinica(English Edition) 2015年第6期89卷 2048-2057页

作者： ZHU Chuanwei WEN Hanjie ZHANG Yuxu LIU Yizhang WEI Rongfei State Key Laboratory of Ore Deposit geochemistry Institute of GeochemistryChinese Academy of Sciences State Key Laboratory of Environmental geochemistry Institute of GeochemistryChinese Academy of Sciences Center for Environment Remediation Institute of Geographic Sciences and Natural Resources ResearchChinese Academy of Sciences

Cadmium（Cd） is a scarce, but not an extremely rare element in the Earth＇s crust（crustal average： 0.2 ppm Cd）. Geochemically, Cd exhibits thiophile, lithophile, and volatile behavior in different geologic processes. Biologically, it is a nutrient-like element that is closely related to p and Zn and is toxic element to organisms. presently, Cd isotopes have been successfully utilized to trace Cd sources and nutrient cycling in marine systems in addition to unearthing other geochemical processes. Using published studies and our recent work, this survey summarizes the chemical preparation and mass spectrometry of Cd isotopes. It also reviews Cd isotopic compositions and fractionation mechanisms in nature as well as experiments.

关键词： Cadmium non-traditional stable isotopes stable isotopic fractionation geochemical tracer

geochemistry of Rare Earth Elements in Lamprophyres in Laowangzhai Gold Orefield, Yunnan province

在线全文

学校读者我要写书评

暂无评论

Journal of Rare Earths 2000年第1期18卷 62-68页

作者：黄智龙肖化云许成刘丛强 Laboratory of Ore Deposit geochemistry Institute of Geochemistry Chinese Academy of Sciences Guiyang 550002 China

Lamprophyres, widely distributed in the Laowangzhai gold orefield, Yunnan province, China, and closely related to gold mineralization in time and space, can be distinguished into three kinds: the fresh (weakly altered ), the altered, and the mineralized lamprophyres. These lamprophyres in the orefield are similar in the range of BEE contents and REE patterns, but definitely different in parameters of LRE/HRE, NLa/Yb etc. The geochemistry of REE in fresh lamprophyre shows flat the rock is a product of different partial melting of the enriched mantle. Calculation results of mass balance of REE activity regularity in the process of alteration and mineralization of the lalnprophyres in the orefield shows that the altering fluids and mineralizing fluids contain REE, and these fluids are mainly [he products of mantle degassing and magma degassing during the lamprophyric magmatism.

关键词： rare earths lamprophyre geochemistry laowangzhai gold orefield

Nature and(in-)coherent metamorphic evolution of subducted continental crust in the Neoproterozoic accretionary collage of SW Mongolia

在线全文

学校读者我要写书评

暂无评论

Geoscience Frontiers 2021年第3期12卷 78-103页

作者： Sergei Skuzovatov vinogradov institute of geochemistry SB RAS Favorskogo str.1AIrkutsk 664033Russia

In continental subduction complexes minor volumes of high-pressure mafic rocks(eclogites)often co-exist with much more abundant felsic(granitic)and metasedimentary rocks,which are vital for resolving the origin and metamorphic evolution of subducted continental *** SW Mongolia,the Alag Khadny eclogite-bearing accretionary complex(AKC)is assumed to represent either a remnant of oceanic slab,or a continental margin,subducted in the Early *** we present geochronological,geochemical and petrological evidence of subduction records for the three major types of lithologies that host mafic eclogites,including Mesoproterozoic and Neoproterozoic granitic basement and overlying Neoproterozoic continental-margin *** deformed,ferroan and peraluminous metagranitoids compose a major part of AKC and are interlayered with eclogites in its southern and eastern *** have geochemical features of post-collisional/intraplate high-K calc-alkaline ***-ICp-MS U-pb zircon geochronology of three distinct metagranite samples show uniform protolith crystallization ages of ca.0.96 Ga and uncertain re-crystallization in the Late Neoproterozoic or Early paleozoic metamorphic event,whereas abundant zircon inheritance indicates older,Mesoproterozoic to paleoproterozoic crustal substrate during granite *** existence of Mesoproterozoic crust is highlighted by finding of distinct metagranitoids with the U-pb zircon crystallization age of ca.1.6 *** isotope signatures(T_(DM)^(C)2.88-1.85 Ga)of zircons from all lithologies preserved the evidence of reworked Neoarchean to paleoproterozoic crust,similar to that of the Baidrag block(southern Mongolia),for both Mesoproterozoic and Neoproterozoic *** of the specific lithology,the rocks display indicators of high-pressure metamorphic re-equilibration,including garnet(X_(Ca)up to 0.65)+epidote+phengite(Si *** to 3.56)±rutile assemblage in metagranitoids,garnet+phengite(Si ***

关键词： Central Asian Orogenic Belt SW Mongolia Subduction Metasedimentary rocks Orthogneisses Trace elements Zircon U-pb age Hf isotopes

Age and geochemical evolution of granite magmatism in Olkhon region from Caledonian syncollisional ore-free granite to the rare metal granite and pegmatite of Middle paleozoic intraplate setting

在线全文

学校读者我要写书评

暂无评论

China Geology 2024年第1期7卷 63-79页

作者： Viktor Antipin Valentina Makrygina Larisa Kushch Nataliya Sheptyakova vinogradov institute of geochemistry SB RAS664033 IrkutskRussia

The detailed description of two granite complexes in the Olkhon subterrane is *** Early paleozoic Sharanur complex was formed by granitization of gneisses of the Olkhon *** includes migmatites,granite-gneisses,granites and pegmatites of normal alkalinity;they belong to the type of syncollisional *** Middle paleozoic Aya granite complex includes mother Aya massif of amazonite-bearing granites and several types of rare-metal *** have elevated alkalinity,low of Ba,Sr,and high LILE and HFSE elements *** Aya pegmatites lie in northwest cracks of stretching and associated with the rise of the territory under the influence of the North Asian *** cracks and pegmatites mark the beginning of a new intraplate geodynamic *** geochemical types are distinguished among the pegmatites of this *** are amazonite pegmatites of Li-F type with Ta mineralization and complex type pegmatite with Be-Rb-Nb-Ta and Li-F mineralization(the Ilixin vein).The Tashkiney pegmatite vein is similar to Ilixin,but lies in the gneisses of the Olkhon *** shows high concentrations of Be,Nb,Ta,as well as W,Sn,but lacks Li and F,due to a greater depth and higher temperature of the melt crystallization of this pegmatite.

关键词： pegmatite geochemistry Submantle plume Magmatism Caledonian collision Middle paleozoic intraplate setting Be-Rb-Nb-Ta-Li-F mineralization Olkhon region Russia

geochemistry of Jinman Copper Vein Deposit,West Yunnan province,China─Ⅱ.Fluid Inclusion and Stable Isotope Geochemical Characteristics

在线全文

学校读者我要写书评

暂无评论

Chinese Journal Of geochemistry 1998年第1期17卷 81-90页

作者：季宏兵李朝阳 Open Laboratory of Ore Deposit geochemistry Institute of Geochemistry Chinese Academy of Sciences Guiyang

The Jinman deposit is a Ag-bearing copper vein deposit located at the north marginof the Lanping-Simao back-arc basin in West Yunnan. Systematic studies of fluid inclusions andstable isotopes are presented in this paper. The filling-replacement stage and the boiling-exhala-tive precipitation stage of mineralization took place at T1 = 140 - 280℃ and T2 = 94 - 204℃under pressure of (600 - 1200) ×105 pa. The salinity of ore-forming solutions ranges from 5 wt%-20. 8 wt% (NaCl). Sulphide δ34S(CDT) values are in the rang of - 9.6‰ - + 11.03% witha range of 22. 66‰ showing an apparent "pagoda"-shaped distribution in histogram. Mean-while, the δ34S values of the various sulphides are consistent with the characters of isotope equi-librium fractionation, i. e., δ34Spy>δ34 SCp> δ34SBn. The TS/TOC ratios of the ores are widelyvariable between 0.16 and 5. 54 with no correlation of any kind can be established. Accirding to themodel of Ohmoto, the oxidation-reduction ratios of sulfur species in ore-forming solutions at the twomineralization stages were calculated to be R’1 = 2. 16×10(-17) and R’2 = 1. 55×104. δ13CCO2 (pDB)values obtained from fluid inclusions in calcite and quartz are between - 8.12‰ - - 3. 18‰, av-eraging - 5. 26‰, which are comparable with the isotopic composition of mantle-derived *** in quartz yield δ13CCH4(pDB) between - 32. 11‰ and - 22. 04‰ (averaging- 26. 69‰),similar to that of methane in modern geothermal gases. For the ore-forming soutions, δ18OH2O(SMOW) values are between - 10. 57‰ and + 9. 77‰ and δDH2O(SMOW) are between - 51‰and - 135‰. Considering the effect of isotope exchange during waterrock reactions, most ofthe data are plotted along or close to the line defined by the reaction of meteoric water withclastic rocks, while a small part of the points fall near the reaction line of magmatic water withclastic rocks. In δ13C vs. δ18O diagram, the ore-forming soutions are plotted for the most partinto the mixing area between the meteoric flu

关键词：成矿流体硫同位素铜矿床氢同位素碳同位素氧同位素云南地球化学