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1.
滇西地区壳型钨锡成矿系列花岗岩全岩δ^18O值多为 9．0- 14．5‰，δD值多为-70--120‰，^87Sr／86Sr(i)>0．708。其中：腾冲-梁河地区K-F(黄玉)花岗岩初始岩浆水δ^18O值为 6- 11‰，δD值为-60--90‰，与华南地区钨锡系列花岗岩相比，δ^18OH2O值略低；云龙铁厂-西盟地区Na-B(电气石)花岗岩初始岩浆水δ^18O值为 6．25- 7．98‰。 相似文献
2.
华南诸广山花岗岩体中段锶氧铅硫同位素研究 总被引：5，自引：1，他引：5
诸广山中段花岗岩体的Rb-Sr同位素等时线年龄为215.23Ma,属印支期。锶同位素初始比值为0.7229,Rb/Sr比值为1.09～15.6,初始~(206)Pb/~(204)Pb(18.216～19.042)和~(207)Pb/~(204)Pb(15.605～15.801)较高。全岩δ~(18)O为10.6‰～12.4‰,δ~(18)O-~(87)Sr/~(86)Sr相关趋势呈水平方向展布。硫同位素绝大部分在零值左右摆动,从早到晚变化范围逐渐变小。这些表明岩体是源于上地壳的改造型花岗岩,并经过了岩浆阶段,且在早期岩浆岩基础上又经过了多次重熔演化。 相似文献
3.
湖南铜山岭花岗岩体的地球化学特征及锆石SHRIMP定年 总被引：7，自引：0，他引：7
铜山岭花岗岩具有贫硅、富铁镁钙、弱到中等铕负异常和K2O/Na2O(1的特点,属高钾钙碱性岩石;花岗岩的ISr值(0.71060~0.71124)和εSr(t)值(77.6~81.0)相对较小,δ18O值(8.62‰~9.67‰)较低;TDM年龄(1226~1536Ma)偏小,εNd(t)值(-7.1~-5.2)相对较高;花岗岩中发育壳幔混合的镁铁质微粒包体。这些特征表明该岩体具有壳幔混合花岗岩的性质。岩体SHRIMP锆石U-Pb年龄为149±4Ma,属于燕山中期晚阶段构造岩浆活动的产物。 相似文献
4.
云南省西部西盟小马撒花岗岩体出露于西盟隆起大黑山复背斜西翼,与上元古界西盟群变质岩呈侵入接触。黑云母Rb-Sr年龄为16.7Ma,Rb-Sr全岩等时线年龄为50.5Ma,属喜山期。熔融包体均—温度750—968℃,气液包体均—温度255—405℃。~(87)Sr/~(86)Sr初始比值为0.7121—0.7183、δ~(18)O值为 9.70— 10.24‰。小马撒花岗岩为陆壳部分熔融的花岗岩浆高侵位结晶的产物,属东南亚含锡S型花岗岩之北延部分。 相似文献
5.
粤北302铀矿床同位素地球化学研究 总被引：11，自引：1，他引：10
位于粤北诸广山岩体东南部的302铀矿床是我国规模较大、埋藏较深的花岗岩型铀矿床之一。该矿床产于印支期油洞岩体和燕山早期长江岩体的断裂蚀变带内,矿区内NWW向基性岩脉十分发育,矿体呈似脉状、扁豆状或透镜状。同位素研究表明,矿石的沥青铀矿Sm-Nd和U-Pb等时线年龄（70 Ma）与油洞岩体（232 Ma）、长江岩体（160 Ma）的年龄相差巨大;主成矿期成矿流体的δDH2O值为-65‰～-82‰（平均为-75‰）,δ18OH2O值为6.8‰～0.6‰（平均为3.9‰）,反映出成矿流体主要由地幔流体组成;方解石的δ13C值为-8.4‰～-5.3‰,表明矿化剂ΣCO2也来自地幔;矿区内辉绿岩的（87Sr/86Sr）i值为0.70861～0.70882,花岗岩的（87Sr/86Sr）i值为0.73519～0.77152,萤石的（87Sr/86Sr）i值为0.71474～0.71697,表明成矿组分Sr可能来源于基性脉岩（幔源）与赋矿花岗岩体（壳源）,并呈不同程度的混合,而主成矿组分铀主要来源于赋矿花岗岩体。 相似文献
6.
浙江莫干山花岗岩体锆石U-Pb、全岩Rb-Sr年代学、Sr-Nd-O同位素地球化学及成因研究 总被引：2，自引：0，他引：2
莫干山花岗岩体位于东天目山晚中生代火山盆地东端,用LA-ICPMS进行锆石U-Pb定年得到年龄为128.1±2.1Ma,全岩Rb Sr等时线定年结果为135.4±4.3 Ma,表明其属燕山晚期岩浆活动产物.莫干山花岗岩的Sr-Nd-O同位素分析结果为:初始87Sr/86Sr=0.70933;εNd(t)=-3.75～ - 6.4;δ18O=8.86‰～10.78‰,表明其成因类型属Ⅰ型花岗岩,是壳-幔物质混合形成的.按Sr Nd双变量二元混合模型计算得出源区物质中地壳端员和亏损地幔端员的贡献份额分别为47％～49％、51％～53％.莫干山花岗岩与建德群黄尖组火山岩的锆石U-Pb年龄、全岩Rb Sr等时线年龄基本一致,其Nd-Sr同位素组成也很相似,表明它们来自同一岩浆源. 相似文献
7.
湖南柿竹园钨锡多金属矿床同位素地球化学研究 总被引：3，自引：0，他引：3
柿竹园钨锡多金属矿床中细粒和中粒黑云母花岗岩Rb-Sr等时线年龄分别为(133±23)Ma和(143±7.3)Ma;初始锶同位素比值分别为0.71774±0.01472和0.73297±0.03454.从花岗岩侵入到成矿作用晚期阶段,δ18OH2o和δDH2O分别从+5.6‰～+11.4‰和-56.0‰～-62.3‰变化到-5.8‰～-8.5‰和-48.0‰～-69.7‰.花岗岩中石英的δ18O值较高,为8.4‰～12.1‰,岩浆水的δ18O为5.6‰～11.4‰,δD为-56.0‰～-62.3‰,但钾长石、黑云母的δ18O值较低,计算出的氧同位素平衡温度低于花岗岩结晶温度,表明花岗岩形成后受到岩浆水和雨水的交换作用和蚀变作用.本矿床流体的氢氧同位素,具有独特的演化规律,用沸腾去气作用和雨水混合作用可以解释其流体氢氧同位素的组成特征. 相似文献
8.
湖南柿竹园钨锡多金属矿田野鸡尾矿床同位素地球化学研究 总被引：4，自引：3，他引：4
湖南柿竹园钨锡多金属矿田野鸡尾矿床产于千里山花岗岩岩体东南缘与泥盆系中统棋梓桥组和泥盆系上统佘田桥组灰岩接触带附近。是一个富含钨、锡、铅锌等多种金属的矽卡岩-云英岩-硫化物复合型矿床,在空间上具有明显的分带现象。研究表明,该矿床中花岗岩造岩矿物的ε~(18)O 值在-1.7‰～ 12.1‰之间,其中石英的δ~(18)O 值较高,变化范围为8.4‰～12.1‰,钾长石为3.8‰～8.6‰,黑云母为-1.7‰～-1.4‰。石英-钾长石和钾长石-黑云母矿物对的氧同位素平衡温度为350℃～630℃,低于一般花岗岩的结晶温度。石英包裹体的δD为-56‰～-62‰,位于正常岩浆水的范围之内。矽卡岩期流体的δ~(18)OH_2O 为8.2‰～9.2‰,δD为-100‰～-156‰;云英岩流体的δ~(18)O_(H_2O)为4.9‰～6.7%e,δD为-69‰;硫化物期流体的δ~(18)O_(H_2O)为2.5‰～-36.1‰,δD为-54‰;晚期石英脉流体的δ~(18)O_(H_2O)为-7.3‰,δD为-58‰。从矽卡岩到晚期石英脉,成矿流体的氢氧同位素组成具有独特的演化特征,可以用沸腾去气作用和岩浆水与雨水混合作用来解释。矿区围岩灰岩和大理岩的占δ~(18)O_(SMOW)值为4.2‰～20.0‰,δ~(13)C_(PDB)为-6.0‰～0.3‰,灰岩与大理岩的δ~(18)O 和δ~(13)C 显著不同,用矿化和蚀变过程中水-岩相互作用和同位素交换反应可以圆满地解释。矿床硫化物的δ~(34)S 值为 2.8‰～ 8.9‰,其中矽卡岩硫化物的δ~(34)S 在 2.8‰～ 8.9‰之间;云英岩中硫化物δ~(34)S 在 3.4‰～ 6.9‰之间;硫化物阶段的δ~(34)S 在 3.7‰～ 6.3‰之间。估算的成矿流体总硫δ~(34)S_(∑S)约为3‰,表明硫的主要来源可能来自千里山花岗岩岩浆。综合氢氧碳硫同位素组成研究,本文认为野鸡尾矿床成矿物质主要来自千里山花岗岩,也可能有少部分物质来源于围岩沉积岩。 相似文献
9.
新疆北天山东段花岗岩类地球化学特征 总被引：11，自引：0，他引：11
本区花岗岩类位于北天山地向斜褶皱带。岩体侵入于石炭纪海相火山-沉积岩系中,呈同期多次侵入的中基性-酸性复式岩体。依据Rb-Sr全岩等时线其年龄为315.7Ma,属于海西中期。SiO_2含量48—78％,钙碱指数为60,硅碱指数ρ为2.2—2.4和σ为1.5—2。稀土元素从基性到酸性,总量从38 ppm增到143ppm,δEu为0.47—0.86,为负铕异常,各岩类标准化曲线相似性很好。上述情况结合微量元素特点,本区为岛弧-陆缘型的钙碱性系列的侵入体。δ~(18)O为5.8—8.9‰,~(87)Sr/~(86)Sr初始值为0.705。岩体物质由上地幔顶部和下地壳岩浆混合组成,可能是同源分异演化的产物。具Ⅰ型花岗岩特征。 相似文献
10.
广西栗木钨锡铌钽矿区流体包裹体及氢氧同位素研究 总被引：2，自引：0，他引：2
本文通过对广西栗木矿区金竹源矿床和水溪庙矿床的流体包裹体研究,得出该矿区流体包裹体主要有两相H_2O-NaCl和H_2O-NaCl-CO_2两种类型。显微测温结果表明:两相H_2O-NaCl型流体包裹体均一温度主要集中于181.9~258.8℃,盐度w(Na Cleq)主要集中于4.01%~6.87%,密度0.690~0.988 g/cm3;H_2O-NaCl-CO_2型流体包裹体均一温度为178.5~331.1℃,主要集中在两个温度段,分别为高-中温段(265.3~315.5℃)和中-低温段(202.3~264.1℃),盐度w(NaCleq)主要集中在0.21%~5.05%,密度为0.678~0.886 g/cm3。栗木矿区成矿流体有两个温度集中段,且具有低盐度、低密度的特征。氢氧同位素研究结果表明:金竹源矿床钨锡铌钽矿化花岗岩石英δD值为-73.6‰~-62.8‰,δ~(18)OV-SMOW值为7.5‰~8.9‰,计算得δ~(18)OH2O值为6.00‰~7.40‰;水溪庙矿床钨锡铌钽矿化花岗岩石英δD值为-73.8‰~-58.3‰,δ~(18)OV-SMOW值为11.0‰~13.2‰,计算得δ~(18)OH2O值为9.50‰~11.70‰,水溪庙矿床含钨锡石英脉石英δD值为-75.3‰~-56.6‰,δ~(18)OV-SMOW值为11.8‰~14.1‰,计算得δ~(18)OH2O值为2.20‰~4.50‰。栗木矿区钨锡铌钽矿化花岗岩成矿流体来源于岩浆水,含钨锡石英脉成矿流体来源于岩浆水和大气降水的混合流体。 相似文献
11.
Gilles Serge Odin 《Comptes Rendus Geoscience》2002,334(6):409-414
Lithostratigraphy, physicochemical stratigraphy, biostratigraphy, and geochronology of the 77–70 Ma old series bracketing the Campanian–Maastrichtian boundary have been investigated by 70 experts. For the first time, direct relationships between macro- and microfossils have been established, as well as direct and indirect relationships between chemo-physical and biostratigraphical tools. A combination of criteria for selecting the boundary level, duration estimates, uncertainties on durations and on the location of biohorizons have been considered; new chronostratigraphic units are proposed. The geological site at Tercis is accepted by the Commission on Stratigraphy as the international reference for the stratigraphy of the studied interval. To cite this article: G.S. Odin, C. R. Geoscience 334 (2002) 409–414. 相似文献
12.
Inter-regional correlation of transgressions and regressions in the Cretaceous period 总被引：1，自引：0，他引：1
T. Matsumoto 《Cretaceous Research》1980,1(4):359-373
Well investigated platforms have been selected in each continent, and the history of Cretaceous transgressions and regressions there is concisely reviewed from the available evidence. The factual records have been summarized into a diagram and the timing of the events correlated between distant as well as adjoining areas.On a global scale, major transgressions were stepwise enlarged in space and time from the Neocomian, via Aptian-Albian, to the Late Cretaceous, and the post-Cretaceous regression was very remarkable. Minor cycles of transgression-regression were not always synchronous between different areas. Some of them were, however, nearly synchronous between the areas facing the same ocean.Tectono-eustasy may have been the main cause of the phenomena of transgression-regression, but certain kinds of other tectonic movements which affected even the so-called stable platforms were also responsible for the phenomena. The combined effects of various causes may have been unusual in the Cretaceous, since it was a period of global tectonic activity. The slowing down of this activity followed by readjustments may have been the cause of the global regression at the end of the Cretaceous. 相似文献
13.
The Afyon stratovolcano exhibits lamprophyric rocks, emplaced as hydrovolcanic products, aphanitic lava flows and dyke intrusions, during the final stages of volcanic activity. Most of the Afyon volcanics belong to the silica-saturated alkaline suite, as potassic trachyandesites and trachytes, while the products of the latest activity are lamproitic lamprophyres (jumillite, orendite, verite, fitztroyite) and alkaline lamprophyres (campto-sannaite, sannaite, hyalo-monchiquite, analcime–monchiquite). Afyon lamprophyres exhibit LILE and Zr enrichments, related to mantle metasomatism. 相似文献
14.
正20140751 Guo Xincheng(Geological Party,BGMRED of Xinjiang,Changji 831100,China);Zheng Yuzhuang Determination and Geological Significance of the Mesoarchean Craton in Western Kunlun Mountains,Xinjiang,China(Geological Review,ISSN0371-5736,CN11-1952/P,59(3),2013,p.401-412,8 相似文献
15.
正20141058 Chen Ling(Key Laboratory of Mathematical Geology of Sichuan Province,Chengdu University of Technology,Chengdu610059,China);Guo Ke Study of Geochemical Ore-Forming Anomaly Identification Based on the Theory of Blind Source Separation(Geosci- 相似文献
16.
正20141334 Chen Kun(Institute of Geophysics,China Earthquake Administration,Beijing100081,China);Yu Yanxiang Shakemap of Peak Ground Acceleration with Bias Correction for the Lushan,Sichuan Earthquake on April20,2013(Seismology and Geology,ISSN0253-4967,CN11-2192/P,35(3),2013,p.627-633,2 illus.,1 table,9 refs.)Key words:great earthquakes,Sichuan Province 相似文献
17.
正20141624 Cai Xiongfei(Key Laboratory of Geobiology and Environmental Geology,Ministry of Education,China University of Geosciences,Wuhan 430074,China);Yang Jie A Restudy of the Upper Sinian Zhengmuguan and Tuerkeng Formations in the Helan Mountains(Journal of Stratigraphy,ISSN0253-4959CN32-1187/P,37(3),2013,p.377-386,5 illus.,2 tables,10 refs.) 相似文献
18.
正20142263Lü Shaojun(Geological Survey of Jiangxi Province,Nanchang 330030,China)Early-Middle Permian Biostratigraphical Characteristics in Qiangduo Area,Tibet(Resources SurveyEnvironment,ISSN1671-4814,CN32-1640/N,34(4),2013,p.221-227,2illus.,2tables,22refs.)Key words:biostratigraphy,Lower Permian,Middle Permian,Tibet 相似文献
19.
正20142560Hu Hongxia(Regional Geological and Mineral Resources Survey of Jilin Province,Changchun 130022,China);Dai Lixia Application of GIS Map Projection Transformation in Geological Work(Jilin Geology,ISSN1001-2427,CN22-1099/P,32(4),2013,p.160-163,4illus.,2refs.) 相似文献
20.
正20140692 Duo Tianhui(No.402 Geological Team,Exploration of Geology and Mineral Resources of Sichuan Authority,Chengdu611730,China);Wang Yongli Computer Simulation of Neptunium Existing Forms in the Groundwater(Computing Techniques for Geophysical and Geochemical Exploration,ISSN1001-1749,CN51-1242/P,35(3), 相似文献