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1.
四川会理小青山铜(金)矿钠长石英板岩的发现及其意义   总被引:3,自引:0,他引:3  
王奖臻  陆彦 《地质论评》1999,45(3):323-327
四川会理小青山铜(金)矿区的钠长石英板岩主要由钠长石及石英组成。钠长石英板岩的化学成分中富有SiO2,Al2O3及Na2O,贫K2O,FeO及MgO;稀土元素特征为:ΣREE=3013-42.11,ΣCe/ΣY=1.80-1.98,δEu=0.23-0.34,δCe=0.48-0.59。  相似文献   

2.
滇西南那邦变质基性岩地球化学与俯冲板片裂离   总被引:4,自引:1,他引:3  
季建清  钟大赉 《岩石学报》2000,16(3):433-442
中缅边界那邦麻粒岩相变质基性岩地球化学特征表明其原岩是岩浆岩,并具有MORB的特性,其岩石化学具有以下特征:岩石的TFe/MgO值低(1.10~2.17),AFM图解上显示拉斑玄武岩演化趋势;TiO2含量(1.14%~1.81%)高稀土亏损、重稀土较有富集的配分形式,稀土元素和总量(∑REE)值十倍于球粒陨石(24~50μg/g),(La/Sm)N=0.43~0.75(La/Yb)N=0.45~0  相似文献   

3.
应用稀土元素及微量元素方法和Gresens方程,研究了小青山铜(金)矿区交代成因钠长石岩,区分出了两类不同原岩性质的钠长石岩。A类钠长石的原岩为绢云母千枚岩,它们的ΣREE为30.13~101.09,ΣCe/ΣY=1.8~7.8,δEu=0.23~0.91,稀土配分曲线为右倾型;Rb等大离子亲石元素强烈亏损。B类钠长石岩的原岩为辉长岩,它们的ΣREE=29.06,ΣCe/ΣY=2.04,δEu=0.93,配分曲线为平坦型,大多数微量元素均为负异常。两类钠长石岩形成过程中K2O、Fe2O3、FeO及MgO等带出,Na2O及SiO2带入。  相似文献   

4.
西藏南迦巴瓦峰地区发现的星叶石   总被引:3,自引:0,他引:3       下载免费PDF全文
在西藏境内喜马拉雅山脉的东端的南迦巴瓦峰地区发现了星叶石。该矿物产出于火成碳酸岩脉中,与白云石、方解石、镁橄榄石、镁铝尖晶石、金云母、韭闪石、磷灰石、镁钛矿、石榴石以及三种未定名副矿物共生。该矿物的晶胞参数为:a0=5.356(1),b0=11.607(4),c0=11.851(6),α=64.57°(3),β=76.98°(4),γ=85.45°(3)。化学成分(%)为:SiO235.22,TiO211.47,Al2O31.18,FeO28.90,MnO5.15,MgO1.51,CaO1.75,K2O5.90,Na2O2.46,总和93.54%,化学式为:(K,Na)3(Fe,Mn,Mg,Ca)7Ti2Si8O24(O,OH)7。  相似文献   

5.
赣南寨背A型花岗岩体的地球化学特征及其构造地质意义   总被引:86,自引:9,他引:77  
陈培荣 《岩石学报》1998,14(3):289-298
赣南寨背岩体主要为黑云母钾长花岗岩,黑云母结晶晚于长石和石英,锆石群型地温测量标尺显示其结晶温度为800℃~900℃,表明寨背岩体形成于一种高温贫水的花岗质岩浆。岩石的化学成分特点为准铝质(Al2O3为12.21%~12.62%),富硅(SiO2为75.66%~76.74%),偏碱(Na2O+K2O为7.93%~8.90%),FeOT/MgO值高(59~148),CaO和MgO含量低(分别为0.10%~0.65%和0.01%~0.02%),富含REE(Eu除外,ΣREE平均为500μg/g),Y、Ga、Nb等高场强元素(HFSE)以及F,Sr和Ba较低。这些特点与本区的I型和S型花岗岩有明显差别,是一种典型的A2型花岗岩。寨背岩体Rb-Sr等时线年龄为176Ma,与辉长岩、双峰式火山岩有密切的时空关系,表明赣南地区在燕山早期即进入拉张裂解阶段。  相似文献   

6.
张旗  张宗清 《岩石学报》1995,11(1):43-54
丹凤祥变质玄武岩可以分为两类:一类是LREE富集型的钙碱性玄武岩,另一类是LREE平坦型的拉斑玄武岩。LREE富集型的变质玄武岩[(Ce/Yb)N为5~20]贫Ti、Nb、Ta,Th>Ta,Nb/La<0.8,Hf/Th>8,Zr/Y<3,表明其形成于消减带之上的洋内岛弧环境。该玄武岩的εNd(t)=+4.9~+7.3,εSr(t)=3.0~+32,可能是亏损地幔端元(DMM)与第二类富集地幔端元(EMⅡ)混合形成的。大多数玄武岩的(206Pb/204Pb)i比值(16.5~17.6)较低,(208Pb/204Pb)i和(207Pb/204Pb)i比值(分别为36.2~36.9和15.3~15.5)较高,ε18O变化较大(5.5‰~9.2‰)。因此,根据微量元素和同位素地球化学资料,丹凤群变质玄武岩的源区可能包括下述组分:1)亏损的软流圈地幔(DM);2)富集地幔(EM);3)洋内岛弧下地壳(镁铁和超镁铁质岩);4)消减带岩片带入的组分。而LREE亏损的拉斑玄武岩具MORB的特征,Th/Ta和La/Ta比值近似等于1,TiO2=1.65%,Ti/V=22,指示来自亏损的软流圈地幔,形成在与消减作用无关的拉张  相似文献   

7.
大兴安岭北部伊列克得组玄武岩的地球化学特征   总被引:20,自引:0,他引:20  
大兴安岭北部伊列克得组玄岩类具有富碱(K2O+Na2O〉6.37%)、高K2O(2.62%~3.11%),高K2O/Na2O比值(0.7~0.8)和Th/Ta、Ce/Nb、Ta/Nb比值,以及强烈富集大离子亲石元素(LILE)和轻稀土元素(LREE)的特征,属于钾玄质系列,低Sr/Nd比值(13~17.5)的特征类似于洋岛玄武岩,但其Ta/Hf,Th/Ta比值特征及与A型花岗岩共生等特征表明,钾玄  相似文献   

8.
出露于加拿大苏必利尔罗灵河杂岩体中的含角闪石斑晶和单斜辉石斑晶的煌斑岩,具有碱性,含霞石标准矿物的玄武岩质成分(SiO2<50wt%),成分变化从原始岩浆到分异岩浆[Mg/Mg+∑Fe)=0.66-0.40;Ni=200-35ppm],岩石富含LREE[Ce/Yb)m=16-26,Cen=60-300;n=球粒陨石标准化],Sr(870-1800ppm),P2O5(0.4-1.3wt%)和Ba(1  相似文献   

9.
李素芝  熊采华 《岩矿测试》2000,19(3):205-208
拟定了电感耦合等离子体原子发射光谱(ICP-AES)测定铅锑合金中As、Bi、Ca、Cd、Co、Fe、Mn、Se和Zn等九个元素的分析方法,考察了Pb、Sb基体对待测元素的干扰情况。样品以HNO3分解,酒石酸抑制Sb水解,ICP-AES同时测定多元素。方法对各元素的测定限在0.07~5.2μg/g,相对标准偏差(n=8)为0.78%~25.5%,加标回收率均大于86%,经与原子吸收光谱法和原子荧光  相似文献   

10.
张宏飞  骆庭川 《现代地质》1994,8(4):453-458
扬子克拉通北缘的铁船山岩体形成于新元古代,其岩石类型为霓石-钠铁门石花岗岩,岩石富碱质、St、Fe、REE和高场强元素,而贫Al、Ca、Mg、Sr、Ba、Co、Ni等组分,δEu=0.20,A/KNC=0.85,K2O+Na2O/Al2O3=1.09,A·R=9.28,岩石属典型的A型花岗岩,Nd、Sr和O同位素示踪反映其成岩物质来自于壳幔混合源区。根据区域地质背景的综合分析,岩体形成于活动陆缘的张裂构造环境,属活动板块边缘拉张型花岗岩。  相似文献   

11.
Pant-y-ffynnon Quarry in South Wales yielded a rich cache of fossils in the early 1950s, including articulated specimens of new species (the small sauropodomorph dinosaur Pantydraco caducus and the crocodylomorph Terrestrisuchus gracilis), but no substantial study of the wider fauna of the Pant-y-ffynnon fissure systems has been published. Here, our overview of existing specimens, a few described but mostly undescribed, as well as freshly processed material, provides a comprehensive picture of the Pant-y-ffynnon palaeo-island of the Late Triassic. This was an island with a relatively impoverished fauna dominated by small clevosaurs (rhynchocephalians), including a new species, Clevosaurus cambrica, described here from a partially articulated specimen and isolated bones. The new species has a dental morphology that is intermediate between the Late Triassic Clevosaurus hudsoni, from Cromhall Quarry to the east, and the younger C. convallis from Pant Quarry to the west, suggesting adaptive radiation of clevosaurs in the palaeo-archipelago. The larger reptiles on the palaeo-island do not exceed 1.5?m in length, including a small carnivorous crocodylomorph, Terrestrisuchus, and a possible example of insular dwarfism in the basal dinosaur Pantydraco.  相似文献   

12.
Robert L. Linnen   《Lithos》2005,80(1-4):267-280
The solubilities of columbite, tantalite, wolframite, rutile, zircon and hafnon were determined as a function of the water contents in peralkaline and subaluminous granite melts. All experiments were conducted at 1035 °C and 2 kbar and the water contents of the melts ranged from nominally dry to approximately 6 wt.% H2O. Accessory phase solubilities are not affected by the water content of the peralkaline melt. By contrast, solubilities are affected by the water content of the subaluminous melt, where the solubilities of all the accessory phases examined increase with the water content of the melt, up to 2 wt.% H2O. At higher water contents, solubilities are nearly constant. It can be concluded that water is not an important control of accessory phase solubility, although the water content will affect diffusivities of components in the melt, thus whether or not accessory phases will be present as restite material. The solubility behaviour in the subaluminous and peralkaline melts supports previous spectroscopic studies, which have observed differences in the coordination of high field strength elements in dry vs. wet subaluminous granitic glasses, but not for peralkaline granitic glasses. Lastly, the fact that wolframite solubility increases with increasing water content in the subaluminous melt suggests that tungsten dissolved as a hexavalent species.  相似文献   

13.
Calcite samples were extracted both from the rock matrix and the superficial coating of a karstified fault plane of an underground quarry, located in the eastern border of the Paris basin. The karstification is dated as Quaternary. Analysis of mechanical calcite twinning reveals that only the calcite matrix has also undergone a compression trending WNW that can be attributed to the Mio-Pliocene alpine collision. Both coating and matrix have undergone a strike-slip regime with σ1 roughly trending north–south, that could correspond to the regional present-day state of stress, a strike-slip compression rather trending NNW, modified by local phenomena. To cite this article: M. Rocher et al., C. R. Geoscience 335 (2003).  相似文献   

14.
HYDROGEOLOGY     
正20141756 Chen Ruige(Mathematical College,China University of Geosciences,Beijing100083,China);Zhou Xun Numerical Simulation of Groundwater Level Fluctuation in a Coastal Confined Aquifer with Sloping Initial Groundwater Level Induced by the Tide(Geological Bulletin of China,ISSN1671-2552,CN11-4648/P,32(7),2013,p.1099-1104,6 illus.,16 refs.) Key words:confined water,groundwater level  相似文献   

15.
正20141408 Cai Jia(Institute of Geology,Chinese Academy of Geological Sciences,Beijing100037,China);Liu Fulai Petrogenesis and Metamorphic P-T Conditions of Garnet-Spinel-Biotitebearing Paragneiss in Danangou Area,Daqingshan-Wulashan Metamorphic Complex Belt(Acta Petrologica Sinica,ISSN1000-0569,CN11-1922/P,29(7),  相似文献   

16.
17.
正20142386An Guoying(China Aero Geophysical Survey and Remote Sensing Center for Land and Resources,Beijing 100083,China)Application of Satellite Remote Sensing in Regional Hydrogeological Investigation:Taking Cenozoic Strata in Wenquan Sheet(1∶250 000)of Karakoram Range as an Example(Geosci-  相似文献   

18.
正20141016An Chengbang(Key Laboratory of Western China’s Environmental Systems,Ministry of Education,Lanzhou University,Lanzhou 730000,China);Zhao Yongtao Lake Records during the Last Glacial Maximum from Xinjiang,NW China and Their Climatic Impli-  相似文献   

19.
正20141538 Cao Qing(School of Earth Sciences and Engineering,Xi’an Petroleum University,Xi’an 710065,China);Zhao Jingzhou Characteristics and Significance of Fluid Inclusions from Majiagou Formation,Yichuan Huangling Area,Ordos Basin(Advances in Earth Science,ISSN1001-8166,CN62-1091/P,28(7),2013,p.819-828,7 illus.,3 tables,43 refs.)  相似文献   

20.
GEOCHEMISTRY     
正20142002 Wei Hualing(Institute of Geophysical and Geochemical Exploration,Chinese Academy of Geological Sciences,Langfang065000,China);Zhou Guohua Element Content and Mineral Compositions in Different Sizes of Soil in Tongling Area,Anhui Province(Geological Bulletin of China,ISSN1671-2552,CN11-4648/P,32(11),2013,p.1861  相似文献   

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