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1.
嵩山A型花岗岩的地质地球化学特征和构造环境   总被引:8,自引:0,他引:8  
薛良伟  尉向东 《岩石学报》1996,12(1):137-144
从岩石学、岩石化学、微量元素、REE等方面讨论了嵩山古元古代钾长花岗岩体的地质地球化学特征,结果表明这些岩体属于A型花岗岩,其SiO2、K2O、K2O/Na2O、F、Ga、Hf、Rb、Y、Co、Ga/Al、REE高,Al2O3、MgO、CaO、Na2O、Ba、Sr、V、Th低,Eu为0.15~0.27,A/CNKM<1.10,这些岩体是与古元古代熊耳群火山岩相伴生的钾质侵入岩,两者均形成于非造山的大陆裂谷环境,表明华北陆台南缘在古元古代晚期处于拉张的非造山构造环境。  相似文献   

2.
浙西石炭纪层状硅质岩地球化学特征及其意义   总被引:7,自引:0,他引:7  
在浙西石炭纪地层中存在与地层整合产出的层状硅质岩。硅质岩中FeO、MnO、TiO2、Al2O3、MgO、CaO、Na2O、K2O等含量相对较高,富集As、Sb、Bi、Au、Ag、Ga,Fe2O3/FeO、SiO2/Al2O3、SiO2/(Na2O+K2O)、SiO2/MgO比值较小,稀土元素总量低,Ce弱负异常,重稀土相对富集,包裹体富含气相组份CH4、CO2、N2、CO、H2,具热水沉积硅质岩的地球化学特征。在Fe—Mn—(Ni+Co+Cu)三角图及SiO2—Al2O3、SiO2—Fe2O3图上均属于热水沉积硅质岩。硅质岩中硅、氧同位素也显示其热水成因之特点。硅质岩的硅同位素和稀土元素Ce/Ce※值表明本区层状硅质岩主要是在浅海环境下沉积的。硅质岩的形成温度较高,为98℃~152℃  相似文献   

3.
八庙—青山金红石矿床化学成分与成矿关系   总被引:1,自引:0,他引:1  
徐少康  李博昀 《河南地质》1996,14(4):249-255
本矿床是我国金红石矿床重要的成因及工业类型,为具有特定化学成分的岩石在特定变质条件下形成的。本文通过对大量数据的处理,查明了化学成分和成矿的关系,高Al2O3,MgO,Fe2O3+FeO,K2O,P2O5,H2O^+,MnO,低SiO2,CaO,Na2O,CO2,S等,利于钛富集;高TiO2,MgO,P2O5,S,低SiO2,CaO,K2O,Al2O3,Fe2O3/FeO,利于金红石形成,高Sf,  相似文献   

4.
河南栾川南部地区与Mo—W矿床有关的燕山期花岗岩特征   总被引:9,自引:0,他引:9  
徐兆文  杨荣勇 《岩石学报》1995,11(4):397-408
河南栾川南部分布着一系列与钼钨矿化有关的燕山期花岗岩小岩体。根据这些岩体的含矿性、地质及地球化学特征可将其分为三类。第一类岩体往往与大型一超大型Mo-W矿床有关,岩体顶部有纹层状石英层,石英辉钼矿脉发育。岩石中SiO2、K2O、Rb含量高,K2O/Na2O、Rb/Sr比值高,Al2O3、FeO、CaO、Na2O、Sr含量低。第二类岩体往往与中小型Mo-W矿床有关,岩体中含辉钼矿石英脉发育较差,岩石中SiO2、K2O含量中等,K2O/Na2O比值中等。第三类岩体不含Mo-W矿,岩体中各种脉体不发育,岩石中SiO2、K2O、Rb含量低,K2O/Na2O、Rb/Sr比值相对较低,Al2O3、Na2O、Sr含量相对较高。研究还表明小岩体的分异演化程度与小岩体的合矿性有密切的内在联系。  相似文献   

5.
湘南地区沉积构造环境的地球化学探讨   总被引:4,自引:0,他引:4       下载免费PDF全文
根据湘南地区出露地层的岩石化学成分特征初步讨论了湘南地区的沉积构造环境。湘南地区细碎屑岩的w(Al2O3)/w(CaO+Na2O),w(K2O)/w(Na2O)比值比较高,w(Al2O3)/w(SiO2)比值比较低,与被动大陆边缘特征类似,各时代地层中硅质岩和页岩的w(MnO)/w(TiO2)比值为0.02 ̄0.3,反映其沉积环境为浅海陆架环境,但下二叠统硅质岩中w(MnO)/w(TiO2)比值达  相似文献   

6.
一个古元古代A型流纹岩   总被引:17,自引:2,他引:15  
于津海  王德滋 《地球化学》1998,27(6):549-558
山西吕梁群流纹岩是一个古元古代的弱碱性火山岩,它具有高SiO2,Na2O+K2O和Zr,Ga等高场强元素和高FeO^*/MgO,Rb/Sr和Ga/Al比值,以及低CaO,Sr和Eu/Eu^*的地球化学特征,相似于A型花岗质岩石。它形成于大陆边缘裂谷环境,化学成分及同位素特征为高εNd(t)值,低(^87Sr/^86Sr)i值,表明流纹岩的原始岩浆由下地壳晚太古代变质岩受裂谷岩浆和热流作用的影响部分  相似文献   

7.
广西煤的常量元素地球化学特征   总被引:4,自引:0,他引:4  
系统分析了广西未变质煤、区域变质煤和热液变质煤的SiO2、Al2O3、Fe2O3、MgO、CaO、Na2O、K2O、TiO2、SO3。低灰分煤的常量元素主要来自古植物对成土母岩的选择性吸收,具明显的超基性或基性特征。随煤变质程度升高,未变质煤、区域变质煤中的常量元素没有发生迁移,而热液变质煤中的SiO2和Al2O3相对增加,SO3和CaO相对减少。  相似文献   

8.
相山新元古代变质岩由泥砂质变夺和斜长角闪岩组成。本文对其已变质为下字石榴云母片岩、石片和变粒岩的泥砂质岩石进行了地球化学研究,并研究了某些元素间存在的线性关系。这套泥砂质石相对富SiO2、TFeO、Al2O3、K2O,贫MgO、CaO、Na2O;总稀土含量高,轻稀土高度富集,负Eu异常较强。其主要岩类岩石化学和地球化学特征它可能形成于大陆岛构造环境,形成的时代为前震旦纪。  相似文献   

9.
东川式铜矿地球化学研究   总被引:2,自引:0,他引:2  
东川式铜矿赋矿围岩落雪组白云岩的常量元素投影点在Al2O3──SiO2──(CaO+MgO)图解、lg(SiO2/Al2O3)──lg[(CaO+NaO)/K2O]图解和(al─alk)──C图解上有一些非正常沉积的特点,并与红海现代热水化学沉积物有相似的特征。黄铜矿Co/Ni值及落雪组白云岩微量元素在Co+Ni─As+Cu+Mo+pb+V+Zn图解上也反映出热水沉积特征。稀土元素研究成果表明落雪组是热水沉积与正常沉积相混合的产物。包裹体研究后认为成矿热水属Na+(Ca2+、Mg2+)─HCO-3─Cl-型,并含CO、H2O(气)、CO2、CH4等气相组分,成矿温度110─214℃,成矿深度3─150m。硫、碳、氧和氢的同位素反映了这四种组分多来自海水,成矿热水主要是下渗对流循环而受加热的海水及部分建造水。结合地质研究成果,本文提出“热水微裂隙喷溢沉积成矿”的新认识,即海水下渗,受裂谷高热流加热,萃取流经围岩中的硅质及矿质在还原环境中,沿落雪期尚未彻底固结沉积物中的微裂隙间断式喷溢沉积成矿。  相似文献   

10.
羊拉地区含矿矽卡岩成因的地球化学证据   总被引:19,自引:0,他引:19  
滇西北羊拉铜矿化集中区现已发现4个矽卡岩体,按成因分为喷流-沉积和接触交代矽卡岩两大类,前者呈层状,是铜的主要赋矿围岩,不同成因的矽卡岩具有不同的岩石化学组成,组成喷流-沉积矽卡岩有贫Al2O3,TiO2,REE和富铁(TFeO)等特征。在ω(TiO2)-ω(Al2O3),ω(SiO2)-(Al2O3)-N(Fe)/N(Ti)-N/(Al)/N(Al+Fe+Mn),ω(SiO2)2-ω(TFeO)  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.
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   

13.
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   

14.
15.
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   

16.
正20141520 Bo Ying(Key Laboratory of Metallogeny and Mineral Assessment,MLR,Beijing 100037,China);Liu Chenglin Saline Spring Hydrochemical Characteristics and Indicators for Potassium Exploration in Southwestern and Northern Tarim Basin,Xinjiang(Acta Geoscientica Sinica,ISSN1006-3021,CN11-3474/P,34(5),2013,p.594-602,5 illus.,3 tables,28 refs.)  相似文献   

17.
正20141243Chen Ge(Hangzhou Research Institute of Petroleum Geology,PetroChina,Hangzhou 310023,China);Si Chunsong Study on Sedimentary Numerical Simulation Method of Fan Delta Sand Body(Journal of Geology,  相似文献   

18.
正20142599Chen Sanming(Guangxi Key Laboratory of Concealed Deposits Exploration,Guilin University of Technology,Guilin541004,China);He Yuzhou Block Model and Reserves Estimation of Panzhihua Iron Deposit Based on 3D Geological Modeling(Journal of Guilin University of Technology,ISSN1674-9057,CN45-1375/N,33(4),2013,p.610-615,9illus.,1table,15refs.)  相似文献   

19.
正20140594 Bai Daoyuan(Hunan Institute of Geology Survey,Changsha 410016,China);Zhong Xiang Faults in the Jingzhou Basin and Their Tectonic Settings(Geotectonica et Metallogenia,ISSN1001-1552,CN44-1595/P,37(2),2013,p.173-183,6illus.,59refs.)Key words:basin evolution,tectonic setting,South China In the Upper Paleozoic and Jurassic se-  相似文献   

20.
正20141912Cao Hui(State Key Laboratory for Continental Tectonics and Dynamics,Institute of Geology,Chinese Academy of Geological Sciences,Beijing 100037,China)Gravitational Collapse and Folding during Orogenesis:A Comparative Study of FIA Trends and Fold Axial Plane Traces(Geology in China,ISSN1000-3657,CN11-1167/P,40(6),2013,p.1818-1828,9illus.,35refs.,with  相似文献   

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