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1.
南秦岭主要类型热水沉积岩的REE地球化学   总被引:1,自引:0,他引:1  
南秦岭泥盆纪沉积柱中产有多种类型海底热水沉积岩.它们的ΣREE偏低(平均63.09×10-6),REE配分曲线平缓右倾,La/Yb=2~8,Ce亏损,总体上与海水相似。产于Sedex含矿层中的热水沉积岩具有正Eu异常,与现代海底热液及红海热液沉积物可比;而产在Sedex含矿层以下地层中的热水沉积岩Eu亏损,与EPR热液沉积物相似。REE地球化学研究和岩石学研究结果一致,支持热水沉积岩REE来源于海水及部分下伏沉积柱(包括基底),含矿热水沉积岩是盆地热演化到一定阶段具有一定深度和规模的循环对流体系在海底的化学沉积,而Sedex含矿层以下地层中的热水沉积岩则是浅部热水对流循环的海底显示.成岩和变质作用对岩石的REE未造成影响。  相似文献   

2.
为了研究甘肃徽县郭家沟铅锌矿床成因,分别对赋矿硅质岩的常量、微量和稀土元素及叠加热液碳酸盐矿物的 C、O、Sr同位素和石英流体包裹体的 D、O 同位素进行了系统分析。结果表明:硅质岩常量元素 Al/(Al+Fe+Mn)比值为0.08~0.30(平均为0.19),介于纯热水硅质岩与正常海相沉积硅质岩之间,靠近热水沉积端元; 其球粒陨石标准化的稀土元素配分曲线显示明显的 Eu正异常,与海底热水沉积物 REE配分曲线类似,指示硅质岩为热水沉积成因,为泥盆纪同生喷流沉积的产物。后期叠加的热液碳酸盐矿物的 C、O 同 位 素 组 成 特 征,指 示热液中的 C、O 主要来自地层中沉积灰岩,并通过灰岩溶解作用过程获得。热液碳酸盐矿物与灰岩Sr同位素比值部分重叠,而高于糜暑岭岩体初始Sr同位素比值,指示热液中的 Sr主要来自灰岩而非花岗岩。石英流体包裹 体
的 D、O 同位素组成与岩浆流体接近,指示石英-硫化物阶段成矿流体主要来自岩浆热液。综上所述,郭家 沟 铅锌矿床为一经历泥盆纪同生喷流、印支期岩浆热液叠加改造成矿的复合型层控铅锌矿床。   相似文献   

3.
秦岭泥盆系铅锌成矿带中闪锌矿微量元素特征表明矿床属海底喷气成矿,成矿流体温度为低温.矿床可划分沉积和热液改造两大成矿期,以前者为主.沉积作用形成的闪锌矿富Ga、Ge、Cd,浅色,晶胞参数小;后期热液改造形成的闪锌矿富Fe、Mn、In、Se,色深,晶胞参数大.  相似文献   

4.
文章通过广西凤凰山银锰矿床中S-Fe-Cu-Ag-Sn系列矿物黄锡矿、含银黄锡矿、银黄锡矿、硫银锡矿的化学成分标型、标型矿物组合特征的研究,为该矿床的成因、深部隐伏银矿化、矿区及其外围的找矿提供了一定的信息。  相似文献   

5.
八家子银-多金属矿床是燕山期形成的热液充填交代脉状矿床。矿床的铁锰矿物组合大致分两期:一期为石英-锰橄榄石-方解石-黄铁矿组合;二期为石英-蔷薇辉石-铁锰碳酸盐矿物及银多金属硫化物组合。成矿溶液中Mn ̄(2+),Mg ̄(2+),Ca ̄(2+),Fe ̄(2+)离子对银的沉淀富集作用十分显著,尤其是Mn ̄(2+),Fe ̄(2+)可使Ag ̄+还原到自然状态。银矿物主要以细粒、微粒、浑圆粒状、乳滴状包裹体的形式赋存在黄铁矿等硫化物中:或以类质同像及杂质的形式与铁、钙矿物形成银-铁、银-锰的共生体。铁锰矿物多形成于中低温热液阶段,因该阶段S ̄(2-)含量较高,故极有利于银-多金属硫化物的形成。  相似文献   

6.
在广东茂名地区二叠系地层中存在与地层整合产出的层状硅质岩。硅质岩富Fe、Mn,相对贫Al;富集As、Sb、Bi,Ga等微量元素;稀土元素总量低,Ce弱负异常,重稀土相对富集;δ30Si值变化范围为0.0003~0.0007,δ18O值变化范围为0.0148~0.0223,均具热水沉积硅质岩的地球化学特征。在Al-Fe-Mn和Fe-Mn-(Ni+Co+Cu)三角图上,本区硅质岩均属于典型的热水沉积硅质岩。硅质岩MnO/TiO2比值、δCe值和δ30Si值分析表明,本区展状硅质岩主要是在大陆边缘的浅海环境下沉积的。  相似文献   

7.
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,查明了化学成分与成矿的关系: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Sc、Zr、Ni、Zn及La/Yb,低Y、Nb、Th、Cd、Ba、Be、ΣREE,利于金红石纯度提高。对研究矿床成因及寻找新的同类矿床等有重要意义  相似文献   

8.
老厂铅锌矿床不同成因类型矿脉中的方铅矿、闪锌矿微量元素组成有明显差别。石英方铅矿脉的方铅矿以高Ag、Sb、Sn和低Ge、Cd、Te为特征,与区域上典型岩桨热液矿床相一致。与闪锌矿共生的方铅矿则以低Ag、Sb、Sn和高Ge、Cd、Te为特征。所有闪锌矿以低Fe、Mn、In、Ag、Sn和高Ga、Ge为特征,均与国内典型的沉积改造型矿床相一致。根据这些特征可把本区叠加在一起的不同成因类型矿床区分开来。因此,老厂地区铅锌矿床中的方铅矿、闪锌矿的特征元素含量及其比值,可作为区分本区不同成因类型铅锌矿床的重要地球化学标志。  相似文献   

9.
对粤东北新丰地区基性岩脉进行了年代学、元素地球化学研究。结 果 表 明:新 丰 地 区 近 SN 向 和 NWW 向 基 性 岩 脉 的锆石 U-Pb年龄分别为(148.6±4.1)Ma(MSWD=1.3)和(85.7±2.0)Ma(MSWD=1.4),成岩时代为晚侏罗世和晚白垩世。基性岩脉具低碱富钠、较高钛含量、富铁、中等镁含量和准铝质特征。稀土元素标准化曲线呈小角度右倾斜型,轻重稀土元素中等分馏、轻稀土元素富集。微量元素表现出富集 Ba、Rb、K,亏损 Ta、Nb、Zr、Hf和 P等 特 征。晚侏罗世基性岩脉轻微 Ce负 异 常(δCe=0.89~0.93)和弱 Eu正异常(δEu=1.00~1.05),Th/Yb比值比较高,表明岩浆源区可能遭受过富 Th俯 冲流 体 交 代。2组 基性岩脉岩浆源区均来自地幔,可能经历了石榴石-尖晶石二辉橄榄岩的部分熔融,并发生了单斜辉石、Ti-Fe氧化物矿物的分离结晶作用。新丰地区基性岩脉具有大陆裂谷玄武岩特征,形成于陆内裂谷环境,但早期基性岩脉(148.6Ma)较晚期 (85.7 Ma)具有相对较浅的岩浆源区。   相似文献   

10.
钢屯超单元花岗岩是一种壳幔混源的同源岩浆在单向性和序列性演化的基础上形成的。在空间上岩体呈北东向带状分布,时间上表现为一个完整的成岩系列;岩浆分异演化则呈酸度、碱度增强的趋势,这种完整的成岩系列及酸碱增高的趋势与钢屯超单元成矿相关联,并且形成了钢屯超单元一个完整的成矿系列:Fe,Pb,Zn-Fe,Pb,Zn,Mn,Cu-Mo,Cu,Pb,Zn成矿系列。  相似文献   

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12.
Based on the hydrographic data in austral summer during the 22nd Antarctic Expedition of China(2005/2006),some features can be found about the northern margin of Emery ice shelf as follows.The heat content in the surface layer(0-50 m) at the eastern end and the western end of the ice-shelf margin is much higher than that at the middle.The upper mixing-layer depth and the seasonal thermocline depth at the middle of the ice-shelf northern margin are much shallower than those at the both ends.However there is much less difference between the middle and the ends in the bottom layer.The remote sensing photos show that the inhomogeneity in the surface-layer water is closely related to the spatial distribution of the floes and polynia in the area.  相似文献   

13.
Phylogenetic analysis based on 16S rDNA of 8 strains of cultivable bacteria isolated from Arctic sea-ice was studied.The results showed that strain BJ1 belonged to genus Planococcus,which was a genus of low mole percent G C gram-positive bacteria;strain BJ6 belonged to genus Burkholderia of β-proteobacteria and the rest 6 strain all belonged to γ-proteobacteria,of which strain BJ8 was a species of Pseudoalteromonas,strain BJ2-BJ5 and BJ7 were members of genus Psychrobacter.Phylogenetic analysis also indicated that bacteria of genus Psychrobacter of the isolates formed a relatively independent phylogenetic cluster in comparison with other bacteria belonged to genus Psychrobacter.  相似文献   

14.
正1 Aims and Scope Advances in Polar Science(APS)is an international,peer-reviewed journal jointly sponsored by the Polar Research Institute of China and the Chinese Arctic and Antarctic Administration.APS is a comprchensive academic journal dedicated to presentation of multi-disciplinary achievements in Arctic and Antarctic expeditions and research.Its primary purpose is to publish achievements in fundamental research,applied  相似文献   

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16.
《山地科学学报》2014,(4):I0004-I0009
<正>AIMS AND SCOPE(Editorial Policy)The Journal of Mountain Science(JMS)is devoted to mountains and their surrounding lowlands-ecoregions of particular global importance,with a particular emphasis on the important highlands/mountains in the world,such as the Tibetan Plateau,the Himalayas,the Alps,the Andes,the Rockies and many other mountain ranges of our planet.  相似文献   

17.
<正>The Journal of Mountain Science(JMS),founded in2004,is an international English-language journal on mountain sciences.JMS is supervised by the Chinese Academy of Sciences(CAS),sponsored by the Chengdu Institute of Mountain Hazards and Environment,CAS,published by Science Press China,and distributed by Springer exclusively throughout the world(excluding Mainland China).The JMS is published bimonthly,fulltexted in SpringerLink and CNKI,indexed/abstracted by  相似文献   

18.
Using the NCEP/NCAR reanalysis monthly 500 hPa height data on a 2.5 latitude-longitude grid and 1°×1° sea ice data,the polar vortex area,intensity index and arctic sea ice area index are calculated respectively,and the meridional distribution,period variation and the abrupts in the long range trend are analyzed to study their relationship.The results show that the meridional distribution of sea ice and polar vortex h-ave distinctive difference,the relative positions of them are different in the eastern and western hemispheres,and exept they have periods of 4 months,quasi half year,quasi year,4-5 years and 10 years commonly,and each of them has its own respective variation as well.The sea ice area is decreasing apparently since 1980's,so is the polar vortex area,but their abrupt changge time are different totally.The area of sea ice and polar vortex has prominent positive correlation,but the relationship of sea ice intensity,polar vortex intensity,polar vortex area is complicated.  相似文献   

19.
The ability of cell to modulate the fluidity of plasma membrane was crucial to the survival of microorganism at low temperature. Plasma membrane proteins, fatty acids and carotenoids profiles of Antarctic psychrophilc yeast Rhodotorula sp. NJ298 were investigated at -3 ℃, 0 ℃ and 8 ℃. The results showed that plasma membrane protein content was greater at -3 ℃ than that at 8 ℃, and a unique membrane polypeptide composition with an apparent molecular mass of 94.7 kDa was newly synthesized with SDS-PAGE analysis; GC analysis showed that the main changes of fatty acids were the percentage of unsaturated fatty acids (C18∶ 1 and C18∶ 2) and shorter chain saturated fatty acid (C10∶ 0) increased along with the decrease of the culture temperature from 8 ℃ to -3 ℃; HPLC analysis indicated that astaxanthin was the major functional carotenoids of the plasma membrane, percentage of which increased from 54.6±1.5% at 8 ℃ to 81.9±2.1% at -3 ℃. However the fluidity of plasma membrane which was determined by measuring fluorescence anisotropy was similar at -3 ℃, 0 ℃ and 8 ℃. Hence these changes in plasma membrane's characteristics were involved in the cellular cold-adaptation by which NJ298 could maintain normal plasma membrane fluidity at near-freezing temperature.  相似文献   

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