排序方式: 共有52条查询结果,搜索用时 15 毫秒
21.
22.
华北地台钼(铜)矿床成矿年代学研究——辉钼矿铼-锇年龄及其地质意义 总被引:31,自引:7,他引:31
华北地台北缘的工产辽和南缘的东秦岭两个钼矿带闻名遐迩。本文用同位素稀释-等离子体质谱法,直接测定了燕辽钼矿带中兰家沟钼矿床的Re-Os等时线年龄为(186.5±0.7)×10^6a,杨家杖和肖家营子钼矿床的Re-Os模式年龄为(187±2)×10^6d-(d191±6)×d10^6a和(177±5)×10^6a,小寺沟和寿王坟铜矿床的Re-Os模式为DD(134±3)×10^4a和(148±4)× 相似文献
23.
我国首次发现的砷钙锌石和羟砷锌石产于内蒙古自治区额济纳旗老硐沟金矿脉
氧化带矿石的空洞中。砷钙锌石多呈半自形或自形晶体,绿或淡绿色,透明,比重4.32(计算)。
Ng=1.778,Nm=1.760,Np=1.756,二轴晶(+),2V=46°。化学分子式为Ca0.99(Zn0.94
Cu0.07)1.01[(AsO4)0.97(CO3)0.03]1.00(OH),其中(CO3)2-取代部分(AsO4)3-为红外光谱分析所
证实,这不同于国外报道的砷钙锌石。据X射线粉末衍射分析的主要谱线,计算得其晶胞参数:
a=0.7473nm,b=0.9017nm,c=0.5916nm。羟砷锌石常呈集合体或单个晶体产出,淡黄绿色
或无色,透明,比重4.44(计算)。Ng=1.761,Nm=1.738,Np=1.719,二轴晶(+),2V=87°。
化学分子式为(Zn1.97Ca0.02)1.99(AsO4)(OH)。据X射线粉末衍射分析的主要谱线,计算得其晶
胞参数:a=0.8304nm,b=0.8516nm,c=0.6054nm。 相似文献
24.
25.
Dating of metallic ore deposits has been one of the problems concerned with by ore geologists for many years.The establishment of the Re-Os Isotope Laboratory at the Institute of Rock and Mineral Analysis,Chinese Academy of Geological Sciences, has provided us with a new technique to carry out geochronological studies of molybdenum ores.As one of the most important Re-bearing minerals, molybdenite contains almost no common osmium, but ^187Os was derived completely from decay of ^187Re, with ^187Os content as the function of Re content in the mineral .An ID-ICP-MS technique has been used in this study,and Re-Os isotopic ages of several large molybdenum deposits of differ-ent types from the East Qinling molybdenum belt have been determined.It is indicated that the Huanglongpu carbonatite vein-type molybdenum-(lead) deposit has a Re-Os age corresponding to Indosinian,while the rest porphyry-type molybdenum deposits and porphyry-skarn-type molybdenum-(tungsten) deposits have Re-Os ages corresponding to Yenshanian. 相似文献
26.
27.
陕西金堆城斑岩钼矿床地质特征及成因探讨 总被引:25,自引:4,他引:25
金堆城花岗斑岩在燕山期侵位于元古代熊耳群变细碧岩中,按其岩石化学特征应属高硅富钾的钙碱性系列岩石。钼矿化发育于斑岩体及其外接触带内,矿体由含钼石英细网脉组成,最大矿化深度约达1000m。围岩蚀变自斑岩体向外为:钾化、绢(云)英岩化→硅化→青磐岩化,其中以硅化最为强烈且与钼矿化关系最密切。气液包裹体与含子矿物多相包裹体常常共存,主要成矿温度为300—400℃。硫、氧和碳同位素特征表明,主要成矿阶段的成矿流体是以岩浆水为主的混合液,硫、钼主要来源于花岗岩浆。低f_(o2)、高f_(s2)的弱酸性还原条件以及成矿流体沸腾是辉钼矿沉淀的主要因素。矿床成因类型属斑岩型中高温热液钼矿床。 相似文献
28.
29.
30.