内蒙古大青山北前壕石英闪长岩锆石 U-Pb年龄及地质意义   总被引：2，自引：0，他引：2  

张玉清  刘俊杰 《华南地质与矿产》2004,(4):22-27

前壕石英闪长岩侵入到新太古界色尔腾山岩群中,它们与斜长花岗岩等共同构成了新太古代花岗岩-绿岩带,石英闪长岩岩石化学、地球化学显示为I型花岗岩系,与太古宙高铝型TTG花岗岩系特征一致,为不同源岩部分熔融的产物(可能有幔源岩浆参与).选自石英闪长岩中的锆石具岩浆型锆石的特点,5个单颗粒锆石U-Pb同位素年龄不一致曲线上交点年龄(2 535±16)Ma,代表了该岩体的结晶年龄.结合色尔腾山岩群的年龄分析,大青山地区花岗岩-绿岩带形成于2 500～2 900 Ma之间.该年龄的确定为华北陆台(或华北克拉通)的地壳演化提供了新证据.  相似文献   

ID-ICP-MS测定高纯石英中微量铀的方法研究   总被引：2，自引：1，他引：2       下载免费PDF全文

谭靖  姚海云  侯艳先  郭冬发  崔建勇  武朝晖  张彦辉 《地球学报》2003,24(6):627-630

采用一种脉冲增压微色谱柱，阴离子交换树脂，分离富集高纯石英中的微量铀，分离效果好，本底低。样品处理用低温密封闷罐酸溶。同位素稀释电感耦合等离子体质谱(ID-ICP—MS)测定高纯石英中的微量铀，方法检出限低：0．1ng/G(3σ，n=10)，分析速度快，是理想的测定微量铀的方法。  相似文献   

Textures and phase relationships in ferrous granulites from Tidjenouine (Hoggar, Algeria): fayalite–ferrossilite–quartz secondary assemblage     

Abderrahmane Bendaoud  Khadidja Ouzegane  Jean-Robert Kienast 《Journal of African Earth Sciences》2003,37(3-4):241

Ferrous granulites in the area of Tidjénouine (Central Hoggar) exhibit a remarkable mineralogical composition characterized by the association orthoferrossilite–fayalite–quartz. These granulites are metamorphosed mafic igneous rocks showing the juxtaposition of different metamorphic parageneses. Peak paragenesis with garnet–clinopyroxene–amphibole–plagioclase–quartz reach to assemblage with orthopyroxene–plagioclase₂. Secondary orthopyroxene reacted with garnet to produce symplectites with fayalite + plagioclase + quartz. The latest stage corresponds to an orthopyroxene–fayalite–quartz–plagioclase assemblage. The metamorphic history of the ferrous granulites is inferred by combining the study of phase relations with the construction of a petrogenetic grid and pseudosection in the CFMASH and CFAS systems using the Thermocalc program of [J. Metamorph. Geol. 6 (1988) 173]. The evolution of paragenetic minerals indicates a metamorphic P–T path through the following conditions: 7.1 ± 1 kbar at 880 °C, 4.9 ± 1.6 kbar at 750 °C and 3–4 kbar at 700 °C, which is consistent with a clockwise P–T path recorded throughout the area.  相似文献   

北祁连加里东造山带南缘钨矿成矿背景及找矿潜力   总被引：8，自引：0，他引：8       下载免费PDF全文

林国芳  刘凤萍 《甘肃地质》2003,12(1):78-84

北祁连加里东造山带主要钨矿类型为夕卡岩—石英脉型 ,其成矿与加里东中、晚期深源中高侵位中酸性侵入体有成因联系。成矿时代集中于 (4 6 2± 1 3)Ma～ (4 36± 32 )Ma ,与加里东期活动大陆边缘俯冲作用过程中的板块重熔—同熔—岩浆分异作用有关 ,由于其形成于区域大规模火山喷发之后 ,深部岩浆有一定分异 ,并存在广泛的矿源层条件 ,对钨的大规模成矿有利。因此 ,寻找大型以上的钨矿床必须综合考虑岩浆作用和矿源层两个主要因素。锰夕卡岩型银 (铅、锌 )矿床是北祁连南缘寻找大型以上规模钨银多金属矿床的重要目标  相似文献   

北塔山地区石英脉红外光密度特征及其意义   总被引：1，自引：0，他引：1  

张保民  高怀忠 《地质科技情报》1998,17(3):107-112

新疆北塔山东南部及小哈甫提克地区石英脉中Ｈ２Ｏ的相对光密度绝大部分大于１．０大部分在３～５之产变化,ＣＯ２的相对光密度大于０．１,大部分在０．３～０．５之间的变化,随着石英脉中Ｈ２Ｏ的相对光密度平均值由于２．５０→３．９５→４．８７,Ｈ２Ｏ与ＣＯ２的相对光密度比值的平均值由６．４３→７．２０→１３．３４,金的平均含量由零逐渐升高,含金石英脉由近地表深部,Ｈ２Ｏ和ＣＯ２相对光密度平均值分别为４．９５  相似文献   

Physicochemical, mineralogical, and geochemical characteristics of lacustrine sediments of the Konya Basin, Turkey, and their significance in relation to climatic change     

K. Inoue  M. Saito  T. Naruse 《Geomorphology》1998,23(2-4)

Physicochemical, mineralogical, and geochemical characteristics of 279 highly calcareous lacustrine sediment samples obtained from a 30 m drilling core in the western part of the Great Konya Basin, Turkey were studied. The sediments have a predominance of silt and clay fractions with a median diameter of 3–5 μm. Vertical changes of the amounts of water soluble components, gypsum, carbonates, and non-salt minerals such as quartz, feldspars, and layer silicates in the sediments suggest that there were climatic changes in the Konya Basin. The dominant clay mineral is smectite followed by kaolinite, illite, and palygorskite. The oxygen isotopic (δ¹⁸O) ratios of six quartz samples from the Konya sediments, a terra rossa soil beside Lake Bey ehir gölü and paleosols at the foot of Mt. Erciyes Da ranged from +18.1 to +20.6‰. The dominant clay minerals and δ¹⁸O ratios suggest that part of quartz and coexisting layer silicates is of long-range transported and/or local aeolian dust origin from arid and semi-arid regions such as North Africa, Israel, and the surroundings. The relatively high deposition rate might be due to aeolian dust input and/or the sediment input introduced by the rivers such as the Çar amba river from the Toros (Taurus) mountains. The vertical distributions of electro-conductivity, amounts of water soluble and non-salt components, and the gypsum content of the sediments suggest that gypsum-rich layers were formed under shallow, saline waters, possibly associated with warm to hot and dry environments such as the Last Interglacial epoch and the Early Holocene. The sediments characterized by relatively high amounts of non-salt sediments, in which gypsum did not accumulate, could be deeper water phases formed under the cold and/or wet environments such as the Glacial epochs.  相似文献   

川西致密砂岩的石英次生加大及其对储层的影响   总被引：7，自引：0，他引：7  

张硝楠 Qing  H 《地质论评》1998,44(6):649-655

石英次生加大以及伴生的自生粘土矿物是影响储层性质的重要因素。石英次生加大是受温度控制的成岩矿物,随着温度的升高,石英次生加大的含量也随之增加,导致孔隙度的降低。钾长石和高岭石的温度〉９０℃反应形成的伊利石,造成了储层渗透率的降低。本文通过对石英次生加大产出特征和流体包裹体温度的研究,进而讨论川西香溪群致密砂岩储层的成因。  相似文献   

Thermoluminescence characteristics of quartz implanted by nickel ion     

Huhou Li 《中国科学D辑(英文版)》1998,41(4):437-441

The implantation of artificial quartz with nickel ion has succeeded in using a heavy ion accelerator. The quartz with nickel ion is called ”nickel quartz“. The sensitivity of their thermoluminescence (TL) response to the beta radiation was decreased with the increasing of irradiating and heating times. Two TL characteristics have appeared: the sensitivity of TL response at lower temperature (ll0°C) peaks of the nickel quartz to beta radiation is higher than that of the pure quartz, this results from the Ni⁺¹ ion entering the quartz lattice; and a new peak appearing at 445°C may be related with both Ni⁺¹ and Ni⁺³.  相似文献   

山东山城金矿Ⅷ号脉矿物找矿标型   总被引：5，自引：1，他引：5  

胡大千  纪宏金等 《地质与勘探》2002,38(1):50-52

对矿体主要载金矿物黄铁矿的晶体形态和电物理性质以及石英的红外光谱特征等进行了较详细的研究，建立了矿物学找矿模型，提出了深部找矿靶区，其深部矿体预测，已为后期勘探所证实。  相似文献   

石英玻璃原料矿的流体包裹体特征   总被引：4，自引：0，他引：4  

周永恒  顾真安 《矿物学报》2002,22(2):143-146

研究不同产地石英玻璃原料矿中包裹体的显微形貌、均一温度及红外光谱特征，矿物加工成高纯石英粉后，在氢气保护高温电炉中溶制成石英玻璃。分析原料矿包裹体特征与石英玻璃气泡、羟基质量的联系，结果表明：高温下不爆破的流体包裹体是形成石英玻璃气泡的主要因素，包裹体中的水发子溶解于SiO2熔体中形成石英玻璃的残余羟基。  相似文献