黄土样中石英单矿物的分离   总被引：10，自引：0，他引：10  

孙有斌 《岩矿测试》2001,20(1):23-26

X射线衍射分析、扫描电镜测试和粒度分析结果表明，用焦硫酸钾熔融－氟硅酸溶解法可有效地分离黄土样中的石英单矿物，且提取后的石英颗粒形状和粒度组成没有明显受到化学反应影响。  相似文献   

陕西八卦庙金矿石英标型特征研究   总被引：1，自引：0，他引：1  

王学明  冯建忠  汪东波  邵世才 《黄金地质》2001,7(2):1-5

八卦庙金矿的石英可分为3期，即早期近EW向顺层脉、中期NE向节理脉和晚期缓倾斜切脉。X光衍射分析表明，石英的日胞参数、晶胞体积及有关衍射强度比值（I101/I100）和石英的Au的含量相关关系不明显，但总体上有关晶胞参数值较一般标准石英的要大；不同标高石英的晶胞参数表现为脉动式的变化。另外，从成矿早期到晚期；c0/a0和I101/I100值随温度降低而有所降低，石英薄片红外光谱研究结果表明，石英包裹体中H2O的相对光密度D1/D0值除一个样品较小（0.32)外，其斜 均在1.23-4.77，平均2.3143。总体上Au含量较高的石英其H2O和CO2的相对光密度D1/D0和D2/D0值也具相对较高的趋势；并且D1/D0和D2/D0具有密切的正相关关系，相关系数为0858。这种同步增长说明H2O和CO2气液丰富有利于Au的矿化定集，标高相差150 m样品的H2O和CO2的相对光密度值未发生显著变化且无意含Au性较好的信息说明八卦庙金矿深部的矿化前景依然不错。  相似文献   

与冬瓜山叠生式层状铜矿有关岩体地质地球化学特征   总被引：4，自引：0，他引：4  

姜章平  陈邦国等 《江苏地质》2001,25(2):87-91

主量元素全碱-硅投影显示青山脚岩体岩性为闪长岩、石英闪长岩；里特曼指数计算结果表明岩性呈钙碱性；岩体中Cu呈明显的正异常，说明含铜岩浆热液一方面叠加改造原始矿胚层，使层状铜矿进一步富集；另一方面含铜的岩浆热液在岩体边缘或接触带形成浸染状、网脉状矿床（既斑岩型矿床）。钾化与Cu富集呈正相关，钾化越强，Cu富集程度越高。稀土元素球粒陨石标准化曲线显示轻稀土富集重稀土亏损；δEu接近1.0，说明岩体分异演化程度不高。该岩体是重要的成矿物质和成矿流体来源，岩浆侵入与岩浆热液的叠加改造促使矿床规模扩大、品位提高。  相似文献   

ESR analysis of the Nojima fault gouge, Japan, from the DPRI 500 m borehole     

Hiroshi Matsumoto  Chihiro Yamanaka  Motoji Ikeya 《Island Arc》2001,10(3-4):479-485

Abstract Electron spin resonance (ESR) analyses of quartz grains in fault gouge were performed for a core sample taken from the Nojima Fault that moved during the 1995 Kobe earthquake (Hyogo-ken Nanbu earthquake). Distribution of radiation-induced defects in the gouge at a depth of 389.4 m was measured by extracting quartz grains from seven discrete positions within 30 mm of the fault plane on the granite side. The decrease in E'₁ and Al centers was observed within 2 mm of the fault plane, suggesting partial annealing due to faulting. Partial annealing even at that depth suggested that conventional ESR dating, which is based on the hypothesis of complete annealing during faulting, was not applicable. Theoretical calculations of the temperature rise and of the thermal annealing of defects have been made by assuming a simple annealing model of heat generation on the fault plane. Thermal energy was calculated to have been approximately 8 MJ/m² to explain the profile of the heat-affected region. Thermal energy was much larger than the one estimated from hydrothermal solution, and corresponded to the frictional heat calculated for a normal stress of 20 MPa, a displacement of 2 m, and a frictional coefficient of 0.2.  相似文献   

Variations of magnetic susceptibility and fine quartz accumulation rate in Daisen loam over the past 200 000 years: Interaction between winter and summer monsoons in south-west Japan     

Jun-Ichi Kimura  Yuji Okada  Katsuhiro Nakayama  Shomei Okada 《Island Arc》2001,10(2):85-97

Abstract A loam section near Daisen volcano, South-west Japan, has been examined for low-field magnetic susceptibility (MS) and fine quartz accumulation rate. Fission track dating of tephra layers interbedded in the deposit shows that the loam age ranges from about 200 ka to the Present. The MS was measured for both bulk sample and the < 63 μm fine fraction. Fine quartz contents in the < 63 μm fraction were also determined using acid-alkali digestions and recalculated to derive fine quartz accumulation rate (Rqz). Grain size analysis was then carried out on the separated fine quartz. Low-field MS varies from low frequency magnetic suspectibility (χ(LF)) 5 to 100 (× 10⁻⁶ m³/kg) for bulk samples and from 1 to 30 for fine fractions. The fine fraction χ(LF) variation correlated with Chinese loess MS stratigraphy, which indicated changes in pedogenic enhancement of the MS and is reflected by summer monsoon intensity. The Rqz are high in cool climate stages, with volumes between 0.2 and 0.4 (× 10⁻² kg/m² per yr), whereas in warm stages the rate falls to about 0.1. These values compare well with those reported from the Hokkaido and Kanto areas, suggesting the fine quartz originates from tropospheric dust. The strong winter monsoons during glacial stages alternated with weak summer monsoons as a result of a southward shift of the jet stream. In interglacials, summer monsoons were stronger. Seasonal alternating monsoons appear to have operated in South-west Japan through the past 200 000 years.  相似文献   

Rb—Sr Isotopic Chronology of the Au—Bearing Quartz Veins in Gold Depostits in the Eastern Part of North China Platform     

魏俊浩  刘丛强  唐红峰 《中国地球化学学报》2002,21(4):374-382

In the eastern part of Chian there had occurred large-scale gold mineralization during the Mesozoic,resulting in a large number of inprotant gold ore-concentrated areas.In this paper we have selected some isotope data(including four gold deposits previously studied and two gold deposis in this work)of Au-bearing quartz veins of the representative gold deposits in six impor-tant gold ore-concentrated areas in the periphery of the North China Platform and calculated their metallogenic ages using the method of Ludwig(2.90 version).The results show that the repre-sentative gold deposits in the six gold ore-concentrated areas were formed during the Mesozoic.  相似文献   

石英位错的会聚束电子衍射研究     

赵文霞  刘祥文 《矿物岩石》1997,17(3):1-4

矿物中位错的柏格斯矢量ｂ反映了矿物发生变形时所经历的条件，对它的精确测定为构造地质学研究提供了定量依据。本文用会聚束电子衍射的方法对石英位错进行了测定，同传统的双束法相比较，此方法更为简单和方便。  相似文献   

陕南勉略宁地区铜厂矿区的钠长岩   总被引：4，自引：0，他引：4  

叶霖  刘铁庚 《矿物岩石》1997,17(4):9-14

本文通过岩石学，稀土元素地球化学及Ｒｂ－Ｓｒ同位素年代学等研究，认为铜厂矿区内所分布的钠长岩形成时代为海西早期，由于海西早期闪长岩的侵入，带来了气液和热，使周围郭家沟组细碧岩中的部分Ｎａ质析出，并交代与之接触的闪长岩而形成钠长岩。  相似文献   

南极普里兹湾柱样中石英颗粒的表面结构   总被引：6，自引：0，他引：6       下载免费PDF全文

王祥珍  吴时国  李传荣  陈虹勋  罗又郎 《极地研究》1997,9(2):12-25

本文统计分析了南极普里兹湾陆坡区一个柱样（ＮＰ９５１）１３个层位的石英颗粒的形态和表面结构。石英表面呈现出强烈的冰川运动和较弱的化学溶蚀－沉淀作用留下的表面特征，表明该沉积物主要是处于低能海洋环境中的冰碛物。石英颗粒因化学溶蚀－沉淀作用形成的组合表面特征的定量统计结果与矿物的Ｘ射线衍射和微体古生物的分析结果相对应，能较好地解释该海区经历的沉积环境和古气候变化。  相似文献   

冀西北东坪金矿床的成矿期次及成矿阶段研究   总被引：1，自引：0，他引：1  

莫测辉  王秀璋  程景平  梁华英 《矿物岩石地球化学通报》1997,(3)

冀西北东坪金矿床的成矿期次及成矿阶段研究莫测辉（华南农业大学资源环境学院，广州５１０６４２）王秀璋程景平梁华英（中国科学院广州地球化学研究所，广州５１０６４０）关键词金矿床石英脉型蚀变岩型成矿期次成矿阶段“石英脉型”与“蚀变岩型”是中温（中深）热液脉...  相似文献