Secular variations of the upper crust composition: Implication of geochemical data on the Upper Precambrian shales from the Southern Urals western flank and Uchur-Maya region

In the mid-1980s, it was concluded based on geochemical study that Th, Sc, La concentrations and ratios Th/Sc, La/Sc and Eu/Eu* did not wary significantly in the post-Archean time. It was impossible to judge about compositional variations of upper crust during the Riphean and Vendian, because data of that time characterized a limited number of samples from the post-Archean basins of Australia, New Zealand, and Antarctic. Considered in this work are variations of Eu/Eu*, LREE/HREE, Th/Sc, and La/Sc ratios in Upper Precambrian fine-grained siliciclastic rock of the Southern Urals western flank (Bashkirian meganticlinorium) and Uchur-Maya region (Uchur-Maya plate and Yudoma-Maya belt). As is established, only the Eu anomaly in the studied siliciclastic rocks is practically identical to this parameter of the average post-Archean shale. Three other parameters plot on the Riphean-Vendian variation curves with positive and negative excursions of diverse magnitude, which do not coincide always in time. It is assumed that these excursions likely mark stages of local geodynamic activity, destruction of pre-Riphean cratons, and progressing recycling of sedimentary material during the Riphean.     

湖南瑶岗仙钨矿中石英的标型特征

以湖南宜章县瑶岗钨矿床为例，较系统地研究了石英的标型特征，如稀土元素，微量元素，铝及碱质含量，热发光性，包体化学成分和温度，红外光谱等，总结了这类矿床的石英标型特征以及含矿石英与无矿石英的区别。     

内蒙古额仁陶勒盖银矿床石英的矿物标型特征研究

对额仁陶勒盖银矿床中石英的稀土元素，包裹体测温、包裹体成分、同位素、化学成分及红外光主普学特征等进行了研究，认为额仁陶勒盖银矿床属于浅成中温热液成因，早期成矿流体为岩浆热液，晚期成矿流体天水臧主导地位，矿床形成于弱碱性条件下及还原环境中。石英的红外光谱学特征、石英的化学成分及形态是该银矿床重要的找矿矿物学标志。     

二道沟金矿床中黄铁矿的标型特征

本文从黄铁矿形态、成分、物理性质和硫同位素方面研究了二道沟金矿床中黄铁矿的标型特征,得出二道沟金矿黄铁矿的标型特征是:晶形以五角十二面体、立方体或其聚形品为主,高S/Fe值,高As、Bi、AuAg,高As/Sb值,高Cu、Pb、Zn,低Hg、Co、Ni,Co/Ni值大于1。黄铁矿导电类型为空穴型、混合型和电子型,以混台型为主;δ~(34)‰直绝大多数为-2—+3。研究表明,黄铁矿标型可直接作为寻找和评价金矿的矿物学标志以及确定矿床成因的指示标志。     

国内空间数据挖掘研究进展与技术体系探讨

基于空间数据具有的海量、非线性、尺度性等特点,分析了空间数据挖掘技术具有的复杂性、尺度性、综合性、空间性、可视化、多样性特征,并结合调研国内5年来空间数据挖掘研究进展,探讨分析了空间数据挖掘技术体系的组成内容。     

安徽庐枞盆地井边铜(金)矿床成矿特征及控矿地质因素探讨

井边矿床位于庐枞盆地中部,为中低温热液脉型铜(金)矿床。矿体沿断裂和构造破碎带呈陡倾脉状产出。矿石构造主要为细(网)脉状、晶洞(簇)状,次为角砾状;矿石结构为交代和结晶作用形成的各种结构。黄铁矿成分标型Co/Ni、Fe/（S+As）、S/Se等比值特征显示成矿热液主要为中低温岩浆热液。黄铜矿单矿物、巴家滩岩浆岩的稀土元素特征与盆地砖桥旋回火山-次火山岩的稀土元素特征总体类似,矿石稀土元素继承或保存了含矿岩浆岩的源区信息。结合区域地质年代学资料以及矿体和正长斑岩脉均产于与火山_次火山安山玢岩相同的构造体系中等现象,推测成矿热液可能来源于火山喷发之后的次火山-侵入岩的岩浆期后热液。断裂构造是控制井边矿床的重要因素。本区构造与中国东部中生代新华夏体系一致,在区域南北左行对扭力场中,发生了强烈的断裂构造活动。“应变菱形解析”显示： 第一序次的NE向、NW向与第二序次NW向、EW向、NNW向断裂共同控制矿床的产出。井边矿化区的分布呈现出从虎栈—张榜总体沿NE40°成带、NW310°成行的特点。     

青海滩间山金矿床找矿矿物学研究

本文重点讨论了滩间山金矿床主要矿石矿物的标型特征及其地质意义,可用于矿床类比及该类型金矿床的找矿评价和预测。     

锆石形态标型特征及标型生长机制探讨

本文在系统总结归纳不同研究者对锆石形态标型特征的研究成果基础上，重点从晶体生长、晶体化学和地球化学理论为重点探讨了锆石形态标型特征的生长机制。研究表明：锆石晶体结构中不同的面网方向，其平面内的原子组成、比例、化学键联结和键力以及面网间距和密度都是有差别的，由此决定了锆石晶体在不同的结晶介质条件下，不同面网的生长速度发生改变，生成相应的晶形。例如，尽管碱性元素并不进入锆石晶格，但它们可以影响Ｚｒ、Ｓｉ、Ｏ离子的扩散速度，但是富钾和富钠的介质对锆石晶形发育的影响是有差别的，表现为：在富钾的介质中，将导致柱面的法向生长速度较锥面快得多，而锥面中，｛１１１｝的法向生长又较｛３１１｝快，由此决定了形成以｛３１１｝锥为主的双锥状晶体；在富钠的介质中，柱面和锥面都有一定程度的发育，但前者弱于后者，而柱面中，｛１００｝的法向生长较｛１１０｝慢，由此决定了形成以｛１００｝柱和｛１１１｝锥为主的短柱锥状晶体。根据类似方法，论证了其它形态标型特征的客观性，从而揭示了标型之间的内在联系和本质，展示了花岗岩研究中锆石形态标型特征应用推广的前景，也可为单颗粒锆石定年研究提供更多的分析应用价值     

鄂霍次克海北部海岸基岩和积雪中石油产品溢油运移的地球化学过程

In selecting methods of liquidation of natural pollution resulted from oil products (OP) in the cold regions, such as in the north coast of the Sea of Okhotsk, it is necessary to take into consideration the peculiarities of the OP and the object polluted in cold and warm periods. Generally, in cold time snow cover with thickness of 1. 0m or more presents, so the OP is partly absorbed by the silt in the snow, then the viscosity of snow is strengthened due to the aggregate of the hard hydrocarbon components (HCC) with negative temperature in the OP. The HCC is the most active when the molecular of carbon atom is less than 10, and could not be harden at the temperature below -30 ℃. However, in summer time the spilled HCC is partly evaporated, but the tar and asphalt enrich the OP there. In the mountainous regions at the deep deposition of underground water, in summer the OP might be brought by the gas stream in the massifs of the fracture rocks upper on the slope. According to the peculiarities, the methods of fighting the nature, polluted by the OP in the regions of the Sub-Arctic; are explained, and they are representative in the north coast of the Sea of Okhotsk.     

陕西东沟坝金银矿床黄铁矿标型性研究

陕西东沟坝金矿床黄铁矿成分亏硫，低Ｃｏ，Ｃｏ／Ｎｉ＜０．５，晶形以ａ，ａｅ和ａｅｏ聚形为主，热电性以ｎ，ｐｎ型为主，矿床四维上的特征表明其具复成因标，通过研究，总结出黄铁矿的矿化标志：硫亏损少，热电系数为常见值，且离散极差大，形态系数在１４～－１５２之间。