158 resultados para 359
Resumo:
建立区域成矿系列的主要作用之一就是利用成矿系列来进行成矿预测。成矿系列具有明确找矿方向的作用,在具体找矿靶区预测时,结合区域物、化探和矿化、蚀变等找矿标志可以起到更为有交的预测效果。本文利用已经建立的区域成矿系列,结合区域地球化学异常和矿化、蚀变分带,对延边金苍地区进行了金矿成矿预测,提出了新的预测区。通过成矿预测工作,认为以成矿系列为理论基础进行成矿预测时,有必要建立相应的区域成矿系列预测体系和预测靶区评价体系,其中分析多种控矿因素和找矿标志的时空分布是其主要研究内容。
Resumo:
从矿物学、地球化学两个方面对钾质斑脱岩的研究进展进行综合评述.矿物学研究表明,钾质斑脱岩为岩浆成因,由粘土矿物与非粘土矿物组成,粘土矿物以伊-蒙混层矿物和伊利石为主,非粘土矿物包括原生斑晶矿物和次生矿物.钾质斑脱岩的矿物学研究有助于地层对比难题的解决,亦将促进古大陆再造研究.钾质斑脱岩及斑脱岩的主量元素数据统计结果显示,钾质斑脱岩以相对富钾为特征,K2O含量一般大于3.5%.微量元素数据统计表明,钾质斑脱岩的微量元素以Th、U的明显富集为特征,同时均具有负Eu异常并缺乏负Ce异常.通过对早寒武世、奥陶纪及志留纪的钾质斑脱岩的微量元素特征进行对比研究,认为不同时期钾质斑脱岩的微量元素与REE的配分模式表现出不同的特征,尤其是Nb/Y、Th/U等微量元素比值及(La/Yb)N、(La/Sm)N、(Gd/Yb)N、δEu和δCe等稀土元素参数的差异明显.经对比,初步判定滇东石岩头组底部钾质斑脱岩与遵义石岩头组钾质斑脱岩可能不属于同一期火山活动的产物.
Resumo:
对云南白牛厂超大型银多金属矿床的地质、地球化学特征厦矿床形成的长期性及多阶段性的研究认为:白牛厂银多金属矿床是热水沉积—叠生成因矿床,早期呈现寒武纪的热水同生沉积成矿作用,晚期为燕山期花岗岩浆热液成矿作用。该矿床是热水沉积成矿作用与岩浆热液成矿作用叠加成矿的产物.
Resumo:
Starting with the research status of bio-metallogenesis of Tl deposits and their geology, this work deals with the geological background of Tl enrichment and mineralization and the mechanism of bio- metal-logenesis of Tl deposits, as exemplified by Tl deposits in the low-temperature minerogenetic province. This research on the bio-metallogenesis of Tl deposits is focused on the correlations between bio-enrichment and Tl, the enrichment of Tl in micro-paleo-animals in rocks and ores, bio-fossil casts in Tl-rich ores, the involvement of bio-sulfur in minerogenesis and the enrichment of bio-genetic organic carbon in Tl ores. Thallium deposits have experienced two ore-forming stages: syngenetic bio- en-richment and epigenetic hydrothermal reworking (or transformation). Owing to the intense epigenetic hydrothermal reworking, almost no bio-residues remain in syngenetically bio-enriched Tl ores, thereby the Tl deposits display the characteristics of hydrothermally reoworked deposits.
Resumo:
Polypyromellitimide molding powder has been prepared. In the 78-370 K range, the dependence of the specific heat capacity (c(p)) on the temperature (T) is given by the polynomial: c(p)=0.8163+0.4592X+0.02468X(2)+0.1192X(3)+0.05659X(4) (J K-1 g(-1)) where X=(T-225.5)/144.5. Thermal decomposition in air starts at 716 K, and is complete at 1034 K. The standard combustion enthalpy is Delta(c)H=-26.442 kJ g(-1). (C) 2000 Elsevier Science B.V. All rights reserved.