Physicochemical Conditions of the Formation of Beryl and Aquamarin in Mufushan Granopegmatite Deposit,Hunan Province,China

The formation of the Mufushan granopegmatite was closely related to the Late Yenshanian multiphase and multistage magmatic activities,More than one generation of beryl and aquamarine occur in different types of pegmatite in the granites.The presence of melt and melt-fluid inclusions strongly indicates a melt-solution character of the pegmatitic magma.Forming temperatures of the different generations of beryl in a Na^ -K^ ,Ca^2 -CO3^2--Cl^--SO4^2- solution ranges from 990℃to 200℃.Aquamarine was formed at 720-180℃.The contents of alkali metals(Na^ K^ )in th ore-formming solution of aquamarine are lower than those in the beryl,but the contents of alkali earths(Ca) and salinity are higher,The granite was generated by remelting of the basement formation(meta-sedimentary rocks of the Lengjiaxi Group)which also served as the source of ore-forming material.Beryllium in the pegmatite was transported mainly in the form of Na[Be(CO3)2],with part of it being complexed with Cl^- and SO4^2-.During the generation and evolution of the pegmatite,equilibrium might have been reached in the solid-melt-fluid or solid-fluid system.The intergranular solutions may have reacted with the early crystallized minerals,resulting in potash-feldsparization,albitization and muscovitization during which the ore-forming elements were mobilized and transported in favour of ore deposition.     

粒间溶液形成条件的实验研究

粒间溶液形成条件的实验研究李兆麟，雷丽红，郭洪中，蒋浩深，赵梅芳（中山大学地质系，广州５１０２７５）（南京大学地球科学系，南京２１００００８）关键词粒间溶液，实验地球化学关于粒间溶液成矿的问题，作者在１９８６年进行过论述，１９８９～１９９２年进行了深...     

粒间溶液与成矿作用

本文通过对20多个矿床的野外地质特征及室内矿物中的包裹体、高温-高压成岩、成矿实验和元素地球化学研究,论述了花岗岩浆性质属熔体-溶液,并分析了岩浆冷凝过程中的局部岩浆分异作用形成粒间溶液的机制,进一步提出与花岗岩有关的矿床成矿溶液主要来源于粒间溶液。这一论点不但可以解释与花岗岩有关的成矿溶液来源问题,而且可以合理解释花岗岩体内自变质蚀变交代作用及其与成矿的关系,此外对研究矿床成因均有重要意义。     

浙江绍兴——龙泉隆起带中金矿床的原生及次生地球化学异常研究

本文对浙江省绍兴一龙泉隆起带内代表性金矿床的原生及次生地球化学异常特征进行了系统研究,确定了异常中最主要的指示元素以及它们自近矿至远矿、从矿下到矿上的分带序列和组合特征,并总结出在本区及邻区金矿勘查中具有实际意义的综合地球化学找矿标志。     

实验地球化学展望

近年来,我国实验地球化学在当前地质事业不景气的情况下,每年国家自然科学基金都注意到支持和扶植这一领域的研究项目,并取得不少成绩。此外,已创立的实验基地及各实验地球化学实验室为科研生产服务,发挥了积极作用。在新的形势下,实验地球化学往何处去?如何走出一条适合于当今科学及经济发展的道路?现提出一点肤浅见解供大家参考。 1.实验地球化学发展应加强矿物中包裹体研究与成岩成矿实验相结合。我们认为实验地球化学是利用专门实验手段测定天然地球化学作用的各种物理化学参数及模拟空间化学、地球化学的学科。涂光炽在《实验地球化学》(1988)一书序言中指出:实验地球化学涉及面较宽,凡在室内对岩石圈、大气圈、外来天体和天体本身的各式各样化学组成、化学作用和化学演化进行基础实验、应用实验和模拟实验热力学和动力学以及气液与熔融包裹体研究,均可包括在内。矿物中包裹体研究可以获得比较客观的天然地球化学作用的各种物理化学参数,     

Distribution Characteristics of Gold and Other Trace Elements in the Proterozoic Lengjiaxi Group,Northeastern Hunan Province

Systematic geochemical studies of the Proterozoic Lengjiaxi Group in northeastern Hunan Province suggest that the Lengjiaxi Group is a Au-As-Sb-W association-type Au-bearing turbidite formation.The contents of Au,As,Sb,W,Cr,Mn,Pb and Zn in the turbidite formation are more than two times as high as the average contents of trace elements in the upper continental crust.The low abundance of Ag and the close correlation between Au and As are two important characteristic features.In the Au-bearing turbidite formation the enrichment of gold is due to the extensive occurrence of Au-bearing pyrites.Higher contents of Au,W,Sb and Ag in the greywacke indicate that they also exist in the form of heavy minerals.Au,Ag,As,Sb,W and REE in the Au-bearing turbidite formation have a close genetic relation with the chemistry of the gold deposits.     

Stratigraphic Geochemistry of Upper—Middle Proterozoic Suberathem in Northern Guangxi,China

The Upper-Middle Proterozoic epimetamorphic rock series in northern Guangxi is a suite of volcanic-terrigenous clastic formations transforming in facies from mobile to stable, which is similar to Eparchean normal argillo-arenaceous sediments both in petrochemistry and in REE geochemistry.The Upper-Middle Proterozoic Suberathem in northern Guangxi is characterized by primordial enrichment of As and Sb, significant depletion in Sr and Hg, bimodal or polymodal distribution of Au and other ore-forming elements, and high variation coefficients and strong mobilities of Sn,Cu,Ni,Au,Ag,As and Sb.The trace element association is characterized by the predominance of siderophile and chalcophile elements occurring in the Middle Proterozoic and that of lithophile ele-ments occurring in the Upper Proterozoic .It is suggested that in northern Guangxi is developed a series of ore-bearing formations with the Sibao Group as the protogenous basement and the Danzhou Group and Lower Sinian series as the derivative cap strata.     

沉积有机质的喇曼光谱研究

本文用激光喇曼光谱显微探针研究了选自广西、湖南和New Caldeonin（澳大利亚）的11个有代表性沉积变质岩样品中的沉积有机质。有机质有两个主要喇曼频率振动区域:1600cm-1峰和1350cm-1峰。文中对这两个特征喇曼谱峰的归属进行了说明,讨论了不同类型沉积有机质特征喇曼谱峰的差异和不同变质演化阶段有机质产生的喇曼光谱系统性变化规律,指出激光喇曼光谱显微探针技术是一种研究沉积有机质特征十分便利、有效的方法。