Hydrothermal Redistribution of Rare—Earth Elements in Pingxiang Dacite,Guangxi

Distribution of the rare-earth elements (REE) in dacite has been studied so as to get a better understanding of the migration behavior of REE during alteration. Both unaltered and altered samples were collected in an unpolluted area of Guangxi Zhuang Autonomous Region, southwest China. The REE concentrations were analyzed by ICP-MS. It is concluded that the REE were enriched during dacite alteration in varying degrees. The chondrite-normalized REE patterns of altered samples approximately maintain the characteristics of unaltered samples. However, if we normalize the REE concentrations of altered samples with unaltered dacite, fractionation of REE will appear. The LREE are more enriched than HREE in all altered samples with the LREE possibly precipitated as carbonate minerals. Both positive and negative Eu anomalies exist. Enrichment, immobility and depletion are noticed for the element Lu. Heavy mineral alteration, difference in stability constant between carbonate LREE and HREE complexes, downward migration of weathering fluid and microenvironment change may be responsible for the fractionation of REE in the altered dacite.     

Geochemical studies on Dachang antimony ore deposit in Qinglong, Guizhou Province

The Dachang antimony deposit in Qinglong,Guizhou Province,is strictly controlled by the “Dachang Layer” which is a complex altered rock occurring at unconformity between the Permian Emeishan basalt and the Maokou limestone.Based on the studies of the hanging-and foot-wall rocks,the trace elements and REE contents of the rocks and ores and heavy placer minerals in the basalt,this paper is focused on the relations between these data and the “Dachang Layer”and its hanging- and oot-wall rocks.The author pointed out that the “Dachang Layer” and basalt are the source-beds of antimony;ilmenite and magnetite are the major mineral carriers of antimony.In the processes of halmyrosis and burial metamorphism of the “Dachang Layer” an basalt,antimony was mobilized along with the mobilization of iron and was preliminarily concentrated in the“ Dachang Layer”.     

火山岩风化过程中难熔元素的活动性研究——以广西凭祥英安岩风化剖面为例

对广西凭祥叫弄英安岩风化剖面中6个难熔元素的活动性进行了研究。结果表明，Ti,Nb和Ta 3种元素在整个风化成土过程中基本上保持了它们的不活动性。Zr,Hf和Th在风化的初期阶段基本上保持不活动，而在风化中期表现出一定的富集，风化高级阶段则有明显的富集。Th的富集可能与风化壳表层（已剥蚀）淋溶出来的Th向下迁移过程中被氧化铁吸附和形成磷酸盐矿物有关，而Zr的富集则可能与淋溶出来的Zr与SiO2或磷酸盐结合形成某种硅酸盐矿物和磷酸盐矿物有关，具体富集原因还需作进一步的研究。     

贵州水城青山铅锌矿床地球化学研究

通过对青山铅锌矿床矿石矿物、蚀变围岩、含矿层、辉绿岩的稀土元素、硫、碳、氧同位素及黔西北岩石地层中铅锌含量的研究,笔者认为,成矿金属并非源于岩浆岩,而源于深部的沉积岩,碳、硫分别源于碳酸盐岩和含矿地层的硫酸盐硫;大气降水经深循环再上升形成成矿介质水。     

贵州晴隆大厂锑矿床成因探讨

晴隆大厂锑矿田是我国锑矿重要产地之一。我们在长期野外地质工作的基础上,结合近年来系统采集的岩矿、光谱、化学、包体、硫同位素及氢同位素等测试资料的综合研究,对大厂锑矿床的成因有一个初步认识,现撰写成此文。限于作者水平有限,谬误之处难免,敬请批评指正。本文所用的测试资料,承蒙中国科学院地球化学研究所、贵州省地质局实验室、冶金工业部地质研究所协助分析,此外还引用了中国科学院地球化学研究所、贵州省地质局原112地质队有关本区的硫同位素测试资料,在此一并致谢。     

富砷钒锌铅矿在贵州横塘的发现与研究

水城黄塘发现的钒锌铅矿是迄今为止国内外已知的最富砷的钒锌铅矿，其中As2O3含量高达5．81％，属于钒锌铅矿与砷名矿的类同质同象系列。本文研究了它的产状、化学组成、X－射线衍射特征、红外光谱和稀土元素组成特征并与国外相似矿物进行了对比。结果表明，As在矿物中替代V进行矿物晶格，是原来的铅锌硫化物在表生条件经次生氧化形成，但V和As的富集机制还有待于进一步研究。     

晴隆大厂锑矿床容矿层硅质来源的研究

在研究大厂锑矿床容矿层及顶底板岩石特征、化学成分及硫同位素组成的基础上,笔者认为其岩石中丰富的硅质与峨眉山玄武岩喷发作用、玄武岩侵入水体发生海解和埋藏变质过程密切有关,成矿过程将硅质运移到位,使大厂层及顶底板岩石多阶段硅化;在风化过程中玄武岩的退变质过程亦能排出大量硅质。     

对脱硫石灰岩质量要求初探

随着火电厂二氧化硫烟气治理工程的陆续开展，需要大量的石灰石作为脱硫剂，目前，我国尚未制定脱硫石灰岩的工业指标，本文就脱硫技术及对石灰岩的质量要求进行了介绍，并针对贵州某电厂脱硫石灰岩的工业指标进行了初步探讨。