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991.
滇中铅锌矿床成矿控制因素及成矿预测 总被引:1,自引:0,他引:1
滇中地区面积大约为4万平方公里,在这范围内有近百处矿床(点)。近年来,在对四种矿床类型和12个典型矿床的研究基础上,系统总结了各种成矿的控制因素,提出了:地层,岩相古地理因素控制矿源层的同生沉积;构造和岩性控制后期金属元素活化和迁移以及工业矿床的形成;时间、空间分布是矿源层形成和后期改造成为矿床的这两种地质作用的综合体现,并且,指出了两个成矿预测区和找矿方向。 相似文献
992.
易门狮山铜矿床地球化学特征与成矿关系 总被引:2,自引:0,他引:2
易门狮山铜矿床产于元古界昆阳群绿汁江组狮山段泥质、炭质白云岩及粉砂岩中。狮山段由黑色层(Mc)、过渡层(Mg)和紫色层(Mp)组成。在矿床地质特征研究基础上,总结了该矿床的微观规律及其特征(包括化学组分、微量元素在狮山段、矿体中的分配;元素共生组合及演化规律;有机碳的含量与成矿;硫同位素及硫源;矿物包裹体特征等)。提出成矿元素经历了离散、合并、分解和矿体形成的演化过程。 相似文献
993.
Geology and Genesis of Peraluminous Granites in East Tianshan Upper Paleozoic Island Arc Belt 总被引:6,自引:1,他引:6
A peraluminous granite belt occurs along the connecting zone between the Turpan-Hami Precambrian block and the Upper Paleozoic island arc belt. Muscovite granite and twomica granite are the essential lithological components of that belt. All the potassium feldspars in these granites are microcline. Heavy minerals are dominated by magnetite. SiO2 contents of these granites are greater than 73% with most of the A/NKC values greater than 1.1, normative corundum values greater than 1. Plots of CIPW norms in the (Al-K-Na)-Ca-(Fe2++ Mg) diagram are mostly situated in the plagioclase-cordierite-muscovite region. The rocks are characterized by very low contents of minor elements and ΣREE with strong Eu depletion, δ18O values between 6.6‰ and 7.0‰, Rb-Sr isochron age of 260.2 ± 6.2 Ma and an initial87Sr/86 Sr ratio of 0.7052. These granites might have been produced by partial melting of moderately acidic volcanites and low-maturity sediments in the basement sequences and could be genetically connected with the southward A-type subduction of the Turpan-Hami block following the closure of the Middle Carboniferous back-arc basin. 相似文献
994.
Genetic Analogy Between Sediment—Hosted Gold Deposits and Sediment—Hosted Copper Deposits in Southwest China 总被引:1,自引:0,他引:1
The sediment-hosted copper deposits according to the authors‘ study were formed from connate formation water during the post-sedimentary or diagenetic stage while the sediment-hosted disseminated gold deposits are unanimously considered to be of post-sedimentary hydrothermal origin.Therefore,apart from their own individulities.These two types of deposits must share some characters in common.Comparisons are attempted,in this paper,between the sediment-hosted copper deposits in southwest China and the Triassic sediment-hosted disseminated gold deposits in the Yunnan-Guizhou-Guangxi Triangle in terms of geological and geochemical features. 相似文献
995.
Geochemistry of the Jinman Vein—Type Copper Deposit,Western Yunnan Province,China——I.Element Geochemical Characteristics 总被引:3,自引:0,他引:3
The Jinman copper deposit,which is situated on the northern margin of the Lanping-Simao back-arc basin,western Yunnan Province,is a silver-bearing,high-grade vein-type copper deposit.Comprehensive element geochemical studies of the host rocks and hydrothermal minerals revealed the regularities in the distribution,mobilization and transport of elements from the host rocks to hydrothermal minerals.In conjunction with the fluid inclusion and isotope data,it is suggested that the ore-forming fluid was derived mainly from a deep source characterized by CO2 enrichment and reduction in nature.It is also suggested that the oreforming materials come largely from a deep source.although the contribution of the country rocks should not be ruled out.It is also found that some hydrothermal minerals are possessed of MREE-enrichment patterns.It is deduced that the REEs in the deep-source ore fluid were transported in the form of CO3^2- complexes and were deposited in a continental basin(or a hot-spring basin). 相似文献
996.
This paper presents a method of establishing a hydrothermal ore-forming reaction system.On the basis of the study of four typical hydrothermal deposits,the following conclusions concerning geochemical dynamic controlling during hydrothermal mineralization have been sions concerning geochemical dynaamic controlling during hydrothermal mineralization have been drawn:(1)The regional tectonic activities control the concentration and dispersion of elements in the ore-forming process in terms of their effects on the thermodynamic nature and conditions of the ore-forming reaction system.(2)During hydrothermal mineralization the activites of ore-bearing faults can be divideb into two stages:the brittle splitting stage and the brittle-tough tensing stage,which would create characteristically different geodynamic conditions for the geochemical thermodynamic ore-forming system.(3)The hydrothermal ore-forming reaaction system is an open dynamic system.At the brittle splitting stage the system was so strongly supersaturated and unequilibrated as to speed up and enhance the crystallization and differentiation of ore-forming fluids.And at the brittle-tough tensing stage,the ore-forming system was in a weak supersaturated state;with decreasing temperature and pressure the crystallization of oreforming material would show down,and it can be regarded as an equilibrated state.(4)In the lates stages of hydrothermal evolution,gold would be concentrated in the residual ore-forming solution.The pulsating fracture activite in this stage led to the crush of pyrite ore and it was then filled with gold-enriched solution,forming high-grage“fissure”gold ore.This ore-forming process could be called the coupling mechanism of ore formation. 相似文献
997.
998.
VAMSD矿床系列最基性端员——青德尔尼大型铜钴矿床的地质特征和成因类型 总被引:8,自引:0,他引:8
在调查分析德尔尼Cu-Co矿床地质特征的基础上,结合矿床剖面,针对矿区容矿蛇纹岩类进行了系统的岩矿鉴定和地球化学研究,确定矿区广泛发育的各类蛇纹岩基原岩主要为超基性角砾集块岩、凝灰岩等火山岩类。将德尔尼型Cu-Co矿床作为火山岩块状硫化物矿床系列中的最基性端员明确划分出来具有重要意义。 相似文献
999.
水/岩作用实验研究表明,在低温条件下柠檬酸、草酸和酒石酸对岩石中的铁、铜都有很高的淋滤率。这表明,在表生地质作用过程中有机酸对成矿元素有很强的活化能力。实验研究同时发现,有机酸对成矿元素的活化能力受其分解温度的限制,由于大部分有机酸的分解温度都在250℃以下,因而有机酸对成矿元素的活化仅限于低温条件。本次研究还显示,判断一种岩石能否成为矿源层,不能简单的以其中成矿元素的含量高低作为标准,其中更关键的因素是元素在岩石中的存在形式,如果成矿元素在岩石中难以活化的形式存在,那么含量再高也无法提供成矿物质 相似文献
1000.