南天山独山锡矿床的成矿特征及成矿模式     

张子敏  马汉峰  蔡根庆 《新疆地质》2001,19(1):49-53

通过对渗沙水锡矿点宏、微观研究，否定了原矽卡岩型锡矿的成因观点，提出锡矿化与早二叠世末碱长花岗岩侵入和热液充填交代有关，矿化受断裂破碎构造控制。以此新观点为指导，我们在南天山东段首次发现了与早二叠世末钾长花岗斑岩有关的成型锡矿床－独山锡矿床。从蚀变、矿期活动及矿石中锡的存在形式等方面对该矿床进行了详细研究，确定了该矿床的形成包括锡石－泥晶碳酸盐充填交代、锡石－石英－铁矿物充填及锡石－石英－硫化物充填3个成矿阶段。根据稳定同位素、稀土特征对矿床成因进行了探讨，并建立了矿床成矿模式。  相似文献   

钾长石包裹体水和蚀变矿物的H同位素之间关系的探讨     

庄龙池 《地球学报》1997,18(Z1):263-265

钾长石的6个H同位素组成表明，钾长石包裹体水的δD值与由其蚀变矿物绢云母的δD计算出的δDH2O不可能相等，因为它们是两个不同阶段的产物，二者没有必然的联系，所以由钾长石热液蚀变矿物δDH2O值就不能代表成矿流体（矿物包裹体水）的δD值。  相似文献   

Lead in K－Feldspar and Its Relations to Rb Metallogenesis     

张乾  刘志浩  裘愉卓  高计元  王一先 《中国地球化学学报》2003,22(2):107-115

In intermediate-acid magmatic rocks,alkaline magmatic rocks,gneisses and migmatitic rocks K-feldspar is a rock-forming rock in which the contents of Pb are highest,just 2-10 times those of the whole rock,3-16 times those of mica minerals and 6-32 times those of quartz.The lowest contents of K-feldspar are recognized in Early Proterozoic and Achaean rocks,with Pb in the K-feldspar accounting for less than 10% of that in the whole rock;in post Middle Proterozoic alkaine magmatic rocks,K-feldspar-rich granites and metamorphic rocks the contents of K-feldspar tend to increase,with the proportion granites and metamorphic rocks the contents of K-feldspar tend to increase,with the proportion of Pb over that in the whole rock being obviously increased.In the alkaline rocks in which K-feldspar accounts for 50%-70% of the total in the whole rock,the contents of Pb in K-feldspar account approximately for 70%-95% of the total lead in the whole rock.Being accessible to hydrothermal alteration in the late periods,K-feldspar was conversed to sericite,calcite,quartz,etc.In the process of such conversion the lead would be leached out and then find its way into fluid phase.This kind of trans-formation can provide sufficient ore-forming material for later Pb metallogenesis.  相似文献   

Early formation of K-feldspar in shallow-marine sediments at near-surface temperatures (southern Israel): evidence from K-Ar dating     

Amir Sandler  Yehudit Harlavan  Gideon Steinitz 《Sedimentology》2004,51(2):323-338

Authigenic K‐feldspar was investigated in two Albian to Turonian sections in Israel using K‐Ar and Ar‐Ar dating, X‐ray diffraction, scanning electron microscopy and chemical analysis. Both sections comprise a similar succession of shallow‐marine limestones, dolomites and marls, with some sandstone and shale beds of continental origin. The HCl‐insoluble residue fraction of the studied samples consists of clays, quartz, feldspars, goethite and trace amounts of heavy minerals. Most of the insoluble residues have a relatively high K‐feldspar content that has an adularia habit and is concentrated in the 4–7 µm size fraction. The authigenic origin of the K‐feldspar in the fine silt fraction is indicated by its high content relative to quartz, the uniform and idiomorphic shape of the crystals and its limited size range. Of the fine silt (4–7 or 4–10 µm) separates, 40% have ages that are similar to stratigraphic ages within the analytical and biostratigraphic errors. Ar‐Ar dating of a fine silt fraction with 94% K‐feldspar (4–10 µm, sample GYP 7) yields a plateau age identical to the total gas age and similar to the stratigraphic age. These results indicate that the K‐Ar age is not a mixture between detrital and late diagenetic K‐feldspar ages, but is rather an age of formation within a few million years after deposition. It is suggested that the early formation of the K‐feldspar was associated with dolomitization and was induced by residual brines as part of a reflux process.  相似文献   

安徽宁国钾长石共烧结工艺研究   总被引：7，自引：0，他引：7  

韩效钊  姚卫棠  金国清  胡波  邓正涛 《矿物岩石地球化学通报》2002,21(3):210-213

以宁国钾长石矿为主要原料，采用共烧结工艺，研究了用CaCl2做添加剂与钾长石共烧结温度、温度、CaCl2用量对溶出率的影响，确定了共烧结最佳参数，同时，通过XRD表征方法，对原矿物相及水浸潭物相进行了研究，探讨了共烧结反应机理，实验结果表明，钾长石中K2O溶出率可达95％。  相似文献   

Igneous origin of K-feldspar megacrysts in deformed granite of the Papoose Flat Pluton, California, USA     

R. H. Vernon  S. R. Paterson 《Visual Geosciences》2002,7(1):1-28

Many points of evidence, especially igneous microstructures and structures resulting from solid-state deformation, indicate that K-feldspar megacrysts in deformed granites of the Papoose Flat pluton are residual phenocrysts, not porphyroblasts. Evidence of an igneous origin includes features such as crystal shapes, simple twinning, zonally arranged euhedral plagioclase inclusions, oscillatory compositional zoning, and local occurrence in microgranitoid enclaves. Evidence of solid-state deformation of the megacrysts (which is consistent with their existence prior to the mylonitic deformation) includes marginal recrystallization and neocrystallization, microcline twinning, marginal replacement by myrmekite, and recrystallized/neocrystallized “tails”. Evidence of porphyroblastic growth, such as overgrown inclusion trails, is absent. This appears to be the situation in most felsic augen gneisses and mylonites.  相似文献   

Authigenetic K—feldspars and Their Relations to Sn—polymetallic Mineralization in the Dachang Ore Field     

潘家华  G.C.AMSTUTZ 《中国地球化学学报》1993,12(3):270-288

Sn-polymetallic ores at Dachang,Guangxi Autonomous Region,China,are hosted in Middle-Upper Devonian reef limestones,siliceous rocks,banded and lenticular limestones,etc.Two types of orebodies can be distinguished according to their telations to the bedding:one is distributed along the bedding and the.other cuts across the bedding.Sn and sulfide orebodies associated with K-feldspare are mostly characterized by laminated ore structure. Microscopic examinations of K-feldspar-bearing rocks,in conjunction with X-ray diffraction,chemical composiion and cathodoluminescence data for K-feldspars,as well as their telations to mineralization,the authors consider that the K-feldspare are of authigenic origin,subordinate to the epigenetic stage of diagenesis,They resulted from the reaction of mixed,deep-seated,circulating underground hot waters rich in K,Al and Si with argillaceous carbonates during the Indo nesian orogenic movement.It is suggested more attention should be paid to the effect of authigenic K-feldspars on Sn mineralization.In the meantime the event related to circulating underground hot waters should also be taken into account so as to provide new clues to blind ore prospecting.  相似文献   

钾长石X射线与红外有序度的对比及与Al占位和平衡温度的关系   总被引：6，自引：0，他引：6  

马鸿文 《矿物学报》1988,(2)

本文在对藏东玉龙斑岩铜矿带花岗斑岩中钾长石斑晶红外光谱与X射线粉末衍射法测定结果的基础上,系统研究了钾长石的红外有序度θ与X射线单斜有序度Sm的对应关系,以及有序度与t_1位Al的占位率和钾长石保持最终结构状态的平衡温度之间的函数关系,并讨论了该成果在火成岩研究中的实用价值。  相似文献   

油气成藏^40Ar-^39Ar定年难题与可行性分析   总被引：6，自引：0，他引：6  

邱华宁  吴河勇  冯子辉  施和生  云建兵  王强  赵令浩 《地球化学》2009,38(4):402-408

油气成藏作用伴生的矿物种类少,主要为碳酸盐矿物,以及少量石英和黄铁矿等,这些矿物均不适合用传统同位素年代学方法进行年龄测定,因此,油气成藏年龄是同位素年代学尚未解决的一大科学难题。^40Ar-^39Ar（K-Ar）法是可能应用于油气成藏年龄测定的首选同位素定年方法。从^40Ar-^39Ar法的优点和实验技术的角度,讨论了油气田样品^40Ar-^39Ar定年面临的主要技术难题、测定对象、测定方法和可行性。有机杂质气体纯化装置的研制成功,为开展油气成藏^40Ar-^39Ar年代学研究,并获得可靠的同位素年龄数据奠定了实验技术基础。  相似文献   

~(40)Ar-~(39)Ar Age of K-feldspar from K-feldspar Granite in the Qiaohuote Copper Deposit, Bayanbulak, Xinjiang, and Its Geological Significance   总被引：1，自引：0，他引：1  

WANG Zhiliang  MAO Jingwen  YANG Jianmin  CHEN Wen  ZHANG Zuoheng Institute of Mineral Resources  Chinese Academy of Geological Sciences  Beijing  Faculty of Geosciences  Resources  China University of Geosciences  Beijing Institute of Geology  Chinese Academy of Geological Sciences  Beijing 《《地质学报》英文版》2004,78(2):428-434

By using the 40Ar-39Ar chronological method to date K-feldspar from K-feldspar granite in the Qiaohuote copper district, the authors obtained a plateau age of 274.78±0.44 Ma and an isochron age of 272.7±3.0 Ma. Because there is no tectonic deformation overprinted or hydrothermal alteration in the K-feldspar granite intrusion after its emplacement, the 40Ar-39Ar age represents the crystallization age of K-feldspar in K-feldspar granite, i.e. the late crystallization age of the K-feldspar granite intrusion, which indicates that the K-feldspar granite formed in the intraplate extensional stage during the Early Permian. Moreover, based on the spatial relationship between the K-feldspar granite intrusion and copper orebodies, variations of copper ore grade, REE characteristics of K-feldspar granite and copper ores, and H and O isotopic compositions of fluid inclusions in copper ores, the metallogenesis of the Qiaohuote copper deposit is directly related to intrusive activities of the K-feldspar granite, and  相似文献