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花岗岩主要呈岩株产于穹窿的东部,在穹窿的核部及西部,晚阶段的细晶岩和花岗斑岩岩墙发育良好。 岩石呈肉红色、中粒斑状至半自形粒状结构,暗色的黑鳞云母1-3％,钠长石20-30％,微斜长石35-45％,石英35-40％。斑晶是微斜长石。 花岗岩的岩石化学是SiO_2>71%,K_2O十Na_2O>8％,Na_2O/K_2O=0.83,F=0.76％,Li_2O>0.11％,FeO+Fe_2O_3<2％,CaO=0.46％,MgO=0.14％,P_2O_5=0.02％。Sr~(87)/Sr~(86)=0.7159-0.746。 从下到上,花岗岩内发育了七个蚀变带:钾化花岗岩; 钾化和钠化花岗岩;强钠化和钾化花岗岩;强钠化和弱云英岩化和钾化花岗岩;云英岩化,钠化及钾化花岗岩;强云英岩化,钠化和钾化花岗岩及云英岩。 花岗岩内部的矿化包括花岗岩蚀变带内的(TR)、Ta、Nb、Sn、W、(Li)矿化及伟晶岩内Be矿化。外接触带的矿化包括条纹岩型Be、W、Sn矿化,萤石型白钨矿化,锡石-硫化物型及裂隙充填型的Sn、Pb、Zn矿化。所以,矿化分带表现为TR-Nb-Ta-Be-W-Sn-Pb-Zn-Fe-Sb。 相似文献
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湘南癞子岭花岗质复式岩体是香花岭锡铅锌多金属矿田的主要成矿岩体,其中云母广泛出现在各期次岩（矿）体之中。笔者等在对癞子岭岩体岩相学研究的基础上,开展全岩主微量元素地球化学分析,同时对岩浆成因云母（花岗岩中的云母）、热液成因云母（矿化云英岩、晶洞矿物集合体以及条纹岩中的云母）进行了电子探针分析。结果表明,癞子岭岩体为一套高钾钙碱性—钾玄质、准铝质—过铝质花岗岩,癞子岭岩体中的云母主要为铁锂云母,从早期到晚期,呈现出FeO和Al2O3含量降低,K2O、F、MnO和Rb2O含量升高,且Pb、Zn、Fe等成矿元素含量逐渐增加的特征。热液成因云母分为以下两种： ① 产于矿化云英岩和晶洞矿物集合体中的云母主要形成于流体出溶的早期,无围岩组分参与,云母类型由铁锂云母演化为锂云母,主要沉淀Fe、Zn、Pb、Mo等成矿元素;② 产于条纹岩中的云母晚于矿化云英岩和晶洞矿物集合体中的云母,有围岩组分参与,云母类型由黑鳞云母变为富镁黑云母和富铁黑云母再变为金云母,主要沉淀Fe、Sn和W等成矿元素。随着流体演化,云母呈现SiO2、F、K2O含量逐渐降低,MgO含量逐渐升高,相应的成矿元素从富Fe 、Zn、Pb、Mo逐渐过渡到富Fe 、Sn和W。 相似文献
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湘南癞子岭花岗质复式岩体是香花岭锡铅锌多金属矿田的主要成矿岩体,其中云母广泛出现在各期次岩（矿）体之中。笔者等在对癞子岭岩体岩相学研究的基础上,开展全岩主微量元素地球化学分析,同时对岩浆成因云母（花岗岩中的云母）、热液成因云母（矿化云英岩、晶洞矿物集合体以及条纹岩中的云母）进行了电子探针分析。结果表明,癞子岭岩体为一套高钾钙碱性—钾玄质、准铝质—过铝质花岗岩,癞子岭岩体中的云母主要为铁锂云母,从早期到晚期,呈现出FeO和Al2O3含量降低,K2O、F、MnO和Rb2O含量升高,且Pb、Zn、Fe等成矿元素含量逐渐增加的特征。热液成因云母分为以下两种： ① 产于矿化云英岩和晶洞矿物集合体中的云母主要形成于流体出溶的早期,无围岩组分参与,云母类型由铁锂云母演化为锂云母,主要沉淀Fe、Zn、Pb、Mo等成矿元素;② 产于条纹岩中的云母晚于矿化云英岩和晶洞矿物集合体中的云母,有围岩组分参与,云母类型由黑鳞云母变为富镁黑云母和富铁黑云母再变为金云母,主要沉淀Fe、Sn和W等成矿元素。随着流体演化,云母呈现SiO2、F、K2O含量逐渐降低,MgO含量逐渐升高,相应的成矿元素从富Fe 、Zn、Pb、Mo逐渐过渡到富Fe 、Sn和W。 相似文献
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著名的盘古山大型钨矿与深部隐伏花岗岩体具有密切成因关系,但因该岩体隐伏深,相关研究资料较为欠缺,很大程度上影响了对矿床岩浆-热液-成矿作用的深入认识。南岭科学钻探(SP-NLSD-2)揭露该岩体后,本文对其开展了岩石学和元素地球化学研究。结果表明,该岩体具有超酸性、富碱、贫钠富钾等特征,属于准铝-过铝质高钾钙碱性花岗岩。形成该岩体的花岗岩浆为高度分异演化的残浆,W、Bi等元素含量明显高于南岭燕山期花岗岩,为盘古山钨铋矿床的形成提供了丰富的矿质。岩浆演化至云英岩化阶段时,岩浆中的Mo、Bi、Cu、Pb及REE含量增加,而W、Sn含量则因已转移到岩浆期后热液而降低。岩体形成于板内伸展环境。 相似文献
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小狐狸山钼多金属矿床是近年来在北山地区发现的一个具中—大型规模的隐伏钼矿床. 该矿床成矿特征典型,赋矿岩体可以明显的划分为三个相带,即边缘相、过渡相和中心相。岩体中心相具强硅化、钾长石化现象,过渡相和边缘相具有明显的钠长石化蚀变特征,并叠加有岩浆期后云英岩化蚀变现象。钼矿体主要产于岩体过渡相和边缘相的钠长石化带和云英岩化带中。小狐狸山钼多金属矿床成矿时代为三叠纪, 属印支期构造-岩浆活动的产物。通过对Mo→Pb-Zn→稀有金属的复合矿化特征分析,推测该矿床可能是不同期次岩浆热液活动形成的热液叠加矿床。结合岩石地球化学、构造环境及其矿化、蚀变特征分析,该矿床应为板内伸展构造环境下形成的高-中温岩浆热液叠加型矿床。 相似文献
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一、红长石化蚀变特征西华山钨矿的蚀变作用主要有云英岩化、硅化、钠长石化及钾微斜长石化(俗称红长石化)。就一条矿脉而言,上部云英岩化发育,中下部硅化发育,根部红长石化发育;综合全部矿脉而言,蚀变受岩体控制,与裂隙有关,自岩体顶部和边部向岩体内云英岩化由强逐渐变弱,而硅化、绢云母化增强,至岩体深部出现强烈的红长石化。各种蚀变平行岩体表面呈明显的圈层状分布,且与接触面的形态有关。岩性不影响蚀变分布的整个趋势,只涉及蚀变的强弱(图1、2)。 相似文献
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大义山岩体内云英岩化电气石化的找矿意义 总被引：1，自引：0，他引：1
大义山复式岩体内发育的云英岩脉和电英岩脉,锡矿化较强。而鳞云母黄玉云英岩、电气石云英岩、白云母云英岩、电英岩、蚀变细粒花岗岩、云英岩－似伟晶岩,亦与锡多金属矿密切有关。显而易见,云英岩化和电气石化是大义山岩体内锡矿的最佳找矿标志。 相似文献
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旗山锡矿是与燕山三期花岗斑岩有关的岩浆期后热液充填的脉状锡矿床,矿床地质特征是矿体呈脉状、透镜状或分支复合状,锡石硫化物矿石,围岩蚀变主要为云英岩化、绢云母化、弱绿泥石化.通过对矿床的成因进行探讨,为寻找同类型矿床提供找矿思路. 相似文献
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梅勇文 《吉林大学学报(地球科学版)》1987,(4)
云英岩化形成于富含挥发组份和氧逸度较高的酸性环境中,钾长石化形成于缺乏挥发组份的碱性条件下。富云母云英岩化和钾长石化为不同条件下的钾质交代蚀变作用,富石英云英岩化和硅化为不同条件下的硅质交代蚀变作用。单纯云英岩化或钾长石化,对钨矿化都不一定有利,而云英岩化外侧具钾长石化锒边,以及钾长石化外侧尚存在富石英云英岩化或硅化时,钨等矿化相对富集。 相似文献
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介绍了湘南地区云英岩的产出类型以及云英岩体型钨锡多金属矿床和云英岩体型铀多金属矿床的矿床特征。 相似文献
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云南文山麻栗坡新寨锡矿成矿条件分析 总被引：3，自引：0，他引：3
早加里东期拗陷区沉积形成矿源层,晚加里东一印支期区域变质作用、混合岩化作用使锡质初步富集,后期热液叠加淬取使成矿元素得以重新活化转移到热液中,成为含矿热液（矿浆）,运移到适当部位聚集形成工业锡矿体。 相似文献
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A.M.R. Neiva 《Chemical Geology》1974,13(4):295-308
Greisenization of a muscovite-biotite albite granite of Alijó-Sanfins, northern Portugal, is studied for both major and trace elements. The principal tin-tungsten mineralization of the region is connected with this granite and the greisenization is accompanied by an increase in Cl, F, W, Nb, Sn, Pb and Rb. Cassiterite is the main carrier of Sn. Muscovite is the concentrator of Cl and F. The muscovite of the greisenized granite contains more Cl, F, W and Nb than the muscovite of the parental granite, but the former contains less Sn. Sn content of the muscovite of the greisenized granite is higher than that of the biotite of the parental granite; W content is similar or higher.When the greisenization is accompanied by albitization, the oxides and trace elements behave in a similar way to that found only with greisenization, except that there is a decrease of Ni and Rb. Li, Zr, Sr, Ba and Rb decrease as albitization increases. 相似文献
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界牌岭矿区出露的地层主要为石炭系,白垩系零星分布。石磴子组不纯灰岩化学性质活泼,同时地层中W,Sn,Be,Pb,Zn成矿元素含量高。界牌岭背斜控制了区内的总体构造格架,断裂构造很发育,其中近南北向断层是区内的控岩导矿构造,它所派生的次一级断裂控制着区内的锡铅锌矿体。区内仅出露燕山晚期的花岗斑岩。围岩蚀变主要有云母化、黄玉化、云英岩化、萤石化。锡铅锌矿体隐伏在80m标高以下,浅部及地表有厚大的萤石矿体。该矿床形成于燕山晚期,经历了从高温-中温-低温的成矿阶段。 相似文献
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A number of polymetallic vein mineralizations of different styles and metal associations, including base, alloy, noble and critical metals, have been discovered around the Sarvlaxviken bay in the westernmost parts of the Mesoproterozoic Wiborg Batholith, south-eastern Finland. The veins occur in two rapakivi granite varieties: coarse-grained wiborgite; and medium-grained Marviken granite. The veins are divided into five groups based on the dominant metal associations.The Li–As–W–Zn–Mn, Pb–Zn and Cu–As–In associations are hosted by wiborgite, and are strongly controlled by a NNW-trending tectonic pattern that evolved in two main stages. The Li–As–W–Zn–Mn association (generation 1) formed in a typical greisen environment with Li-bearing mica in significant alteration halos around a narrow quartz vein. This greisenization was accompanied by silicification, followed by sericitization and chloritization. The Pb–Zn association occurs in a similar vein type but without typical high-temperature minerals and is considered to have formed at a higher crustal level. Generations 2a and 2b formed under more brittle conditions leading to fracturing, quartz veining and metal precipitation of ore minerals. This metal association is characterized by very high contents of Cu, As and up to 1490 ppm In but with ≤ 0.4% Zn, which leads to very high In/Zn ratios (up to 8400) enabling formation of abundant roquesite.The As–Sn–Cu and Mo–Bi–Be associations are hosted by alteration zones without hydrothermal quartz in the Marviken granite. Mineralization with moderately high contents of As, Sn and Cu is associated with greisenization while mineralization with spectacular contents of Be as well as high contents of Mo and Bi is associated with sericitization, chloritization and berylification.The internal age relations between the wiborgite-hosted, NNW-trending veins show a clear evolution from a typical greisen type environment (the Li–As–W–Zn–Mn and Pb–Zn associations of generation 1) to cooler and more brittle conditions governing quartz veining and precipitation of ore minerals belonging to the Cu–As–In association (generations 2a and 2b). The age relations between these wiborgite-hosted veins and the veins in the Marviken granite are more uncertain but the presence of a NS-trending granitic dyke on the eastern side of the Sarvlaxviken bay, with similar ore-fertile geochemical composition as the Marviken granite, indicates that the tectonically controlled veins formed simultaneously with the emplacement of the Marviken granite and associated hydrothermal activity.The polymetallic veins in the Sarvlaxviken bay are unique for the Fennoscandian Shield, not the least for the locally high indium grades and spectacular roquesite grains. There is an obvious exploration potential for similar veins (and hence a number of base, alloy, noble and critical metals) also elsewhere in the entire Wiborg Batholith. 相似文献
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《International Geology Review》2012,54(7):1279-1293
Greisenization does not occur apart from ore bodies associated with the Kounrad granite massif. Primary minerals in granite altered and replaced during greisenization are quartz, feldspars, biotite, sphene, ore minerals, and apatite. Zircon, cyrtolite, and monazite are virtually unaffected by greisenization. Greisen-introduced minerals are muscovite, rutile group minerals, pyrite, fluorite, topaz, and molybdenite. Greisenization of Kounrad granite massif resulted in addition of more material than leached in all levels except at the base of vein zones. The excess of addition over leaching in middle and upper levels is mainly associated with upward migration of material. The value of total and individual factors of addition and leaching depends primarily on original rock composition more so than original porosity and rock structure. --R.M. Hutchinson. 相似文献
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西盟锡矿群是云南锡矿主产区,存在五类锡矿床：“面型”云英岩型,大理岩型,矽卡岩型,断裂破碎带型及层间破碎带型。深入了解其不同成因空间、成矿规律、岩矿组合、赋矿条件,并结合隐伏花岗岩体特征,十分有利扩大找矿远景。 相似文献