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秦岭凤太地区八卦庙式金矿成矿地质条件及其成矿预测
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摘要
位于陕甘交界的凤县八卦庙金矿床是迄今发现的,产于秦岭地区泥盆系沉积岩中规模最大的金矿床。金矿床的含矿地层为下泥盆统星红铺组,容矿岩石为浅变质细碎屑岩系,其中发育有海底热水沉积成因的条带状的钠钙硅质岩和纹层状钠长石岩。
     条带状钠-钙-硅质岩呈纹层、条带状构造,在走向上与千枚岩渐变过渡。条带宽度多<1cm,少数达几cm,岩性类型包括(含)铁碳酸盐硅质岩、含铁碳酸盐钠长石硅质岩、石英钠长石岩、(含)石英铁碳酸盐岩。剖面上出现条带岩带→斑点板岩带→含碳质千枚岩带的沉积旋回;薄片下常见到富硅质纹层(或富钠长石纹层)→富铁碳酸盐纹层→泥质纹层的沉积韵律,纹层厚度0.1~1.2mm不等。
     位于矿区北部的钠长石岩呈透镜状产出,岩石纹层构造发育,Sr/Ba值均<1,属沉积成因而非侵入成因。
     上述两类岩石的Fe_2O_3/FeO、SiO_2/Al_2O_3、SiO_2/MgO、SiO_2/(Na_2O+K_2O)等比值均与秦岭泥盆纪铅锌矿的热水沉积岩及现代海底热泉沉积物的组成一致,在Fe-Mn-(Co+Ni+Cu)×10三角图解上的投影点均落在现代海底热水沉积物区和秦岭泥盆纪铅锌矿的热水沉积岩分布区内,通过稀土元素及氢、氧、碳、硅同位素等综合研究,表明它们属于热水沉积成因。随着泥盆纪秦岭裂陷槽的形成,伴随凤太裂陷海盆边缘的同生断裂活动,形成金丰度较高的热水沉积岩系,它们与金矿化关系密切。
     八卦庙矿床的金矿体主要沿褶皱构造破碎带分布,形态为大的透镜状、似层状,其产状与围岩产状基本一致。已鉴定出的矿物有30余种,常见矿物仅10余种,金属矿物总量一般<3%,以磁黄铁矿、黄铁矿、自然金最为常见,还见有白铁矿、黄铜矿、方铅矿、闪锌矿、钛铁矿等,脉石矿物中绢云母和白云母占30-50%,石英占10-25%,碳酸盐矿物占12-20%。元素组合为Au—Hg—Ag—B—Zn—Cu—Pb—Sb—As组合,以Au—Ag组合关系最为密切。矿床以具有独特的磁黄铁矿和黄铁矿组合、围岩蚀变褪色、斑点构造及发育顺层、穿层石英脉为特征。就其容矿岩石性质、矿物组合、元素组合及成矿机制等,均与典型的卡林型金矿床存在差异。
     八卦庙矿区的金矿物主要以独立矿物形式产出,绝大部分为自然金,呈中细粒金—显微金为主,多以粒间金的形式存在,其次是裂隙金和包裹金,主要载金矿物为石英、磁黄铁矿和黄铁矿。矿石的金品位与其石英脉带的发育程度和揉皱(破碎)程度、共生硫化物的含量成正比,与脉体的厚度、共生硫化物的粒度成反比;节理脉的含金量比顺层脉的含金量高;石英细脉的含金量高于脉旁围岩的含
The Baguamiao is the largest gold deposit found so far in Devonian sediments in Qinling Region, which located in Fengxian, Shaanxi near Gansu province. The Baguamiao deposit is hosted in the Xinghongpu group of lower Devonian, which consists low-grade fined-grained clasts, with striped Na- and Ca-bearing silicates and laminated albite. It is showed to be hydrothermal sediments on seabed.The natrium- calcium-silicalites with strip structure is gradually changing into phyllite. The thickness of the rocks is thinner than 1 cm in general and the minority reaches several cm. The rock types include the iron-bearing carbonate silicalite, the iron-bearing carbonate albite silicalite, and quartz albite, quartz- and iron-bearing carbonate. On the section in the field, there is depositional cycle with the change of the strip rock zone → the spot slate zone → carbon-bearing phyllite from the bottom upward.. There is a series of lamina change interbedded by iron-riching carbonate lamina, albite-bearing lamina and argillaceous lamina in thin section. The thickness of the lamina is from 0.1 to 1.2 mm.The albite, shaped in lense, is located in the northern of the deposit and the ratio of Sr/Ba is smaller than 1, which was identified to be sedimentary genesis rather than intrude.The ratios of Fe_2O_3/FeO, SiO_2/Al_2O_3, SiO_2/ MgO and SiO_2/(Na_2O+K_2O) of the two type rocks above are similar to those of the hydrothermal sedimentary rock of the lead-zinc deposits in Devonian, Qinling and the hydrothermal sediments on the sea floor. The projection pots locate in the area of the lead-zinc deposits in Devonian, Qinling and the modern hydrothermal sediment on the sea floor in the triangle diagrammatize of Fe-Mn- (Co+Ni+Cu)× 10. According to the synthesis study by their REE element and H, O, C, Si isotope, they belong to the hydrothermal sedimentary origin. Along with forming of the Qinling crack and sink trough in Devonian and the movement of the syngenetic rupture, the hydrothermal sedimentary rock series with gold-riching are formed, which is close relative to gold mineralization.The orebodies in Baguamiao gold deposit occurred as lens-like and bed-like orebodies along the fault zone with showing approximately comfortable attitudes with the host rocks. There are 30 various minerals about in ores. Of which, about 10 various minerals are common. The metal minerals less than 3%. Pyrotite, pyrite and native gold are common. Binerite, chalcopyrite, galena, sphalerite and ilmenite can be seen also. The element assemblage is Au-Hg-Ag-B-Zn-Cu-Pb-Sb -As, in which the Au-Ag assemblage is the most important. Baguamiao gold deposit is characteristic with the alone pyrotite and pyrite assemblage, altered and depigment of wall rock, spot structure and the quartz veins occur along or cut the stratum, which is different with the typical Carlin type or similar Carlin type gold deposits.The gold mineral of Baguamiao gold deposit is independent gold. The gold is usually in middle-, fine and micro- size. Gold is mainly occurred as intercrystal—gold and Crach—gold, and inclusion—gold is little. The gold mainly hosted in quartz, pyrotite and pyrite. It is shown by the gold ore selectation that Baguamiao gold deposit can be developed and utilized. The gold content in Baguamiao giant gold deposit is in direct proportion to the development and folded broken degree of quartz vein and to the content of co-existed sulphide, and is in inverse proportion to vein thickness and the grain size of co-existed sulphide. The gold content in joint vein is higher than that in bedding vein.the gold content is several to more than ten times of the content in surrounding rock nearby. Nevertheless industrial ore body isn't alone consisted of gold-quartz vein. In view of the points mentioned above, the authors put forward that the gold mineralization type is
引文
1 郑明华,现代成矿学导论,重庆:重庆大学出版社,1988.10
    2 郑明华,层控金矿床概论,成都:成都科技大学出版社,1989
    3 郑明华,等,一个海底喷流——地下水热液改造成因的Au-Cu-U-Pt矿床的新矿例。科学通报,1991,36期
    4 郑明华,等,当前金矿成矿理论的进展。武汉:中国地质大学出版社,1992
    5 郑明华、刘家军,西秦岭南亚带Au-Cu-U成矿带中硅岩的海底喷流沉积特征,成都地质学院学报,1993(2)
    6 郑明华,等,喷流型与浊流型层控金矿床,成都:四川科学技术出版社,1994.9
    7 郑明华,等,川西北地区金矿床中宇宙尘的发现及其意义,地质学报,1995,2期,146-
    8 郑明华,等,层控金矿床研究现状。当代矿产资源勘查评价的理论与方法,北京:地质出版社,1998
    9 郑明华等,西南天山萨瓦亚尔顿金矿床成矿地球化学特征,矿物岩石地球化学通报,2000,4期,226-
    10 郑明华,等,西南天山穆龙套型金矿床产出地质背景与成矿机制,北京:地质出版社,2001.10
    11 郑明华、刘家军、张寿庭,等,萨瓦亚尔顿金矿床的同位素组成特征及其成因意义。成都理工学院学报,2002,29(3):237~245
    12 蔡蕴华等,1990,西秦岭泥盆系岩石中的斑点状构造与金矿化,西北铀金地质情报,203研究所
    13 陈丹玲,1992,八卦庙金矿床地质地球化学特征及成矿机制研究(西北大学硕士研究生论文)
    14 陈毓川,等,中国金矿床及其成矿规律,北京:地质出版社,2001.10
    15 陈毓川、王高尚、韦龙明,等编,矿产资源可持续供应问题及对策研究,中国工程院咨询项目研究报告(内部资料),2002.3
    16 陈远荣、尹意求、贾国相,等,1999,地球化学综合方法找矿应用试验研究——以广西贵港庆丰—平南旺石铅锌矿带为例。有色金属矿产与勘查,8(6):569~573
    17 樊硕诚、金勤海,陕西双王金矿床。见:刘东升主编,中国卡林型(微细浸染型)金矿。南京:南京大学出版社,1994,254~285
    18 冯建忠、邵世才、汪东波,等,陕西八卦庙金矿脆~韧性剪切带控矿特征及成矿构造动力学机制。中国地质,2002,29(1):58~66
    19 高斌等,围岩蚀变过程中地球化学组分质量迁移计算-以湖南沃溪金锑钨矿床为例,地质学报,1999,3,272
    20 桂林矿产地质研究院,陕西八卦庙卡林型金矿成矿条件及成因分析(科研报告),1992.3
    21 桂林矿产地质研究院、西北有色地质勘查局、甘肃有色地质勘查局,秦岭卡林型金矿成矿条件及成矿预测(科研报告),1992年3月
    22 桂林矿产地质研究院,我国沉积岩容矿浅成低温热液金矿成矿条件及综合成矿预测。(科研报告)1994.7
    23 桂林矿产地质研究院等,重要类型金矿床(体)快速定位预测的综合示范研究(科研报告),2000.12
    24 郭健,等,1995,陕西风太矿田同生断裂的确定及找矿方向。矿产与勘查,1990(9)
    25 韩发,等,大厂锡-多金属矿床热液喷气沉积成因证据——含矿建造及热液沉积岩。矿床地质,1989,8(2)
    26 胡凯、刘英俊、贾蓉芳等,1993,低温热液条件下有机质富集金机理的实验研究,中国科学(B辑),23(8):880~888
    27 隗合明,陕西风太铅锌矿田的海底喷气成矿类型及其空间分布规律。地质论评,1990,36(5)
    28 隗合明等,风太矿田层控铅锌矿床成矿物质来源探讨。西安地质学院学报,1990,12(1)
    29 李舒,等,中国金矿床工业类型及其特征。北京:地震出版社,1999
    30 李广之,吸附态轻烃的分析技术与应用,油气化探,1999,6(1):1~10。
    31 李广之、岳向阳,浅析酸解烃机理,油气化探,1999,6(3):17~19。
    32 林丽,等,西成铅锌矿床的生物成矿模拟实验研究。矿床地质,2002,21(增刊):423~426
    33 刘东升、谭运金、王建业,等,中国卡林型(微细浸染型)金矿。南京:南京大学出版社,1994
    34 刘方杰、方维萱、赫英,等,秦岭造山带热水沉积矿石建造特征及意义。有色金属矿产与勘查,1999,8(6):343~347
    35 刘家军、郑明华,硅质岩的新成因——热水沉积作用,四川地质学报,1991(4)
    36 刘家军、郑明华,热水沉积硅岩的地球化学,四川地质学报,1992(2)
    37 刘家军,论西秦岭喷流沉积硅岩建造及其控制的金矿床(成都理工大学博士学位论文),1996.5
    38 刘家军、郑明华,顾雪祥,等,海底喷流作用对金富集成矿的意义,矿产与地质,1997a,5期
    39 刘家军、刘建明,黔西南微细浸染型金矿床的喷流沉积成因。科学通报,1997b,42(19):2126~2127
    40 刘建明,海底喷流型层控矿床。见:朱上庆、郑明华主编,层控矿床学,地质出版社,1991,101~120
    41 刘建明,金热液运移形式的化学观。见:中国博士后首届学术大会论文集,国防工业出版社,1993
    42 刘建明、业杰、刘家军,等,盆地流体中有机组分的成矿效应。矿物岩石地球化学通讯,2000,19(3):141~148
    43 刘建明,我国非传统矿产资源的实例及其所涉及的科学问题。地球物理学进展,2001,16(4):133~143
    44 刘建明、业杰、刘家军、顾雪祥,论我国微细浸染型金矿床与沉积盆地演化的关系——以右江盆地为例。矿床地质,2001,20(4):412~420
    45 刘显凡、金景福、倪师军.滇黔桂微细浸染型金矿深部物源的稀土元素证据.成都理工学院学报,1996,2:(4):25-30.
    46 柳淼,厂坝铅锌矿床的海底喷出成矿特征及成因模式。矿产与地质,1988(3)
    47 卢纪英、李作华、张复新,等著,秦岭板块金矿床,西安:陕西科学技术出版社,2001.4
    48 马国良,等,陕西桐木沟锌矿床钠质喷气岩的岩石学及地球化学特征。西安地质学院学报,1993,15(2)
    49 祁思敬,等著,秦岭热水沉积型铅锌(铜)矿床。北京:地质出版社,1993
    50 邵世才、汪东波,2001,南秦岭三个典型金矿床的Ar-Ar年代及其地质意义。地质学报,75(1):106~110
    51 石准立,等著,1989,陕西双王金矿床地质特征及其成因,陕西科学技术出版社。
    52 王学明,等,2001a,陕西八卦庙金矿石英标型特征研究,黄金地质,7(2):1~5
    53 王学明,等,2001b,陕西八卦庙金矿钠长石的成因,矿床地质,3,223~
    54 王祖伟等,粤西廉江银金矿床热液围岩蚀变特征及元素迁移的定量估算,地球化学,1998,3,251
    55 韦龙明、朱桂田、吴烈善等,八卦庙特大型金矿床热水沉积岩初探,矿床地质,1998,17(增刊):271~274
    56 西北有色地勘局717总队,八卦庙—青崖沟金矿成矿地质条件、富集规律及找矿远景研究报告,1990.12
    57 西北有色地勘局717总队,陕西省风县八卦庙金矿床(1300m标高以上)地质详查报告,1995.6
    58 西北有色地勘局717总队,陕西省风县八卦庙金矿床(1300m标高以下)地质普查报告,1998.6
    59 西北有色地质研究所、桂林矿产地质研究院、西北有色地勘局717总队,陕西八卦庙金矿床成矿地质背景、矿床特征及成矿预测研究(科研报告),1994.12
    60 刑新田、余中平主编(中国矿业联合会),我国黄金矿产资源可持续供应问题及对策研究专题报告(内部资料),2001.10
    61 薛春纪,等,1990a,秦岭东段泥盆系中似碧玉层纹钠长石岩的发现及意义,西安地质学院学报,12(4)
    62 薛春纪,等,1990b,风太矿田硅质岩与成矿关系。见:《中国科学院矿床地球化学开放研究实验室年报》,贵阳:贵州科学技术出版社
    63 薛春纪,银洞子似碧玉岩的海底热液沉积特征研究。矿物岩石,1991,11(2)
    64 薛春纪、马国良,东秦岭泥盆纪海盆中的一种(准)同生热水蚀变岩的岩石学和地球化学研究。矿物岩石,1992,12(1)
    65 薛春纪,等,1995a,南秦岭泥盆纪同生热水沉积环境的沉积学及地球化学信息。西北地质,16(4)
    66 薛春纪,等,1995b,对南秦岭海底热液沉积若干基本问题的思考。西北地质,16(4)
    67 薛春纪,等,南秦岭主要类型热水沉积岩的REE地球化学。西安地质学院学报,1996,18(3)
    68 薛春纪著,秦岭泥盆系热水沉积,西安地图出版社,1997.12
    69 薛春纪,秦岭泥盆系热水沉积环境及热水沉积成岩成矿学研究(成都理工大学博士学位论文)1998.10
    70 薛春纪、祁思敬、郑明华,等,热水沉积研究及相关科学问题,矿物岩石地球化学通报,2000,3期
    71 叶连俊,等著,1998,生物有机质成矿作用和成矿背景。北京:海洋出版社
    72 殷鸿福,谢树成,1992,四川松潘东北寨金矿预富集过程中的菌藻成矿作用。地球科学,17(3):241~249
    73 殷鸿福,等著,1999,生物成矿系统论。武汉:中国地质大学出版社。
    74 于学元,等,1996,八卦庙大型金矿床稀土元素地球化学研究。地球化学,25(2):140~149
    75 张本仁主编,1989,地球物理勘查地球化学文集(第九集)。北京:地质出版社。
    76 张复新等,秦岭卡林型金矿床及相关问题探讨。矿床地质,1998/2/172

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