2. 中国地质调查局天津地质调查中心, 天津 300170;
3. 华北理工大学矿业学院地质系, 唐山 063009
2. Tianjin Center of Geological Survey, China Geolocical Survey, Tianjin 300170, China;
3. Department of Geology, School of Mining, North China University of Science and Technology, Tangshan 063009, China
位于乌兹别克斯坦、吉尔吉斯坦和中国境内的南天山是中亚重要的金成矿带(Wilde et al., 2001; Mao et al., 2004; Graupner et al., 2006; Abzalov, 2007; Liu et al., 2007; Morelli et al., 2007; Yang et al., 2007; Frimmel, 2008; Bierlein and Wilde, 2010;Biske and Seltmann, 2010; Pašava et al., 2010, 2013;Goldfarb et al., 2014; 薛春纪等, 2014;Goldfarb and Groves, 2015;Kempe et al., 2015, 2016; Zhang et al., 2017),也是世界著名的成矿带之一。该带由西向东已发现几十个巨型(金储量250t以上)、世界级/超大型(金储量100~250t)和大型(金储量20~100t)金矿床,构成了举世瞩目的“亚洲金腰带”(薛春纪等, 2014)。目前,在中国邻区的南天山造山带相继发现了乌兹别克斯坦的穆龙套(Muruntau)金矿(Au 6137t; Frimmel, 2008)、道吉兹套(Daugyztau)金矿(Au 186t;Bierlein and Wilde, 2010)、阿曼泰套(Amantaitau)金矿(Au 120t; Pašava et al., 2010)、扎尔米坦(Zarmitan)金矿(Au 314t; Abzalov, 2007),塔吉克斯坦吉老(Jilau)金矿(Au 110t; Cole et al., 2000),吉尔吉斯斯坦的库姆托尔(Kumtor)金矿(Au 1100t;Mao et al., 2004)等一大批巨型、超大型金矿(图 1)。新疆南天山是中亚南天山的东延部分,与境外南天山成矿地质条件相似,在此区先后发现了萨瓦亚尔顿、大山口、萨恨托亥、布隆等金矿床和一些金矿(化)点(杨富全等, 2005, 2007; Yang et al., 2006, 2007; Liu et al., 2007),其中,萨瓦亚尔顿金矿储量已超过100t,远景资源量约300吨(Rui et al., 2002; 薛春纪等,2014),是目前中国南天山最大的金矿(Rui et al., 2002; Chen et al., 2012a, b; 薛春纪等, 2014; Zhang et al., 2017)。这些金矿(点)的发现,显示出中国南天山具有良好的找矿前景,不过就其矿床数量及规模来说,尚无法与境外西南天山相比,其矿产资源开发和研究程度尚显不足。
阿沙哇义金矿,位于萨瓦亚尔顿金矿的东延部分,北东侧紧邻吉尔吉斯坦的库姆托尔(Kumtor)世界级金矿。近年来随着地质勘查工作的投入,阿沙哇义金矿储量已由原来的金矿点增大至中型规模,已成为境内西南天山地区继萨瓦亚尔顿金矿之后的第二大金矿床。但目前有关该矿床的基础研究工作极其有限(陈奎等, 2007),且矿石Au品位总体较低(1.00~3.00g/t),基于矿山后续开发的经济效益考虑,需探寻本区富矿(指矿石品位高于矿区平均品位的矿石)的关键标志特征。
本文试图通过对阿沙哇义金矿的岩相学、矿相学、成矿流体温压条件、成矿流体组分、硫化物成分的综合研究,为深入认识该金矿成因类型、成矿机制提供约束,并揭示本区寻找富矿的关键标志特征。
1 区域及矿区地质背景天山造山带由北向南划分为北天山、中天山、南天山3个构造单元(图 1b),北天山位于Nikolaev-那拉提北缘断裂以北,主体为哈萨克斯坦-伊犁板块及其南、北活动边缘;中天山介于Nikolaev-那拉提北缘断裂与Atbash-Inylchek-那拉提南缘断裂之间;南天山主体为卡拉库姆-塔里木板块北缘,处在Atbash-Inylchek-那拉提南缘断裂的南侧(图 1b; Gao et al., 2009; Zhao et al., 2014, 2015; 薛春纪等, 2014; Zhang et al., 2017)。上述3个构造单元被北西走向的Talas-Fergana断裂横切。其中:在南天山,前寒武变质结晶基底多有出露,盖层为寒武纪-石炭纪海相碳酸盐、碎屑岩及火山岩夹层(Allen et al., 1993; Gao et al., 2009)。在南天山的中部区域,二叠纪的河流相沉积物和火山岩不整合在石炭纪碳酸盐层上(Carroll et al., 1995; Huang et al., 2012)。沿Atbash-Inylchek-那拉提南缘断裂带断续出露蛇绿岩和低温高压变质岩(图 1b; 高俊等, 2006; Xiao et al., 2013)。来自蛇绿岩里的蓝闪石获得K-Ar年龄为360±10Ma, 认为这些蛇绿岩形成于南天山洋向北俯冲的过程中(Gao et al., 2009)。来自低温高压变质岩中多硅白云母和变质锆石分别获得了331~310Ma的40Ar-39Ar年龄和320Ma的U-Pb年龄(Klemd et al., 2005; Su et al., 2010; Gao et al., 2011),代表了塔里木板块与中天山在晚石炭世发生了碰撞(Gao et al., 2009; Huang et al., 2012)。侵入岩出露较少,约占整个南天山面积的5%,时代主要集中在早二叠世到晚石炭世(Huang et al., 2012)。后碰撞花岗岩的年龄分布在298~260Ma之间(Konopelko et al., 2007; Solomovich, 2007; Long et al., 2008; Gao et al., 2011),与南天山洋在晚石炭世闭合相一致(Zhang et al., 2017)。
阿沙哇义金矿大地构造位置属于南天山造山带塔里木板块北缘活动带,位于区域上北东向卡拉铁克大断裂和喀勒铁别克大断裂之间的买当他乌复向斜上,该复向斜由一系列向斜夹背斜组成(图 2)。矿区主要位于东南侧的次级背斜上,表现为轴面倾向北西的倒转背斜,主要矿化破碎蚀变带发育在背斜的南翼和背斜轴部附近。矿区主要出露上石炭统含炭绢云千枚岩、变砂岩、粉砂岩。岩浆岩出露有限,仅见几条规模较小的闪长玢岩脉出露。岩石普遍遭受浅变质作用,发育硅化、黄铁矿化(次生褐铁矿化)、绢云母化、碳酸盐化、绿泥石化、高岭土化等,局部有千糜岩化现象,并常伴有金矿化,其中硅化、黄铁绢英岩化与金矿化关系最为密切。
矿(化)体严格受NNE-NE(30°~50°)走向的断裂破碎蚀变带控制,后期NW走向断裂横切这些矿化破碎蚀变带(图 3),矿化破碎蚀变带主要发育在背斜轴部附近或背斜南翼,矿体总体倾向北西,局部倾向南东,在近地表由于重力坍塌作用,或处于皱褶转折端附近,或由于后期南东向北西的推覆作用,导致矿体局部常呈现南东倾向,但向深部逐渐转为近直立或北东倾向。
矿体主要赋存于上石炭统碳质千枚岩和灰色变粉砂岩(图 4c, d)接触带附近靠近含炭千枚岩一侧,其次赋存于含炭千枚岩或变粉砂岩中。矿(化)体在浅表为氧化矿石(图 4a, b),十分破碎,褐铁矿化强烈,向深部逐渐转变为原生黄铁矿化矿石,破碎程度也具有减弱趋势。矿化破碎蚀变带与区域构造方向一致,断续延长约7000m,宽约500m,共计圈定矿体51条,其中主矿体7条。7条主矿体控制长度在300~1100m之间,真厚度多为0.55~8.91m之间,局部厚度达21m。矿体主要受地表探槽、平硐、浅部钻孔控制,矿体在走向及倾向上均未封闭,目前主矿体控制最大斜深一般在80~160m之间,局部控制斜深达300m,Au品位一般介于0.77~4.36g/t之间,平均品位为1.31~2.14g/t,少数矿石品位达10g/t以上,最高可达14g/t。
根据脉体穿插关系、矿石组构和矿物组合,可以将成矿作用分为以下3个阶段:
Ⅰ阶段为无矿或贫矿石英阶段,为早期成矿阶段,无矿石英脉多呈脉状或透镜状顺层产出,矿物组合简单,主要由粗粒(0.5~1mm)乳白色石英组成(图 4e),石英脉一般厚1~3cm,最厚可达30cm。本阶段石英脉中含少量立方晶型的黄铁矿分布,基本不含矿或弱矿化。这一阶段与穆龙套金矿最早期石英脉特征相似(Wilde et al., 2001)
Ⅱ阶段为石英-多金属硫化物阶段,为金矿化主要阶段,含矿石英脉与无矿石英脉相比,含矿石英脉遭受强烈的构造变形、破碎和热液作用的叠加。含矿石英脉呈细脉或网脉产于蚀变破碎带中,石英为烟灰色、灰色或灰白色,晶体较小(0.05~0.2mm),含较多金属硫化物(图 4f-i),主要金属硫化物以自形-半自形黄铁矿为主,其次为毒砂、辉锑矿,偶见方铅矿、闪锌矿、黄铜矿等(图 5a-f),黄铁矿和毒砂为主要载金矿物,金属硫化物常沿着早期矿化石英脉裂隙分布或交代早期矿化石英角砾(图 4f-h),且黄铁矿常发育环带特征(图 5c, e),显示出多期热液叠加的特征。锑矿体常在金矿体相对上部呈鸡窝状独立产出,局部辉锑矿含量高时呈块状(图 4i),但产出规模较小,基本不含金,生成时间可能略晚于金矿化。
Ⅲ阶段为石英-碳酸盐阶段,为成矿的晚期阶段,以发育石英-碳酸盐细脉为特征,多形成毫米至厘米宽的网脉,可见石英碳酸盐集合体交代Ⅱ阶段石英硫化物细脉(图 4g)以及充填于破碎蚀变带中。石英碳酸盐细脉宽0.2~3cm,其中石英脉发育晶洞、梳状构造,碳酸盐矿物主要是方解石,其次是铁白云石。该阶段几乎不含硫化物,金矿化也很微弱。
3 样品采集和分析方法由于地表矿石均已氧化且风化破碎严重,为了保证样品的代表性,本次采集的样品主要取自矿区钻孔深部岩芯,仅有极少部分相对新鲜样品取自地表和平硐,共采样品92件。经流体包裹体岩相学观察后,从中挑选主成矿阶段的具有不同Au含量的样品8件,进行石英群体流体包裹体成分分析;挑选各成矿阶段代表性样品15件、不同围岩地层2件及岩体1件,对其中所含的黄铁矿和毒砂进行电子探针Au、As、Fe元素面分析,并对不同晶型的黄铁矿和毒砂进行了主量、微量元素点分析。
流体包裹体成分测试分析工作在中国科学院地质与地球物理研究所进行,气相成分在日本真空技术株式会社生产的RG202四极质谱仪(QMS)上测定,液相成分在日本SHIMADZU公司HIC-6A型离子色谱仪上测定,仪器重复测定的精度均为<5%(朱和平和王莉娟, 2001)。
电子探针测试分析工作在中国地质调查局天津地质调查中心实验室完成。测试仪器为日本岛津公司制造EPMA-1600,工作条件为:加速电压为15kV;电流为20nA;束斑直径5μm。峰值计算时间20~60s。采用ZAF法修正数据,定量分析精度:含量>5%时精度好于1%,含量1%~5%时精度好于5%,总量100%±1.5%,标准样品为:SPI硫化物标样和金银标样。分析元素为As、Fe、S、Cu、Pb、Zn、Se、Co、Ni、Sb、Te、Ag、Au,各元素平均检测限为0.01%。
4 流体包裹体研究 4.1 流体包裹体岩相学和分类各类矿石的原生流体包裹体可划归为3种类型:NaCl-H2O型包裹体、含CO2水溶液包裹体、纯CO2包裹体。
Ⅰ型:NaCl-H2O型包裹体,室温下由两相(LNaCl-H2O+VH2O)组成(图 6a-d),约占包裹体总数的90%,由气相和液相组成,该类包裹体均为富液相包裹体,气液比区间范围5%~30%,多数在5%~10%左右,包裹体形态有椭圆形、近圆形、不规则形,一般椭圆形和近圆形的包裹体偏小,长轴长4~12μm,不规则形的包裹体要大一些,可达30μm。该类包裹体分布最广泛,在各成矿阶段的石英中均有分布。
Ⅱ型:含CO2水溶液包裹体,约占包裹体总数的10%,室温下多表现为两相(LH2O-NaCl +LCO2),偶见三相(LH2O-NaCl+LCO2±VCO2)(图 6b)。该类型包裹体主要出现在成矿早、中期阶段,其中早期阶段比中期阶段更发育,晚期阶段不发育。根据CO2相(LCO2+VCO2)在包裹体总体积的所占比例,可进一步划分为贫CO2包裹体(Ⅱ1型,图 6b)和富CO2包裹体(Ⅱ2型,图 6c),其中前者CO2相占包裹体总体积的10%~50%,主要集中在20%~30%;后者CO2相(LCO2+VCO2)占包裹体总体积的50%~90%,主要集中在80%。该类型包裹体(Ⅱ型)长轴长5~35μm,相对大于H2O溶液包裹体(Ⅰ型)。形状多为椭圆形、不规则形,偶有卡脖子现象。
Ⅲ型:纯CO2包裹体,该类型包裹体较少,不足包裹体总数的1%,主要出现在成矿早、中期阶段,晚期阶段未见此类包裹体。室温下表现为单相或两相(图 6c),前者冷冻过程中出现CO2气相;多呈椭圆形、长条形或不规则形产出,大小为5~25μm。
4.2 流体包裹体均一温度和盐度通过对矿区16件流体包裹体样品共147个包裹体显微测温,获得了成矿早、中、晚三个阶段的流体包裹体均一温度、盐度等参数,现将各阶段石英流体包裹体测试分析结果总结于均一温度、盐度直方图(图 7)。
各阶段流体包裹体类型及占比存在明显变化,在成矿早期的无矿石英阶段,H2O-NaCl包裹体(Ⅰ型)约占75%,其次为CO2-H2O包裹体(Ⅱ型),纯CO2包裹体(Ⅲ型)不足1%;在成矿中期的石英-多金属硫化物阶段,即主成矿阶段,与成矿早期少硫化的无矿石英阶段相比,H2O-NaCl包裹体(Ⅰ型)所占比例增加,约占90%,CO2-H2O包裹体(Ⅱ型)所占比例明显减少,约占10%;在成矿晚期的石英-碳酸盐阶段,主要以H2O-NaCl包裹体(Ⅰ型)为主,偶见CO2-H2O包裹体(Ⅱ型)。从早阶段到晚阶段,总体呈现出CO2-H2O包裹体(Ⅱ型)数量逐渐减少的趋势。
各阶段流体包裹体的均一温度都出现了两个峰值(图 7),且不同阶段石英包裹体的均一温度峰值集中范围存在大体一致的叠加现象,如早阶段的低温峰、中阶段低温峰以及晚阶段高温峰三者的重叠,显示了中晚阶段流体对早阶段矿物的叠加作用。因此,在剔除各阶段流体相互叠加影响因素外,早期阶段石英包裹体的均一温度范围集中在320~360℃,晚期阶段石英包裹体的均一温度范围集中在180~200℃,中阶段的石英包裹体存在两个峰值(220~250℃,280~300℃)的原因可能不是由于不同阶段脉体叠加作用所致,因为这两个峰值分别对应不同的包裹体类型,其低温峰值(220~250℃)是H2O-NaCl包裹体(Ⅰ型)的均一温度,而高温峰值(280~300℃)主要是CO2-H2O包裹体(Ⅱ型)的均一温度,因此,造成这一结果的原因可能与流体包裹体被捕获于不混溶体系有关。
各阶段流体包裹体的盐度总体较低,早阶段石英流体包裹体的盐度峰值范围(3%~5%NaCleqv)最低,集中在4%NaCleqv左右,中阶段石英的流体包裹体盐度总体较早阶段流体包裹体呈现随温度降低盐度增高的现象,并出现了两个峰值,Ⅱ型包裹体主要分布在低盐度区,高盐度区均为Ⅰ型包裹体。晚阶段石英的流体包裹的盐度峰值范围总体较中阶段的流体包裹体盐度降低。
4.3 流体包裹体气、液相成分不同Au品位矿石中石英的群体流体包裹体成分分析结果见表 1,成矿流体中阳离子以Na+为主,含少量K+、Ca2+离子,阴离子以Cl-为主,SO2-次之,未检测到F-;气相成分以H2O为主,摩尔含量为75%~93%,其次为CO2,摩尔含量为6%~25%,其余为CH4、C2H6、H2S、N2和Ar,这些气体的量虽然很少,但它们的存在反映了成矿环境为还原环境。值得注意的是,Au品位较高的矿石与相对较低的CO2含量、较低的O/R值以及较高的K+含量密切相关。
选择矿区岩体、代表性围岩地层以及各成矿阶段代表性矿石,磨制成探针片,对其中所含的黄铁矿、毒砂进行电子探针(EMPA)面分析(图 8)和点分析(数据见表 2),分析结果总结如下:
(1) 岩体中黄铁矿几乎不含金(图 8d),而围岩地层和各类矿石中的黄铁矿、毒砂含金明显,金矿化明显受黄铁矿和毒砂控制(图 8h, i, p, t, x),以包体金或裂隙金形式产出。
(2) 毒砂以自形晶为主,其次为他形晶;黄铁矿晶型以他形为主,其次为自形(立方体和五角十二面体),黄铁矿、和毒砂的Au含量与其自形程度没有明显的相关性。
(3) 部分黄铁矿(图 8v)和毒砂(图 8n)可见环带结构,环带状黄铁矿多见于成矿主阶段,环带状黄铁矿(图 8x)较其它均质黄铁矿(图 8l, p, t)具有更为明显的Au异常(背景均为石英长石矿物),如:As56-1较其它样品,即环带状黄铁矿较其它均质黄铁矿具有更高的Au含量,但不同环带Au含量几乎均一分布,没有明显区别(图 8x)。
(4) 黄铁矿和毒砂共存于同一矿石时,从电子探针面分析(图 8p, t)发现,毒砂中Au含量总体略高于黄铁矿Au含量,电子探针点分析数据也显示同样的特点(表 2、图 9),黄铁矿Au含量分布范围为0~0.09%,平均值为0.03%;毒砂Au范围为0~0.28%,平均值为0.07%。
造山型金矿床是指那些在时空上与造山作用有关的,主要受构造控制的金矿床(Groves et al., 1998; Kerrich et al., 2000)。这类矿床具有相似的地球动力学背景,且具有相似的地球化学特征,产于汇聚板块边缘的增生体以及碰撞造山带的挤压和转换挤压变形构造环境(Groves et al., 2000; Goldfarb et al., 2001)。这类矿床可形成于自地表向下2~20km的不同深度,Groves等(1998)将造山型金矿划分为3个亚型,即浅层(<6km)、中层(6~12km)和深层(>12km)。造山型金矿作为重要的成矿类型,全球已有23个储量大于500t的金矿属于此类型(Bierlein et al., 2006)。自该矿床类型提出后,就掀起了广泛的研究和讨论热潮,众多学者对其产出构造背景、成矿特征、形成时代、成矿流体特征及成矿机制等方面开展了大量的卓有成效的研究(Bierlein et al., 2001; Goldfarb et al., 2001; Wilde et al., 2001; Mao et al., 2002; 毛景文等, 2002; Groves et al., 2003; Chen et al., 2004; 陈衍景, 2006),同时伴随着此类型金矿的不断被发现和识别。我们将阿沙哇义金矿与造山型金矿的地质和成矿流体特征做综合对比(表 3)后发现,在构造环境、赋存岩性、控矿构造、矿体形态、矿石类型、矿石矿物组合、矿化元素组合、包裹体类型、流体标志特征、主成矿温度以及流体演化等方面均具有一致性,因此我们认为阿沙哇义金矿成因类型应属于造山型金矿。
成矿热液中金主要以Au-S络合物和Au-Cl络合物形式迁移(Benning and Seward, 1996; Ilchik and Barton, 1997; Mikucki, 1998),高温时金以Au-Cl络合物形式迁移,低温时以Au-S络合物形式迁移。实验研究表明,在中低温热液金矿床中金主要以Au(HS)2-络合物形式迁移(Benning and Seward, 1996; Ilchik and Barton, 1997; Mikucki, 1998; Wilkinson, 2001)。前人研究表明,造山型金矿床中的金主要以Au(HS)2-络合物形式运移(Groves et al., 2003; Goldfarb et al., 2005),考虑到阿沙哇义金矿为造山型金矿,Au的沉淀与金属硫化物密切相关,且成矿流体为中低温,综合流体包裹体成分分析结果,认为本区金主要以Au(HS)2-络合物形式运移。
阿沙哇义金矿流体包裹体不均一捕获现象普遍,且出现Ⅰ型、Ⅱ型、Ⅲ型同时共存于同一样品的现象(图 6c),特征迥异的两类包裹体出现在同一样品中,并紧密相临,属于同时被捕获,矿物同时捕获性质迥异的流体最可能是不均一捕获所致,是流体不混溶或混合的重要标志(Ramboz et al., 1982; Roedder, 1984)。各成矿阶段流体包裹体盐度及均一温度演化特征也说明流体经历了不混溶作用,如:①从成矿早期到成矿中期,流体盐度随温度降低而增高和分散,这与物质溶解度随温度降低而降低的普遍规律相矛盾,且高盐度主要出现在Ⅰ型包裹体中,而Ⅱ型包裹体主要位于低盐度范围(图 7),可能为流体气相逸失导致流体浓缩的结果,即沸腾;②部分流体包裹体在近似相同的温度范围内具有不同的盐度。因此,阿沙哇义金矿成矿过程与世界多数脉状中温热液矿床一样,在金矿形成过程中发生了流体不混溶作用(Sibson et al., 1988; Cox et at., 1995; McCuaig and Kerrich, 1998; Jia et al., 2000; Chen et al., 2005, 2006, 2012a, b)。
流体包裹体岩相学观察表明,成矿中期的石英-多金属硫化物阶段,即主成矿阶段,与成矿早期少硫化物的无矿石英阶段相比,CO2-H2O包裹体(Ⅱ型)所占比例明显减少,说明从成矿早期阶段到主成矿阶段,CO2不断逃离成矿流体系统,同时伴随着Au的富集和沉淀。流体包裹体成分分析结果也得到了进一步的佐证:较高Au品位矿石的流体包裹体具有较低的CO2含量,矿石Au含量与其流体包裹体的CO2和O/R值大体呈负相关(图 10a,b),CO2的逃逸会破坏Au(HS)2-络合物在流体中的稳定性,促使Au(HS)2-络合物分解,形成Au的富集和沉淀,反应式如下:
① 4Au(HS)2-+C+4H++2H2O=4Au+CO2+8H2S (Craw, 2002; Craw et al., 2007; Zoheir et al., 2008; Hu et al., 2015, 2017)
② 2HCO3-+Au(HS)2-+Fe3+=Au+FeS2+2H2O+2CO2 (Zhang et al., 2012)
因此,金矿成矿作用与流体不混溶作用有重大关系的认识(Goldfarb et al., 1989, 1997; Naden and Shepherd, 1989; Guha et al., 1990, 1991; Craw, 1992; McCuaig and Kerrich, 1998; Jia et al., 2000; 胡芳芳等, 2005; 卢焕章, 2008a, b),对于阿沙哇义金矿同样适用。
6.3 流体混合与金的富集沉淀尽管流体不混溶(沸腾)是本区Au的主要富集和沉淀机制,但一些成矿流体特征不能用单一的流体不混溶机制解释,如:在同一样品中流体盐度的异常变化、复杂的气、液相组分(CO2、CH4、N2、H2S、K+),这些流体特征均暗示了流体混合机制对金的富集和沉淀也发挥了作用。流体包裹体成分分析结果显示,Au品位较高的矿石的流体包裹体具有较高的K含量(图 11),已有数据表明,矿区闪长玢岩相对富Na贫K,K含量极低,且低于围岩地层的K含量,而拥有相对富Na贫K流体的矿石的Au含量却相对较低,如:表 1中样品As35、As36、As57均具有此特征。因此,这种相对富K的流体是流体与围岩反复作用而形成,与矿区岩体无关。考虑到赋矿围岩多是含炭的碎屑岩,有利于流体萃取CH4等有机质成分和K、S等组分,因此认为,循环于赋矿建造的大气降水热液在与围岩的反复作用下,其K、S、CH4等含量较高,在成矿阶段混入到流体成矿系统,导致流体成分改变,诱发金、硫化物等成矿物质沉淀,当然,围岩含炭物质的作用不仅如此,含炭物质同样会促使Au(HS)2-络合物分解和流体的浓缩,进而导致金的富集和沉淀,如前述①式及下式:C+2H2O=CO2+2H2 (Cox et al., 1995; Naden and Shepherd, 1989)。显然,水岩反应不仅可以从围岩中萃取成矿物质促使流体成分发生改变,诱发金沉淀,也会因为流体与围岩作用过程中H2O的消耗,以及CO2逃逸进一步促使H2O的消耗而导致流体浓缩,可见,流体混合与流体不混溶成矿机制在本区并不是独立存在的。
事实上,流体混合也是诸多造山型金矿的成矿机制,在中国西南天山的萨瓦亚尔顿金矿也是如此(Brown, 1998; Bierlein and Maher, 2001; Chen et al., 2012a),值得说明的是,这种流体混合成矿机制与本区赋矿断裂多次开合、压扭性向张扭性转变、成矿深度较浅等事实可以相互支持印证。
6.4 硫化物振荡环带对金的成因指示EMPA面分析结果(图 8v)显示,含砷黄铁矿中各振荡环带间As含量存在突变,但Au、Fe几乎均一分布,并没有呈现出相应的环带特征,尽管诸多学者基于所获数据得出了含砷黄铁矿中的Au和As含量呈现正相关(Cook and Chryssoulis, 1990; Simon et al., 1999; Reich et al., 2005; Large et al., 2009; Deditius et al., 2014)的认识,但本区含砷黄铁矿中Au和As的含量并没有显著相关性(图 8)。EMPA点分析结果同样显示Au和As的含量没有显著相关性(图 12)。但仔细对比观察发现,环带状黄铁矿较其它均质结构黄铁矿具有相对明显的Au异常(不同结构的黄铁矿背景相同,均以石英长石矿物为主),即Au含量相对较高。
黄铁矿和毒砂的成分环带可能由两个独立的机制引发:①相分离作用使得流体被分离成两种不同的组分;②两种不同组分流体的混合(Deditius et al., 2009)。
由于本区的黄铁矿环带呈现周期性循环,且各环带之间成分突变,缺少中间组分过渡,这种成分突变环带最可能原因是:流体压力波动引发相分离所形成的结果,这种流体压力的波动是由断层裂-合作用而造成的(Hazarika et al., 2017)。
我们利用流体包裹体均一时的压力估算成矿流体的最小捕获压力,将主成矿阶段包裹体的均一温度剔除晚期阶段流体带来的干扰因素后(剔除均一温度<200℃的包裹体),利用其它所有Ⅰ型和Ⅱ型包裹体作为最小捕获压力进行估算。其中Ⅰ型包裹体的压力估算据Bodnar and Vityk (1994), Ⅱ型包裹体压力利用Flincor(Brown, 1989)程序,选择H2O-CO2-NaCl体系进行计算。所有包裹体求得的压力形成两个明显不同的压力范围,即低压范围(16.21~36.72MPa)和高压值范围(75.04~103.57MPa)。在流体沉淀过程中成矿深度基本不变,压力的波动实际上是不同压力类型的改变所致,断裂闭合和张开过程中静岩压力与静水压力频繁转换,当被捕获的流体包裹体所记录下来的压力值中同时包括了两种压力类型时,可以考虑将求得的流体捕获压力的两个区间端元近似看做压力类型的端元,由于在相同深度上,静岩压力大于静水压力,故低压值端元接近静水压力,高压值端元接近静岩压力(徐启东等, 1995)。阿沙哇金矿化主要赋存在逆冲的断裂系统中,矿石组构特征也表明成矿过程曾经历过压性向张性应力的转换以及多阶段多期次活动的特点,说明断裂系统存在多次裂-合作用,造成流体压力出现持续波动变化是完全可能的。据此,我们假设高压范围和低压范围流体分别处于静岩压力和静水压力系统下,利用压力与深度关系的通式P=ρgh进行估算,在流体处于静岩压力系统时取ρ为矿区平均岩石密度2.6g/cm3,在流体处于在静水压力系统时,ρ为各类包裹体当时计算得到的密度,分别对应的流体深度范围为1.84~4.24km和2.94~4.18km,前后两者深度范围的高值接近,因此,流体可能在1.84~4.24km深度范围内,由于静岩压力和静水压力状态的共存和交替而发生的复杂的不混溶过程,造成了流体成分的波动,形成了黄铁矿和毒砂的振荡环带结构,同时伴随着金的沉淀。
前人研究也表明,这种静岩压力和静水压力的共存和交替现象是造山型矿床之赋矿断裂振荡性愈合-破裂的结果(Sibson et al., 1988; Kerrich et al., 2000; Cox et al., 2001),流体由(超)静岩压力突变为静水压力时会起流体减压沸腾,成矿流体浓缩,表现为流体盐度增加,金发生富集和沉淀(程南南等, 2018)。因此,硫化物振荡环带进一步佐证了流体不混溶作用是本区金富集和沉淀的重要机制。
6.5 硫化物含金对找矿的意义诸多学者认为造山型金矿床中金的沉淀过程与先存含铁矿物的硫化作用有关(Phillips and Groves, 1984; Groves et al., 2003; Goldfarb et al., 2005; Hu et al., 2015, 2017),认为金和硫在流体中是同时搬运的(Chang et al., 2008),黄铁矿的析出伴随着金的沉淀,这个过程可用如下反应式(Large et al., 2011)表示:
Fe2++2Au(HS)2-+2H2=FeS2+Au0+2H2S
本次EMPA分析结果显示,黄铁矿和毒砂为主要载金矿物也支持了这一观点。流体包裹体成分分析结果显示,Au品位较高的矿石的流体包裹体具有较低的O/R值(表 1),矿石Au含量与其流体包裹体的O/R值(表 1)大体呈负相关(图 10b),这与在相对还原环境更有利于硫化物(黄铁矿、毒砂)富集沉淀,且黄铁矿和毒砂是主要载金矿物的研究结果相一致。
值得注意的是,矿石中黄铁矿的周围往往富集含炭物质(图 13a-d),特别是这种呈脉状展布的含炭物质显示出随成矿流体运移的特征(图 13a,b,d),前人研究发现,寄主在变质沉积岩中的造山型金矿,含炭物质与金和硫化物在空间上广泛共存(Bierlein et al., 2001; Berge, 2011; Craw et al., 2015; Hu et al., 2015; Kříbek et al., 2015),这种含炭物质可分为两种,一种是从有机质中获得并就地同沉积岩一起沉淀,伴随变质变形而成熟度发生变化(Bierlein et al., 2001; Berge, 2011),另一种可能是,从成矿流体中沉淀出来(Pitcairn et al., 2005; Kříbek et al., 2015)。Hu et al.(2017)对新西兰、澳大利亚、加拿大和西部非洲寄主在变质沉积岩中的造山型金矿的研究结果表明,黄铁矿和含炭物质共存主要是因为它们从含矿流体中共同沉淀,来自围岩中就地沉积的含炭物质仅占少部分,黄铁矿和含炭物质的沉淀会降低成矿流体中H2S的浓度,进而破坏Au(HS)2-络合物的稳定性,导致金沉淀。
基于上述认识,在本区后续的勘查找矿过程中,含炭物质较高的地质区域应作为勘查重点区域。鉴于本区黄铁矿和毒砂是主要载金矿物,且毒砂中的Au含量总体高于黄铁矿的Au含量(表 2、图 9),因此,黄铁矿、毒砂发育及含炭物质较高三者组合共存应是本区寻找富矿的关键标志。
7 结论(1) 南天山阿沙哇义金矿的矿体严格受韧脆性剪切带控制,成矿阶段从早到晚可分为3个阶段:早期无矿或贫矿石英阶段、中期石英多金属硫化物阶段、晚期石英-碳酸盐阶段,中期阶段为成矿主要阶段。成矿流体属于NaCl-H2O-CO2体系,总体显示低盐度、富CO2特征,成矿温度范围为180~360℃,主成矿阶段温度集中在220~250℃,从早到晚,流体盐经历了先增高后降低的过程,流体可能在1.84~4.24km深度范围内存在静岩压力和静水压力状态的共存和交替,发生了复杂的不混溶过程,最终导致了金富集和沉淀。鉴于该矿成矿构造背景、成矿流体特征及演化、金矿富集机制、成矿温压条件等方面,与世界上大多数造山型金矿具有相似特征,识别出阿沙哇义金矿床属于浅剥蚀的造山型金矿。
(2) 断层阀作用控制的断层愈合-破裂导致的流体不混溶作用是本区金富集、沉淀的最重要机制,但一些成矿流体特征不能用单一的流体不混溶机制解释,这些流体特征暗示了流体混合机制对金的富集沉淀也发挥了作用。
(3) 含炭物质较高的地质区域应作为本区找金的重点区域,黄铁矿、毒砂发育及含炭物质较高三者组合出现应是寻找富矿的关键标志。
致谢 野外工作中得到阿沙哇义金矿所属的阿合奇县合得利矿业有限公司相关工作人员的支持与帮助;在实验测试分析过程中得到中国地质调查局天津地质调查中心周红英教授级高工、中国科学院地质与地球物理研究所朱和平高级工程师大力协助;论文写作过程中得到中国科学院地质与地球物理研究所秦克章研究员的启发和指导;二位审稿人提出了宝贵的修改意见;特致谢意!
Abzalov M. 2007. Zarmitan granitoid-hosted gold deposit, Tianshan belt, Uzbekistan. Economic Geology, 102(3): 519-532 |
Allen MB, Windley BF and Zhang C. 1993. Palaeozoic collisional tectonics and magmatism of the Chinese Tien Shan, Central Asia. Tectonophysics, 220(1-4): 89-115 DOI:10.1016/0040-1951(93)90225-9 |
Benning LG and Seward TM. 1996. Hydrosulphide complexing of Au(Ⅰ) in hydrothermal solutions from 150~400℃ and 500~1500bar. Geochimica et Cosmochimica Acta, 60(11): 1849-1871 DOI:10.1016/0016-7037(96)00061-0 |
Berge J. 2011. Paleoproterozoic, turbidite-hosted, gold deposits of the Ashanti gold belt (Ghana, West Africa):Comparative analysis of turbidite-hosted gold deposits and an updated genetic model. Ore Geology Reviews, 39(1-2): 91-100 DOI:10.1016/j.oregeorev.2010.12.001 |
Bierlein FP and Maher S. 2001. Orogenic disseminated gold in Phanerozoic fold belts:Examples from Victoria, Australia and elsewhere. Ore Geology Reviews, 18(1-2): 113-148 DOI:10.1016/S0169-1368(01)00019-1 |
Bierlein FP, Cartwright I and McKnight S. 2001. The role of carbonaceous "indicator" slates in the genesis of lode gold mineralization in the western Lachlan Orogen, Victoria, Southeastern Australia. Economic Geology, 96(3): 431-451 |
Bierlein FP, Groves DI, Goldfarb RJ and Dubé B. 2006. Lithospheric controls on the formation of provinces hosting giant orogenic gold deposits. Mineralium Deposita, 40(8): 874-886 DOI:10.1007/s00126-005-0046-2 |
Bierlein FP and Wilde AR. 2010. New constraints on the polychronous nature of the giant Muruntau gold deposit from wall-rock alteration and ore paragenetic studies. Australian Journal of Earth Sciences, 57(6): 839-854 DOI:10.1080/08120099.2010.495705 |
Biske YS and Seltmann R. 2010. Paleozoic Tian-Shan as a transitional region between the Rheic and Urals-Turkestan oceans. Gondwana Research, 17(2-3): 602-613 DOI:10.1016/j.gr.2009.11.014 |
Bodnar RJ and Vityk MO. 1994. Interpretation of microthermometric data for H2O-NaCl fluid inclusions. In: De Vivo B and Frezzotti ML (eds.). Fluid Inclusions in Minerals: Methods and Applications. Blacksburg: Virginia Technology, 117-130
|
Brown PE. 1989. FLINCOR:A microcomputer program for the reduction and investigation of fluid-inclusion data. American Mineralogist, 74(11-12): 1390-1393 |
Brown PE. 1998. Fluid inclusion modeling for hydrothermal systems. In: Richards JP and Larson PB (eds.). Techniques in Hydrothermal Ore Deposits Geology. Littleton, Colorado: Society of Economic Geologists, 10: 51-171
|
Carroll AR, Graham SA, Hendrix MS, Ying D and Zhou D. 1995. Late Paleozoic tectonic amalgamation of northwestern China:Sedimentary record of the northern Tarim, northwestern Turpan, and southern Junggar basins. Geological Society of America Bulletin, 107(5): 571-594 DOI:10.1130/0016-7606(1995)107<0571:LPTAON>2.3.CO;2 |
Chang ZS, Large RR and Maslennikov V. 2008. Sulfur isotopes in sediment-hosted orogenic gold deposits:Evidence for an early timing and a seawater sulfur source. Geology, 36(12): 971-974 DOI:10.1130/G25001A.1 |
Chen HY, Chen YJ and Baker MJ. 2012a. Evolution of ore-forming fluids in the Sawayaerdun gold deposit in the southwestern Chinese Tianshan metallogenic belt, Northwest China. Journal of Asian Earth Sciences, 49: 131-144 DOI:10.1016/j.jseaes.2011.05.011 |
Chen HY, Chen YJ and Baker M. 2012b. Isotopic geochemistry of the Sawayaerdun orogenic-type gold deposit, Tianshan, Northwest China:Implications for ore genesis and mineral exploration. Chemical Geology, 310-311: 1-11 DOI:10.1016/j.chemgeo.2012.03.026 |
Chen K, Tian XW, Yang GR and Zhang YT. 2007. The geological characteristics and exploration guides at the Ashawayi gold deposit. Xinjiang Geology, 25(4): 384-388 |
Chen YJ, Pirajno F and Sui YH. 2004. Isotope geochemistry of the Tieluping silver-lead deposit, Henan, China:A case study of orogenic silver-dominated deposits and related tectonic setting. Mineralium Deposita, 39(5-6): 560-575 DOI:10.1007/s00126-004-0429-9 |
Chen YJ, Pirajno F and Sui YH. 2005. Geology and D-O-C isotope systematical of the Tieluping silver deposit, Henan, China:Implications for ore genesis. Acta Geologica Sinica, 79(1): 106-119 DOI:10.1111/acgs.2005.79.issue-1 |
Chen YJ. 2006. Orogenic-type deposits and their metallogenic model and exploration potential. Geology in China, 33(6): 1181-1196 (in Chinese with English abstract) |
Chen YJ, Pirajno F, Qi JP, Li J and Wang HH. 2006. Ore geology, fluid geochemistry and genesis of the Shanggong gold deposit, eastern Qinling Orogen, China. Resource Geology, 56(2): 99-116 DOI:10.1111/rge.2006.56.issue-2 |
Chen YJ, Ni P, Fan HR, Pirajno F, Lai Y, Su WC and Zhang H. 2007. Diagnostic fluid inclusions of different types hydrothermal gold deposit. Acta Petrologica Sinica, 23(9): 2085-2108 (in Chinese with English abstract) |
Cheng NN, Liu Q, Hou QL, Wei W, Shi MY, He M and Guo QQ. 2018. Discussions on the stress-chemical process of gold precipitation and metallogenic mechanism in shear zone type gold deposits. Acta Petrologica Sinica, 34(7): 2165-2180 |
Cole A, Wilkinson JJ, Halls C and Serenko TJ. 2000. Geological characteristics, tectonic setting and preliminary interpretations of the Jilau gold-quartz vein deposit, Tajikistan. Mineralium Deposita, 35(7): 600-618 DOI:10.1007/s001260050266 |
Cook NJ and Chryssoulis SL. 1990. Concentrations of invisible gold in the common sulfides. The Canadian Mineralogist, 28(1): 1-16 |
Cox SF, Sun SS, Etheridge MA, Wall VJ and Potter TF. 1995. Structural and geochemical controls on the development of turbidite-hosted gold quartz vein deposits, Wattle Gully mine, central Victoria, Australia. Economic Geology, 90(6): 1722-1746 DOI:10.2113/gsecongeo.90.6.1722 |
Cox SF, Knackstedt MA and Braun J. 2001. Principles of structural control on permeability and fluid flow in hydrothermal systems. In: Richards JP and Tosdal RM (eds.). Structural Controls on Ore Genesis. Littleton, Colorado: Society of Economic Geologists, 14: 1-24
|
Craw D. 1992. Fluid evolution, fluid immiscibility and gold deposition during cretaceous-recent tectonics and uplift of the Otago and Alpine schist, New Zealand. Chemical Geology, 98(3-4): 221-236 DOI:10.1016/0009-2541(92)90186-9 |
Craw D. 2002. Geochemistry of late metamorphic hydrothermal alteration and graphitisation of host rock, Macraes gold mine, Otago Schist, New Zealand. Chemical Geology, 191(4): 257-275 |
Craw D, MacKenzie DJ, Pitcairn IK, Teagle DAH and Norris RJ. 2007. Geochemical signatures of mesothermal Au-mineralized late-metamorphic deformation zones, Otago Schist, New Zealand. Geochemistry:Exploration, Environment, Analysis, 7(3): 225-232 DOI:10.1144/1467-7873/07-137 |
Craw D, Mortensen J, MacKenzie D and Pitcairn I. 2015. Contrasting geochemistry of orogenic gold deposits in Yukon, Canada and Otago, New Zealand. Geochemistry:Exploration, Environment, Analysis, 15(2-3): 150-166 DOI:10.1144/geochem2013-262 |
Deditius AP, Utsunomiya S, Ewing RC, Chryssoulis SL Venter D and Kesler SE. 2009. Decoupled geochemical behavior of As and Cu in hydrothermal systems. Geology, 37(8): 707-710 DOI:10.1130/G25781A.1 |
Deditius AP, Reich M, Kesler SE, Utsunomiya S, Chryssoulis SL, Walshe J and Ewing RC. 2014. The coupled geochemistry of Au and As in pyrite from hydrothermal ore deposits. Geochimica et Cosmochimica Acta, 140: 644-670 DOI:10.1016/j.gca.2014.05.045 |
Frimmel HE. 2008. Earth's continental crustal gold endowment. Earth and Planetary Science Letters, 267(1-2): 45-55 DOI:10.1016/j.epsl.2007.11.022 |
Gao J, Long LL, Qian Q, Huang DZ, Su W and Klemd R. 2006. South Tianshan:A Late Paleozoic or a Triassic orogen?. Acta Petrologica Sinica, 22(5): 1049-1061 (in Chinese with English abstract) |
Gao J, Long LL, Klemd R, Qian Q, Liu DY, Xiong XM, Su W, Liu W, Wang YT and Yang FQ. 2009. Tectonic evolution of the South Tianshan orogen and adjacent regions, NW China:Geochemical and age constraints of granitoid rocks. International Journal of Earth Sciences, 98(6): 1221-1238 DOI:10.1007/s00531-008-0370-8 |
Gao J, Klemd R, Qian Q, Zhang X, Li J, Jiang T and Yang Y. 2011. The collision between the Yili and Tarim blocks of the southwestern Altaids:Geochemical and age constraints of a leucogranite dike crosscutting the HP-LT metamorphic belt in the Chinese Tianshan Orogen. Tectonophysics, 499(1-4): 118-131 DOI:10.1016/j.tecto.2011.01.001 |
Goldfarb RG, Baker T, Dubé B, Groves DI, Hart CJR and Gosselin P. 2005. Distribution, character, and genesis of gold deposits in metamorphic terranes. In: Hedenquist JW, Thompson JFH, Goldfarb J and Richards JP (eds.). One Hundredth Anniversary Volume. Colorado USA: Society of Economic Geologists, 407-450
|
Goldfarb RG and Groves DI. 2015. Orogenic gold:Common or evolving fluid and metal sources through time. Lithos, 233: 2-26 DOI:10.1016/j.lithos.2015.07.011 |
Goldfarb RJ, Leach DL, Rose SC and Landis GP. 1989. Fluid inclusion geochemistry of gold-bearing quartz veins of the Juneau gold belt, southeastern Alaska: Implications for ore genesis. In: Keays RR, Ramsay WRH and Groves DI (eds.). The Geology of Gold Deposits: The Perspective in 1988. Littleton, Colorado: Society of Economic Geologists, 6: 363-375
|
Goldfarb RJ, Miller LD, Leach DL and Snee LW. 1997. Gold deposits in metamorphic rocks of Alaska. In: Goldfarb RJ and Miller LD (eds.). Mineral Deposits of Alaska. Littleton, Colorado: Society of Economic Geologists, 9: 151-190
|
Goldfarb RJ, Groves DI and Gardoll S. 2001. Orogenic gold and geologic time:A global synthesis. Ore Geology Reviews, 18(1-2): 1-75 DOI:10.1016/S0169-1368(01)00016-6 |
Goldfarb RJ, Taylor RD, Collins GS, Goryachev NA and Orlandini OF. 2014. Phanerozoic continental growth and gold metallogeny of Asia. Gondwana Research, 25(1): 48-102 DOI:10.1016/j.gr.2013.03.002 |
Graupner T, Niedermann S, Kempe U, Klemd R and Bechtel A. 2006. Origin of ore fluids in the Muruntau gold system:Constraints from noble gas, carbon isotope and halogen data. Geochimica et Cosmochimica Acta, 70(21): 5356-5370 DOI:10.1016/j.gca.2006.08.013 |
Groves DI, Goldfarb RJ, Gebre-Mariam M, Hagemann SG and Robert F. 1998. Orogenic gold deposits:A proposed classification in the context of their crustal distribution and relationship to other gold deposit types. Ore Geology Reviews, 13(1-5): 7-27 DOI:10.1016/S0169-1368(97)00012-7 |
Groves DI, Goldfarb RJ, Knox-Robinson CM, Ojala J, Gardoll S, Yun GY and Holyland P. 2000. Late-kinematic timing of orogenic gold deposits and significance for computer-based exploration techniques with emphasis on the Yilgarn Block, Western Australia. Ore Geology Review, 17(1-2): 1-38 DOI:10.1016/S0169-1368(00)00002-0 |
Groves DI, Goldfarb RJ, Robert F and Hart CJR. 2003. Gold deposits in metamorphic belts:Overview of current understanding, outstanding problems, future research, and exploration significance. Economic Geology, 98(1): 1-29 |
Guha J, Lu HZ and Gagnon M. 1990. Gas composition of fluid inclusions using solid probe mass spectrometry and its application to study of mineralizing processes. Geochimica et Cosmochimica Acta, 54(3): 553-558 DOI:10.1016/0016-7037(90)90352-L |
Guha J, Lu HZ, Dubé B, Robert F and Gagnon M. 1991. Fluid characteristics of vein and altered wall rock in Archean mesothermal gold deposits. Economic Geology, 86(3): 667-684 DOI:10.2113/gsecongeo.86.3.667 |
Hazarika P, Mishra B and Pruseth KL. 2017. Trace-element geochemistry of pyrite and arsenopyrite:Ore genetic implications for Late Archean orogenic gold deposits in southern India. Mineralogical Magazine, 81(3): 661-678 DOI:10.1180/minmag.2016.080.128 |
Hu FF, Fan HR, Shen K, Zhai MG, Jin CW and Chen XS. 2005. Nature and evolution of ore-forming fluids in the Rushan lode gold deposit, Jiaodong Peninsula of eastern China. Acta Petrologica Sinica, 21(5): 1329-1338 |
Hu SY, Evans K, Craw D, Rempel K, Bourdet J, Dick J and Grice K. 2015. Raman characterization of carbonaceous material in the Macraes orogenic gold deposit and metasedimentary host rocks, New Zealand. Ore Geology Reviews, 70: 80-95 DOI:10.1016/j.oregeorev.2015.03.021 |
Hu SY, Evans K, Craw D, Rempel K and Grice K. 2017. Resolving the role of carbonaceous material in gold precipitation in metasediment-hosted orogenic gold deposits. Geology, 45(2): 167-170 |
Huang H, Zhang ZC, Kusky T, Zhang DY, Hou T, Liu JL and Zhao ZD. 2012. Geochronology and geochemistry of the Chuanwulu complex in the South Tianshan, western Xinjiang, NW China:Implications for petrogenesis and Phanerozoic continental growth. Lithos, 140-141: 66-85 DOI:10.1016/j.lithos.2012.01.024 |
Ilchik RP and Barton MD. 1997. An amagmatic origin of Carlin-type gold deposit. Economic Geology, 92(3): 269-288 |
Jia Y, Li X and Kerrich R. 2000. A fluid inclusion study of Au-bearing quartz vein systems in the central and North Deborah deposits of the Bendigo gold field, Central Victoria, Australia. Economic Geology, 95(3): 467-494 |
Kempe U, Seltmann R, Graupner T, Rodionov N, Sergeev SA, Matukov DI and Kremenetsky AA. 2015. Concordant U-Pb SHRIMP ages of U-rich zircon in granitoids from the Muruntau gold district (Uzbekistan):Timing of intrusion, alteration ages, or meaningless numbers. Ore Geology Reviews, 65: 308-326 DOI:10.1016/j.oregeorev.2014.10.007 |
Kempe U, Graupner T, Seltmann R, de Boorder H, Dolgopolova A and van Emmichoven MZ. 2016. The Muruntau gold deposit (Uzbekistan):A unique ancient hydrothermal system in the Southern Tien Shan. Geoscience Frontiers, 7(3): 495-528 DOI:10.1016/j.gsf.2015.09.005 |
Kerrich R, Goldfarb R, Groves D, Garwin S and Jia YF. 2000. The characteristics, origins, and geodynamic settings of supergiant gold metallogenic provinces. Science in China (Series D), 43(Suppl. 1): 1-68 |
Klemd R, Bröcker M, Hacker BR, Gao J, Gans P and Wemmer K. 2005. New age constraints on the metamorphic evolution of the high-pressure/low-temperature belt in the western Tianshan Mountains, NW China. The Journal of Geology, 113(2): 157-168 DOI:10.1086/427666 |
Konopelko D, Biske G, Seltmann R, Eklund O and Belyatsky B. 2007. Hercynian post-collisional A-type granites of the Kokshaal Range, southern Tien Shan, Kyrgyzstan. Lithos, 97(1-2): 140-160 DOI:10.1016/j.lithos.2006.12.005 |
Kříbek B, Sykorová I, Machovič V, Knésl I, Laufek F and Zachariáš J. 2015. The origin and hydrothermal mobilization of carbonaceous matter associated with Paleoproterozoic orogenic-type gold deposits of West Africa. Precambrian Research, 270: 300-317 DOI:10.1016/j.precamres.2015.09.017 |
Large RR, Danyushevsky L, Hollit C, Maslennikov V, Meffre S, Gilbert S, Bull S, Scott R, Emsbo P, Thomas H, Singh B and Foster J. 2009. Gold and trace element zonation in pyrite using a laser imaging technique:Implications for the timing of gold in orogenic and Carlin-style sediment-hosted deposits. Economic Geology, 104(5): 635-668 DOI:10.2113/gsecongeo.104.5.635 |
Large RR, Bull SW and Maslennikov VV. 2011. A carbonaceous sedimentary source-rock model for Carlin-type and orogenic gold deposits. Economic Geology, 106(3): 331-358 DOI:10.2113/econgeo.106.3.331 |
Liu JJ, Zheng MH, Cook NJ, Long XR, Deng J and Zhai YS. 2007. Geological and geochemical characteristics of the Sawaya'erdun gold deposit, southwestern Chinese Tianshan. Ore Geology Reviews, 32(1-2): 125-156 DOI:10.1016/j.oregeorev.2006.11.003 |
Long LL, Gao J, Wang JB, Qian Q, Xiong XM, Wang YW, Wang LJ and Gao LM. 2008. Geochemistry and SHRIMP zircon U-Pb age of post-collisional granites in the Southwest Tianshan Orogenic Belt of China:Examples from the Heiyingshan and Laohutai plutons. Acta Geologica Sinica, 82(2): 415-424 |
Lu HZ. 2008a. Fluid inclusions in mantle rocks. Acta Petrologica Sinica, 24(9): 1954-1960 (in Chinese with English abstract) |
Lu HZ. 2008b. Role of CO2 fluid in the formation of gold deposits:Fluid inclusion evidences. Geochimica, 37(4): 321-328 (in Chinese with English abstract) |
Mao JW, Qiu XM, Goldfarb RJ, Zhang ZC and Ren FS. 2002. Geology, distribution, and classification of gold deposits in the western Qinling belt, central China. Mineralium Deposita, 37(3-4): 352-377 DOI:10.1007/s00126-001-0249-0 |
Mao JW, Han CM, Wang YT, Yang JM and Wang ZL. 2002. Geological characteristics, metallogenic model and criteria for exploration of the large South Tianshan gold metallogenic belt in Central Asia. Geological Bulletin of China, 21(12): 858-868 (in Chinese with English abstract) |
Mao JW, Konopelko D, Seltmann R, Lehmann B, Chen W, Wang YT, Eklund O and Usubaliev T. 2004. Postcollisional age of the Kumtor gold deposit and timing of Hercynian events in the Tien Shan, Kyrgyzstan. Economic Geology, 99(8): 1771-1780 DOI:10.2113/gsecongeo.99.8.1771 |
McCuaig TC and Kerrich R. 1998. P-T-t-deformation-fluid characteristics of lode gold deposits:Evidence from alteration systematics. Ore Geology Reviews, 12(6): 381-453 |
Mikucki EJ. 1998. Hydrothermal transport and depositional processes in Archean lode-gold systems:A review. Ore Geology Reviews, 13(1-5): 307-321 DOI:10.1016/S0169-1368(97)00025-5 |
Morelli R, Creaser RA, Seltmann R, Stuart FM, Selby D and Graupner T. 2007. Age and source constraints for the giant Muruntau gold deposit, Uzbekistan, from coupled Re-Os-He isotopes in arsenopyrite. Geology, 35(9): 795-798 DOI:10.1130/G23521A.1 |
Naden J and Shepherd TJ. 1989. Role of methane and carbon dioxide in gold deposition. Nature, 342(6251): 793-795 DOI:10.1038/342793a0 |
Pašava J, Vymazalová A, Košler J, Koneev RI, Jukov AV and Khalmatov RA. 2010. Platinum-group elements in ores from the Kalmakyr porphyry Cu-Au-Mo deposit, Uzbekistan:Bulk geochemical and laser ablation ICP-MS data. Mineralium Deposita, 45(5): 411-418 DOI:10.1007/s00126-010-0286-7 |
Pašava J, Frimmel H, Vymazalová A, Dobes P, Jukov AV and Koneev RI. 2013. A two-stage evolution model for the Amantaytau orogenic-type gold deposit in Uzbekistan. Mineralium Deposita, 48(7): 825-840 DOI:10.1007/s00126-013-0461-8 |
Phillips GN and Groves DI. 1984. Fluid access and fluid-wall rock interaction in the genesis of the Archaean gold-quartz vein deposit at Hunt mine, Kambalda, Western Australia. In: Foster RP (ed.). Gold' 82: The Geology, Geochemistry and Genesis of Gold Deposits. Rotterdam: Balkema, 389-416
|
Pitcairn IK, Roberts S, Teagle DAH and Craw D. 2005. Detecting hydrothermal graphite deposition during metamorphism and gold mineralization. Journal of the Geological Society, 162(3): 429-432 DOI:10.1144/0016-764904-139 |
Ramboz C, Pichavant M and Weisbrod A. 1982. Fluid immiscibility in natural processes:Use and misuse of fluid inclusion data:Ⅱ. Interpretation of fluid inclusion data in terms of immiscibility. Chemical Geology, 37(1-2): 29-48 |
Reich M, Kesler SE, Utsunomiya S, Palenik CS, Chryssoulis SL and Ewing RC. 2005. Solubility of gold in arsenian pyrite. Geochimica et Cosmochimica Acta, 69(11): 2781-2796 DOI:10.1016/j.gca.2005.01.011 |
Roedder E. 1984. Fluid inclusions. In: Ribbe HP (ed.). Reviews in Mineralogy. Washington DC: Mineralogical Society of America, 12: 1-644
|
Rui ZY, Goldfarb RJ, Qiu YM, Zhou TH, Chen RY, Pirajno F and Yun G. 2002. Paleozoic-Early Mesozoic gold deposits of the Xinjiang Autonomous Region, northwestern China. Mineralium Deposita, 37(3-4): 393-418 |
Sibson RH, Robert F and Poulsen KH. 1988. High-angle reverse faults, fluid-pressure cycling, and mesothermal gold-quartz deposits. Geology, 16(6): 551-555 DOI:10.1130/0091-7613(1988)016<0551:HARFFP>2.3.CO;2 |
Simon G, Kesler SE and Chryssoulis S. 1999. Geochemistry and textures of gold-bearing arsenian pyrite, Twin Creeks, Nevada:Implications for deposition of gold in Carlin-type deposits. Economic Geology, 94(3): 405-421 |
Solomovich LI. 2007. Postcollisional magmatism in the South Tien Shan Variscan Orogenic Belt, Kyrgyzstan:Evidence for high-temperature and high-pressure collision. Journal of Asian Earth Sciences, 30(1): 142-153 DOI:10.1016/j.jseaes.2006.08.003 |
Su W, Gao J, Klemd R, Li JL, Zhang X, Li XH, Chen NS and Zhang L. 2010. U-Pb zircon geochronology of Tianshan eclogites in NW China:Implication for the collision between the Yili and Tarim blocks of the southwestern Altaids. European Journal of Mineralogy, 22(4): 473-478 DOI:10.1127/0935-1221/2010/0022-2040 |
Wilde AR, Layer P, Mernagh T and Foster J. 2001. The giant Muruntau gold deposit:Geologic, geochronologic, and fluid inclusion constraints on ore genesis. Economic Geology, 96(3): 633-644 |
Wilkinson JJ. 2001. Fluid inclusions in hydrothermal ore deposits. Lithos, 55(1-4): 229-272 DOI:10.1016/S0024-4937(00)00047-5 |
Xiao WJ, Windley BF, Allen MB and Han CM. 2013. Paleozoic multiple accretionary and collisional tectonics of the Chinese Tianshan orogenic collage. Gondwana Research, 23(4): 1316-1341 DOI:10.1016/j.gr.2012.01.012 |
Xu QD, Zhong ZQ, Suo ST and Qi XM. 1995. Ore-forming fluids in mesothermal gold deposits of Tongbo-Dabie area:Their properties and precipitation mechanism. Mineral Deposits, 14(1): 59-72 (in Chinese with English abstract) |
Xue CJ, Zhao XB, Mo XX, Dong LH, Gu XX, Nurtaev B, Pak N, Zhang ZC, Wang XL, Zu B, Zhang GZ, Feng B and Liu JY. 2014. Asian gold belt in western Tianshan and its dynamic setting, metallogenic control and exploration. Earth Science Frontiers, 21(5): 128-155 (in Chinese with English abstract) |
Yang FQ, Mao JW, Wang YT, Li MW, Ye HS and Ye JH. 2005. Geological characteristics and metallogenesis of Sawayaerdun gold deposit in Southwest Tianshan Mountains, Xinjiang. Mineral Deposits, 24(3): 206-227 (in Chinese with English abstract) |
Yang FQ, Mao JW, Wang YT and Bierlein FP. 2006. Geology and geochemistry of the Bulong quartz-barite vein-type gold deposit in the Xinjiang Uygur Autonomous Region, China. Ore Geology Reviews, 29(1): 52-76 DOI:10.1016/j.oregeorev.2005.07.033 |
Yang FQ, Mao JW, Wang YT, Bierlein FP, Ye HS, Li MW, Zhao CS and Ye JH. 2007. Geology and metallogenesis of the Sawayaerdun gold deposit in the Southwestern Tianshan Mountains, Xinjiang, China. Resource Geology, 57(1): 57-75 DOI:10.1111/rge.2007.57.issue-1 |
Yang FQ, Mao JW, Wang YT, Zhao CS, Zhang Y and Liu YL. 2007. Major types, characteristics and metallogeneses of gold deposits in Southwest Tianshan Mountains, Xinjiang. Mineral Deposits, 26(4): 361-379 (in Chinese with English abstract) |
Zhang GZ, Xue CJ, Chi GX, Liu LY, Zhao XB, Zu B and Zhao Y. 2017. Multiple-stage mineralization in the Sawayaerdun orogenic gold deposit, western Tianshan, Xinjiang:Constraints from paragenesis, EMPA analyses, Re-Os dating of pyrite (arsenopyrite) and U-Pb dating of zircon from the host rocks. Ore Geology Reviews, 81: 326-341 DOI:10.1016/j.oregeorev.2016.10.038 |
Zhang L, Chen HY, Chen YJ, Qin YJ, Liu CF, Zheng Y and Jansen NH. 2012. Geology and fluid evolution of the Wangfeng orogenic-type gold deposit, Western Tian Shan, China. Ore Geology Reviews, 49: 85-95 DOI:10.1016/j.oregeorev.2012.09.002 |
Zhao XB, Xue CJ, Chi GX, Wang HG and Qi TJ. 2014. Epithermal Au and polymetallic mineralization in the Tulasu Basin, Western Tianshan, NW China:Potential for the discovery of porphyry Cu-Au deposits. Ore Geology Reviews, 60: 76-96 DOI:10.1016/j.oregeorev.2013.12.018 |
Zhao XB, Xue CJ, Chi GX, Pak N and Zu B. 2015. Re-Os pyrite and U-Pb zircon geochronology from the Taldybulak Levoberezhny gold deposit:Insight for Cambrian metallogeny of the Kyrgyz northern Tien Shan. Ore Geology Reviews, 67: 78-89 DOI:10.1016/j.oregeorev.2014.12.002 |
Zhu HP and Wang LJ. 2001. Analysis of fluid inclusion gases, using quadrupole mass spectrometry. Science in China (Series D), 31(7): 586-590 (in Chinese) |
Zoheir BA, El-Shazly AK, Helba H, Khalil KI and Bodnar RJ. 2008. Origin and evolution of the Um Egat and Dungash orogenic gold deposits, Egyptian Eastern Desert:Evidence from fluid inclusions in quartz. Economic Geology, 103(2): 405-424 |
陈奎, 田新文, 杨桂荣, 张玉坛. 2007. 阿沙哇义金矿地质特征及找矿标志. 新疆地质, 25(4): 384-388. DOI:10.3969/j.issn.1000-8845.2007.04.010 |
陈衍景. 2006. 造山型矿床、成矿模式及找矿潜力. 中国地质, 33(6): 1181-1196. DOI:10.3969/j.issn.1000-3657.2006.06.001 |
陈衍景, 倪培, 范宏瑞, Pirajno F, 赖勇, 苏文超, 张辉. 2007. 不同类型热液金矿系统的流体包裹体特征. 岩石学报, 23(9): 2085-2108. DOI:10.3969/j.issn.1000-0569.2007.09.009 |
程南南, 刘庆, 侯泉林, 卫巍, 石梦岩, 何苗, 郭谦谦. 2018. 剪切带型金矿中金沉淀的力化学过程与成矿机理探讨. 岩石学报, 34(7): 2165-2180. |
高俊, 龙灵利, 钱青, 黄德志, 苏文, Klemd R. 2006. 南天山:晚古生代还是三叠纪碰撞造山带?. 岩石学报, 22(5): 1049-1061. |
胡芳芳, 范宏瑞, 沈昆, 翟明国, 金成伟, 陈绪松. 2005. 胶东乳山脉状金矿床成矿流体性质与演化. 岩石学报, 21(5): 1329-1338. |
卢焕章. 2008a. 地幔岩中流体包裹体研究. 岩石学报, 24(9): 1954-1960. |
卢焕章. 2008b. CO2流体与金矿化:流体包裹体的证据. 地球化学, 37(4): 321-328. |
毛景文, 韩春明, 王义天, 杨建民, 王志良. 2002. 中亚地区南天山大型金矿带的地质特征、成矿模型和勘查准则. 地质通报, 21(12): 858-868. DOI:10.3969/j.issn.1671-2552.2002.12.009 |
徐启东, 钟增球, 索书田, 齐先茂. 1995. 桐柏-大别地区中温热液金矿床成矿流体性质与沉淀机理. 矿床地质, 14(1): 59-72. |
薛春纪, 赵晓波, 莫宣学, 董连慧, 顾雪祥, Nurtaev B, Pak N, 张招崇, 王新利, 俎波, 张国震, 冯博, 刘家瑛. 2014. 西天山"亚洲金腰带"及其动力背景和成矿控制与找矿. 地学前缘, 21(5): 128-155. |
杨富全, 毛景文, 王义天, 李蒙文, 叶会寿, 叶锦华. 2005. 新疆西南天山萨瓦亚尔顿金矿床地质特征及成矿作用. 矿床地质, 24(3): 206-227. DOI:10.3969/j.issn.0258-7106.2005.03.002 |
杨富全, 毛景文, 王义天, 赵财胜, 张岩, 刘亚玲. 2007. 新疆西南天山金矿床主要类型、特征及成矿作用. 矿床地质, 26(4): 361-379. DOI:10.3969/j.issn.0258-7106.2007.04.002 |
朱和平, 王莉娟. 2001. 四极质谱测定流体包裹体中的气相成分. 中国科学(D辑), 31(7): 586-590. |