摘要
研究区位于内蒙古自治区阿拉善盟额济纳旗境内,地处中亚荒漠东南部,靠近巴丹吉林沙漠的北部边缘,大地构造位置处于天山-阴山东西向构造带东段,甜水井-乌珠尔嘎顺-雅干成矿带。
本人于2010年5月至2010年10月、2011年5月至2011年11月两次赴研究区,先后开展了1:25000土壤地球化学测量工作、1:25000地质草测、1:10000土壤地球化学综合剖面31.54km及2032m~3的槽探等工作,其中取土壤地球化学样品3354件、岩石化学分析样品87件、薄片鉴定样品125件、包裹体测温样7件。
通过2010~2011年所做的野外及室内分析工作,取得以下成果:
1、研究区主要出露地层为石炭系下石炭统的白山组(C_1b_1)与绿条山组(C_1l),白山组分为3个岩性段,即:C_1b_1~1、C_1b_1~2和C_1b_1~3;呈条带状分布于工区的主体部分,北东东-南西西方向展布。此外还圈定了出露在研究区东北部的北山群(Pt_1b)斜长片麻岩,而以往的区域资料中,在研究区内并未见北山群斜长片麻岩。区内断裂构造较为发育,规模相对较大,主要为贯穿预查区中南部的石块地-蓬勃山逆冲断层,总体走向为270~290°,北倾,倾角60°~70°。区内岩浆岩主要分布于北部、南部及东部边缘。侵入岩岩性主要为华力西期闪长岩,呈岩基和岩株状产出,集中分布于大断裂的两侧。
2、通过野外工作及室内分析,研究区的主要成矿元素由原来的铜多金属确定为金元素,且区内金矿化类型较为单一,为石英脉型。石英脉主要受主断裂下盘的次级断裂控制,其矿化类型主要为硅化、黄铁矿化等。根据槽探工作所取得成果,在研究区内划分出8处品位大于0.1g/t的含矿石英脉,矿脉均产于横穿研究区的韧性剪切带南北两侧,整体呈北西向展布。
3、对上述矿脉的流体包裹体研究表明:矿脉中气液两相包裹体为主体,约占80%以上,此外还见有含CO_2三相包裹体。通过包裹体测温算出流体总体盐度为2.22~9.86wt%NaCl;均一温度为182~300℃。由流体包裹体测试结果中可看出,矿脉成矿流体为NaCI-CO_2-H_2O体系,且盐度较低,初步判断,其流体来源可能与岩浆水有关,且矿脉分布在地层与闪长岩体接触部位,说明成矿早期阶段主要为岩浆余热作用;从均一温度-盐度散点图中可看出成矿流体的密度为0.70~0.95g/cm~3,集中的主要密度范围为0.85-0.90g/cm~3,是属于低密度流体,初步判断晚期阶段与大气降水有关。
4、通过对研究区的土壤地球化学测量,共圈出多元素异常66处,其中Au元素异常7处,有望异常分别为Au-HT10-4、Au-HT10-5、Au-HT10-6、Au-HT10-7号异常,为甲类异常;根据各元素异常的套合情况,研究区内又分出4处组合异常,具有异常规模较大,强度高,成矿地质条件有利,异常区石英脉极为发育等特点。通过对研究区3处局部的激电中梯剖面测量,共圈出9条高电阻异常带。
5、综合考虑研究区的金元素土壤地球化学异常、土壤地球化学组合异常及激电中梯剖面异常所在的位置、异常特征及异常与地质体、矿脉的关系,结合地质条件,在研究区内圈定了三个找矿靶区。
6、此外,为了进一步证实找矿靶区,工作组人员对3号靶区的Ⅵ、Ⅶ号矿脉进行了钻探工程,钻探工程编号分别为ZK009和ZK007。ZK009号钻孔是针对于Ⅵ号矿脉而设计,孔深为215m,共分19层,普遍见有硅化、绢云母化及绿泥石化现象,主要矿化类型为褐铁矿化及黄铁矿化,共取样品56个,取样测试Au品位在0.05~0.47g/t。ZK007号钻孔设计在离Ⅶ号矿脉100m处,孔深为200m,共分17层,主要矿化类型为褐铁矿化及黄铁矿化,共取122个测试样品,测试结果Au品位在0.05~2.66g/t。
钻探工程所取得成果,验证了找矿靶区的合理性,证实了该研究区具有非常好的成矿前景,为进一步探矿工作提供了有力依据。
The study area in Ejinaqi of Alashan Union of Inner Mongolia is located at thesoutheastern part of Central Asia desert, near the northern margin of Jilin desert atBadan. The tectonic position is in the eastern Tianshan–Yinshan structure belt withWE trending and Tianshuijing–Wuzhuergashun–Yagan metallogenic belt.From May2010to October2010and May2011to November2011, respectively, theauthor investigated the study area. The major work were measurement of1:25000soilgeochemistry,1:25000simply geological measurement,1:10000soil geochemistryprofiles of which are31.54Km long and trenching of2032M~3and so on. We selected3354samples of soil geochemistry, analyzed87petrochemistry samples, identified125thin sections and tested7inclusions. Based on our field and measurement workfrom2010to2011, we suggested that:
1. The Lower Carboniferous Baishan group (C_1b_1) and Lvtiaoshan group (C_1l)arethe main strata in the study area. In northeastern part, we found the Early PaleozoicBeishan group (Pt_1b),which are consisted mainly of plagioclase gneiss. It has neverbeen mentioned in the past regional references. Fault structures in the region werewell developed and the scale is relatively large. The most important fault throughoutsouth central research area is Shikuaishan-Pengboshan thrust fault, the main trend is270-290°, dig angle is60-70°and the direction is northward. A series of N-Sextensional faults and extensional-shear faults and shear faults with NW and NEtrends are subordinate. Magmatic rocks mainly distributed in the northern, southernand eastern margin. Intrusive rocks dominated by the Variscan diorites can be foundon both sides of the large faults. Diorites are characterized by batholiths and stock.
2. The major ore-forming element of study area was identified as gold, notcopper-multielements. However, the gold mineralization type of study area isrelatively single, mainly the type of quartz vein that is our object research. Partly quartz veins are intensive, and the features are higher gold grade and some level ofscales. Quartz veins are generally controlled by the subordinate fractures of footwallsof main faults, and the mineralization types are siliconization, pyritization and so on.Based on the results of slot work, we divided the quartz veins into8places in ourstudy area. The grade is greater than0.1g/tons. All the veins distribute in the north andsouth sides of ductile shear zones which traversed our study area, and NW trending.
3. According to study on the fluid inclusions of quartz veins, our results indicatedthat fluid inclusions can be divided into two types: two-phase inclusions of gas-liquidand three-phase inclusions combined with CO_2. The former one is dominated,accounting for more than80%. The major fluid salinity is2.23-9.86wt%NaCl.Uniform temperature range of inclusions is182–300℃. Testing results of fluidinclusions show that the ore-forming of veins is NaCI-CO_2-H_2O system, and thesalinity is low. We preliminary suggested that the source of fluid are probably relatedto magmatic water and the earlier stage of ore forming is mainly magmatic afterheateffect because the ore veins distribute in the contact part between stratum and dioritebody. Scatter diagram of uniform-salinity shows the density of ore-forming fluid is0.70-0.95g/cm3, the main density range are0.85-0.90g/cm3, therefore, theore-forming fluid is low density type, preliminarily indicating that the later stage ofore-forming is related to atmospheric precipitation.
4. We analyzed the soil geochemistry data of study area and found66multi-element anomalitic places. There are7abnormal places of Au. Youwanganomalous is Au-HT10-4, Au-HT10-5, Au-HT10-6and Au-HT10-7, respectively.They all belong to A-class anomaly. Based on the overlap situation amongmulti-element anomaly, our study area can be divided into four places of assemblageanomaly. These places are characterized by large scale, high intensity, and favorableore-forming geological condition and well developed quartz veins in abnormal places.Based on the measurement of partly explosive electron middle grad sections anomaly,our study area can be divided into nine high resistance belts.
5. Combined with soil geochemistry anomaly of Au, assemblage anomaly of soilgeochemistry, locations and anomaly features of explosive electron middle gradsections anomaly, relationship among anomaly, geological body and ore-vein,geological condition, we chose three prospecting target zones in our study area.
6. In order to further confirm the prospecting target zones, we chose VI and VIIveins at No.3target zone and operated drilling engineering, and the drills were marketed as ZK009and ZK007. Drill of ZK009was designed for VI vein. Its depth is215M. This drilling can be divided into19layers. It is easy to find the phenomenonof siliconization, sericitization and chloritization on mineralized zones the mainmineralization types of which are limonitization and pyritization. We selected andtested56samples. The gold grade of samples is0.05-0.47g/t. Drills of ZK007is100M from the ore-vein of VII. The depth is200M. This drill can be divided into17layers. The main mineralization types are limonitization and pyritization. Testingresults of122samples show that the gold grade is0.05-2.66g/t.
Our results from drilling engineering fully verified the reasonable of prospectingtarget zones, confirmed that the study area has a good mineralization prospect andprovided a strong evidence for future prospecting work
引文
[1]姚凤良,孙丰月.矿床学教程[M],地质出版社,2006
[2]裴荣富.中国矿床模式[M].北京:地质出版社,1995.39-42.
[3]袁见齐,朱上庆,翟裕生.矿床学[M].北京:地质出版社,1984.
[4]韩吟文,马振东.地球化学[M].北京:地质出版社,2003.
[5]江培谟.地质热力学基础[M].北京:科学出版社,1989.
[6]卢焕章,范宏瑞,倪培.流体包裹体[M].北京:科学出版社,2004
[7]毕诗健,李建威,赵新福.热液锆石U-Pb定年与石英脉型金矿成矿时代:评述与展望[J].地质科技情报,2008,27(1):69-76.
[8]陈明辉,杨洪超,荆亭山等.湘西南金矿成矿规律与成矿预测[J].矿产与地质,2007,21(3):232-236.
[9]陈锡光,周文芳.广西乐业县浪全金矿床地质特征与矿床成因探讨[J].黄金科学技术,2001,9(2):13-17.
[10]陈衍景,王亨治,张玫玫等.小秦岭石英脉型金矿的地质地球化学特征和成矿模式[J].河北地质学院学报,1993,16(6):594-604.
[11]成杰.陕西省凤县佐家庄金矿床地球化学特征及找矿前景[J].陕西地质,2011,29(1):72-76.
[12]冯建忠,汪东波,邵世才等.西秦岭小沟里石英脉型金矿床成矿地质特征及成因[J].矿床地质,2002,21(2):159-167.
[13]顾俊法.山东省招掖地区金矿化类型及找矿远景[J].黄金地质科技,1991,27:1-7.
[14]郭晓东,李强之,金宝义等.北山地区金和铜等成矿规律及找矿方向探讨[J].黄金地质,2003,9(2):33-37.
[15]黄德志,戴塔根,孔华等.安徽张八岭构造带石英脉型金矿成矿流体来源研究[J].大地构造与成矿学,2000,24(3):235-236.
[16]蒋礼贤,陈竹英.大崎山地区含金石英脉型金矿地质特征及其成因[J].成矿理论,1990,12(2):9-12.
[17]李东风.北票市头道营子金矿区物化探方法的综合应用[J].辽宁工程技术大学学报,2011,30(6):849-852.
[18]廖桂琴,夏立君.1/万不规则测网土壤地球化学测量方法在安图金星金矿床中的应用及效果[J].吉林地质,2011,30(4):67-72.
[19]吕军,岳邦江,王建民等.黑河市三道湾子金矿床特征及找矿标志[J].地质与资源,2005,14(4).
[20]吕军,王建民,王洪波等.土壤地球化学测量在三道湾子金矿床的应用[J].物探与化探,2005,29(6):515-518.
[21]罗卫,戴塔根,游先军.湘西南金矿成矿规律与成矿预测研究[J].地质与勘探,2007,43(6):42-46.
[22]莫测辉,王秀璋,程景平等.冀西北东坪金矿床的成矿期次及成矿阶段研究[J].矿物岩石地球化学通报,1997,16(3):169-172.
[23]潘文,何明华,安正泽等.梵净山蚀变岩金矿地质特征及其成因探讨[J].资源环境与工程,2008,22(2):168-171.
[24]祁腾飞,石振华,赵晓敏等.内蒙古阿尔善地区土壤地球化学异常特征及找矿意义[J].吉林地质,2011,30(4):73-79.
[25]沈远超,曾庆栋,谢宏远等.山东乳山石英脉型金矿侧伏规律及找矿方向[J].黄金地质,1999,5(3):1-5.
[26]石玉臣,刘长春,杨承海等.胶东地区蚀变岩型与石英脉型金矿的空间分布关系及形成机制[J].山东国土资源,2005,21(8):19-21.
[27]孙丰月,王力,霍亮等.黑龙江乌拉嘎大型金矿床流体包裹体特征及矿床成因研究[J].中国地质,2008,35(6):1267-1273.
[28]汪校锋,矫东风,秦雅东等.海南岭头地区金土壤地球化学特征及找矿潜力分析[J].地质与勘探,2011,47(3):406-413.
[29]王厚庭.湖南新邵大新金矿床地质特征及成矿阶期次划分浅析[J].甘肃冶金,2009,31(3):45-48.
[30]王景腾,马丽,刘娇.剑河南加石英脉型金矿地质特征[J].贵州地质,2008,25(4):253-264.
[31]王可勇,任云生,程新民等.黑龙江团结沟金矿床流体包裹体研究及矿床成因[J].大地构造与成矿学,2004,28(2):171-178.
[32]王可勇,卿敏,张欣娜等.黑龙江金厂金矿床流体包裹体特征及成矿作用研究[J].岩石学报,2011,27(5):1275-1286.
[33]王可勇,万多,刘正宏等.辽宁丹东四道沟金矿床构造控矿规律及其机制分析[J].吉林大学学报(地球科学版),2011,41(4):1048-1054.
[34]王可勇,卿敏,孙丰月等.吉林小西南岔金-铜矿床成矿流体地球化学特征及矿床成因研究[J].岩石学报,2010,26(12):3727-3734.
[35]王尚彦,张立新,陶平等.贵州东部石英脉型金矿地质特征和成矿作用[J].贵州地质,2006,23(1):36-43.
[36]魏刚锋,张维吉,王力群等.商州市石英脉型金矿地质特征及找矿方向研究[J].长安大学学报(地球科学版),2003,25(3):24-28.
[37]徐研非.元阳大坪石英脉型金矿床地质特征[J].云南地质,1989,8(2):171-177.
[38]杨帅师,王可勇,郝通顺等.辽宁丹东四道沟金矿床流体包裹体特征及矿床成因[J].吉林大学学报(地球科学版),2010,40(4):773-780.
[39]姚晓峰,王友,白云等.西藏洞嘎普东铜金矿化探、物探异常特征及找矿方向浅议[J].科技信息,2010,5:733-734.
[40]叶丹.内蒙白乃庙石英脉型金矿成因探讨[J].有色金属矿产与勘查,1997,6(3):155-162.
[41]袁升云.赣南某地区土壤地球化学金异常分布特征及找矿意义[J].江西地质,1998,12(4):279-283.
[42]张国义,张连发.土壤地球化学测量在山东蓬莱地区普查找金的效果[J].地质找矿论丛,2003,18:141-145.
[43]张松,曾庆栋,刘建明等.吉林省海沟石英脉型金矿床流体包裹体特征及地质意义[J].岩石学报,2011,27(5):1287-1298.
[44]赵成峰,胡光道.云南保山黄家地石英脉型金矿床成因[J].云南地质,2008,27(4):442-447.
[45]赵明悦,满永录,薄继荣等.吉林省红旗沟金矿床地质地球化学特征及成因分析[J].吉林地质,2010,29(2):37-40.
[46]周德忠,叶大元,余大龙.湖南漠滨石英脉型金矿成因探讨[J].矿床地质,1989,8(1):51-64.
[47]周学武,李胜荣,鲁力等.辽宁丹东五龙矿区石英脉型金矿床的黄铁矿标型特征研究[J].现代地质,2005,19(2):231-238.
[48]祝德平,张晓梅,李守全等.平邑县铜石次火山杂岩体区金矿化类型及其成矿地质特征[J].黄金,2000,21(8):8-11.
[49]宗静婷,蔡平.铧厂沟金矿床成矿期次划分[J].咸阳师范学院学报,2003,18(6):44-47.
[50]李士辉,张静,邓军,王欢,刘江涛,赵凯.哀牢山南段长安金矿床成矿流体特征及成因类型探讨[J].岩石学报,2011,27(12):3777-3786.
[51]王恩德,孙丽娜.半宽金矿床流体包裹体特征及成因讨论[J].辽宁地质,1996,96(1):47-52.
[52]王永生,王建国,刘玉祥.北祁连西段金矿成矿流体特征及成因分析-以鹰咀山、寒山及车路沟金矿为例[J].中国科技信息,2011,2011(14):25-27.
[53]刘纲,金宝义,王桂娟.赤峰—朝阳地区金矿床流体包裹体特征及成因[J].黄金地质,2001,7(3):8-14.
[54]王朝文,洪汉烈,钟增球,张小文,王婧,李方林.海南抱伦金矿含金石英脉流体包裹体特征及其意义[J].中国地质大学学报,2011,36(6):1009-1020.
[55]赖勇,张宇,高栏,李文博,李士辉.河南洛宁段河金矿流体包裹体研究和矿床成因[J].中国地质,2008,35(6):1206-1219.
[56]李诺,赖勇,鲁颖淮,郭东升.哀牢山南段长安金矿床成矿流体特征及成因类型探讨[J].中国地质,2008,35(6):1230-1239.
[57]张德会,刘伟,魏俊浩,王思源.河南西峡石板沟金矿成矿流体地球化学及矿床成因讨论[J].现代地质,1999,13(2):130-136.
[58]倪智勇,李诺,管申进,张辉,薛良伟.河南小秦岭金矿田大湖金一钥矿床流体包裹体特征及矿床成因[J].岩石学报,2008,24(9):2058-2068.
[59]杨言辰,张兰玲,叶松青,王可勇.黑龙江省逊克县新民金矿床流体包裹体研究[J].黄金,2009,3(30):17-22.
[60]张宝琛,覃功炯,王凤阁.辽宁省岫岩县东堡子金矿流体包裹体研究[J].现代地质,2002,16(1):26-30.
[61]刘伟,范永香,余金元,赵百胜.陇南阳山金矿床流体包裹体研究[J].华东地质学院学报,2003,26(4):328-336.
[62]周振菊,蒋少涌,秦艳,赵海香,胡春杰.小秦岭文峪金矿床流体包裹体研究及矿床成因[J].岩石学报,2011,27(12):3787-3799.
[63]曹勇华,赖健清.新疆白干湖钨锡矿流体包裹体特征及成因[J].中南大学学报,2012,43(2):644-650.
[64]张继武,张玉杰,路彦明,张栋,赵军,范俊杰,董华芳.新疆卡拉麦里地区与韧-脆性剪切带有关的金矿床成因分析—来自流体包裹体、同位素的证据[J].黄金地质,2009,3(30):23-29.
[65]张莉,刘春发,武广.新疆望峰金矿床流体包裹体地球化学及矿床成因类型[J].岩石学报,2009,25(6):1465-1473.
[66]陈雷,孙景贵,赵俊康,门兰静,梁树能,陈冬,逄伟.延边五凤五星山金(银)矿床的流体包裹体特征及成因模式[J].吉林大学学报(地球科学版),2008,38(4):566-575.
[67]任云生,雷恩,赵华雷,王辉,鞠楠.延边杨金沟大型白钨矿矿床流体包裹体特征及成因探讨[J].吉林大学学报(地球科学版),2010,40(4):764-772.
[68] X. Cazanas, P. Alfonso, J. C. Melgarejo, Joaquin A. Proenza, and A. E. Fallick.Source ofore-forming fluids in El Cobre VHMS deposit (Cuba); evidence from fluid inclusions andsulfur isotopes (in Proceedings of Geofluids IV)[J],Journal of Geochemical Exploration(May2003),78-79(2003):85-90
[69] Paul Polito, Kurt Kyser, David Lawie, Steven Cook, and Chris Oates,Application of sulphurisotopes to discriminate Cu–Zn VHMS mineralization from barren Fe sulphidemineralization in the greenschist to granulite facies Flin Flon–Snow Lake–Hargrave Riverregion[J], Manitoba, Canada, Geochemistry: Exploration, Environment, Analysis, May2007;7:129-138.
[70] Ross Large, Mark Doyle, Oliver L. Raymond, David Cooke, Andrew Jones, and LachlanHeasman,Evaluation of the role of Cambrian granites in the genesis of world class VHMSdeposits in Tasmania (in The conjunction of processes resulting in the formation of orebodies)[J]Ore Geology Reviews (May1996),10(3-6):215-230
[71] Louise Corriveau and Anne-Laure Bonnet.Diagnostic geological tools to recognizemetamorphosed VHMS, sedex and iron oxides-Cu-Au hydrothermal systems in the frontierhigh-grade metamorphic terrains of the Grenville Province (in Geological Society of America,Northeastern Section,38th annual meeting; Geological Society of America, SoutheasternSection[J],53rd annual meeting, Anonymous.Geological Society of America (March2004),36(2):51
[72] Hou Zengqian, Qu Xiaoming, Xu Minggi, Fu Deming, Hua Lichen, and Yu Jinjie,TheGacun VHMS deposit in Sichuan; from field observation to genetic model Mineral Deposits[J](2001),20(1):44-56
[73] Dominik J. Weiss, Thomas F. D. Mason, Svetlana G. Tessalina, Matthew S. A. Horstwood,Jamie J. Wilkinson, John B. Chapman, and Randall R. Parrish,Controls of Cu and Zn isotopevariability within a VHMS deposit (in Geological Society of America,2004annual meeting,Anonymous,)[J].Geological Society of America (November2004),36(5):515
[74] Anderson,Potential problems in the characterisation of VHMS deposits using the Zn ratio(in IAMG'97; proceedings of the Third annual conference of the International Association forMathematical Geology, Pawlowsky-Glahn,)Annual Conference of the InternationalAssociation for Mathematical Geology (IAMG)(September1997)[J],3, Addendum5-10
[75] Richard J. Herrington, Valeriy Maslennikov, and Igor Seravkin,Diverse VHMS deposits inthe Paleozoic of the South Urals, a reflection of diverse settings and sea-floor evolution (inGeological Society of America,2003annual meeting[J], Anonymous,Geological Society ofAmerica (November2003),35(6):13
[76] Chen Shouwu, Jia Weiguang, and Han Zhengwen,Characteristics of two kinds of VHMSsilver deposits in China[J],Guijinshu Dizhi=Journal of Precious Metallic Geology (March1998),7(1):21-31
[77] E. V. Belogub, K. A. Novoselov, V. A. Yakovleva, and B. Spiro,Supergene sulphides andrelated minerals in the supergene profiles of VHMS deposits from the South Urals (inDevelopments in applied mineralogy[J],Ore Geology Reviews (June2008),33(3-4):239-254
[78] G. J. Corlett and K. Akiro,VHMS mineralisation in NW Papua New Guinea (in,Weber,)Publication Series [J]-Australasian Institute of Mining and Metallurgy (1999),4-99243-245
[79] Wang Denghong,Geology, geochemistry and geodynamics of the Ashele VHMS Cu-Zndeposit, northwestern Xinjiang (in Tectonic evolution and metallogeny of the Chinese Altayand Tianshan)[J].IAGOD Guidebook Series (2003),10153-168
[80] Ari Tryggvason, Alireza Malehmir, Johiris Rodriguez-Tablante, Christopher Juhlin, and P rWeihed, Reflection Seismic Investigations in the Western Part of the PaleoproterozoicVHMS-Bearing Skellefte District[J], Northern Sweden,Economic Geology, Aug2006;101:1039-1054.
[81] Prakash Golani,Controls on distribution pattern and base metal composition of vhms depositsin the proterozoic south delhi fold belt in western india (in33rd international geologicalcongres[J], abstracts, Anonymous, Congres Geologique International, Resumes (2008),33