古生代新元古代晚期造山型金矿课件

1、Part III) Paleozoic/late Neoprot Orogenic Au古生代/新元古代晚期造山型金矿Terra Australis OrogenTerra Australis 造山带 Series of N-S Pz fold belts一系列南北向古生代褶皱带80 Moz Au 80百万盎司金Veining & defm=ca. 440 Ma脉和变形 = 大约440百万年LachlanThomsonHodgkinson-Broken RiverNew England (Permo-Tr)The Tasmanides inEastern Australia: Au-Rich

2、Pz Fold Belts & Younger Cover 澳大利亚东部的塔斯曼域：富金的古生代褶皱带和盖层Lode Gold Deposits, Tasman Fold Belt塔斯曼褶皱带中的造山带型金矿床Westland, South Island南部岛屿，西岸Eastern Gondwana东冈瓦纳PALEOZOIC ANTARCTICA古生代南极洲EASTERN CORDILLERA:A POTENTIAL WORLD-CLASS OROGENIC GOLD PROVINCE?东科迪嘞拉：一个潜在的世界级的造山型金矿省？Paleozoic Gold 古生代金矿7 Moz prod.1

3、00 Moz100 Moz250 Moz150 MozGOLD DEPOSITSOF ARABIAN-NUBIAN SHIELDARABIAN-NUBIAN地盾金矿100 Moz in ancient times储量曾达100 MozAlmost all orogenic gold几乎全为造山型金矿Microcontinents off Rodinia and GondwanaDistinct ore-forming events during 600-250 Ma growth of Asia古特提斯洋Rodinia和Gondwana古陆之外的微陆块600-250 Ma独特的成矿事件亚洲大陆

4、的生长中亚造山带Early-Middle PaleozoicOn Craton Margins of Siberia=Oldest Gold in Asia位于西伯利亚克拉通边缘的早中古生代金矿是亚洲最老的金矿Olympiada760-720 Ma?, 512 Ma? East Sayan500-450 MaBaikal450-440 Ma? 345 Ma?Tectonic Setting for Orogenic Gold造山带金矿构造背景古特提斯洋E. Pz. orogenic gold deposits of NW Kazakhstan=accretion onto Kazakstani

5、a哈沙克斯坦西北部早古生代造山型金矿床=哈萨克大陆的增生作用(after Windley et al, 2007; Seltmann, 2010)Microcontinents off GondwanaDistinct ore-forming eventsChina Cratonic Blocks about 350 MaSouth Margin of North China as it Migrated Across the OceanW. Qinling gold province=110-103oE (400-300 Ma collision)Qilian gold province=o

6、nly along NW edge (380-360 Ma collision)Enkelmann et al, 2007Qilian Belt 祁连带Au in N Qilian Ord vx and N Qaidam Mesoprot phyllite 北祁连奥陶纪yx和柴北缘中元古代千枚岩中的金Superterrane accreted ca. 380-360 Ma (Xiao et al, 2009) 超级地块增生Hanshan=60 t Au, 220 Ma (Mao et al, 2000); Tanjianshan=50 t Au, 275 Ma (Zhang et al, 20

7、09)西秦岭金矿带（210-170 Ma Au）Yangshan Gold Belt 阳山金矿带Anba deposit, 281 t Au (largest in China?)Both disseminated and vein ores in Devonian phylliteGeochron conflicting from 197-51 Ma安坝金矿，281吨金（中国最大？）都是位于泥盆纪千枚岩中的细脉侵染状矿体地质年代学变化于197-51 MaPERMO-TR. NAPANJING BASIN 二叠-三叠纪南盘江盆地 Carlin-like deposits in SW China

8、 and NE Vietnam中国西南部及Vietnam东北部类卡林型矿床Dian-Qian-Gui province滇-黔-贵省Au-Sb-Hg ores in Perm-Tr domes with carbonate coresAu-Sb-Hg矿位于核部为碳酸盐的二叠-三叠纪穹窿中Ores perhaps 200 Ma成矿于约200 MaCentral Asian Orogenic Gold Giants中亚造山带超大的造山带型金矿Permian orogenic gold belts 二叠纪造山型金矿带2 major belts of orogenic Au: Kalba and Sou

9、th Tien Shan两条主要的造山型金矿带：Kalba和南天山Geologic reconstruction based on Filippova et al. (2001) and Yakubchuk (2002).L. Pz. orogenic gold deposits of NE Kazakhstan=accretion onto Siberia(after Windley et al, 2007; Seltmann, 2010)Kalba Prov.向西伯利亚的增生作用造就了哈萨克斯坦东北部晚古生代造山型金矿床after Yakubchuk et al (2005)Most ou

10、tboard deposits: ca. 285 Ma for 5000 kmUzbekistan orogenic gold 乌兹别克斯坦造山型金矿after Drew et al (1998); Yakubchuk et al (2005)Muruntau (W. Tien Shan)Muruntau（西天山）Early Pz carbonaceous siltstone; dissem. pyrrhotite; 20-50 ppb Au?Mid Pz metamorphism; carb platform to NLate Carb.-Permian magmatism/defmtn/

11、gold ( 285 Ma)175 Moz Au; 3.5-5 g/t; PGE produced早古生代含碳粉砂岩; 浸染状磁黄铁矿 20-50 ppb Au（？）古生代中期变质作用，向北为碳酸盐台地晚石炭二叠纪岩浆活动及变形作用，金矿形成( 285 Ma)175百万盎司金； 3.5-5 g/t; 还有PGEApproximately 6 kilometresMURUNTAU: Why So Large?穆龙套：为何如此之大？Approximately 6 kilometresApproximately 300m deepMajor jog in South TS-Central TS su

12、ture?中南天山缝合带的主要交汇处？Carbonate platform rocks (e.g., Carlin processes)?碳酸盐台地（如卡林型？）Besopan sediments originally gold rich?沉积围岩富金？Kumtor (E. Tien Shan) 东天山Kumtor矿Vendian carbonaceous phyllites (Dzhetymtau Fm) Vendian 含碳千枚岩Late Pz mineralization ( 297-284 Ma argon dates) 晚古生代矿化（ 297-284 Ma 氩氩年龄）Veins, s

13、tockworks, breccia 脉形，网脉型，角砾岩型570 t Au, 3.58 g/tAlong major offset & sheared batholith margin 沿主要断裂带及剪切变形的岩基边缘分布Fine gold in pyrite黄铁矿中的纯金Hg-Sb depositXafter Sengor and Natalin 1996Hg-Sb Lodes Southern Tian Shan南天山Hg-Sb矿脉 Late Pz orogenic belts between Angaran/Yili/Tarim cratons Angaran、Yili和 Tarim

14、克拉通之间的晚古生代造山带 Altay Shan: Dev Fe-Cu-Zn VMS, Carb-Perm orogenic Au, placers 阿尔泰山：泥盆纪Fe-Cu-Zn VMS型，石炭-二叠造山带型金矿、砂金矿 W Junggar: L. Carb orogenic Au 西准葛尔：晚石炭造山带型金矿 E. Junggar: E. Carb epithermal, Carb-Perm orogenic Au东准葛尔：早石炭浅成热液，石炭-二叠造山带型金矿 Tian Shan: Carb-Perm epithermal, porphyry, & replacement 天山：石炭-

15、二叠浅成热液，斑岩型和交代型矿床Phanerozoic Goldfields 显生宙采金区Precambrian Orogenic Gold 前寒武纪造山型金矿BoringBillion Granite (30%) - greenstone (10%); high-grade gneiss terrains (60%) 花岗岩(30%) 绿岩(10%); 高品位片麻岩地体中(60%) Greenstone belts = broad greenschist facies 绿岩带广泛的绿片岩相 Plate tectonics (plume-driven?) vs. anorogenic tect

16、onics; lateral vs. vertical growth 板块构造（地幔柱驱动？）还是非造山；侧向生长还是垂向生长 Crustal heat production = 2x-4x present 地壳热产率是目前的24倍 Tectono metamorphic ages decrease with structural level 构造变质年龄随构造层下降而减少 Late Archean = 50% cont. crust 晚太古代：50大陆地壳ArcheanGold Preserved in Cratons克拉通中保存的太古宙金矿 NA/Greenland +/- central

17、 Australia, Africa/SA. N. Asia 63% gneiss, 12% plutonic, 25% metasupracrustal (mostly gs) Supracrustal = turbidites and greestone belts (Churchill, Guyanas, Birimian) Stable shelf facies; uplift and erosion of shelves/Archean cratons Paleoproterozoic= 25% cont. crustPaleoprot.Gold古元古代金矿after Zhao et

18、 al. (2004), Teixera et al. (2007)Paleoprot. Orogenic Au(2.1-1.8 Ga) 早元古造山带型金矿Cratonization = Buoyant SCML克拉通化=上浮的次大陆岩石圈地幔SCLM depleted in Fe & Al, so lighter than surrounding mantle SCLM亏损Fe和Al，因此比周围的地幔轻SCLM has melt-depleted peridotite buoyancy so balances isostatic equilibrium (i.e., still dense enough to prevent significant uplift)TECTONIC RECONSTRUCTION OF RODINIA: EVIDENCE OF PHANEROZOIC-STYLE PL