古生代新元古代晚期造山型金礦課件

1、Part III) Paleozoic/late Neoprot Orogenic Au古生代/新元古代晚期造山型金礦Terra Australis OrogenTerra Australis 造山帶 Series of N-S Pz fold belts一系列南北向古生代褶皺帶80 Moz Au 80百萬(wàn)盎司金Veining & defm=ca. 440 Ma脈和變形 = 大約440百萬(wàn)年LachlanThomsonHodgkinson-Broken RiverNew England (Permo-Tr)The Tasmanides inEastern Australia: Au-Rich

2、Pz Fold Belts & Younger Cover 澳大利亞?wèn)|部的塔斯曼域：富金的古生代褶皺帶和蓋層Lode Gold Deposits, Tasman Fold Belt塔斯曼褶皺帶中的造山帶型金礦床Westland, South Island南部島嶼，西岸Eastern Gondwana東岡瓦納PALEOZOIC ANTARCTICA古生代南極洲EASTERN CORDILLERA:A POTENTIAL WORLD-CLASS OROGENIC GOLD PROVINCE?東科迪嘞拉：一個(gè)潛在的世界級(jí)的造山型金礦??？Paleozoic Gold 古生代金礦7 Moz prod.1

3、00 Moz100 Moz250 Moz150 MozGOLD DEPOSITSOF ARABIAN-NUBIAN SHIELDARABIAN-NUBIAN地盾金礦100 Moz in ancient times儲(chǔ)量曾達(dá)100 MozAlmost all orogenic gold幾乎全為造山型金礦Microcontinents off Rodinia and GondwanaDistinct ore-forming events during 600-250 Ma growth of Asia古特提斯洋Rodinia和Gondwana古陸之外的微陸塊600-250 Ma獨(dú)特的成礦事件亞洲大陸

4、的生長(zhǎng)中亞造山帶Early-Middle PaleozoicOn Craton Margins of Siberia=Oldest Gold in Asia位于西伯利亞克拉通邊緣的早中古生代金礦是亞洲最老的金礦Olympiada760-720 Ma?, 512 Ma? East Sayan500-450 MaBaikal450-440 Ma? 345 Ma?Tectonic Setting for Orogenic Gold造山帶金礦構(gòu)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礦床=哈薩克大陸的增生作用(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 祁連帶Au in N Qilian Ord vx and N Qaidam Mesoprot phyllite 北祁連奧陶紀(jì)yx和柴北緣中元古代千枚巖中的金Superterrane accreted ca. 380-360 Ma (Xiao et al, 2009) 超級(jí)地塊增生Hanshan=60 t Au, 220 Ma (Mao et al, 2000); Tanjianshan=50 t Au, 275 Ma (Zhang et al, 20

7、09)西秦嶺金礦帶（210-170 Ma Au）Yangshan Gold Belt 陽(yáng)山金礦帶Anba deposit, 281 t Au (largest in China?)Both disseminated and vein ores in Devonian phylliteGeochron conflicting from 197-51 Ma安壩金礦，281噸金（中國(guó)最大？）都是位于泥盆紀(jì)千枚巖中的細(xì)脈侵染狀礦體地質(zhì)年代學(xué)變化于197-51 MaPERMO-TR. NAPANJING BASIN 二疊-三疊紀(jì)南盤(pán)江盆地 Carlin-like deposits in SW China

8、 and NE Vietnam中國(guó)西南部及Vietnam東北部類(lèi)卡林型礦床Dian-Qian-Gui province滇-黔-貴省Au-Sb-Hg ores in Perm-Tr domes with carbonate coresAu-Sb-Hg礦位于核部為碳酸鹽的二疊-三疊紀(jì)穹窿中Ores perhaps 200 Ma成礦于約200 MaCentral Asian Orogenic Gold Giants中亞造山帶超大的造山帶型金礦Permian orogenic gold belts 二疊紀(jì)造山型金礦帶2 major belts of orogenic Au: Kalba and Sou

9、th Tien Shan兩條主要的造山型金礦帶：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.向西伯利亞的增生作用造就了哈薩克斯坦東北部晚古生代造山型金礦床after Yakubchuk et al (2005)Most ou

10、tboard deposits: ca. 285 Ma for 5000 kmUzbekistan orogenic gold 烏茲別克斯坦造山型金礦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早古生代含碳粉砂巖; 浸染狀磁黃鐵礦 20-50 ppb Au（？）古生代中期變質(zhì)作用，向北為碳酸鹽臺(tái)地晚石炭二疊紀(jì)巖漿活動(dòng)及變形作用，金礦形成( 285 Ma)175百萬(wàn)盎司金； 3.5-5 g/t; 還有PGEApproximately 6 kilometresMURUNTAU: Why So Large?穆龍?zhí)祝簽楹稳绱酥?？Approximately 6 kilometresApproximately 300m deepMajor jog in South TS-Central TS su

12、ture?中南天山縫合帶的主要交匯處？Carbonate platform rocks (e.g., Carlin processes)?碳酸鹽臺(tái)地（如卡林型？）Besopan sediments originally gold rich?沉積圍巖富金？Kumtor (E. Tien Shan) 東天山Kumtor礦Vendian carbonaceous phyllites (Dzhetymtau Fm) Vendian 含碳千枚巖Late Pz mineralization ( 297-284 Ma argon dates) 晚古生代礦化（ 297-284 Ma 氬氬年齡）Veins, s

13、tockworks, breccia 脈形，網(wǎng)脈型，角礫巖型570 t Au, 3.58 g/tAlong major offset & sheared batholith margin 沿主要斷裂帶及剪切變形的巖基邊緣分布Fine gold in pyrite黃鐵礦中的純金Hg-Sb depositXafter Sengor and Natalin 1996Hg-Sb Lodes Southern Tian Shan南天山Hg-Sb礦脈 Late Pz orogenic belts between Angaran/Yili/Tarim cratons Angaran、Yili和 Tarim

14、克拉通之間的晚古生代造山帶 Altay Shan: Dev Fe-Cu-Zn VMS, Carb-Perm orogenic Au, placers 阿爾泰山：泥盆紀(jì)Fe-Cu-Zn VMS型，石炭-二疊造山帶型金礦、砂金礦 W Junggar: L. Carb orogenic Au 西準(zhǔn)葛爾：晚石炭造山帶型金礦 E. Junggar: E. Carb epithermal, Carb-Perm orogenic Au東準(zhǔn)葛爾：早石炭淺成熱液，石炭-二疊造山帶型金礦 Tian Shan: Carb-Perm epithermal, porphyry, & replacement 天山：石炭-

15、二疊淺成熱液，斑巖型和交代型礦床Phanerozoic Goldfields 顯生宙采金區(qū)Precambrian Orogenic Gold 前寒武紀(jì)造山型金礦BoringBillion Granite (30%) - greenstone (10%); high-grade gneiss terrains (60%) 花崗巖(30%) 綠巖(10%); 高品位片麻巖地體中(60%) Greenstone belts = broad greenschist facies 綠巖帶廣泛的綠片巖相 Plate tectonics (plume-driven?) vs. anorogenic tect

16、onics; lateral vs. vertical growth 板塊構(gòu)造（地幔柱驅(qū)動(dòng)？）還是非造山；側(cè)向生長(zhǎng)還是垂向生長(zhǎng) Crustal heat production = 2x-4x present 地殼熱產(chǎn)率是目前的24倍 Tectono metamorphic ages decrease with structural level 構(gòu)造變質(zhì)年齡隨構(gòu)造層下降而減少 Late Archean = 50% cont. crust 晚太古代：50大陸地殼ArcheanGold Preserved in Cratons克拉通中保存的太古宙金礦 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古元古代金礦after Zhao et

18、 al. (2004), Teixera et al. (2007)Paleoprot. Orogenic Au(2.1-1.8 Ga) 早元古造山帶型金礦Cratonization = Buoyant SCML克拉通化=上浮的次大陸巖石圈地幔SCLM depleted in Fe & Al, so lighter than surrounding mantle SCLM虧損Fe和Al，因此比周?chē)牡蒯］pSCLM 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