斑岩型矿床：岩浆侵入和热液蚀变.pdf

Porphyry Deposits Hydrothermal Alteration and mineralisation 斑岩型矿床岩浆侵入和热液蚀变斑岩型矿床岩浆侵入和热液蚀变 Porphyry Deposits Hydrothermal Alteration and mineralisation 斑岩型矿床岩浆侵入和热液蚀变斑岩型矿床岩浆侵入和热液蚀变 Stockwork veins in biotite-altered dolerite, Ray, ArizonaStockwork veins in biotite-altered dolerite, Ray, Arizona Alteration assemblagesAlteration assemblages蚀变组合蚀变组合蚀变组合蚀变组合 Qz-mt-cp veins in potassic-altered monzodiorite, Grasberg Hydrothermal Alteration热液蚀变热液蚀变 Potassic Potassic 钾化钾化钾化钾化 CalcCalc- -silicatesilicate钙硅酸岩化钙硅酸岩化钙硅酸岩化钙硅酸岩化 CalcCalc- -potassic potassic 钙钙钙钙- -钾化钾化钾化钾化 PropylitiPropylitic青磐岩化青磐岩化青磐岩化青磐岩化 EarlyEarly Intermediate Intermediate ArgillicArgillic 中性泥化中性泥化中性泥化中性泥化 Advanced Advanced ArgillicArgillic 高级泥化高级泥化高级泥化高级泥化 PhyllicPhyllic绢英岩化绢英岩化绢英岩化绢英岩化 LateLate From Garwin, 2000 Early Alteration Early Alteration - - Batu HijauBatu Hijau 早期蚀变早期蚀变早期蚀变早期蚀变 What characterises potassic alteration Weakly to intensely developed secondary alteration assemblages that can destroy or preserve primary rock textures Can occur as pervasive or selectively pervasive replacements, or as vein halos Associated veins have similar mineralogies Biotite-altered trachyandesite and orthoclase-altered monzonite MineralogyMineralogy OrthoclaseOrthoclaseKAlSiKAlSi 3 3 OO 8 8 common in common in felsicfelsic rockrockss BiotiteBiotiteKMg,FeKMg,Fe2 2 3 3 AlSiAlSi 3 3 OO10 10OH,F OH,F 2 2 common icommon in n maficmafic rocksrocks QuartzQuartzSiOSiO 2 2 MagnetiteMagnetiteFeFe 3 3 OO4 4 important for important for explorationexploration AnhydriteAnhydriteCaSOCaSO 4 4 AlbiteAlbiteNaAlSiNaAlSi 3 3 OO8 8 ChalcopyriteChalcopyriteCuFeSCuFeS 2 2 BorniteBorniteCuCu 5 5 FeSFeS 4 4 MolybdeniteMolybdeniteMoSMoS 2 2 Biotite Alteration Potassic 黑云母蚀变（钾化）黑云母蚀变（钾化） 闪长岩中的黑云母磁铁矿团块闪长岩中的黑云母磁铁矿团块闪长岩中的黑云母磁铁矿团块闪长岩中的黑云母磁铁矿团块不均匀黑云母蚀变不均匀黑云母蚀变不均匀黑云母蚀变不均匀黑云母蚀变 碱性碱性碱性碱性PCDPCD 钙碱性斑岩铜矿钙碱性斑岩铜矿钙碱性斑岩铜矿钙碱性斑岩铜矿 K-Feldspar Alteration Potassic 钾长石蚀变（钾化）钾长石蚀变（钾化） Orthoclase and biotite Orthoclase and biotite alteration, E27, NSWalteration, E27, NSW Orthoclase alteration and Orthoclase alteration and hypersalinehypersaline FIsFIs, Ampucao, Philippines, Ampucao, Philippines Alkalic PCDAlkalic PCDCalcCalc- -alkalic PCDalkalic PCD K-Feldspar Alteration Potassic Orthoclase alteration and quartz vein Orthoclase alteration and quartz vein stockwork, Boyongan, Philippinesstockwork, Boyongan, Philippines Potassic AlterationPotassic Alteration Orthoclase alteration and quartz vein stockwork, Cerro Casale, Chile Orthoclase alteration and quartz vein stockwork, Cerro Casale, Chile Potassic alteration associated with ‘stockwork’ vein arrays 脉体展布方式脉体展布方式 RidgewayRidgewayCadia HillCadia Hill E26NE26NE26NE26N Main ore minerals chalcopyrite, bornite, gold, molybdenite 主要矿石矿物黄铜矿、斑铜矿、金、辉钼矿主要矿石矿物黄铜矿、斑铜矿、金、辉钼矿 Hypogene Mineralisation深成成矿作用深成成矿作用 11,000E E26 - Cu Au Grades 10,800E10,600E11,200E 200 m 2 g/t Au 1 - 2 g/t Au 0.5 - 1 g/t Au 2 Cu 1- 2 Cu 0.5 – 1 Cu Gangue qz, or, anh, mt, bt ser py脉石石英、正长石、硬脉石石英、正长石、硬 石膏、磁铁矿、黑云母＋绢云母石膏、磁铁矿、黑云母＋绢云母 ＋黄铁矿＋黄铁矿 Within deposit zonation 在矿化带内在矿化带内 low pyrite, Cu-rich core 贫黄铁矿、富铜内核贫黄铁矿、富铜内核, outer pyrite-rich halo 富黄铁矿外带富黄铁矿外带 Cu-Au rich core surrounded by Mo-rich zone outer pyrite halo 有些矿床内核富有些矿床内核富Cu-Au，核外，核外环环 绕着中性富钼带和黄铁矿外带绕着中性富钼带和黄铁矿外带 Free gold in qz-mt vein, Ridgeway, NSW 石英－磁铁矿脉不含金石英－磁铁矿脉不含金 Cu, Au and quartz veins, Grasberg 铜、金和石英脉铜、金和石英脉,Grasberg Kavaleris, 1994 Gold and magnetite, Grasberg, Indonesia 金和磁铁矿金和磁铁矿,Grasberg Kavaleris, 1994 A veins These are typically granular quartz-K-feldspar-anhydrite-sulfide veins that generally lack internal symmetry, and are irregular and discontinuous “A” veins “A” veins “B” veins “B” veins “D” veins “D” veins Vein Types Gustafson and Hunt, 1975 B veins These transitional quartz veins occupy continuous planar fractures, contain molybdenite, and lack K- feldspar and associated alteration halos D veins Late sulfide veins contain pyrite and lesser bornite, chalcopyrite, enargite, tennantite, sphalerite and gl, with quartz-anhydrite gangue and phyllic alteration halos From Garwin, 2000 PotassicPotassic and and PropyliticPropylitic Alteration Alteration - - Batu Hijau Batu Hijau AMIRA P765 What characterises propylitic alteration Weakly to moderately developed secondary alteration assemblage that typically preserves primary rock textures Can occur as pervasive or selectively pervasive replacements, or as vein halos Associated veins have similar mineralogies Epidote, Baja California, Mexico. Image from http//www.johnbetts- PyritePyriteFeSFeS2 2 Smectite Ca,NaSmectite Ca,Na0.7 0.7Al,Mg,Fe Al,Mg,Fe 4 4 Si,AlSi,Al 8 8 OO20 20OH OH 4 4 . . H H2 2 OO MineralogyMineralogy ActinoliteActinoliteCaCa 2 2 Mg,FeMg,Fe2 2 5 5 SiSi 8 8 OO22 22OH OH 2 2 AlbiteAlbiteNaAlSiNaAlSi 3 3 OO8 8 Calcite / Calcite / MnMn- -calcitecalciteCaMnCOCaMnCO3 3 Chlorite Chlorite Mg,FeMg,Fe2 2 6 6 Al SiAl Si 3 3 OO10 10OH OH8 8 HematiteHematiteFeFe 2 2 OO 3 3 EpidoteCa2Al,Fe33Si3O12OH EpidoteCa2Al,Fe33Si3O12OH Alkalic PCDAlkalic PCD CalcCalc- -alkalic PCDalkalic PCDAlkalic PCDAlkalic PCD Epi-cp-py veins with hematitic alteration selvage, Ridgeway, NSW Propylitic alteration, Mankayan, Philippines Epi-ab alteration, North Parkes, NSW Propylitic Alteration 青磐岩化蚀变青磐岩化蚀变 From Holiday and Cooke 2007, with inspiration from Sillitoe and Thompson 2006 qz-cp veins in orthoclase-altered dacite porphyry, Ampucao, Philippines Epidote veins and alteration, Mankayan, PhilippinesVuggy quartz, Lepanto, Philippines Bladed calcite-cemented breccia, Kelian, Indonesia Biotite-magnetite and orthoclase- altered trachyandesite, E27, NSW Biotite-magnetite-altered hb-qz diorite porphyry, Philex, Philippines Actinolite-cemented hydrothermal breccia, El Teniente, Chile Prehnite-calcite-pyrite vein in chlorite- altered basalt, Ridgeway, NSW Lepanto mineLepanto mine Mankayan lithocap, Philippines 岩盖岩盖 LS/IS 脉脉 青盘岩化带青盘岩化带 钾化核钾化核 富砷硫铜矿高硫矿化富砷硫铜矿高硫矿化 黄铁矿带黄铁矿带 绿色岩石环境绿色岩石环境 青盘岩化带青盘岩化带 From Garwin, 2000 Late Alteration Late Alteration - - Batu HijauBatu Hijau 晚期蚀变晚期蚀变晚期蚀变晚期蚀变 Intermediate Argillic Alteration 中性泥化蚀变中性泥化蚀变 IntInt argarg alt cut by alt cut by qzqz- -il il alteration, FSE, Philippinesalteration, FSE, Philippines Pervasive int. arg. alteration, Pervasive int. arg. alteration, PhilexPhilex, Philippines, Philippines ChlChl- -altered rock flour matrix breccia altered rock flour matrix breccia hem alteration halo, Cadia Hill, NSWhem alteration halo, Cadia Hill, NSW Alkalic PCDAlkalic PCD CalcCalc- -alkalic PCDalkalic PCDCalcCalc- -Alkalic PCDAlkalic PCD Phyllic AlterationPhyllic Alteration绢英岩化蚀变绢英岩化蚀变 Sericitic vein halo, Goonumbla, NSW Alkalic PCDAlkalic PCD CarbCarb- -BMS vein with phyllic BMS vein with phyllic alteration halo in QMP, E27, NSWalteration halo in QMP, E27, NSW SerSer- -qzqz- -tm alteration, tm alteration, Cadia East, NSWCadia East, NSW Alkalic PCDAlkalic PCD Alkalic PCDAlkalic PCD Alkalic PCDAlkalic PCD Phyllic vein Phyllic vein halos, E26N, NSWhalos, E26N, NSW Pervasive phyllic Pervasive phyllic alteration, E48, NSWalteration, E48, NSW Vuggy Quartz, PeruVuggy Quartz, Peru CalcCalc- -Alkalic PCDAlkalic PCD Advanced Argillic and Silicic Advanced Argillic and Silicic Alteration, FSE, PhilippinesAlteration, FSE, Philippines CalcCalc- -Alkalic PCDAlkalic PCD Advanced Argillic Alteration 高级泥化蚀变高级泥化蚀变 Lithocaps - Sillitoe, 1995 Lithocaps are large, topographically prominent masses of pyritic advanced argillic and argillic alteration that in the shallow subsurface. They can overlie subvolcanic intrusions that host porphyry Cu, Au, Mo or Sn deposits. Lithocaps are large, topographically prominent masses of pyritic advanced argillic and argillic alteration that in the shallow subsurface. They can overlie subvolcanic intrusions that host porphyry Cu, Au, Mo or Sn deposits. Propylitic Alteration Chloritic Alteration Porphyry Stock K-silicate alt. Cu-Au-Mo stockwork 1 km 1 km HS massive sulfide lode Adv. Arg. Alteration Sericitic Alteration LS vein HS breccia/ stockwork Modified from Sillitoe 1995 Topographic Controls on Fluid FlowTopographic Controls on Fluid Flow Lithocaps commonly exceed 20 km2in original areal extent and 1 km in thickness, but in most cases their dimensions have been reduced appreciably by erosion. The large areal extent of lithocaps relates in part to lateral flow of acidic solutions down hydraulic gradients, typical of volcanic edifices. Lithocaps commonly exceed 20 km2in original areal extent and 1 km in thickness, but in most cases their dimensions have been reduced appreciably by erosion. The large areal extent of lithocaps relates in part to lateral flow of acidic solutions down hydraulic gradients, typical of volcanic edifices. Mankayan lithocapMankayan lithocap Lepanto mine Lithocap, East AsiaLithocap, East Asia Vuggy quartz-alunite Vuggy quartz-alunite Alteration Zonation 蚀变分带蚀变分带 蚀变分带矿化分带蚀变分带矿化分带 青盘岩化青盘岩化青盘岩化青盘岩化 石英绢云岩化 钾化 石英绢云岩化 钾化钾化 边缘带 钾化 边缘带 低黄铁矿壳低黄铁矿壳 边缘带边缘带 矿壳 低品位矿 矿壳 低品位矿 黄铁矿壳黄铁矿壳 Alteration Zoning 蚀变分带蚀变分带 Alteration Zoning 蚀变分带蚀变分带 →→→→ Silicic 硅化硅化 Potassic 钾化钾化 Propylitic 青磐岩化青磐岩化 ↓ ↓ ↑ ↑ Advanced argillic 高级泥化高级泥化 Phyllic and argillic 绢英岩化和泥化绢英岩化和泥化 Phyllic alteration can be produced by magmatic- hydrothermal fluids 绢英岩化蚀变 由岩浆－热液 流体产生 绢英岩化蚀变 由岩浆－热液 流体产生 The phyllic alteration zone can cut through potassic alteration zones, and be independently mineralised 绢英岩化蚀变 可以切穿钾 化，独立形成 矿化。 绢英岩化蚀变 可以切穿钾 化，独立形成 矿化。 Alteration Zoning蚀变分带蚀变分带Alteration Zoning蚀变分带蚀变分带 Lowell and Guilbert 1970 model South American porphyry model potassicpotassic potassicpotassicpotassicpotassic phyllic propylitic wall rocks wall rocks propylitic Alteration Overprinting 蚀变叠加蚀变叠加 Modified after Gustafson and Hunt 1975 Major genetic classes Magmatic-hydrothermal Volcanic-hydrothermal Hydrothermal breccias phreatic, hydraulic, corrosive Tectonic Breccias in Magmatic - Hydrothermal Systems Polymict tourmaline Polymict tourmaline breccia, Sierra breccia, Sierra GordaGorda, Chile, Chile Generated by explosive fluid release from crystallising porphyry Angular clasts -implies limited clast transport abrasion High temperature alteration rinds clastsand altered matrix Sulfide cement Magmatic- hydrothermal breccias TourmalineTourmaline- - chalcopyrite cement, chalcopyrite cement, Rio BlancoRio Blanco Sulfide Mineralisation Styles 硫化物矿化类型硫化物矿化类型Sulfide Mineralisation Styles 硫化物矿化类型硫化物矿化类型 Clast alterationClast alteration 蚀变碎屑蚀变碎屑蚀变碎屑蚀变碎屑 VeinVein 矿化脉矿化脉矿化脉矿化脉 CementCement 胶结物胶结物胶结物胶结物 Tourmaline breccia, Tourmaline breccia, R R o Blanco, Chileo Blanco, Chile Hydrothermal cementHydrothermal cement热液胶结热液胶结热液胶结热液胶结 Alteration of matrixAlteration of matrix岩石蚀变岩石蚀变岩石蚀变岩石蚀变 Alteration of clastsAlteration of clasts碎屑蚀变碎屑蚀变碎屑蚀变碎屑蚀变 CrossCross- -cutting veinscutting veins交切脉体交切脉体交切脉体交切脉体 Maar- diatreme breccia complex 角砾岩体角砾岩体 Late intrusion into active hydrothermal system 后期侵入至 活动的热液 系统 后期侵入至 活动的热液 系统 2 - 5 km paleodepth 古深度古深度 2 – Phreatomagmatic breccias 岩浆蒸气作用角砾岩岩浆蒸气作用角砾岩 Clastic matrix milled clasts 碎屑状基质和粉碎的碎屑丰富碎屑状基质和粉碎的碎屑丰富 Surficial and subsurface deposits 在地表及地下均有角砾岩形成在地表及地下均有角砾岩形成 Bedded and massive breccias 条带状、块状构造的角砾岩相条带状、块状构造的角砾岩相 Venting of volatiles to surface 地表挥发份气孔地表挥发份气孔 ⇒⇒death of a porphyry deposit 斑岩矿床的消逝斑岩矿床的消逝 ⇒shortcut to the epithermal environment 形成浅成环境的捷径形成浅成环境的捷径 Breccias in Hydrothermal Systems 热液体系中的角砾岩热液体系中的角砾岩 Capillitas diatreme, Fallon Negro district, ArgentinaCapillitas diatreme, Fallon Negro district, Argentina Volcanic-Hydrothermal Breccias – Nature’s DrillholesVolcanicVolcanic- -Hydrothermal Breccias Hydrothermal Breccias – – NatureNature’ ’s s DrillholesDrillholes SericiteSericite- -chlorite altered chlorite altered polymict matrixpolymict matrix- -rich breccia, rich breccia, Acupan Gold Mine, PhilippinesAcupan Gold Mine, Philippines Chalcopyrite clast in polymictic matrix-rich breccia, Amacan, Philippines LateLate- -stage diatreme breccia at Acupan Austage diatreme breccia at Acupan Au- -Ag mine, Philippines Ag mine, Philippines Supergene Mineralisation 次生成矿作用次生成矿作用 BoyonganBoyongan, , PhilippinesPhilippines Idealised supergene enrichment blanket 次生矿床富集层位理想模式次生矿床富集层位理想模式 From Titley, 1982 Enrichment Blanket 次生矿化 深成矿化 青盘岩化 低品位核 钾化 青盘岩化 高岭土化 高岭土 绢云母 低黄铁矿化带 黄铁矿化带 次生矿化 深成矿化 青盘岩化 低品位核 钾化 青盘岩化 高岭土化 高岭土 绢云母 低黄铁矿化带 黄铁矿化带 Examples of Fe minerals in leached caps 淋滤盖层中的淋滤盖层中的Fe矿实例矿实例 Cuajone, Peru Cuajone, Peru Overburden 覆盖层覆盖层 Overburden 覆盖层覆盖层 Hematitic capHematitic cap 赤铁矿盖层赤铁矿盖层赤铁矿盖层赤铁矿盖层 Chalcocite oreChalcocite ore 辉铜矿矿石辉铜矿矿石辉铜矿矿石辉铜矿矿石 Examples of Fe minerals in leached caps 淋滤盖层中的淋滤盖层中的Fe矿实例矿实例 Jarositic leached cap in a highly pyritic Ag-Au bearing epithermal system, Bolivia Goethitic leached cap above a pyritic Sn-Ag porphyry system, Bolivia 含含Sn-Ag黄铁矿 斑岩体系黄铁矿 斑岩体系 上的针铁矿淋滤层上的针铁矿淋滤层 含含Ag-Au的富黄铁矿浅成热 液矿床 中的黄钾铁钒淋滤层 的富黄铁矿浅成热 液矿床 中的黄钾铁钒淋滤层 IdentIdentifyingifying residuals minerals in leached capsresiduals minerals in leached caps 淋滤盖层中的残留矿的淋滤盖层中的残留矿的淋滤盖层中的残留矿的淋滤盖层中的残留矿的鉴鉴鉴鉴别别别别 Iron oxide characterization chart for comparing smudges from leached outcrops and drill holes intervals 氧化铁特征图，用于对比经淋滤的露头与钻孔中的烟灰色差异氧化铁特征图，用于对比经淋滤的露头与钻孔中的烟灰色差异 Mixtures of red hematite, goethite and jarosite will produce gradational colors as shown in the standard box 用红色赤铁矿、针铁矿及黄钾铁矾进行混合，会产生象标准图标中一样的颜 色等级 用红色赤铁矿、针铁矿及黄钾铁矾进行混合，会产生象标准图标中一样的颜 色等级 Note that the standard smudges are derived from leached capping environments and represents XRD analyzed end-member iron oxides 注意，标准的烟灰色淋滤层环境，代表经注意，标准的烟灰色淋滤层环境，代表经XRD分析了的铁氧化物的一个端元分析了的铁氧化物的一个端元 Hematite赤铁矿赤铁矿 Goethite 针铁矿针铁矿Jarosite黄钾铁钒黄钾铁钒 LimonitesLimonites褐铁矿褐铁矿 -From Peterson and Chavez 2002.From Peterson and Chavez 2002. Neotocite on fractures in phyllic altered quartz monzonite porphyry, Quellaveco, Peru 绢英岩蚀变石英二长斑岩裂隙中 的硅锰矿 绢英岩蚀变石英二长斑岩裂隙中 的硅锰矿 Brochantite along oxidised qtz- cp veins in quartz monzonite porphyry Quellaveco, Peru 氧化脉中的水胆矾氧化脉中的水胆矾 Examples of Cu minerals in leached caps 淋滤盖层中的淋滤盖层中的Cu矿矿 Examples of Cu minerals in leached caps 淋滤盖层中的淋滤盖层中的Cu矿石矿石 Azurite on fractures from in- situ oxidation of chalcocite, Escondida, Chile Antlerite Turquoise绿松石绿松石 Azurite 蓝铜矿蓝铜矿 Native Cu 自然铜自然铜 Uplift and Exhumation隆升和剥蚀隆升和剥蚀 QzQz- -bnbn- -cpcp veins cut by veins cut by epiepi vein, Ridgewayvein, Ridgeway Propylitic Alteration 青磐岩化青磐岩化 Chlorite 绿泥石化蚀变绿泥石化蚀变绿泥石化蚀变绿泥石化蚀变 PorphyryPorphyry StockStock K K- -silicate alt. silicate alt. CuCu- -AuAu- -Mo Mo stockworkstockwork 1 km 1 km Modified from Sillitoe 1995 KSi酸岩蚀变酸岩蚀变 Cu-Au-Mo 网脉网脉 斑岩株斑岩株 Propylitic Alteration Chloritic Alteration Porphyry Stock K-silicate alt. Cu-Au-Mo stockwork 1 km 1 km HS massive sulfide lode Adv. Arg. Alteration Seric