【作者】 叶会寿；

【导师】 毛景文； 王瑞江；

【作者基本信息】 中国地质科学院 ， 矿物学、岩石学、矿床学， 2006， 博士

【摘要】 近些年来，华北陆块南缘铅锌银矿床勘查评价取得了重大进展，发现了沙沟、冷水北沟、老代丈沟等大中型矿床，显示了巨大的找矿潜力。因此，本区的铅锌银矿床类型、特征及成矿的地球动力学背景就成为重要的研究内容之一。本论文在野外地质调查的基础上，总结了华北陆块南缘中生代陆内构造演化，对典型的铅锌银矿集区进行了解剖，运用区域矿床学、地球化学、稳定同位素、年代学的方法和手段，划分了铅锌银矿床类型、厘定了成矿作用的时限，研究了成矿机制，探讨了其形成的地球动力学背景。测定太山庙花岗岩体的SHRIMP年龄为115±1.4Ma，蒿坪沟花岗斑岩体为113.5±1.4Ma，东沟花岗斑岩体为112±1Ma。在研究了花岗岩的成因和形成的构造环境基础上，将华北陆块南缘中生代构造演化划分为晚三叠世—中侏罗世后碰撞阶段、晚侏罗世构造体制大转换阶段、早白垩世岩石圈大减薄阶段、晚白垩世—新生代陆内俯冲与裂陷阶段。测定东沟钼矿床辉钼矿的Re-Os同位素模式年龄为116±1.7Ma，蒿坪沟银铅锌矿床和三元沟铅锌矿床热液蚀变绢云母⁴⁰Ar-³⁹Ar坪年龄分别为134.9±0.8Ma和110.1±9.0Ma。将华北陆块南缘铅银成矿作用划分为2期：①140Ma左右，矿床类型为矽卡岩型、热液脉型，②130～110Ma，矿床类型为热液脉型，包括石英脉型、构造蚀变岩型。140Ma左右的矽卡岩型多金属矿床和热脉型铅锌银矿床主要分布于晚侏罗世斑岩体的外围矽卡岩带和围岩的断裂带中。矽卡岩型多金属矿床成矿温度总体属中高温。热液脉型铅锌银矿床成矿流体属中温（252～331℃）、中低盐度（8.28％～16.43％）、中等密度的含CO₂的H₂O-NaCl体系。成矿流体的δD为-83‰～-80‰，δ¹⁸O_H20为4.28％～7.65％表明成矿流体以岩浆水为主，混有大气降水。硫铅同位素示踪成矿物质主要来源于下地壳。温度降低、水-岩反应、成矿流体的混合和不混溶作用是矿质沉淀的主要因素。130～110Ma的热液脉型铅锌银矿床主要分布于小秦岭—外方山金银铅锌钼成矿带上，赋存于断裂带中。构造蚀变岩型银（金）铅锌矿床成矿流体总体属中温（147～360℃）、中-低盐度（4.6％～22.71％）、中等密度的（0.52～0.99g／cm³）的含CO₂的H₂O-NaCl体系。氢氧碳同位素组成表明成矿流体以岩浆水为主，混有大气降水，硫铅同位素示踪成矿物质主要来自下地壳结晶基底太华岩群。流体的混合、水-岩反应和温度降低是矿质沉淀的主要因素。东闯石英脉型金铅矿床的成矿流体属中温（180～340℃）、中低温盐度（7.0％～22.3％）、中等密度（0.82～0.98g／cm³）的含H₂S的H₂O-NaCl-CO₂-CH₄体系。氢氧碳同位素组成及流体成分说明成矿流体以地幔流体参与的岩浆水为主，混有大气降水。成矿物质除来自下地壳结晶基底太华岩群外，还可能来自地幔。流体的沸腾和混合是矿质沉淀的主要因素。华北陆块南缘铅锌银成矿作用与区域地球动力学背景关系密切。140Ma左右铅锌银成矿作用形成于中国东部构造体制大转换的地球动力学背景，与晚侏罗世同熔型花岗斑岩体形成有关。130～110Ma铅锌银金成矿作用形成于中国东部岩石圈大减薄过程的地球动力学背景。铁炉坪矿集区和康山矿田的构造蚀变岩型银（金）铅锌矿床与重熔型花岗岩形成有关；东闯石英脉型金铅矿床形成与地幔流体参与的岩浆活动有关；付店矿集区构造蚀变岩型铅锌矿床与太山庙A型花岗岩形成有关。更多还原

【Abstract】 In recent years, many large-medium scale lead-zinc-silver deposits were found in the southmargin of North China Craton such as Shagou, Lengshuibeigou, Laodaizhanggou and so on. Sothere has been wide interest in the types and features of lead-zinc-silver deposits and metallogenicgeodynamics background in this area. Based on the detailed field investigation, this paperconcluded the Mesozoic intracontinental tectonic evolution in the south margin of North ChinaCraton, analyzed the typical lead-zinc-silver deposit clusters, classified the types of lead-zinc-silverdeposits, determined the metallogenic time, studied the mineralizing style and discussed themetallogenic geodynamics background.This paper provided the highly precise zircon SHRIMP U-Pb ages of 115±1.4Ma forTaishanmiao granitic body, 133.5±1.4Ma for Haopinggou granite porphyry body and 112±1Mafor Donggou granite porphyry body. On the basis of the genesis and tectonic setting of granite,Mesozoic tectonic evolution in the south margin of North China Craton were divided into fourstages: post-collisional stage from upper Triassic to middle Jurassic, huge tectonic regimetransformation stage in upper Jurassic, huge lithospheric thinning stage in lower cretaceous andintrocontinental subduction and rifting stage from upper cretaceous to Cenozoic.According to the Re-Os isotopic model age of 116±1.7Ma for the molybdenite in Donggoumolybdenum deposit and ⁴0Ar-³9Ar plateau age of 134.9±0.8Ma in Haopinggou lead-zinc-silverdeposit and 110.1±9.0Ma for hydrothermal altered sericite in Sanyuangou lead-zinc deposit,lead-zinc-silver mineralizing process were divided into two episodes: The first episode includedskarn type and hydrothermal vein-type deposits in 140Ma and the second episode includedhydrothermal vein-type deposits from 130Ma to ll0Ma. The hydrothermal vein-type depositsincluded quartz vein deposits and tectonic altered rock type deposits.Skarn type polymetallic deposit and hydrothermal vein type lead-zinc-silver deposit of 140Mawere located in the peripheral skam belt and the fracture belt of wall rock of upper Jurassicporphyry body. The ore-forming temperature of Skarn type polymetallic deposit was medium tohigh. And the ore-forming temperature of hydrothermal vein type lead-zinc-silver deposit had aH₂O-NaCl system of medium temperature （252～331℃） , medium to low salinity （8.28%～16.43%）, medium density, and CO₂ contained. The dD value and d¹⁸O_H2O value of ore-formingfluid are-83‰～80‰and 4.28%～7.65% which suggested the origin of ore-forming fluid wasmagmatic water predominately mixing meteoric water. Sulfur and lead isotope-tracing suggestedthe crustal origin of ore forming materials. Temperature decrease, water-rock interaction, mixingand miscibility of ore forming fluid are the main factors of mineral precipitation.Hydrothermal vein type lead-zinc-silver deposits from 130Ma to 110Ma were mainly locatedin the fracture belt of Xiaoqinling-Waifangshan gold-silver-lead-zinc-molybdenum metallogeniczone. Tectonic altered rock type silver（gold）-lead-zinc deposits had a H₂O-NaCl system of mediumtemperature （147～360℃）, medium to low salinity （4.6%～22.71%）, medium density （0.52～0.99g/cm³） and CO₂ contained. The composition of hydrogen, oxygen and carbon suggested theorigin of ore-forming fluid was magmatic water predominately mixing meteoric water. Sulfur and lead isotope-tracing suggested ore forming materials derived from the lower crust crystalbasement-Taihua Group. Ore forming mixing, water-rock interaction and temperature decrease arethe main factors of mineral precipitation. The ore forming fluid of Dongchuang quartz vein typegold-lead deposit had a H₂O-NaCl-CO₂-CH₄ system of medium temperature （180～340℃）,medium to low salinity （7.0%～22.3%）, medium density （0.82～0.98g/cm³） and H₂S contained.The composition of hydrogen, oxygen and carbon and the constituents of ore forming suggested theorigin of ore-forming fluid was magmatic water with the participation of mantle fluidpredominately, mixed meteoric water. Ore forming materials probably came from mantle besidesthe origin of the lower crust crystal basement-Taihua Group. Boiling and mixing of ore forming arethe main factors of mineral precipitation.Lead-zinc-silver mineralizing process in the south margin of North China Craton had a closerelationship with regional geodynamic background. Lead-zinc-silver mineralizing process of140Ma formed in the huge tectonic regime transformation stage of eastern China and was relatedwith syntexis（Ⅰ） type granite porphyry body of upper Jurassic. Lead-zinc-silver deposit of 130Ma to110Ma formed the lithospheric thinning process of eastern China: tectonic altered rock type silver（gold）-lead-zinc deposit of Tieluping deposit clusters and Kangshan ore-field was related withremelting type granite; Dongchuang quartz vein type gold-lead deposit was close to the magmaticactivity with the participation of mantle fluid; and tectonic altered rock type lead-zinc deposit ofFudian deposit clusters was close to A-type granite of Taishanmiao.Key words: tectonic evolution, mineralizing process, metallogenic geodynamics background,lead-zinc-silver deposit, the south margin of North China Craton更多还原