节点文献
元谋地区地质地球化学特征与成矿作用研究
【作者】 姬琦；
【导师】 张世涛；
【作者基本信息】 昆明理工大学 ， 矿产普查与勘探， 2009， 硕士
【摘要】 元谋地区位于扬子板块西缘,区内地质构造复杂,断层发育,岩浆活动和变形变质作用广泛,矿产丰富,矿化普遍,以往地质找矿工作研究程度较低,具有较大的找矿潜力。论文选择这一颇具前景的地区开展研究,洞察其地质地球化学特征,总结其成矿规律,试图建立符合实际的成矿模式,期望为建立该区区域成矿理论和开展找矿工作提供参考。研究区地处扬子板块西缘,经历了多期次构造作用,出露地层有元古界、震旦系、三叠系、侏罗系、白垩系及第四系,以元古界普登岩群和羊臼河岩群为主；岩浆活动持续时间长、期次多、岩性复杂,以晋宁-澄江期酸性花岗岩分布最广,华力西期基性-超基性岩次之；变形变质作用以晋宁-澄江挤压-伸展运动为主,形成了以元谋变质核杂岩为主体,元谋-绿汁江断裂为导向的构造格局。通过岩石和土壤化探分析测量,圈定了异常区域,结合地层岩性、构造等地质要素归纳总结出四种有较大经济意义的异常推测：Cu异常,受普登岩群中变质火山岩系控制；Cu、Au异常,与岩浆活动有关,受构造控制不太明显；Cu、Au、Pb、Zn异常,与岩浆活动有关,受断裂控制明显；Ni、Pt、Pd异常,与超基性岩体关系密切。研究区内矿化普遍,矿床类型丰富,主要有分布于普登岩群中的火山-沉积变质改造型铜铁矿床、分布于元谋变质核杂岩韧性剪切带或元谋大断裂带中的热液交代充填型铜金多金属矿床和分布于基性-超基性岩体中的岩浆熔离型铂钯矿床三种。总结地质地球化学特征,矿床(点)类型及分布规律,分析各种成矿作用,综合得出三个成矿模式：岩浆熔离型铂钯矿床成矿模式、火山-沉积变质改造型铜铁矿床成矿模式、热液交代充填型铜金多金属矿床成矿模式,为该区矿产资源的勘探开发奠定了理论基础。基于对元谋地区地质地球化学特征、成矿作用和成矿模式的认识,提出在阿洒姑一带的普登岩群中寻找火山-沉积变质改造型铜铁矿,在元谋变质核杂岩韧性剪切带和元谋—绿汁江断裂带及其次级断裂中寻找液交代充填型铜金多金属矿,在黑泥一带超基性岩体中寻找岩浆熔离型铂钯矿的找矿方向。
【Abstract】 Located in the west edge of Yangtze Plate, Yuanmou region is complicated in geological structure, in which the fault richly grows, frequent magmatic activities, wide for deformation and metamorphism, rich in mineral resources, popularized in mineralization, it’s much lower for research extent in previous geological ore-exploration, there’s much greater potentiality for ore-exploration inside. By selecting this region with bright prospect, this paper researches and observes its geological & geochemical characteristics, summarizes its mineralizing rules, tries to set up mineralizing modes conforming to the actuality, expects to make a reference to mineralizing theory-building and ore-exploration.The research area is located in the west edge of Yangzi plate, has experienced tectonism for many times, outcropped strata are Proterozoic, Sinian, Triassi, Jurassic, Cretaceous and Quaternary, mainly Proterozoic Pudeng and Yangjiuhe rock groups; magma activity lasts very long and frequently, the lithology is complicated, acid granite of jinningian-Chengjiangian is mostly and widely distributed, basic or ultrabasic rock of variscan takes the second place; deformation and metamorphism is mainly jinningian-Chengjiangian extrusion or extension movement, the structural pattern is thus formed with main body of Yuanmou Metamorphic core complex and orientation of Yuanmou-Lvzhijiang fault zone.By rock and soil geochemistryl analysis and survey, the anomalies have been circled, Combined with the geologic factors including strata and structure, summed up 4 kinds of anomaly presumes with high economic value:Cu anomaly is controlled by meta-volcanic rocks from Pudeng group; Cu & Au anomaly is related to magma activity and not so obvious by structural control; Cu, Au, Pb and Zn anomalies is concerned with magma activity and distinctly controlled by the fault; Ni, Pt and Pd anomalies is closely related to ultrabasic rocks.The research area is popularized in mineralization and rich in mineral deposit type, there’re mainly three types:volcano-sedimentary metamorphosed Copper-Iron deposit distributed in Pudeng group, hydrothermal metasomatic-filling type Copper Gold-polymetallic deposit distributed in ductile shear zone of Yuanmou metamorphosed core complex or Yuanmou fault zone, and magma-segregation platinum-palladium deposit distributed in basic or ultrabasic rocks.By summarizing its geological & geochemical characteristics, mineral deposit (occurrences) type and distributing rules, three mineralizing modes has been concluded as follows:magma-segregation platinum-palladium deposit ore-forming, volcano-sedimentary metamorphosed Copper-Iron deposit ore-forming, hydrothermal metasomatic-filling type Copper Gold-polymetallic deposit ore-forming. It lays a theoretic foundation for exploration & development of mineral resources in this area.Based on the knowledge of geological & geochemical characteristics, mineralizing process and modes in Yuanmou district, it’s proposed to look for metamorphosed Copper-Iron deposit in Pudeng rock group around Asagu, search for hydrothermal metasomatic-filling type Copper Gold-polymetallic deposit in ductile shear zone of Yuanmou metamorphosed core complex or Yuanmou-Lvyejiang fault zone and its sub-fault, explore magma-differentiated platinum-palladium deposit in ultrabasic rocks around Heini.