(1. 中南大學(xué) 有色金屬成礦預(yù)測與地質(zhì)環(huán)境監(jiān)測教育部重點(diǎn)實(shí)驗(yàn)室，長沙 410083；
2. 中南大學(xué) 地球科學(xué)與信息物理學(xué)院，長沙 410083)
摘 要: 山西繁峙縣義興寨金礦田位于晉東北地區(qū)NW向中生代構(gòu)造巖漿活動帶中。以義興寨、辛莊金礦床為研究對象，分析本區(qū)關(guān)鍵控礦因素、成礦物質(zhì)來源、成礦流體來源及其演化，進(jìn)而開展礦田成礦機(jī)理的研究。結(jié)果表明：本區(qū)構(gòu)造具有多期活動的特征，規(guī)模較大的NW向區(qū)域性張性大斷裂為本區(qū)的控巖、導(dǎo)礦及配礦構(gòu)造，次級NNW向壓-張扭性斷裂裂隙為容礦構(gòu)造，不同形式、不同級別的構(gòu)造是成礦最重要的控制因素。S、Pb、H、O同位素組成及微量元素地球化學(xué)特征表明，巖漿活動為本區(qū)提供了成礦物質(zhì)及成礦流體。流體包裹體特征及宏觀地質(zhì)特征表明，成礦過程中成礦流體發(fā)生了沸騰作用，引起CO2、H2S等的逸失，含金絡(luò)合物穩(wěn)定性遭受破壞，導(dǎo)致Au的大規(guī)模沉淀，流體的沸騰是礦質(zhì)沉淀的主要機(jī)制。
關(guān)鍵字: 義興寨金礦田；關(guān)鍵控礦因素；成礦物質(zhì)；成礦流體；演化；成礦機(jī)理
（1. Key Laboratory of Metallogenic Prediction of Nonferrous Metals and Geological Environment Monitor Ministry of Education, Central South University, Changsha 410083, China;
2. School of Geoscience and InfoPhysics, Central South University, Changsha 410083, China）
Abstract:Yixingzhai gold ore field is located in NW-trending Mesozoic tectonic magmatic belt of the northeast region in Shanxi province. Key ore control factors, ore-forming materials, ore-forming fluid source and its evolution were studied relied on Yixingzhai and Xizhuang gold deposits. Based on these, the metallogenic mechanism of this gold ore field was studied. The results show that structures in this area have multi-phase activities characteristics, the regional NW-trending tensional fractures are the ore-transmitting structure, the secondary NW-trending tensional fractures are the ore distribution structure and the NNW-trending compressive-tensional-shearing fractures are the ore hosting structure. Different forms and different levels of structures are the most important controlling factors of mineralization. Isotopic compositions of S, Pb, H, O and trace element geochemical characteristics show that the magmatic activity of Yanshanian is the first factor of mineralization, providing massive ore forming material and ore forming fluid. The characteristics of fluid inclusions and macroscopic geological features indicate that the ore-forming fluid occurred boiling in the major metallogenic stage, which caused the loss of CO2, H2S and so on, and the stability of the gold complex was destroyed, which resulted in the large-scale precipitation of Au. The boiling action of ore-forming fluid is the main mechanism of ore material precipitation.
Key words: Yixingzhai gold ore field; key ore control factor; ore-forming material; ore-forming fluid; evolution; metallogenic mechanism
