(1. 中南大學(xué) 地球科學(xué)與信息物理學(xué)院 有色金屬成礦預(yù)測(cè)與地質(zhì)環(huán)境監(jiān)測(cè)教育部重點(diǎn)實(shí)驗(yàn)室,長沙 410083;
2. 貴港市金地礦業(yè)有限責(zé)任公司,貴港 537100)
摘 要: 龍頭山金礦是欽杭成礦帶南段大瑤山地區(qū)重要的金礦床之一,礦區(qū)發(fā)育大量不同階段的黃鐵礦,根據(jù)其產(chǎn)出特征和先后關(guān)系劃分為5個(gè)世代,對(duì)應(yīng)著5個(gè)成礦階段:電氣石-石英-硫化物階段(Ⅰ)、石英-黃鐵礦-黃銅礦階段(Ⅱ)、石英-多金屬硫化物階段(Ⅲ)、石英-黃鐵礦-閃鋅礦階段(Ⅳ)和石英-黃鐵礦階段(Ⅴ)。黃鐵礦單礦物的稀土、微量元素分析結(jié)果表明:與金成礦有關(guān)的成礦流體主要為中高溫巖漿熱液,具有還原性,且流體富Cl-貧F-,Au主要以(AuCl2)-絡(luò)合物形式遷移。黃鐵礦δ34SCDT值介于+1.29×10-3~+2.01×10-3,表明成礦物質(zhì)來源于深部巖漿;鉛同位素μ值為9.63~9.84,Th/U值為3.87~4.00,變化范圍窄,為穩(wěn)定性鉛同位素。綜合分析認(rèn)為:礦區(qū)成礦物質(zhì)主要來源于基底地殼重熔形成的深部巖漿巖,其中巖漿期后熱液為主要成礦熱液。
關(guān)鍵字: 黃鐵礦;稀土元素;微量元素;硫同位素;鉛同位素;成礦流體;成礦物質(zhì)
(1. Key Laboratory of Metallogenic Prediction of Nonferrous Metals and Geological Environment Monitoring, Ministry of Education, School of Geosciences and Infophysics, Central South University, Changsha 410083, China;
2. Guigang Jindi Mining Co., Ltd., Guigang 537100, China)
Abstract:The Longtoushan gold deposit, located in southern Qinhang metallogenic belt, is one of the important deposits in the Dayaoshan region, different stages of pyrite were found in the deposit. According to the characteristics of occurrence, pyrites are divided into 5 types, corresponding to 5 stages: tourmaline-quartz-sulfide stage (Ⅰ), quartz-pyrite-chalcopyrite stage (Ⅱ), quartz-polymetallic sulfide stage (Ⅲ), quartz-pyrite-sphalerite stage (Ⅳ) and quartz-pyrite stage (Ⅴ). REE and trace element analysis data of pyrites show that the ore-forming fluid of gold mineralization is mainly magmatic hydrothermal with medium-high temperature and reducing, and the fluid is characterized by rich Cl- and poor F-. Au mainly is migrated by the way (AuCl2)- complexes. δ34SCDT values of pyrites range from +1.29×10-3 to +2.01×10-3, showing that ore-forming materials is derived from deep magma. Values of μ and Th/U are 9.63-9.84 and 3.87-4.00, respectively. The narrow range of Th/U shows the characteristics of stable lead isotope. Based on the above analysis, ore-forming materials are from deep magma caused by basement crust remelting and the ore-forming fluid is mainly post-magmatic hydrothermal.
Key words: pyrite; rare earth element; trace element; S isotope; Pb isotope; ore-forming fluid; ore-forming material


