论文部分内容阅读
鹿鸣超大型钼矿(钼金属量89万吨,平均品位0.084%)产于小兴安岭-张广才岭成矿带北段,矿体呈细脉浸染状赋存于二长花岗斑岩和二长花岗岩体内,围岩蚀变有钾化、绢云母化、硅化、绿泥石化、碳酸盐化等,矿化类型主要为斑岩型矿化。鹿鸣矿区含矿岩体二长花岗斑岩和二长花岗岩的锆石U-Pb定年、Hf同位素及辉钼矿Re-Os同位素定年研究表明:二长花岗岩和二长花岗斑岩锆石的U-Pb年龄分别为186.8±2.1Ma和183.2±1.9Ma,形成于燕山早期,二长花岗斑岩晚于二长花岗岩。6个样品辉钼矿Re-Os等时线年龄为176.7±4.4Ma(MSWD=0.92),Re含量变化于30×10-6~49×10-6。二长花岗岩的锆石εHf(t)值变化于1.1~3.8,Hf单阶段模式年龄为729Ma,两阶段模式年龄为1055Ma;二长花岗斑岩的锆石εHf(t)值变化于0.4~5.9,Hf单阶段模式年龄为741Ma,两阶段模式年龄为1075Ma。研究表明成矿与二长花岗斑岩有关,并且二长花岗岩和二长花岗斑岩岩浆为中新元古代新生的地壳物质熔融的产物,成岩成矿作用与古太平洋板块俯冲作用(或佳木斯与松嫩地块的拼合)有关。
Luming ultra-large molybdenum (molybdenum metal amount of 890,000 tons, the average grade of 0.084%) produced in the Xiaoxing’anling - Zhangguangcailing metallogenic belt north section, the ore vein was disseminated in the occurrence of two long granite porphyry and two long In the granite body, the wall rock alteration has potassium, sericite, silicification, chloritization, carbonate, etc. The mineralization types are mainly porphyry mineralization. The zircon U-Pb dating, Hf isotopes and Re-Os isotopic dating of molybdenite from the ore-bearing porphyry monzonitic granites in Luming ore district show that the monzonitic and porphyry zircons The U-Pb ages of the rocks were 186.8 ± 2.1Ma and 183.2 ± 1.9Ma, respectively, formed in the early Yanshanian period and the lateritic granites were later than the monzonitic granites. The Re-Os isochron age of the six samples of molybdenite is 176.7 ± 4.4Ma (MSWD = 0.92), and the Re content varies from 30 × 10-6 to 49 × 10-6. The εHf (t) values of zircons in the monzonitic granite range from 1.1 to 3.8, the Hf single-stage model ages are 729Ma and the two-stage model ages are 1055Ma. The zircon εHf (t) 5.9, Hf single-stage model age 741Ma, two-phase model age 1075Ma. The study shows that the mineralization is related to the monzonitic granite porphyry and that the monzonitic granite and the monzonitic granite porphyry are the melting products of the crustal material of Mesozoic and Neoproterozoic freshmen. Diagenesis and mineralization are associated with the subduction of the Paleo-Pacific plate (or Jiamusi and Songnen plots of the combination) about.