摘要
武义矿田萤石矿矿床赋存于上侏罗—下白垩系火山岩地层中,其同位素年龄值为160—111Ma,萤石为85 Ma,矿化年龄比围岩年龄滞后75—25 Ma,因此与火山岩岩浆活动无直接关系。通过Pb、Sr、Nd 、S、C、H、O等多种同位素研究表明,F主要来源于基底变质岩特别是黑云斜长片麻岩,成矿物质是多源的,成矿流体以大气降水补给的地热水为主,为论证该区地热体系成矿提供了重要依据。
The fluorite field at Wuyi, Zhejiang Province is located in the high temperature hydro-thermal zone, which was formed by Shaoxing-Jingshan and Yuyou-Lishui transcrustal faults. The deposit occurs in the Upper Jurassic-Lower Cretaceous volcanics. The isotopic ages of the rocks range from 160-111 Ma, but the age of fluorite mineralization is estimated at 85 Ma(Sm-Nd isotope and fission-track isochron methods), so its mineralization age is 75-25 Ma younger than that of its country rocks. The fluorite deposit is indirectly related to volca-no-magmatism.From the Sr-Nd isotopic ages, Sr/Nd radios and Nd model ages, it is known that F is derived mainly from the basement metamorphic rocks, especially from biotite-plagioclase gneiss. Pb, S and C isotope data indicate that the ore-forming materials are of multiple origin. 6D and δ18O values indicate that the medium fluid of ore formation is geothermal water recharged by meteoric water. It is suggested that ore deposition in this region is closely related to the geothermal system.
出处
《地球化学》
CAS
CSCD
北大核心
1992年第4期354-365,共12页
Geochimica
