大别----苏鲁超高压变质带变质矿物的铀-铅同位素年代学

U-Pb isotopic geochronology of metamorphic minerals like rutile, garnet, monazite and sphene from ultrahigh pressure metamorphic rocks of Dabie-Sulu ultrahigh pressure metamorphic belt was studied. The new method to date the metamorphic minerals was bult and some precision U-Pb isotopic data of the metamorphic minerals were obtained. One of the most important ages is rutile U-Pb age of (218.2+/-1.2)Ma for the ultrahigh pressure eclogite from the Dabie Mountains. The closure temperature for U-Pb diffusion in rutile is about (470+/-50)oC by our calcalation. Thus, this U-Pb age of rutile proves that (218.2+/-1.2)Ma should be the cooling age of eclogite at (470+/-50)oC instead of the peak metamorphic age. These results are very important to study metamorphism geochronology of Dabie-Sulu ultrahigh pressure metamorphic belt and other places.

对我国大别----苏鲁地体超高压变质岩石中的金红石、石榴子石、独居石、榍石等变质成因矿物进行系统的铀-铅同位素地质年代学研究，通过此项研究建立准确测定这些变质成因矿镉?铅同位素地质年龄的新技术方法，并获得一批精确可靠的变质成因矿物铀-铅同位素年洌舛猿哐贡渲首饔媚甏У难芯烤哂惺种匾囊庖濉