DIRECT ISOTOPE DATING FOR METALLIC ORE DEPOSITS
ZHAO Kui-dong, JIANG Shao-yong(State Key Laboratory for Mineral Deposits Research, Department of Earth Sciences,Nanjing University, Nanjing 210093,China)
In recent years, many direct isotope dating for metallic ore deposits have been developed owing to the use of the new generational thermal ionization mass spectrometry with high precision and high sensitivity. The direct isotope dating means the direct determination of metallogenic ages of ore-forming fluids or ore minerals. Therefore, the results of direct isotope dating represent the true mineralization ages. The main direct isotope dating methods include: Rb-Sr isotope dating of fluid inclusions in quartz or sphalerite; Ar-Ar isotope dating of fluid inclusions in pyrite and quartz; Rb-Sr isotope dating of sulfides; Sm-Nd isotope dating of sulfides and oxides; Re-Os isotope dating of sulfides; and stepwise leaching Pb-Pb isotope dating of single ore mineral. In this paper, these methods are summarized and discussed, and we hope that these methods will offer more contributions to improving the research on economic geology in China.