Re-Os Isotope ages of molybdenum deposits in East Qinling and their significance

• DOI: 10.1007/bf02872630
• Publication Date: 2008-03-30T09:51:08Z
• Authors: Dianhao Huang; Chengyu Wu; Andao Du; Hongliao He
• Keywords: 01 natural sciences; 0105 earth and related environmental sciences

Dating of metallic ore deposits has been one of the problems concerned with by ore geologists for many years. The establishment of the Re-Os Isotope Laboratory at the Institute of Rock and Mineral Analysis, Chinese Academy of Geological Sciences, has provided us with a new technique to carry out geochronological studies of molybdenum ores. As one of the most important Re-bearing minerals, molybdenite contains almost no common osmium, but187Os was derived completely from decay of187Re, with187Os content as the function of Re content in the mineral. An ID-ICP-MS technique has been used in this study, and Re-Os isotopic ages of several large molybdenum deposits of different types from the East Qinling molybdenum belt have been determined. It is indicated that the Huanglongpu carbonatite vein-type molybdenum-(lead) deposit has a Re-Os age corresponding to Indosinian, while the rest porphyry-type molybdenum deposits and porphyry-skarn-type molybdenum-(tungsten) deposits have Re-Os ages corresponding to Yenshanian.