Research on the fluid inclusion and Re-Os dating of Donggebi Mo deposit,eastern Tianshan,Xinjiang
Yang Xiaomei1,2, Wang Zhongmei1,2, Ding Jiaxin1,2, Han Chunming1
1. Institute of Geology and Geophysics, Chinese Academy of Sciences, Key Laboratory of solid mineral resources, Beijing 100029;
2. Graduate University of Chinese Academy of Sciences College of Earth Sciences, Beijing 100049
The Donggebi Mo deposit,located in the eastern Tianshan,Xinjiang Province,is the largest molybdenum deposit ever found in the eastern Tianshan area.The Mo metal resources are more than 500 000 tons.The Donggebi Mo deposit formed in the outer contact zone of the porphyritic granite and its main ore minerals are molybdenite and pyrite.The wall-rock alteration is characterized by silicification,potassium alternation,pyritization,tourmalinization,carbonatization and fluoritization.The mineralization can be divided into two stages:the metallogenic period and the post-metallogenic period.Study on fluid inclusions indicates that the deposit is a meso-low temperature magmatic hydrothermal Mo deposit formed at depth ranging from 1.76 km to 2.87 km and at temperature 140℃ to 380℃ with the ore-forming fluid salinity 0.88～21.33 wt%NaCl.The Re-Os isotopic study of eight molybdenite samples yield the isochron age 234.3±1.6 Ma,which suggests that the Donggebi Mo deposit formed in Indo-Chinese epoch.This study plays great role in the further understanding of this deposit and further exploration of blind metallic ore deposits in this area.