Formation Age of Ore-bearing Strata from the Laobing Iron Deposit in Taxkorgan area of Western Kunlun, Xinjiang and Its Geological Significance

The Maeryang formation is important ore-bearing strata of the iron deposits in Taxkorgan area of western Kunlun. Many large-sized iron deposits were found within this formation, such as Laobing, Zankan, Mokaer and Yelike iron deposits. Due to the Bulunkuole Group was formed in Proterozoic or early Paleozoic has always been controversial, the formation age and attribution of Maeryang formation are not quite clear, which affect the determination of the formation age of this iron deposits. In this paper, the distribution, metamorphic and deformation characteristics of Maeryang formation have been discussed, and its ore-forming age has been dated and confirmed. The study shows that the Maeryang formation is different from the Bulunkuole Group in the aspects of metamorphic, deformation and ore-bearing characteristics. The results suggest that the average age of felsic schist from Maeryang formation in Laobing iron deposit is (532±3.9) Ma, while the ones of biotite-quartz schist is (526±5) Ma. Thus, it's believed that the formation of Maeryang formation was later than 510 Ma, and this formation was separated from the Bulunkuole Group. The formation of the Laobing iron deposit is closely related to sedimentary mineralization, and the main ore-bodies are co-existed with Maeryang formation. Its ore-forming age keeps pace with the age of ferruginous strata in Maeryang formation, which provides the prospecting direction and theoretical basis for discovering magnetite deposits in this area.