U-Pb and Re-Os ages of the huaheitan molybdenum deposit, NW China

Abstract

The Huaheitan molybdenum deposit in the Beishan area of northwest China consists of quartz-sulfide veins. Orebodies occur in the contact zone of the Huaniushan granite. LA-ICPMS U-Pb zircon dating constrains the crystallization of the granite at 225.6 ± 2.2Ma (2σ, MSWD = 4.5). Re-Os dating of five molybdenite samples yield model ages ranging from 223.2 ± 3.5Ma to 228.6 ± 3.4Ma, with an average of 225.2 ± 2.4Ma. The U-Pb and Re-Os ages are identical within the error, suggesting that the granite and related Huaheitan molybdenum deposit formed in the Late Triassic. Our new data, combined with published geochronological results from the other molybdenum deposits in this region, imply that intensive magmatism and Mo mineralization occurred during 240Ma to 220Ma throughout the Beishan area. © 2013 The Society of Resource Geology.