Five samples of molybdenite from the three types of ores have been collected for Re/Os dating. The results show Re/Os model ages ranging from 138.4 Ma to 143.8 Ma, with an isochron age of 139.18 ¡À 0.97 Ma (MSWD = 2.9). The quite low Re content in molybdenite falls between 0.5 ppm and 7.8 ppm that is indicative of the upper crustal source. This is quite different from molybdenites in the YRB Cu-Au-Mo-Fe porphyry-skarn deposits that contain between 53 ppm and 1169 ppm Re, indicating a mantle source.
The Dahutang tungsten system is sub-parallel with the YRB porphyry-skarn Cu-Au-Mo-Fe system. Both are situated in the north margin of the Yangtze Craton and have a close spatial-temporal relationship. This possibly indicates a comparable tectonic setting but different metal sources. Both systems are related to subduction of the Paleo-Pacific plate beneath the Eurasian continent in Early Cretaceous. The Cu-Au-Mo-Fe porphyry-skarn ores are believed genetically related to granitoids derived from the subducting slab, whereas the porphyry W deposits are associated with S-type granitoids produced by remelting of the upper crust by heat from upwelling asthenoshere.