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Located in the East Qinling molybdenum metallogenic belt on the southern margin of the North China craton, the Nannihu Mo (-W) orefield comprising Nannihu, Sandaozhuang, and Shangfanggou deposits is a superlarge skarn-porphyry Mo (-W) orefield in the world. Re-Os dating was performed of six molybdenite samples from the Mo deposits in the Nannihu Mo orefield with inductively coupled plasma mass spectrometry (ICP-MS). The results show that the Re-Os model ages are 145.8±2.1-141.8±2.1 Ma for the Nannihu deposit, 145.4±2.0-144.5±2.2 Ma (averaging 145.0±2.2 Ma) for the Sandaozhuang deposit and 145.8±2.1-143.8±2.1 Ma (averaging 144.8±2.1 Ma) for the Shangfanggou deposit; dating of the six samples yields an isochron age of 141.5±7.8 Ma (2σ), which accurately determines the timing of mineralization. The results also suggest that the ore-forming materials were mainly derived from the lower crust, mixed with minor mantle components. These Mo deposits were formed during the transition of the Mesozoic tect
Located in the East Qinling molybdenum metallogenic belt on the southern margin of the North China craton, the Nannihu Mo (-W) orefield comprises Nannihu, Sandaozhuang, and Shangfanggou deposits is a superlarge skarn-porphyry Mo (-W) orefield in the world. Re-Os dating was performed on six molybdenite samples from the Mo deposits in the Nannihu Mo orefield with inductively coupled plasma mass spectrometry (ICP-MS). The results show that the Re-Os model ages are 145.8 ± 2.1-141.8 ± 2.1 Ma for the Nannihu deposit, 145.4 ± 2.0-144.5 ± 2.2 Ma (for averaging 145.0 ± 2.2 Ma) for the Sandaozhuang deposit and 145.8 ± 2.1-143.8 ± 2.1 Ma (averaging 144.8 ± 2.1 Ma) for the Shangfanggou deposit; dating of the six samples yield an isochron age of 141.5 ± 7.8 Ma (2σ), which exactly determines the timing of mineralization. These results also suggest that the ore-forming materials were mainly derived from the lower crust, mixed with minor mantle components. These Molays were formed during the transition o f the Mesozoic tect