Late Jurassic magmatism and tungsten mineralization in the Caledonian Penggongmiao granite batholith, Nanling Range, South China

The Nanling Range is recognized as a globally significant critical metal metallogenic belt. It is widely believed that Late Jurassic granitic magmatism shares close temporal, spatial, and genetic ties to the W Sn mineralization. However, recent discoveries of W Sn mineralization within and adjacent to the Caledonian granite batholith have raised a key issue: whether these mineralization events are genetically associated with Caledonian magmatic-hydrothermal activities. Based on detailed geological investigations, we performed whole-rock geochemical analyses, zircon U Pb geochronology on granites from the southern of Penggongmiao batholith, muscovite 40 Ar 39 Ar isotopic dating of the ore-bearing quartz veins for the Yangmeikeng and Zhangjialong W deposits, to establish the regional petrogenetic-metallogenic temporal framework. LA-ICP-MS zircon U Pb dating of the Yangmeikeng granites yielded weighted average ages of 153.0 ± 1.6–158.7 ± 1.6 Ma. Whole-rock geochemical analyses indicate that the granites are highly fractionated S-type granites, derived from the partial melting of the Paleoproterozoic crustal materials. Muscovite 40 Ar/ 39 Ar plateau ages for the ore-bearing quartz veins form the Yangmeikeng and Zhangjialong W deposits were determined as 145.0 ± 1.4 Ma and 160.0 ± 0.7 Ma, respectively. The obtained Late Jurassic ages stand in sharp contrast to the older crystallization age of the Penggongmiao granite batholith. Geochemical and isotopic analyses collectively demonstrate that the highly fractionated Late Jurassic S-type granites possess greater metallogenic potential than the Caledonian Penggongmiao granite batholith. Integrating new high-precision geochronological data with previous findings, at least two episodes of magmatic activity (i.e., the Caledonian and Yanshanian) occurred in the Penggongmiao area, with W mineralization closely associated with Late Jurassic granites. Given these results, W deposits associated with Late Jurassic granites should be prioritized for exploring within or near the margins of the Caledonian granite batholith in the eastern Nanling Range.