⁴⁰Ar-³⁹Ar age of the late stage veins in central Zhuguangshan pluton of South China and its relationship with uranium metallogenesis

Late stage dykes like granite porphyry and lamprophyre veins are common around the ore deposits in Lujing area, the central section of Zhuguangshan pluton.K-feldspar ⁴⁰Ar-³⁹Ar isotope geochronologic analysis indicates that the granite porphyry vein was formed at 116.24±0.49 Ma while the lamprophyre vein intruded at 128.27±0.86 Ma, indicating that their intrusion corresponded to crustal extension magmatism during the Early Cretaceous.The magmatic chronologies recorded by the dykes are consistent with the uranium mineralization age of the Lujing orefield.Both the granite porphyry vein and the uranium ore present the characteristics of mantle source, indicating that the acidic magma source of the former one might have provided not only metallogenic materials but also heat source for uranium mineralization.During the process of uranium mineralization, the basic magma source of the lamprophyre provided favorable conditions such as heat generation, mineralizer, fluid and dynamic conditions for uranium mineralization.