Seismic Evidence for a Transcrustal Magmatic Pathway Contributing to Critical Metal Deposits

The Nanling metallogenic belt in South China hosts similar to 50 percent of the world's tungsten (W), similar to 20 percent tin (Sn), and other critical metals. However, the factors controlling ore distribution and types are still debated, due partly to the lack of high-resolution crustal models. We apply an array-based receiver function imaging method to resolve the fine-scale crustal structure using a newly deployed dense nodal array across the belt. We find weak Moho converting phases in the northern belt, indicating a gradual crust-mantle transition distinct from the sharp transitions observed elsewhere. The weak Moho spatially correlates with a major fault zone, A-type granite distribution, and Sn ore deposits. Combining with geochemical and petrological evidence, we propose that the gradual crust-mantle transition is attributed to, and likely facilitated, the mixing of mantle materials with the crust, thus contributing to Sn and other Mesozoic ore formations in the northern Nanling belt.Mapping the detailed crustal structure plays a critical role in ore characterization and exploration, which is essential to keep pace with societal needs for green energy and sustainability. Here we apply seismic imaging to delineate the subsurface structure of the Nanling metallogenic belt in South China using hundreds of sensors. We find the crustal structure, particularly the Moho geometries, spatially correlates with the types of ore deposits. Specifically, the tin and tungsten-tin-bearing granites that have mantle chemical signatures are distributed near a major fault zone with a gradual crust-mantle transition. In contrast, tungsten and other metal deposits in the central belt show evidence of mostly crustal origin with a seismically sharp and elevated Moho. We propose that the imaged gradual crust-mantle transition, which corresponds likely to an inherited lithospheric weak zone, could serve as a magmatic pathway for mantle materials to flux into the lower crust, thus contributing to critical ore deposits.We apply receiver function imaging using a dense nodal array to the largest metallogenic belt in South ChinaWe observe weak Moho converted phases near a major fault zone and an uplifted Moho by similar to 4 km in the central metallogenic beltThe obtained crustal structure correlates spatially with the characteristic geochemical signature of the ore deposits