Paleo-Tethys tectonic-magmatic evolution and mineralization in the Truong Son metallogenic belt, Laos-Vietnam

The Truong Son metallogenic belt which spans Laos and Vietnam is located in the southeast part of the Tethys tectonic-metallogenic domain. It develops a large number of Paleo-Tethys igneous rocks and Cu-Au-Fe-Sn polymetallic deposits, which makes the Truong Son belt a natural laboratory for studying the tectonic-magmatic evolution and mineralization of the Eastern Tethys. This paper systematically combs the research findings of diagenetic and metallogenic age, deposit assemblage and whole-rock geochemistry in the Truong Son metallogenic belt, and reveals the temporal and spatial framework of igneous rocks in the Paleo-Tethys period of the Truong Son metallogenic belt, and establishes the tectonic evolution processes, including the subduction of Ailaoshan-Song Ma ocean plate in the Late Carboniferous to Middle Permian (317~264 Ma), the collision between the South China block and the Indochina block in the middle Permian to Late Triassic (263~235 Ma), and the post-collision extension process in the Late Triassic (234~202 Ma). The metallogenic model of the Truong Son belt is preliminary established, including porphyry-skarn type Fe-Cu-Au and epithermal type Cu-Au-Ag mineralization (305~279 Ma) in subduction period, porphyry-skarn type Sn and skarn type Fe-Au mineralization (249~236 Ma) in collision period and hydrothermal vein type Au mineralization (212~204 Ma) in extension period. Since there are few reports on magmatism and mineralization in the Late Triassic, the mineralization of extensional period still needs to be further studied.