Distribution and metallogenic mechanism of Mesozoic-Cenozoic ore deposits in the Antarctic Peninsula

Influenced by the ongoing subduction of the Paleo-Pacific Plate and the rifting of the Gondwana supercontinent, the Antarctic Peninsula has undergone complex tectonic deformation and multiple phases of magmatic-hydrothermal mineralization since the Mesozoic. Two main metallogenic periods occurred during the Early Cretaceous (137~93Ma) and the Paleocene-Eocene (62~46Ma). Mineralization generally distributed along negative magnetic anomaly zones at the margins of intrusive bodies and extensive hydrothermal alteration has developed in negative magnetic anomaly areas, including potassic, argillic, propylitic and phyllic alteration, exhibiting porphyry mineralization characteristics. Geological processes, coupling with geochemical indicators, such as copper content, Sr/Y ratio, Sr-Nd isotopes and V/Sc ratio, indicated that the input of melts derived from the partial melting of dehydrated oceanic crust or asthenospheric mantle under a slab subduction setting triggering localized copper enrichment and elevated magmatic oxygen fugacity in certain regions of the Antarctic Peninsula. This process may have been one of the key factors controlling the formation and emplacement of multiple porphyry copper deposits in the region. Accordingly, this study further delineates several key areas with high porphyry copper mineralization potential within four mineralization areas, i. e., the South Shetland Islands area, the Anvers Island-Graham Land area, the Adelaide Island-Marguerite Bay area, and the Black-Lassiter-Orville area.