Ore forming process of magmatic nickel-copper-cobalt sulfide deposits in China.

The magmatic Ni-Cu-Co deposits are the main source of critical mineral resources in China, such as nickel, cobalt, and platinum group elements, which are formed generally in a continental rift setting or gravitational collapse at the end of an orogeny. Different from the deposits formed during the Archaean to Early Proterozoic in other countries, the magmatic Ni-Cu-Co deposits in China are of the Neoproterozoic to Paleozoic in age. The typical ones are represented by the world-class Neoproterozoic Jinchuan and the super-large Paleozoic Xiarihamu deposits, as well as many Early Permian to Early Triassic deposits in Tianshan-Beishan and Altai areas. As a product of mantle plume activity, the primitive magma (ca. 827 Ma) at Jinchuan was formed by the high degree of deep partial melting of asthenospheric mantle, resulting in the immiscibility between sulfide liquid phase and silicate melt. The extensive distributions of magmatic Ni-Cu-Co deposits in Phanerozoic orogens have also been discovered in China, and are classified as the "Tethys" and "Central Asian" types. The Palaeozoic (ca. 411 Ma) Xiarihamu deposit, one of the most representative Tethys type deposits, is associated with a mantle plume in a rifting tectonic setting, which is distal to the subduction and closure of the Proto-Tethys Ocean during the Devonian. The pyroxenite mantle source may be a characteristic of its mineralization. The Central Asian type is represented by many Early Permian deposits distributed in the Tianshan-Beishan and Altai areas of the Central Asian Orogen. The majority of them are related to the subduction of the Ancient Asian Ocean in the Carboniferous and the action of mantle plumes in the Tarim Large Igneous Province.