The exploration potential of the subduction-collision associated porphyry copper deposits in the Gangdise metallogenic belt, southern Xizang

The exploration potential of the subduction-collision associated porphyry (skarn-type) copper deposits dated at 195 to 80 Ma in the Gangdise metallogenic belt, southern Xizang are approached in the light of tectonic-magmatic evolution and characteristics of the representative copper deposits. Three metallogenic periods are separated, including the Early to Middle Jurassic, Late Jurassic to Early Cretaceous and Late Cretaceous corresponding to the tectonic-magmatic events such as the northward subduction of the Yarlung Zangbo Ocean and southward subduction of the Bangong Lake-Nujiang Ocean, collision-closure of the Bangong Lake-Nujiang Ocean and steadily northward subduction of the Yarlung Zangbo Ocean, and finally northward subduction of the Yarlung Zangbo Ocean. The Xiongcun-type copper deposits associated with the early opposite subduction of the Yarlung Zangbo Ocean and Bangong Lake-Nujiang Ocean occur in the Dagze-Gongbo'gyamda zone east of Lhasa as more promising areas. The Duolong-type copper deposits associated with the subduction-collision of the Bangong Lake-Nujiang Ocean and steadily northward subduction of the Yarlung Zangbo Ocean in the middle stages are hosted in the volcanic-magmatic arc areas as the favourable metallogenic areas in Nganglong Kangri, Dongqiaco and Sangri. The Gar'erqiong-type copper deposits associated with the finally northward subduction of the Yarlung Zangbo Ocean in the Late Cretaceous are considered highly prospective in the eastern and western parts of the Gangdise metallogenic belt.