Paleoelevation variations and exhumation history of the Tibetan Plateau control spatiotemporal distribution of porphyry system deposits

Porphyry deposits, due to their significant size and economic value, have long been a focus of research. Nevertheless, the majority of studies concentrate on the genesis of porphyry deposits, with relatively few considering how post-formation preservation conditions go on to influence their present-day distribution. The unique geographical setting of the Tibetan Plateau makes it a key region for investigating the interplay between ore deposits, tectonic deformation, and geomorphic evolution in an intraplate setting. In particular, its abundant tectonic and magmatic events have facilitated the formation of numerous porphyry deposits. This study combines big datasets of whole-rock geochemistry, zircon geochronology, and low-temperature thermochronology to reconstruct the tectonic and magmatic evolution, paleoelevation variations, and exhumation history of various terranes within the Tibetan Plateau since Jurassic times and explores how these processes relate to the formation and preservation of porphyry deposits. Our results show that the Qiangtang terrane contains a higher and more clustered concentration of porphyry Cu-Au deposits during intervals of decreasing paleoelevation, whereas the Lhasa terrane predominantly hosts porphyry Cu-(Mo) deposits during intervals of increasing paleoelevation. We propose that intense tectonic and magmatic activity is a critical factor in the formation of porphyry deposits, while significant fluctuations in the paleoelevation of terranes also favor their development. Conversely, regions of the Tibetan Plateau with high degrees of exhumation host fewer porphyry system deposits, and their deposits tend to be of smaller tonnage. This indicates that post-formation exhumation plays a critical role in the preservation of porphyry deposits, with intense exhumation likely leading to erosional loss of previously formed deposits. Areas with lower exhumation volumes should therefore be prioritized as key targets for future mineral exploration.