Metallogenic geological characteristics and newly discovered orebodies in Northwest China

Abstract: Northwestern China lies in the intersection region between Central Asia and Tethyan tectonic domains, with Tarim craton and western North China craton in the middle. The formation and motion of the two cratons and their cracked micromassif formed during geological evolution basically constrained the process of tectonic development in Northwest China. The Phanerozoic orogenic belt surrounding cratons and micromassif resulted from peripheral accreting, with the addition of other products of continental edge accreting during continental convergence at about 210 Ma because of continental migration. All orogenic belts and continental edge accretions constituted very important formation settings of endogenic metallic ore deposits in Northwest China. In recent years, the newly discovered ore deposits in Northwest China have confirmed the idea that magmatic mineralization resulted from craton edge tectonic accreting and intraplate mantle magmatism, which challenges traditional understanding of geological tectonic settings. Among these deposits, three large or superlarge deposits, i.e., early Carboniferous Awulale volcanic-subvolcanic magmatic outpouring type magnetite deposit of Western Tianshan Mountains, early Devonian Xiarihamu magmatic Ni-Cu sulfide deposit of eastern Kunlun Mountains and Jurassic-Cretaceous Huoshaoyun tectonic hydrothermal Pb-Zn deposit in western Kunlun Mountains, have especially important economic value and geological implications. Awulale is the first volcanic-subvolcanic magma outpouring type magnetite deposit in China, which is comparable with the Laco superlarge magnetite deposit in Chile, and hence the exploration and study of Awulale are of great importance for understanding deeply rifted volcanic magmatism and mineralization of Carboniferous in Tianshan and its adjacent areas of Central Asia Orogenic Belt. The Xiarihamu magmatic Ni-Cu sulfide deposit with one million tons of Ni metal is also very important, and its discovery provides a research area for magmatism and mineralization in the early Paleozoic Ni metallogenic event and its prospecting potential. The discovery of the Huoshaoyun Pb-Zn deposit with superlarge reserves is a very important discovery in Mesozoic giant Pb-Zn metallogenic belt of the Kunlun-Sanjiang orogenic belt. These discoveries supply new basis for the understanding of ore-forming material source and structural control of ore deposits in the giant Pb-Zn metallogenic belt on the northeastern margin of the Tibetan Plateau.