This paper is the result of mineral exploration engineering.
[Objective]Stretched across the Paleo-Asian Ocean and the Paleo-Tethys Ocean, the long-term ocean-land transformed process of Xinjiang Region has created a unique history of crustal accretion and diverse mineralization. As an important resource base for energy, nonferrous metals, iron ore, potash, and non-metals in China, there are 152 kinds of minerals had been discovered and over 3000 mines had been built in Xinjiang. Furthermore, abundant exploration and development bases, dominated by dominant minerals including oil, natural gas, coal, iron, manganese, lead, zinc, copper, nickel, gold, antimony, uranium, rare metals, fluorite, potassium salt, etc, have been formed by the end of 2019. For further analyzing the coupling relationship between multi-stage and multi-cycle crustal growth process and mineralization in Xinjiang, the research on division of tectonic units in Xinjiang is expected for more accurate metallogenic prediction and evaluation, and is urgent for better serving the national energy and resource security strategy.
[Methods]Based on the comprehensive analysis of sedimentary formation, volcanic formation, intrusive formation, metamorphic formation, structural deformation, and metallogenic regularity in Xinjiang, a new division scheme of tectonic units in Xinjiang is put forward under the guidance of "Ocean Plate Geology" and the analysis of accretionary orogenic process, combined with the metallogenic response under different tectonic backgrounds.
[Results]The new structural unit division scheme includes 6 primary structural units, 14 secondary structural units, 32 tertiary structural units, and 99 quaternary structural units. It is proposed that the Tarim craton is bounded by the Paleo-Asian Ocean tectonic domain in the north and the Tethys Ocean tectonic domain in the south. According to the relationship between crustal evolution and mineralization in Xinjiang, the metallogenic theory of "three systems, two belts, one block, and one edge" is creatively proposed.
[Conclusions]Four tectonic metallogenic stages in Xinjiang are systematically proposed, including the formation of the Archean to Paleoproterozoic ancient continental core with iron-copper metallogenic stage, the formation of the middle-Proterozoic to middle-Neoproterozoic Tarim ancient basement and the Paleozoic ocean continental block with iron-lead-zinc-apatite-asbestos-gem-quartzite metallogenic stage, the accretion and aggregation of continental crust in Nanhua to Triassic with oil-gas-gold-copper-nickel-lead-zinc-iron-manganese-antimony-tungsten-molybdenum-rare metals-asbestos-raphite-mica-andalusite-gem metallogenic stage, and the formation and evolution of basin mountain structures from Jurassic to present with oil-gas-coal-uranium-lead-zinc-salt metallogenic stage.
Highlights: (1) Guided by "the theory of Ocean plate geology" and combined with the metallogenic specificity of different tectonic environments, a new tectonic pattern of "three systems, two belts, and one block" in Xinjiang is put forward. (2) The deposit types in Xinjiang are mainly magmatic hydrothermal type, biochemical sedimentary type, chemical sedimentary type, marine volcanic rock type, magmatic type, and metamorphic type. (3) There are four tectonic metallogenic stages are divided, and a new metallogenic theory of "three systems, two belts, one block, and one edge" is creatively proposed in Xinjiang. The Mesozoic mineralization is considered as the main metallogenic period of geological exploration and prospecting in Xinjiang in the future.