Magmatism and Cu–Au–Mo mineralization of the Darbut tectono‐magmatic zone in West Junggar (Xinjiang), NW China: An updated review

Abstract

The Darbut tectono‐magmatic zone in the West Junggar terrane (NW China) is an important component of the famous Circum‐Balkhash‐West Junggar metallogenic province. In this region, the discovery of some small but high‐quality Cu–Au deposits/prospects indicate substantial exploration potential for large porphyry Cu–Au deposits, for example, those in the neighbouring Kazakhstan. In this contribution, we concluded that the Dulunhe granite and small ore‐bearing granitoids in Baogutu are adakitic petrogenesis, and the Buerkesitai and Tasikuola granites (formed by magma mixing) are well comparable with the Xiaerpu granite. In summary, granitoids with similar petrogenesis and mineralization are distributed on both sides of the Darbut fault zone and show good correlations with the sinistral movement of the latter. We propose that the porphyry Cu–Mo–Au mineralization potential of the small calc‐alkaline I‐type granitic stocks in southern West Junggar region is significantly higher than that of alkaline A‐type large granitic batholiths. Besides, the magma mixing‐derived and adakitic granites have great prospecting potentialities. We argue that the Cu–Mo–Au mineralization in the Darbut tectono‐magmatic zone was originally E‐W trending, and then displaced by the Darbut sinistral strike‐slip faulting, instead of being controlled by NE‐NNE trending faults. The main regional mineralization pattern comprises a northern magmatic‐hydrothermal Au belt (~318 Ma), a middle porphyry Mo belt (~296 Ma), and a southern adakite and magma mixing granite‐related Cu–Au belt (~313 Ma). We infer that the Bieluagaxi Au belt may continue eastward to east of Sartohay.

Tectonic‐magmatic framework identified by remote sensing analyses and geochronology in West Junggar, Central Asian Orogenic Belt

“…Remote sensing results of granitoid batholiths in the West Junggar, NW China. The formation ages of granitoid batholiths in the Darbut tectono‐magmatic zone are after Duan et al (2018) [Colour figure can be viewed at wileyonlinelibrary.com]…”

Late Carboniferous adakitic porphyries in the Huangliangzi pluton, West Junggar (Xinjiang), NW China: Petrogenesis and their tectonic implications

“…The most remarkable feature of the Late Carboniferous–Early Permian intermediate–felsic intrusions of the Western Junggar is the fact that they are characterized by positive ε Nd (t) values (+4.6 to +9.2) and very young Nd model ages (T 2DM ; 300–700 Ma; Chen & Arakawa, ; Gao et al, ; Huang et al, ; Liu et al, ; Shen et al, ; Su et al, ; Tang et al, ; Tang et al, ; Wei & Zhu, ; Yang et al, ), providing crucial information on Phanerozoic crustal growth, which is also a common feature of the CAOB. Moreover, numerous Carboniferous to Early Permian intermediate gold, copper, and molybdenum deposits and/or occurrences have been discovered in southern West Junggar (Figure b), and most of which have been confirmed associated with small (high‐K) calc‐alkaline dioritic stocks and porphyries (Duan, Li, Zhi, Yang, et al, ; Li et al, ; Shen, Pan, Shen, Yan, & Zhong, ; Shen & Shen, ; Shen, Shen, Liu, Lu, et al, ).…”

“…The West Junggar region is generally divided into a northern and southern part by the Xiemisitai Fault. Geologically, the northern part comprises E‐W‐trending Saur, Sharburti, and Xiemisitai fold belts and is characterized by continuously developed volcanic rocks, while roughly NE‐striking sinistral strike‐slip faults are predominant in the southern West Junggar, including the Barleik, Hatu, Anqi, and Darbut faults from west to east and their secondary faults (Figure b), of which the Darbut Fault is the most spectacular and important in the region, and all show multiphase tectonic activities and controlled the distribution of regional stratigraphy, magmatic rocks, and mineralizations (Chen, Yang, Ye, Wang, & Chen, ; Duan et al, ; Wei et al, ). Strata in the region are dominated by Devonian to Carboniferous volcano‐originated sediments, and Carboniferous volcanic sedimentary strata, including mainly the Baogutu (C 1 b ), Xibeikulasi (C 1 x ), and Chengjisihanshan (C 2 c ) formations, are widespread throughout the southern West Junggar, particularly on both sides of the Darbut Fault.…”

Tianshan Orogen along the Silk Road (Volume 3): Orogen links, geochemistry, geochronology, mineral deposits, and environments

“…In the study by Zhang, Wang, Wang, Liu, and Li ( ) , the Mengxi porphyry copper deposit in eastern Junggar was considered to have formed as a result of metasomatic alteration of volcano‐sedimentary rocks in the early Devonian, which was intruded by granite porphyry emplaced at 432.6 ± 6.7 Ma. An updated review of porphyry Cu–Au–Mo mineralization of the Darbut region in West Junggar is given by Duan, Li, Zhi et al ( ) . They distinguish separate E–W‐trending Au, Mo, and Cu–Au belts related to Late Carboniferous–Early Permian I‐ and A‐type granitoids, which were later affected by sinistral strike‐slip faulting.…”