Geology, Geochronology and Geochemistry of Weilasituo Sn-Polymetallic Deposit in Inner Mongolia, China

Abstract

The recently discovered Weilasituo Sn-polymetallic deposit in the Great Xing’an Range is an ultralarge porphyry-type deposit. The mineralization is closely associated with an Early Cretaceous quartz porphyry. Analysis of quartz porphyry samples, including zircon U-Pb dating and Hf isotopies, geochemical and molybdenite Re-Os isotopic testing, reveals a zircon U-Pb age of 138.6 ± 1.1 Ma and a molybdenite Re-Os isotopic age of 135 ± 7 Ma, suggesting the concurrence of the petrogenetic and metallogenic processes. The quartz porphyry has high concentrations of SiO2 (71.57 wt %–78.60 wt %), Al2O3 (12.69 wt %–16.32 wt %), and K2O + Na2O (8.85 wt %–10.44 wt %) and A/CNK ratios from 0.94–1.21, is mainly peraluminous, high-K calc-alkaline I-type granite and is relatively rich in LILEs (large ion lithophile elements, e.g., Th, Rb, U and K) and HFSEs (high field strength elements, e.g., Hf and Zr) and relatively poor in Sr, Ba, P, Ti and Nb. The zircon εHf(t) values range from 1.90 to 6.90, indicating that the magma source materials were mainly derived from the juvenile lower crust and experienced mixing with mantle materials. Given the regional structural evolution history, we conclude that the ore-forming magma originated from lower crust that had thickened and delaminated is the result of the subduction of the Paleo–Pacific Ocean. Following delamination, the lower crustal material entered the underlying mantle, where it was partially melted and reacted with mantle during ascent. The deposit formed at a time of transition from post-orogenic compression to extension following the subduction of the Paleo–Pacific Ocean.

Genesis of the Bairendaba Ag-Zn-Pb Deposit, Southern Great Xing’an Range, NE China: A Fluid Inclusion and Stable Isotope Study

“…Additional Pb isotope data exist for unmineralized rock units in the region [17,[49][50][51] and allow for a comparison with the Bairendaba deposit. These data plot over a broader range than the ore sulfides from the Bairendaba deposit (Figures 9(a) and 9(b)).…”

“…[48]. Lead isotope data for ore are from Ouyang [33] and from Jiang et al [17], Chu et al [49], and Zeng et al [50] for Permian strata; Jiang et al [17] for gneiss; and Jiang et al [17] and Wang [51] for the Beidashan granite.…”

Ore Genesis of the Baishitouwa Quartz–Wolframite Vein-Type Deposit in the Southern Great Xing’an Range W Belt, NE China: Constraints from Wolframite In-Situ Geochronology and Geochemistry Analyses

“…Three episodes of W mineralization are identified, including Triassic (240-250 Ma), Early-Middle Jurassic (170-200 Ma), and Late Jurassic-Early Cretaceous (125-160 Ma) [5]. Previous studies mainly focused on the Jurassic and Early Cretaceous W mineralization [13][14][15][16][17][18][19][20][21][22][23][24][25][26][27][28][29][30]. In contrast, only a limited amount of research has been conducted on the Triassic deposits, especially the quartz-wolframite vein-type deposits [31,32], which hinders our understanding of regional W mineralization.…”

Petrogenesis, W metallogenic and tectonic implications of granitic intrusions in the southern Great Xing’an Range W belt, NE China: insights from the Narenwula Complex

“…All of these W deposits are spatially and genetically related to granitic intrusions (Xie et al 2021). Although some studies have been conducted on the petrogenesis of these W-related granitic plutons, the petrogenesis of the these granitoids remains controversial (Mei et al 2015;Zeng et al 2015b;Wang et al 2017;Gao et al 2019;Yang et al 2019). In addition, the distribution of W-related and W-barren granitoids commonly overlaps.…”