Multistage Genesis of the Haerdaban Pb-Zn Deposit, West Tianshan: Constraints From Fluid Inclusions and H-O-S-Pb Isotopes

Abstract

The Haerdaban Pb-Zn deposit is located on the western edge of the Chinese Western Tianshan Orogen. This deposit consists of stratiform and veined mineralization hosted in Proterozoic carbonaceous and dolomitic limestone. Three metallogenic stages were recognized: an early sedimentary exhalative stage (stage 1), an intermediate metamorphic remobilization stage (stage 2), and a late magmatic-hydrothermal stage (stage 3). Fluid inclusions (FIs) present in stage 1 are liquid-rich aqueous, with homogenization temperatures of 206–246 C and salinities of 5.9–11.6 wt% NaCl eq. FIs present in stage 2 are also liquid-rich aqueous, with homogenization temperatures of 326–349 C and salinities of 3.4–6.6 wt% NaCl eq. FIs present in stage 3 include halite-bearing, vapor-rich aqueous, and liquid-rich aqueous FIs. Homogenization temperatures for these FIs span a range of 249–316 C. Halite-bearing, vapor-rich aqueous, and liquid-rich aqueous FIs yield salinities of 33.8–38.9, 2.6–3.5, and 4.2–8.1 wt% NaCl eq., respectively. Oxygen and hydrogen isotopic data (δ18OH2O = 2.6–13.6‰, δDH2O = −94.7 to −40.7‰) indicate that the ore-forming fluids of stages 1–3 were derived from modified seawater, metamorphic water, and magmatic-meteoric mixed water, respectively. Sulfur isotopic data (δ34S = 2.1–16.3‰) reveal that ore constituents were derived from mixing of marine sulfate and magmatic materials. Lead isotopic data (206Pb/204Pb = 17.002–17.552, 207Pb/204Pb = 15.502–15.523, 208Pb/204Pb = 37.025–37.503) reveal that ore constituents were derived from a mixed crust-mantle source. We propose that the Haerdaban deposit was a Proterozoic sedimentary exhalative deposit overprinted by later metamorphic remobilization and magmatic-hydrothermal mineralization.

Geology, geochemistry and genesis of Tabei: A newly identified intermediate‐sulphidation epithermal Pb–Zn deposit adjacent to low‐sulphidation Au deposit in the Tulasu Basin, Chinese Western Tianshan

“…As a prominent component of the Central Asian Orogenic Belt (CAOB), the Western Tianshan experienced multiple and prolonged accretionary orogenesis and hosts a large amount of economic deposits with diverse types of mineralization, including porphyry, skarn, epithermal, sedimentary exhalative (SEDEX), and iron oxide‐copper‐gold (IOCG)‐type deposits (Figure 1b; X. X. Gu et al, 2016; J. Y. Li et al, 2006; Y. Liu, 2015; Man et al, 2020; Z. S. Jiang et al, 2021; Peng et al, 2016, 2017, 2020; Peng, Gu, Chi, Xue, Zhang, et al, 2021; Peng, Gu, Chi, Zhang, Zhao, et al, 2021; Peng, Gu, Chi, Zhang, Zheng, et al, 2021; Xia et al, 2021; X. Zhang et al, 2014; Zuo et al, 2008). The Late Palaeozoic epithermal Au deposits in the Yili‐Central Tianshan Plate are all hosted by the Lower Carboniferous Dahalajunshan Formation volcanic rocks, mainly including the Axi, Jingxi‐Yelmand and Jiamante Au deposits in the Tulasu‐Yelimodun volcanic belt and the Kuruer Cu–Au and Bogutu Au deposits in the Wusun Range (Figure 1b).…”

“…Y. Li et al, 2006;Y. Liu, 2015;Man et al, 2020; Z. S. Jiang et al, 2021;Peng et al, 2016Peng et al, , 2017Peng et al, , 2020Peng, Gu, Chi, Xue, Zhang, et al, 2021;Peng, Gu, Chi, Zhang, Zhao, et al, 2021;Xia et al, 2021;Zuo et al, 2008). The Late Palaeozoic epithermal Au deposits in the Yili-Central Tianshan Plate are all hosted by the Lower Carboniferous Dahalajunshan Formation volcanic rocks, mainly including the Axi, Jingxi-Yelmand and Jiamante Au deposits in the Tulasu-Yelimodun volcanic belt and the Kuruer Cu-Au and Bogutu Au deposits in the Wusun Range (Figure 1b).…”