S, Pb, and Sr isotope geochemistry and genesis of Pb–Zn mineralization in the Huangshaping polymetallic ore deposit of southern Hunan Province, China

Abstract

The Huangshaping Pb-Zn-W-Mo polymetallic deposit, located in southern Hunan 9 Province, China, is one of the largest deposits in the region and is unique for its metals 10 combination of Pb-Zn-W-Mo and the occurrence of significant reserves of all these metals. The 11 deposit contains disseminated scheelite and molybdenite within a skarn zone located between 12 Jurassic granitoids and Carboniferous sedimentary carbonate, and sulfide ores located within distal 13 carbonate-hosted stratiform orebodies. The metals and fluids that formed the W-Mo 14 mineralization were derived from granitoids, as indicated by their close spatial and temporal 15 relationships. However, the source of the Pb-Zn mineralization in this deposit remains 16 controversial. 17 Here, we present new sulfur, lead, and strontium isotope data of sulfide minerals (pyrrhotite, 18 sphalerite, galena, and pyrite) from the Pb-Zn mineralization within the deposit, and these data are 19 compared with those of granitoids and sedimentary carbonate in the Huangshaping deposit, 20 thereby providing insights into the genesis of the Pb-Zn mineralization. These data indicate that 21 the sulfide ores from deep levels in the Huangshaping deposit have lower and more consistent 22

Genesis of the Huangshaping W–Mo–Cu–Pb–Zn deposit, South China: Role of magmatic water, metasomatized fluids, and basinal brines during intra‐continental extension

“…The higher ΣREE in granite porphyry skarn mineralization could be explained by the influence of high‐temperature, high‐salinity magmatic‐metasomatized fluids, determined by Banks, Yardley, Campbell, and Jarvis () to be the best candidates for carrying large amounts of REE. Previous fluid inclusion microthermometry analyses revealed that Stage II mineralization took place in a significantly higher temperature and more saline environment, compared to other mineralization stages (Figure ; Ding, Ma, Lu, Zhang, & Zhang, , Ding et al, , ; Huang et al, ; Li et al, ). Moreover, δ 18 O values also differ between W–Mo ores ( δ 18 O = 8.10–8.41‰) and Cu ores ( δ 18 O = 4.34–4.96‰; Li et al, ), suggesting that two kinds of redox environments were favoured for the different types of ores.…”

“…This conclusion is supported by the relatively large variation in 87 Sr/ 86 Sr ratios (Figure b) and the positive correlation between 87 Sr/ 86 Sr ratios and δ 18 O values (Li et al, ). On the other hand, the wall rock (carbonate) in the Huangshaping deposit does have extremely high Sr contents (initial 87 Sr/ 86 Sr = 0.707484–0.708034; Ding, Ma, Lu, Zhang, & Zhang, ), and contamination by carbonates may have significantly changed the Sr isotope signatures in mineralized granitoids. All of this evidence may indicate that the granite porphyry experienced pronounced fluid–rock interaction and was metasomatized by derived fluids.…”

“…The mineralized granite porphyry yielded lower Pb/Pb ratios, intermediate between those of unaltered granite porphyry and wall rock limestone. The mineralized granophyre shows two trends with increased 206 Pb/ 204 Pb and 208 Pb/ 204 Pb ratios and lower 207 Pb/ 204 Pb ratios (Ding, Ma, Lu, Zhang, & Zhang, ; Li et al, ). All correlations indicate that the quartz porphyry‐related Stage I Cu mineralization originated from a magmatic fluid without significant contamination from sedimentary wall rocks, whereas Stage II W–Mo mineralization‐associated granite porphyry may have undergone pronounced fluid–rock interaction, fluid metasomatism, and degassing processes.…”

“…In addition to magmatic fluids related to Jurassic intrusions, formation‐derived fluids have also been advocated for the genesis of the deposit, especially for the Pb–Zn ores (Ding, Ma, Lu, & Zhang, , ; Ding, Ma, Lu, Zhang, & Zhang, ; Yuan, Yuan, Liu, et al, ). Previous studies mainly focused on the Sr–Nd isotopic compositions of unaltered granitoids (Ding, Ma, Lu, Zhang, & Zhang, ; Ding, Ma, Lu, Zhang, Zhang, & Gao, ; Hu et al, ) and fluid inclusions in gangue minerals (Huang et al, ; Li et al, ), leaving the altered and mineralized granitoids and metallic minerals relatively less studied. However, recent work indicates that the mineralization‐related porphyries in the Huangshaping area are A‐type granites formed during intra‐continental extension (Li, Watanabe, & Yonezu, ; Quan et al, ).…”

Indium Mineralization in the Xianghualing Sn-Polymetallic Orefield in Southern Hunan, Southern China

“…The outcropping strata in the belt consists of Sinian to Cambrian low-grade metamorphic rocks, Devonian to Lower Triassic limestone intercalated with clastic rocks, and Upper Triassic to Tertiary sandstone and siltstone. The Yangshanian granites intrude extensively in southern Hunan with the largest being the Qitianling intrusion [31][32][33], and they control the formation of a number of large-scale porphyry, skarn, and vein-type W-Sn-Pb-Zn deposits (Figure 1b), e.g., the Shizhuyuan [34], Baoshan [35], Huangshaping [36][37][38], Xianghualing [39], Xintianling [35], Yaoganxiang [30], Baiyunxian, and Furong deposits [35,40].…”