Trace elements of sulfides in the Dengjiashan Pb–Zn deposit from West Qinling, China: Implications for mineralization conditions and genesis

Abstract

Dengjiashan is a large‐scale Pb–Zn deposit discovered in the western part of the Xicheng ore field within the West Qinling metallogenic belt. Information regarding the distribution and occurrence of trace elements in ore minerals and mineralization, as well as the genesis of this deposit, remains scarce. Laser ablation inductively coupled plasma mass spectrometry (LA‐ICP‐MS) analysis and elemental mapping were used to determine the distribution and occurrence of trace elements in the sulfide minerals of the Dengjiashan deposit, as well as delineate the process of its genesis. Our results showed that the trace elements enriched in the different sulfides were significantly different. Sphalerite is the main carrier mineral of the scattered elements Cd, Ge and Ga. Based on the trace element content and ratio, principal component analysis and colour of the sphalerite and pyrite, the deposit likely formed in a medium‐temperature environment. The comparative analysis of trace elements from multiple deposits of different origins, combined with the geological characteristics and distribution of sulfide trace elements, suggests that Dengjiashan is a sedimentary exhalative (SEDEX)‐type deposit. As the metallogenic process had a closer relationship to medium‐low temperature hot brine and later tectonic metamorphic hydrothermal fluid, than with magmatic hydrothermal fluid, the deposit is likely of non‐magmatic SEDEX–hot brine superimposed transition origin. This study provides additional insight on the distribution of trace elements in the sulfide minerals of the Dengjiashan deposit, as well as the processes that led to its formation, and may further facilitate ongoing and future key metal prospecting and exploration efforts.

Genesis of Caoziwa Pb–Zn Deposit in Tengchong Block, SW China: Constraints from Sulfur Isotopic and Trace Elemental Compositions of Sulfides

“…Numerous studies have investigated the substitution mechanisms of trace elements in the sphalerite lattice, suggesting that divalent cations such as Mn 2+ , Fe 2+ , Cd 2+ , Co 2+ , and Ni 2+ could directly replace Zn 2+ in the crystal lattice of sphalerite because their ionic radii and valence states are similar to Zn 2+ [34][35][36]38,39]. Monovalent (Ag + , Cu + ), trivalent (Sb 3+ , Sn 3+ ), and tetravalent (Sn 4+ ) cations with larger ionic radii and different valence states are usually substituted for Zn 2+ in the sphalerite lattice by forming cation groups, such as (Ag, Cu) + + (Sb, Sn) 3+ ↔ 2Zn 2+ and 2(Ag, Cu) + + Sn 4+ ↔ 3Zn 2+ [34,[40][41][42][43][44][45][46][47]. However, in sphalerite from the Caoziwa deposit, the concentration of Pb varies in several orders of magnitude, implying that it is significantly affected by Pb-rich inclusions (e.g., galena).…”

“…George et al (2015) proposed that there is an isomorphic substitution of Bi 3+ + (Ag, Tl) + ↔ 2Pb 2+ in galena [39]. Meanwhile, Guo et al (2023) suggested that Ag, Sn, Cd, Tl, and Bi could enter the galena by the isomorphic substitution of Bi 3+ + (Cd, Sn) 2+ + (Ag, Tl) + ↔ 3Pb 2+ [47]. In the Caoziwa deposit, the time-resolved analytical signals of galena are relatively flat (Figure 6d), indicating that the detected elements mainly enter the galena grains by isomorphic substitution.…”