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Geoscience ›› 2024, Vol. 38 ›› Issue (01): 198-213.DOI: 10.19657/j.geoscience.1000-8527.2023.093

• Mineralogy, Petrology, Ore Deposits • Previous Articles     Next Articles

Mineralogy, Trace Element Chemistry, and Their Metallogenic Implications of Sphalerites from the Haopinggou Ag-Au-Pb-Zn Polymetallic Deposit, Xiong’ershan Area, Western Henan

LIU Jinbo1,2(), ZHANG Dexian1,2(), HU Ziqi1,2, CHEN Shaowei1,2, XIE Xiaoyu1,2   

  1. 1. Key Laboratory of Metallogenic Prediction of Nonferrous Metals and Geological Environment Monitoring (Central South University), Ministry of Education, Changsha, Hunan 410083, China
    2. School of Geosciences and Info-physics, Central South University, Changsha, Hunan 410083, China
  • Received:2023-03-20 Revised:2023-12-14 Online:2024-02-10 Published:2024-03-20

Abstract:

The Haopinggou Ag-Au-Pb-Zn deposit is an important Pb-Zn polymetallic deposit in the Xiong’ershan area, Western Henan.The orebodies are identified as mainly occurring in the altered fractures and fault zones, and the metallogenesis of the deposit is associated with magmatic intrusions.Previous studies on this deposit mainly focuses on geochronology and isotopic geochemistry, constraining the ore-forming age and tracing ore-forming materials.Few studies focus on interpreting the mineralization processes from a mineralogy perspective.In this study, we studied the mineralogy, major and trace elements of different types of sphalerite, using EPMA and in situ LA-ICP-MS techniques, with an aim to invert the ore-forming physicochemical conditions and to constrain the genetic types of the deposit.Our study identified two types of sphalerites in this deposit.Sphalerite I contains higher Fe, Mn, Cd, Cu, and In contents, with a dark or light brown color, and is mostly associated with pyrite and chalcopyrite occurrence.Sphalerite II is relatively enriched in Co, Ge, Sn, and Pb contents, with a yellowish or dark brown color, and predominantly coexists with galena, and the fractures of sphalerite II are usually infilled by pyrite and carbonate grains.Sphalerite was investigated to have a considerable Fe, Co, and In contents, and Fe, Mn, Cd, Co, and In basically occur as substitutions in the crystal, but Ag, Sb, Cu, and Pb minerals present as mineral inclusions within the sphalerite.Moreover, the trace elements, element ratios (Zn/Cd, Zn/Fe, and Ga/In), and combined with the geothermometric result indicate a low to medium temperature (229-259 ℃ of the ore-forming fluid) and low sulfur fugacity (lgƒ(S2)=-12.0--10.1) mineralized environment and the mineralization temperature may have changed significantly from stage II (Sp1) to stage III (Sp2), and the formation temperature of sphalerite grain gradually decreases from the core to the edge based on the elemental mapping analysis.Comparisons with the previous studies on sphalerite from typical Pb-Zn deposits, the low Ga/In and Ge/In ratios, as well as the low Ge content, indicated that this deposit has a close relationship with the magmatic hydrothermalism.Based on those evidence, we propose that the Haopinggou Ag-Au-Pb-Zn polymetallic deposit may belong to the post-magmatic hydrothermal alteration rock type and vein type deposit.

Key words: Haopinggou Ag-Au-Pb-Zn polymetallic deposit, trace element in sphalerite, LA-ICP-MS, oregenesis

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