Geology, Mineralogy, and Isotopic Characteristics of the Zhonghe Ag-Pb-Zn Deposit, Western Henan Province, Central China

• 作者: Jiannan Xu Changqian Ma Shuo Yin Yunzhen Chang Huimin Jia Zhongjie Wang Liangliang Shi
• 来源期刊: 地球科学学刊（英文版）
• 年，卷（期）: 2022,（1）
• 所属期刊栏目: Special Issue on Isotope Geochronology and Isotope Geochemistry
• 页码范围: 177-192
• 页数: 16页
• 语种: 英文

摘要

Located in Luoning County, western Henan Province, Central China, the Zhonghe Ag- Pb-Zn ore field, is a newly discovered deposit in the Xiaoshan District. Ore bodies controlled by NNW Faults occur as veins within the Paleoproterozoic Xiong ' er Group or the Early Cretaceous porphyritic granite. Given that the Zhonghe deposit has been covered by thick Quaternary sediments, the parage- netic mineral assemblage was determined mainly by microscopic observations, including the quartz- siderite-pyrite alteration (Stage I), polymetallic sulfide precipitation (Stage Ⅱ), silver mineralization (StageⅢ), and quartz-carbonate stage (StageⅣ). The host minerals for silver are diverse, such as frei- bergite, pyrargyrite, polybasite, argyrodite, canfieldite, argentite, and native silver, whereas those for Pb and Zn are galena and sphalerite, respectively. In order to constrain the ore-forming components of the Zhonghe deposit, a combined in-situ analysis was conducted on represented sulfides from StageⅡ and StageⅢ. In-situδ34S values of the analyzed sulfides, including the pyrite, chalcopyrite, sphalerite, and galena, display a relatively narrow range (0.90‰-5.0‰), which is close to magmatic sulfur source. The 206Pb/204Pb and 207Pb/204Pb ratios show a narrow range (17.140-17.360 and 15.385-15.490), whereas the 208Pb/204Pb ratios exhibit a broad variation (36.601-37.943), indicating a contamination of the Xiong ' er Group. Synthesis of geochronological and geochemical data from the Xiaoshan District, we contend that the ore-forming materials of the Zhonghe Ag-Pb-Zn deposit are originated from the lower crust, which has presumably been influenced by the large-scale lithospheric delamination of the east- ern North China Craton during the Early Cretaceous. In consideration of the geological setting, miner- alogy, and geochemical compositions, we suggest that the Zhonghe Ag-Pb-Zn deposit is characterized as intermediate sulfidation type epithermal deposit, and may be a potential exploration target for por- phyry Mo-Cu deposits.