Sha Poling Mo Deposit In Xiong'er Mountain Area Research On Geological And Geochemical Characteristics And Genesis

The Sha Poling molybdenum deposit is located in the southern margin of the North China Craton,north of the Ma Chaoying fault,and exists in the metamorphic rocks of the Late Paleozoic Tai Hua rock group.The ore body is vein-like or network-like,and the metallogenic age is Early Cretaceous.The research level of this molybdenum deposit is low.The previous research focused on the age and geological characteristics of the deposit.Based on the geological characteristics of the deposit,this article focuses on the fine characterization of the characteristics of ore-forming fluids and discusses the genesis and mineralization process of the deposit.This study will provide a new perspective for the theoretical study of the genesis of hydrothermal vein molybdenum deposits,and provide new ideas and directions for the prospecting and exploration work of this type of deposits,which has important theoretical and practical significance.At present,the main results and opinions are as follows:1.The fault structure is developed in the mining area.The ore body is mainly vein-shaped or network-shaped.Molybdenum mineralization is mainly found in quartz veins and network veins.Surrounding rock alteration is relatively developed,mainly including silicification,potashization and chlorite.The metallogenic process is divided into three phases:quartz-pyrite phase,quartz-pyrite-molybdenite phase,and quartz-molybdenite phase.2.According to the characteristics of fluid inclusions,ore-forming hydrothermal fluids are mainly NaCl-H₂O-CO₂ system with medium and high temperature,medium and deep formation,medium and low salinity and low density.And it was diluted by atmospheric precipitation in the late period.3.The research of quartz H-O isotope shows that the fluid forming ore mainly comes from magma hydrothermal fluid,and atmospheric precipitation is added later.The?³⁴S of pyrite in the Sha Poling molybdenum mine indicates that the sulfur is directly derived from the magmatic system or indirectly from the leaching or desulfurization of sulfide minerals in the magmatic system.4.The content of?REE content of quartz single mineral indicates that the content of?REE in the Sha Poling ore-forming hydrothermal fluid may be subject to both pH changes and thermochemical composition of the ore-forming fluid from stage?to stage??addition of atmospheric precipitation?.From the high?REE value of quartz in stage I,the original hydrothermal fluid may be alkaline,and as the fluid evolves to the late stage,the hydrothermal fluid evolves from alkaline to acidic.5.The value of?Eu of quartz single mineral as a whole is less than 1,which is shown as a negative anomaly on the REE distribution pattern map,indicating that the fluid is mainly formed in the reducing environment,and?Ce also has characteristics similar to that of?Eu.The samples at different stages in the Y/Ho-La/Ho diagram have similar Y/Ho ratios,indicating that the sources of ore-forming materials are homologous,and quartz may have recrystallized during fluid evolution.