Geological Characteristics And Genesis Of Baolin Fluorite Deposit In Linxi, Inner Mongolia

Linxi County,Chifeng City,Inner Mongolia Autonomous Region is located in the southern section of the Greater Xing’an Mountains.It is located at the interactive position of the two major tectonic mineralization areas—the paleo-Asian ore-forming and the Pacific Rim.Although the predecessors have done in-depth and meticulous research work on the metal deposits in the study area,the degree of attention and research level of non-metallic minerals such as fluorite in this area is still insufficient,which has restricted the development of the fluorite industry to a certain extent.Therefore,this paper systematically analyzes the ore-forming geological characteristics of the Baolin fluorite deposit in Linxi,and enriches the research on the genesis of the fluorite deposit in this area and the evaluation of mineral resources through the analysis of indoor rare earth elements and fluid inclusions.The main results and understanding are as follows:1.The Baolin fluorite deposit occurred in the Yanshan early granodiorite rock mass,and the deposit was controlled by the NE and SN fault zones;the ore body was soothing and wavy;the ore structure was self-shaped and semi-self-shaped-it The granular structure is dominant;the ore structure is mainly strip-like,massive and breccia-like;the type of surrounding rock alteration is simple,mainly silicification,sericitization,chlorite and kaolin.2.The REE composition of Baolin fluorite deposit shows that the early stage fluorite REE is higher and the distribution curve is flat.The fluorite REE is lower in the late stage,and the distribution curve is left-angled,HREE enrichment.The Eu anomaly and the Ce anomaly reflect that the fluids in the early and late stages are all reducing environments.3.By studying the fluorite fluid inclusions in the early and late stages,the rich liquid inclusions are very rich.The temperature distribution of ore-forming fluids is concentrated between 160 °C and 220 °C,and the salinity is between 0.35 and 1.05% NaCleqv.The density concentration is in the range of 0.88 to 0.94 g/cm3.The laser Raman test results show that the ore-forming fluid is dominated by H2 O.The T-p phase diagram shows that the fluid pressure is concentrated at 0.4~2 MPa.The hydrologic pressure gradient(10 MPa/km)is used to estimate the ore-forming depth of the Baolin fluorite deposit,which is about 40-800 m.It belongs to the epithermal deposit of epithermal deposit.4.Comprehensive research on rare earth elements and fluid inclusions,combined with previous research results,it is believed that the ore-forming element F mainly comes from surrounding rock,and the ore-forming element Ca is derived from leaching and extraction of surrounding rock and Linxi formation by atmospheric precipitation;It is believed that the water-rock reaction is the main mechanism for the precipitation of fluorite ore in this deposit.