赣东上水桥萤石矿床萤石微量元素地球化学特征及其对矿床成因的指示OA北大核心CSTPCD

The Shangshuiqiao fluorite deposit in Lichuan,eastern Jiangxi,is located at the northern end of the Wuyi metallogenic belt in the South China fold system and is produced in the fractured fracture zone of Yansha-nian biotite granite.This paper investigates the geological characteristics of the deposit,as well as the trace ele-ment geochemical features of different-colored fluorites and the surrounding biotite granite.The results show that fluorite shows positive Eu anomalies and negative Ce anomalies as a whole,but the REE distribution pat-tern characteristics of different colors of fluorite are different.Light green,dark green and purple fluorite are light rare earth enriched types,and white fluorite is heavy rare earth enriched type.Enriched type.The REE dis-tribution pattern of the surrounding rock is light rare earth enriched type,and the overall negative Eu anomaly is present.The Y/Ho-La/Ho relationship diagram and REE partitioning model diagram show that Y-REE fractiona-tion occurred during the fluorite mineralization process,and the white fluorite mineralization period was the lat-est.The Tb/Ca-Tb/La relationship diagram shows that the fluorite deposits in the study area are of hydrothermal origin.The change trend of the trace element distribution curve of the surrounding rock biotite granite is basical-ly the same as that of fluorite,and the Sm/Nd values of the surrounding rock and fluorite are very close.At the same time,the F content in the surrounding rocks closer to the ore body is higher,and the surrounding rocks near the ore undergo alterations such as silicification and sericitization.It is inferred that Ca and F in the fluorite ore mainly come from the surrounding rocks.The fluorite in the mining area was formed in a medium-low tem-perature oxidation environment,and the deposit formation type is a multi-stage medium-low temperature hy-drothermal filling type fluorite deposit.