Investigations on Bagher Abad and Darreh Badam fluorite deposits based on REE data, Southeast Mahallat, Markazi Province

Bagher Abad and Darreh Badam fluorite mineralizations are located in southeast Mahallat city (Markazi province) and occured as veins with common trend of East-West within slate and phyllite of Shemshak Formation (Lower Jurassic). The fluorite is the main mineral of the veins and quartz, barite, calcite, dolomite, pyrite, chalcopyrite, goethite and covellite are the sub-ordinary minerals of deposits. The distribution of rare earth elements (REE) indicates that the violet, colorless and gray fluorites in primary mineralization stage have been enriched in LREE (result of digestion and wall rock replacement) and and the blue types of fluorites enriched in MREE and HREE, formed in post mineralization stage. Tb/La vs Tb/Ca and Y/Ho ratios diagrams are used for determination of genesis and differentiation of fluorite mineralization. These data show all samples can have a hydrothermal source for Bagher Abad and Darreh Badam deposits. Negative anomaly of Eu in all samples of fluorite can be caused by the formation of fluorite at above 200°C temperatures. In addition to, depletion of Ce in fluorites of studied areas indicated a reduced fluid and presence of pyrite and chalcopyrite sulphide minerals confirming this.