Geochemical Characteristics of Trace Elements and REE in Zhangcuo Fluorite Deposit in Shaowu Area, Fujian Province

Abstract

Zhangcuo fluorite deposit is one of the typical fluorite deposits in Shaowu area, Fujian Province. The fluorite ore body occurs in the fault structure of Late Jurassic porphyry (little porphyry) medium-fine grain (fine grain) syenogranite, and the occurrence of the ore body is strictly controlled by the fault. In this study, trace elements and rare earth elements (REE) in fluorite ore and surrounding rock were systematically analyzed. The results of trace element analysis showed that the depletion of high field strength elements Nb and Zr and large ion lithophile elements Sr and Ba, and enrichment of high field strength elements U, Hf, Ti and large ion lithophile elements Rb. The REE distribution curves of fluorite and surrounding rock have similar synchronization, therefore it is considered that the sources of ore-forming materials of fluorite in the study area are the same and the provenance is similar. The results revealed that the REE distribution pattern of fluorite ore is a right-leaning LREE enrichment type, with an evident “V” shape in Eu, negative Eu anomaly and weak Positive Ce anomaly, indicating that the ore was formed in a reductive environment. The Tb/Ca-Tb/La diagram shows that the fluorite deposit is hydrothermal filled type. Comprehensive analysis shows that F and Ca are mainly derived from leaching and extraction of surrounding rock by hydrothermal solution, and the ore-forming hydrothermal solution is primarily derived from meteoric water.