鄂东南丰山矿田铜金矿床方解石的稀土元素地球化学特征OA

The genetic connection between skarn Cu-Au deposits and peripheral distal low-temperature Au deposits re-mains controversial.Calcite,a ubiquitous alteration mineral in both deposit types,provides a valuable geochemi-cal tracer for mineralization processes.This study investigates the hydrothermal rare earth element(REE)geo-chemistry of calcites from the Jilongshan skarn Cu-Au deposit,and the Caojiashan and Zhulintang distal low-temperature Au deposits within the Fengshan orefield,southeastern Hubei,to elucidate genetic links between these contrasting deposit styles.Results show that calcites from both deposit types exhibit light REE(LREE)-en-riched patterns(LaN/YbN=2.21～20.28),primarily controlled by REE complex stability in the fluid and mineral crystallization differentiation.REE patterns indicate a dominant magmatic-hydrothermal fluid source associated with Yanshanian magmatism.Europium anomalies(δEu)effectively record redox conditions and temperature:calcites from the Jilongshan Cu-Au deposit display positive δEu anomalies(0.92～1.45),indicating a high-temper-ature reducing environment;ore-stage calcites from Zhulintang typically show negative δEu anomalies(as low as 0.56)and lower ΣREE,reflecting a low-temperature oxidizing environment;ore-stage and post-ore calcites from Caojiashan differ significantly in both ΣREE and δEu,with the latter's elevated values attributed to Mn2+influence.Integrating these findings with regional geological evidences,we propose that the distal low-temperature Au depos-its and the skarn Cu-Au deposit constitute a unified magmatic-hydrothermal mineralization system.