New type of niobium-tantalum-zirconium mineralization of the Saima eudialyte nepheline syenite in Fengcheng area, Liaoning Province

The Saima alkaline rock mass, located within the Neoproterozoic-Paleozoic depression zone in eastern Liaoning, intruded into the core of brachyanticline formed by the Paleoproterozoic, Neoproterozoic and Paleozoic strata during the Triassic, and was then overlain by the Jurassic strata. Previous studies identified the Saima deposit within the Saima alkaline rock mass as the most typical alkaline rock-type U-Th-Nb-REE deposit in China. In recent years, medium-large scale Nb-Zr deposits have been discovered around Saima deposit, with the ore-bearing rock of eudialyte nepheline syenite of residual magma phase, representing a newly identified ore type. The eudialyte nepheline syenites are primarily occurred as concealed stocks in Saima-Beitaiyanggou-Zhuanshanzi area, also outcropped in Beitaiyanggou and Nantaiyanggou, exhibiting the characteristics of whole-rock Nb mineralization. The niobium ore bodies hosted in the eudialyte nepheline syenite appear as stratoid and lenticular formations, generally exhibiting a nearly horizontal and gently dipping attitude. The discovery of this new type of Nb-Zr deposit is a significant breakthrough in the rare metalrare earth exploration in Saima area, not only enriching the mineralization types and enhancing its resource potential, but also indicating a new direction for the exploration of alkaline rock-type rare metal-rare earth deposits in the area.