On the Occurrence and Genesis of Rare Earth and Scandium in Jiuzigou Rock Mass of Fengxian County, Shaanxi Province

Jiuzigou rock-mass is a basic-ultrabasic complex, mainly composed of apatite-biotite-pyroxenite, syenite and peridotite. Rare earth and scandium occur in apatite-biotite-pyroxenite, and the bearing minerals are orthite and apatite. Through deep exploration, it is found that rare earth and scandium exists in forms of independent mineral and isomorphism in inner rock mass, while in forms of independent mineral, isomorphism and ionic state in weathering crust. The main rare earth elements in the ore are La, Ce, Pr, Nd, Sm and heavy rare earth elements Gd, Y. The average grade of rare earth (REO) is 0.07%, scandium (Sc) 40×10^-6. The genetic type in Jiuzigou is ultrabasic rock of the rare earth and scandium deposit, and the mantle source crystallization type. It was formed during the Caledonian. The study of the occurrence state and metallogenetic regularity is of guiding importance to the exploration and processing of deposits of rare earth and scandium in this area.