Abstract：Huishishan REE-Nb polymentallic deposit located in the northern margin of Alxa Massif ang is a large-scale REE-Nb polymetallic deposit discovered in recent years. Through the systematic trench drilling, field geological investigation and petrographic study, the authors investigated the genesis and the ore-forming materials source of this REE-Nb deposit. The deposit is closely related with the alkali syenite and is of two different genetic types respectively magmatic crystallization differentiation type and hydrothermal metasomatism type. The metallogenic model was establieshed by summarizing the prospecting criteria of the deposit. The hydrothermal metasomatic deposit was controlled by faults, and the syenite magma was passively emplaced along faults. Then the fluid emerged out of the melt, with the further drastic drop of the temperature and pressure. The siliceous fluid rich in Nb, REE and volatile elements (mainly F and Cl) reacted with wall rocks, and finally the REE-Nb deposits were formed in favorable places. The alteration degree of limonization, pyritization and silicification in the wall rocks of the deposit is positively related to the contents of rare earth and niobium, and the boundary between the ore body and wall rocks is not obvious. The syenite magma was proactively emplaced along faults, with crystallization differentiation. The incompatible elements (Nb, REE, etc.) enriched in the residual melt and formed the magmatic crystallization differentiated deposit in the syenite. The alkaline syenite magmatism in Huishishan area provides material source for the formation of REE-Nb polymetallic deposit.
陈海东, 王占富, 鲁宁, 张海峰, 谢建玺. 内蒙古额济纳旗灰石山稀土铌多金属矿床地质特征及成因[J]. 中国地质调查, 2020, 7(6): 13-19.
CHEN Haidong, WANG Zhanfu, LU Ning, ZHANG Haifeng, XIE Jianxi. Geological characteristics and genesis of the REE-Nb polymetallic deposit in Huishishan of Ejinaqi in Inner Mongolia. , 2020, 7(6): 13-19.
2020, Vol. 7 
