中文摘要：

余石山铌钽矿床是近年来发现的一大型矿床,位于阿尔金造山带之红柳沟-拉配泉蛇绿构造混杂岩带、祁连造山带、欧龙布鲁克微陆块的结合部位。对矿区进行成矿背景研究时发现,矿区赋矿地层主要为长城系熬油沟组,岩性组合为变质火山岩及大理岩,穿插有霓辉正长岩体,其中发育细粒烧绿石与霓辉石等富铌钽矿物。并对霓辉正长岩进行锆石LA-ICP-MS年代学测定,结果表明霓辉石正长岩成岩年龄为（776.8±2.5）Ma,成矿与成岩年龄相近或稍晚,表明该霓辉正长岩和铌钽矿床可能形成于南华纪Rodinia超大陆裂解时所产生的大陆边缘裂谷构造环境。

英文摘要：

Lying in the joint of Hongliugou-Lapeiquan ophiolitic melange zone （eastern part of the Ahun Mountains）, Qilian orogenic belt and Oulongbuluke microcontinent, Yushishan Nb-Ta De- posit is a large-size deposit recently discovered. Based on the study of its metallogenic back- ground, the major ore-bearing strata is found to be Ao＇ yougou Formation of Changchengian Pe- riod. The lithological association includes metamorphic volcanic rock and marble, mixed with aegirine-augite syenite, where develop minerals rich in Nb-Ta such as fine-grain pyrochlore and ae- girine-augite. The LA-ICP-MS dating for zircons from an aegirine-augite syenite sample yields the diagenetic age of 776.8±2.5 Ma, indicating that the metallogenic age is similar or slightly later than the mineralization of the rock. Combined with petrological-mineralogical characteristic under the microscope and metallogenic age, the aegirine-augite syenite and Nb-Ta deposit were probably formed in continental rift tectonic background induced by the breakup of Rodinia supercontinent in Nanhua Period.