关键词: 中三叠世岩体, 岩浆热液系统, 深部过程, 典型矿床特征, 成矿潜力, 找矿靶区

Abstract: Nanshan area in Qinghai Province is located in the turning part of the junction of Qinling-Kunlun orogenic belt，a set of medium-acid batholiths is formed in the Middle Triassic.Previous studies focused on the geochemical and chronological characteristics of rocks，which gave very little attention on the retationship between magmatic hydrothermal activity and mineralization.Based on abundant field geological data，the occurrence，emplacement depth and denudation degree of the Middle Triassic intrusive rock mass，the interaction process，emplacement mechanism and mixing effect of fluid during the same magmatic period，magmatism background and deep process，geological characteristics，genesis and ore-controlling factors of the deposits associated with the hydrothermal activity of this period are analyzed systematically.The study results show that:①the Middle Triassic intrusive rock mass is the unstable “mountain roof” formed by the thickened lower crust in the early stage of collision.Under the tectonic background of lithospheric subsidence，emplacement and mixing effects of magmatic hydrothermal system with different sources are controlled by regional fault pulse activities，and associated with abundant synmagmatic (metallogenic) fluid activites，so，two kinds of metallogenic backgrounds associated with deposits with different genesis types and different metallogenic material sources are formed；②at present，the study area is in the upper part of middle Triassic hidden rock foundation and its adjacent favorable metallogenic part，the next step is to strengthen the prospecting work in the regional fault zone and the fluid discharge site on the top of the concealed apophysis；③by summarizing the characteristics of two typical deposits of Heimahe skarn type iron polymetallic deposit and Qieru pegmatite type niobium tantalum rubidium rare polymetallic deposit，the metallogenic potential of the study area is discussed and three prospecting target areas are delineated，which can provide reliable reference for the further prospecting work in the area.

Key words: Intrusive mass in Middle Triassic period, Magmatic hydrothermal system, Deep process, Characteristics of typical deposit, Metallogenic potential, Prospecting target area