我国是世界上造山带产出岩浆铜镍硫化物矿床最多的国家。由于缺乏有效的地球化学示踪手段，目前对造山带岩浆硫化物矿床地幔源区性质及地球化学特征的研究非常薄弱，严重制约了对该类矿床成矿物质起源的理解。鉴于造山带板片俯冲过程中熔体/流体的交代可能显著改造上覆地幔的Mg、Fe同位素组成，因此，硫化物含矿/矿化镁铁-超镁铁质岩体的Mg、Fe同位素研究将为探讨上述重要科学问题提供关键约束。本项目以东昆仑造山带夏日哈木超大型铜镍矿床和石头坑德含硫化物岩体为研究对象，以橄榄石和斜方辉石的Mg、Fe同位素研究为核心，结合矿物学、岩石学及Sr-Nd同位素分析，深入对比和揭示岩体地幔源区的性质、地球化学特征及其形成机制，阐明造山带有利于岩浆硫化物成矿的大规模镁铁质岩浆活动的关键控制因素和动力学过程，从而深化对造山带岩浆硫化物成矿前提条件的认识，并促进Mg、Fe同位素在岩石学和矿床学上的应用。

It has been discovered the largest number of magmatic Cu-Ni sulfide deposits within orogenic belts in China. Due to lack of effective geochemical tracers, the natural and geochemical features of the mantle source of magmatic Cu-Ni sulfide deposits within orogenic belts are still poorly understood, which are critical to realize the origin of metal sources of magmatic Cu-Ni sulfide deposits within orogenic belts. Since melt/fluid metasomatism could fractionate Mg and Fe isotopes of mantle peridotite during slab subduction, studies of Mg and Fe isotopes of Ni-Cu-bearing mafic-ultramafic intrusions may provide important constraints on these issues mentioned above. In this project, we will focus on investigation of the Mg and Fe isotopic variations in olivine and orthopyroxene from the Xiarihamu giant Cu-Ni deposit and Shitoukengde sulfide-bearing intrusion, East Kunlun Orogenic Belt. By combined results of mineralogy, petrology, and Sr-Nd isotopes, we attempt to compare and reveal the nature, geochemical features, and petrogenesis of mantle sources of these two intrusions. Furthermore, we will clarify the critical control factor(s) and geodynamics of large-scale mafic magma activities that is conductive to form magmatic sulfide deposits within orogenic belts. By doing this project, a better understanding on the precondition of formation of magmatic sulfide deposits within orogenic belts will be achieved, and also wider implication of Mg-Fe isotope geochemistry for investigations of igneous petrology and mineral deposits will be promoted.