Geochemical characteristics of the Ni-Cu-PGE bearing mafic-ultramafic layered intrusion at Zhubu, Yuanmou, Yunnan province

摘要

1 IntroductionThe Emeishan large igneous province (ELIP) is one of the major LIPs in the world, which is considered to be products of the Late Permian Emeishan mantle plume activity in recent years (Chung et al., 1995; Xu et al., 2001; 2004). There are two kinds of important magmatic deposits related to the mantle plume in the ELIP: V-Ti magnetite deposits within the layered mafic-ultramafic intrusions(Zhang et al, 1985; Zhong et al., 2002, 2004) and Cu-Ni-PGE deposits in the mafic-ultramafic intrusions(Song et al., 2003; Tao et al., 2004,2007). A medium-sized Cu-Ni-PGE deposit is hosted in Zhubu mafic-ultramafic intrusion in Yuanmou area, Yunnan Province. Plenty of data on petrology and ore deposit has been accumulated; however, the data about geochemistry is still relatively less. This paper reports the results of geochemical study of Zhubu mafic-ultramafic intrusion. Representative samples from the intrusion were analyzed for whole-rock major oxides, trace elements, platinum-group elements (PGE) and Rb-Sr and Sm-Nd isotope compositions. The objectives of this study are to provide a test for the genesis of the intrusion and Cu-Ni-PGE metallogeny.