Os isotopic systematics of Ni-Cu-PGE deposits in the Emeishan large igneous province, SW China: Implications for ore forming processes in dynamic magma conduits

摘要

1 IntroductionAll Ni-Cu-PGE deposits discovered to date in China are hosted in small mafic-ultramafic intrusions. Although it is clear that these intrusions were fractionates of basaltic melts, the genetic relations between the intrusive and extrusive rocks remain elusive. In the Emeishan Large Igneous Province (ELIP), some ore-bearing intrusions are possibly volcanic feeders in which immiscible sulfide liquids segregated and reacted with continuous surges of magmas en route to the surface, some others are blind sills that may have formed by injections of sulfide-bearing magmas from the staging magma chambers below the sills.