Generation, transport, and collection of Fe-Ni-Cu sulfide melts

摘要

1 IntroductionPrimary magmatic Ni-Cu-(PGE) mineralization can be subdivided into three types on the basis of distributions and textures (Lesher and Keays, 2002): Type Ⅰ stratiform contact mineralization occurs at or near the base of the host unit, commonly exhibits an ore segregation profile comprising (from base to top) massive or inclusion-bearing semi-massive, net-textured (Ol-rich) or matrix (Ol-poor), and/or disseminated sulfides, and appears to have formed early in the crystallization history of the host unit. Type Ⅱ strata-bound internal mineralization occurs within the host unit, comprises coarse disseminated, fine disseminated, net-textured, or inclusion-bearing semi-massive sulfides, and appears to have formed later in the crystallization history of the host unit. Type Ⅲ stratiform "reef mineralization occurs within the host unit, normally comprises disseminated sulfides and PGMs often associated with chromite, and appears to have formed though fractional crystallization, magma-magma or magma-fluid mixing, and/or contamination processes.