Think of the Pluton as being like a big very hot and hard Sponge full of all sorts of Mantle Mafic Material all hot and gooey. It is being forced up into the overlying Greenstone Belt (another hard Sponge but cold in comparison, until the Mantle Mafic gets working on it from beneath). As the Mantle Mafic material interacts with the Greenstone material, much mixing occurs along the interface and Many minerals chemically interact to cause some to group closer together. These contain much of the ORE Grade Minerals we Humans value so much. Another way to view the situation is that it is a sandwich. The RFI is the Sweet Jam caught in the middle and it got there by being injected from the Mantle slice of bread. Thus, is is most likely that the Mantle slice of bread has channels of Jam (Ni enriched areas or Conduits) running through it and into the RFI Sweet Jam. The Greenstone slice may also have many pockets of Jam due to seepage from the RFI under pressure coming from the Mantle slice. Some of the Greenstone Bread deposits could contain Ni but due to the pressure more Greenstone Bread Deposits are likely to be Cr, Cu, Zn, and who knows what other types of sweet stuff??? Old Joe