Figure 3. A and B. Binary plots of one immobile-element ratio vs. another. Altered samples are also included. The ratios remove the effects of mass changes caused by alteration. A: The primary rock types at Kristineberg merge one into the other; with the exception of rhyolite X, they show a continuous trend that is probably due to magmatic fractionation. Rhyolite X has a distinct and tightly defined composition -- this rhyolite bounds massive sulfide horizon A on its southern side. B: Most of the felsic rocks are calc-alkaline, excluding rhyolite X, which straddles the transitional and calc-alkaline fields. Globally, a majority of VMS deposits are hosted in sequences of tholeiitic affinity (e.g. the Matagami camp) or transitional affinity (e.g. the Noranda camp). The Kristineberg deposit probably formed in an evolved island-arc setting.