“…Hydrothermalists point to the inferred secondary characteristics of the ore mineral suite, the virtual absence of detrital grains of iron oxides and ilmenite, greenschist facies metamorphism, and the two basinwide geochemical associations (Au-S-Fe-As in conglomerates and C-U-Au in carbon seams) that elsewhere are associated with hydrothermal processes. The interpretation of compact rounded pyrite grains associated with the gold ores as allogenic detrital (e.g., Ramdohr, 1958;Saager, 1970;Koppel and Saager, 1974;Hallbauer, 1986) has always been important (perhaps essential) evidence favoring a placer model. However, Phillips et al (1988a, p. 322) note that chemical rounding and pseudomorphous replacement of iron oxides and ilmenite have been invoked as explanations for some of this rounded pyrite (e.g., Ramdohr, 1958;Ramdohr, 1969, fig.…”