Research on base metal sulfide deposits is among the oldest and best-documented subjects of economic geologists worldwide, c- sidering that copper was first mined about 3000 years ago on the island of Cyprus. During the past 10 years, after the exciting discovery of active sulfide formation on the modem ocean floor, a considerable flow of new ideas has stimulated and influenced the discussion of o- forming processes for copper-zinc-Iead sulfides in sedimentary and volcanic environments. The development of new genetic concepts consequently led to reinterpretation of some apparently well-est-...