In ensimatic arcs, initial submarine eruptions of island-arc tholeiites are succeeded by subaerial and submarine volcanism which is either calcalkaline or island-arc tholeiitic. Besshi-type massive stratiform sulfides develop in deep water on the submarine flanks of islands. Pluton emplacement beneath waning volcanoes is accompanied by mercury, porphyry copper, and gold mineralization. Renewed calc-alkaline or island-arc tholeiitic volcanism commonly follows arc reversal or splitting; Kuroko-type massive sulfides form in shallow-water clastic dacitic rocks and gold is concentrated around monzonites and in meta-andesites. Reef limestone deposition, block faulting, and uplift may be followed by formation of bauxite on karstic limestones, and of stratiform manganese deposits near the limestone base. Upper mantle and ocean crust rocks, emplaced as ophiolites in mélanges on the arc side of the trench and as obducted slices during arc-arc collision, contain Cyprus-type stratiform massive sulfides, podiform chromite, and nickel sulfides ; nickeliferous laterites may develop on the upper mantle rocks. Increase in island-arc crustal thickness and emplacement of granitic plutons is accompanied by tin-tungsten-molybdenum-bismuth mineralization. Following arc-continent collision, massive sulfides, gold, tin, and ores associated with ophiolites are preserved.