Abstract

Metals and lithophile element deposits related to four types of high-level magmatic systems, each characterized at the surface by a distinct volcanic landform; stratovolcano, flow-dome complex, caldera, and maar. Porphyry copper-bearing stocks and base metal-rich, precious metal veins are known from the deeper central zones of andesitic stratovolcanoes. Precious and base metal veins and breccias as well as Cu-Pb-Zn-Ag replacement orebodies and lithophile element mineralization were emplaced in the shallow parts of flow-dome complexes. Tin, beryllium, uranium, and fluorine mineralization in rhyolite flow domes may be a manifestation of subjacent porphyry molybdenum systems. Precious metal vein deposits are associated with ring fracture domes around resurgent calderas, and moat sediments are known to carry dispersed silver or mercury-uranium mineralization. Many large calderas appear to be relatively deficient in temporally related ore deposits, possibly as a result of volatile dissipation during pyroclastic eruption.--Modified journal abstract.

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