Ore genesis with igneous rocks. The world's major copper deposits are formed within the granitic porphyry copper style. Copper is enriched by processes during crystallisation of the granite and forms as chalcopyrite — a sulfide mineral, which is carried up with the granite. Sometimes granites erupt to surface as volcanoes, and copper mineralisation forms during this phase when the granite and volcanic rocks cool via hydrothermal circulation. Sedimentary copper forms within ocean basins in sedimentary rocks. Generally this forms by brine from deeply buried sediments discharging into the deep sea, and precipitating copper and often lead and zinc sulfides directly onto the
Kambalda type komatiitic nickel ore deposits These flanking channels mimic the sinuous meandering ore shoots. Why extremely hot and superfluid komatiitic lavas and nickel sulfides would deposit themselves in parallel systems can only be described by Horst-Graben type faulting which is commonly seen at rift zones. One of the major problems in classifying and identifying komatiite-hosted NiS ore deposits as Kambalda type is the structural complication and overprint of metamorphism upon the volcanic morphology and textures of the ore deposit. This is especially true of the peridotite and dunite hosted low-grade disseminated Ni-Cu-(PGE) deposits such as Perseverance, Mount Keith MKD5, Yakabindie and Honeymoon Well, which occupy