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
Ore shoot for hundreds or thousands of feet horizontally and vertically. Such a structure could contain an area of enhanced metal content extending horizontally and vertically. This would be termed an "ore shoot." The existence of the ore shoot could be recognized visually in a tunnel or "drift" excavated along the structure, or by the assaying of rock samples cut from the walls and roof of the tunnel. Ore shoot In mining and geology, an ore shoot is a long seam of mineral or metal bearing rock that can be profitable to extract. The term may have originated in the 17th and