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 condition condition ensures "R" is an essential submodule of "D". Lastly, there is even an example of a domain in a division ring which satisfies "neither" Ore condition (see examples below). Another natural question is: "When is a subring of a division ring right Ore?" One characterization is that a subring "R" of a division ring "D" is a right Ore domain if and only if "D" is a flat left "R"-module . A different, stronger version of the Ore conditions is usually given for the case where "R" is not a domain, namely that there should be a common multiple