Geology of Mauritania ore. A Neoproterozoic carbonate unit, part of a synformal nappe overturned in the Paleozoic, now forms a major copper deposit 250 kilometers northeast of Nouakchott in the Mauritanides Belt. The one kilometer, 250 meter wide deposit spans the West and East Moghrein Guelb hills. Forty meters below the deposit is a secondary deposit of cuprite, azurite, malachite and tenorite, with an additional 2.25% copper, some gold and sulfide mineralization including cubanite, chalcopyrite, pyrrohitite and aresnopyrite. In the 2000s, mining at the site had mostly ceased except for gold mining in the tailings pile. Gypsum is extracted from the N'Drahamcha quarry,
Ore condition with "u", "v" not zero divisors. In this case, Ore's theorem guarantees the existence of an over-ring called the (right or left) classical ring of quotients. Commutative domains are automatically Ore domains, since for nonzero "a" and "b", "ab" is nonzero in . Right Noetherian domains, such as right principal ideal domains, are also known to be right Ore domains. Even more generally, Alfred Goldie proved that a domain "R" is right Ore if and only if "R" has finite uniform dimension. It is also true that right Bézout domains are right Ore. A subdomain of a division ring which