The book presents isotope-geochemical investigations of the world's largest reserves of copper, nickel, and platinum-group elements in the Norilsk ore region. Ever since its discovery, generations of geologists have been fascinated by the geology of these deposits, described as a 250 Ma magmatic formation with mafic and ultramafic layered intrusions, disseminated ore and continuous copper-nickel ore bed. The book includes the results of more than 5,000 analyses of eleven isotopic systems, performed at the Russian Research Geological Institute's Center of Isotopic Research between 2005 and 2014. The book is intended for specialists in isotope geology, metallogeny, ore geology and students of geology.