We present for the first time the mineralogical and isotope-geochemical particularities of zircon and
baddeleyite from various rocks of the economic ore-bearing Noril¡¯sk-1 intrusion located in the northwestern part of the Siberian platform. The ultramafic-mafic Noril¡¯sk-1 intrusion hosts one of the world¡¯s major economic platinum-group-element (PGE)-Cu-Ni sulphide deposits.
A detailed study of crystal morphology and internal structure identify four zircon populations, characterized by different U-Pb (SHRIMP-II) ages. The U-Pb ages of baddeleyite and the defined zircon populations cover a significant time span (from 290 ¡À 2.8 to 226.7 ¡À 0.9 Ma). The established U-Pb ages imply that crystallization of baddeleyite and zircon populations corresponds to several stages of protracted evolution of the ore-forming magmatic system (290 ¡À 2.8, 261.3 ¡À 1.6, 245.7 ¡À 1.1, 236.5 ¡À 1.8, and 226.7 ¡À 0.9 Ma, respectively) that served as the favorable factor for accumulation of magmas and ores of unique scales and concentrations.
