Oxygen Isotope Composition of Zircons from the Talnakh Economic Intrusion of the Noril’sk Province: First Data

Abstract

This study presents the first results of oxygen isotope analyses (δ¹⁸O) collected on zircons from the Talnakh economic intrusion within the Noril’sk province. Zircons from gabbro-diorite, gabbroic rocks of the layered series and plagioclase-bearing wehrlite have similar mantle-like mean δ¹⁸O values (5.39 ± 0.48‰; 5.63 ± 0.48‰ and of 5.28 ± 0.34‰, respectively), which differ from δ¹⁸O in zircons from sulfide-bearing melanocratic troctolite with taxitic texture in the lower part of the intrusion (mean δ¹⁸O = 6.50 ± 0.98‰). These new oxygen isotope data support (i) the mantle-derived origin of the primary magma(s), parental to the Talnakh intrusion, and (ii) possible involvement of a crustal component during the formation of sulfide-bearing taxitic-textured rocks.