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 (18O) collected on zircons from the Talnakh economic intrusion within the Norilsk province. Zircons from gabbro-diorite, gabbroic rocks of the layered series and plagioclase-bearing wehrlite have similar mantle-like mean 18O values (5,39 0,49; 5,64 0,48 and of 5,28 0,34, respectively), which differ from 18O in zircons from sulfide-bearing melanocratic troctolite with a taxitic texture in the lower part of the intrusion (mean 18O = 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.