N.I. GUSEV, L.YU. SERGEEVA (VSEGEI), S.G. SKUBLOV (IGGD RAS, SPGU)

Evidence of the reworked Eoarchean crust in the Anabar Shield (Siberian Craton)

Paleoarchean (3.4 Ga) anatectic tonalite-granodiorite plagiogneiss hosts xenoliths of mafic (metagabbro) and plagioclase (metamonzodiorite) rocks. Xenoliths are characterized by T_Nd(DM) = 3.65 to 3.67 Ga and contain Eoarchean zircon: in mafic schist, zircon discordant analyses give upper intersections of 3987 ± 71 to 3599 ± 33 Ma; in plagioclase schist, the age of zircon is 3631 ± 5 Ma. Xenoliths are considered as remnants of the Eoarchean mafic crust.
Keywords: Anabar Shield, Daldyn Group, Eoarchean, Paleoarchean, granulite, zircon, U-Pb age SHRIMP II, Sm-Nd systematics.