Age and structural setting of the Slieve Gamph Igneous Complex, Co. Mayo, Eire

Abstract
A Rb-Sr whole-rock isochron age of 487 ± 6 Ma for the Slieve Gamph Igneous Complex is interpreted as a minimum age for the regional metamorphism of the ?pre-Dalradian country rock. It is also believed to date deformation in the local Dalradian, and thus raises the question of diachronous deformation and metamorphism in the Dalradian of Ireland and Scotland.