An Rb-Sr age of the Åmål granite at Åmål, Sweden

Abstract

Abstract An Rb-Sr dating of the type occurence of Åmål granite around the town of Åmål in southwestern Sweden yielded an isochron age of 1684+88 Ma (λ =1.42 × 10−11 a −1). This age agrees with datings of lithologically similar rocks farther south in the Åmål tectonic mega-unit and in the Stora Le—Marstrand and “Western Pregothian” crustal segments. It confirms the extensive development of the provisional Åmål I group of granitoids in south-western Sweden.