Metamorphism of the Southern Meguma terrane and emplacement of the Barrington Passage and Quinan Plutons, southwestern Nova Scotia

The Meguma terrane, the most outboard terrane of the northern Appalachians, was affected by low-grade (sub-greenschist to greenschist facies) metamorphism during the Devonian Acadian Orogeny. Voluminous syn- to post-tectonic plutonism occurred in the southern part of the terrane, including the Pubnico-Shelburne area. This region experienced amphibolite facies metamorphism.; The host rocks of the Barrington Passage Pluton and Quinan Pluton, two late syn- to post-tectonic plutons in the southern part of the Pubnico-Shelburne area, were variably metamorphosed, ranging from chlorite through amphibolite grades. The distribution of isograds about the plutons suggested the rocks were thermally metamorphosed; however, hornfels is absent from the thermal aureoles.; Based on petrographic studies, microprobe analyses and geothermobarometric calculations, it has been concluded that the host rocks of the Barrington Passage and Quinan plutons were affected by two metamorphic events: a low-pressure regional event that was closely followed by a contact event related to intrusion of the plutons. The contact event enhanced the effects of the regional metamorphism.