The metamorphosed stratified and intrusive rocks of late Precambrian, Ordovician, Silurian and Devonian age in New England records an extremely complicated "Acadian" collisional history. Recent results of radiometric age dating in the Bronson Hill anticlinorium and Merrimack synclinorium of central Massachusetts has revealed two distinct age groups of "Acadian" (early and late Devonian) metamorphism separated by a generally higher pressure zone of late Pennsylvanian metamorphism. This project will follow these features i the region to determine their spatial distribution and to obtain a more precise picture of the temporal evolution of the New England appalachians, and to improve understanding of its setting within the larger framework of the orogen.
