The Acadian tectonic belt of New England records several pulses of compression from the Ordovician to the carboniferous before the onset of extension in the Triassic. The evolution of the Bronson Hill anticlinorium and the Merrimack synclinorium of central Massachusetts has received much work and has been the cornerstone of understanding the paleozoic compressional orogenies of New England. Recent advances in single-crystal age determinations and petrographic microbeam techniques have provided an opportunity to rigorously test previous conclusions and have already provided suggestions of considerable revisions to the tectonic history of this classic area. This project will combine the wealth of prior work with the results of new age determinations and quantitative petrology to address several key problems and to integrate the results into a new synthesis of the evolution of the northern Appalachians.