This proposal is a request for a renewal of funding for the collaborative effort between F. S. Spear (RPI) and T. M. Harrison (UCLA) to investigate the pressure-temperature-time evolution of central New England through detailed petrological, structural and geochronologic studies. This is an ongoing research project, the ultimate goal of which is to understand better the tectonic and therm evolution of the New England orogenies. Work completed and in progress under the current grant has delineated several projects where additional, detailed research will provide needed constraints on the evolution of the Acadian orogen. Proposed studies include: (1) detailed petrology, kinematic analysis and 40Ar/39Ar geochronology along the Bronson Hill anticlinorium; (2) detailed petrology, kinematic analysis and geochronology and in the vicinity of the Strafford dome, Vermont; (3) geochronologic and petrologic study of amphibolites that display anomalously old (415-440 Ma) hornblende 40Ar/39Ar ages in eastern Vermont; (4) additional 40Ar/39Ar data throughout New England to delineate better the axis of hinged uplift between New Hampshire and Vermont; and, (5) theoretical analysis of cooling histories based on a novel treatment of 40Ar/39Ar release spectra from K- feldspars. We will integrate our findings with stratigraphic, structural, paleontological and geophysical constraints and attempt to reconcile these data into a coherent and consistent interpretation.
