Progressive evolution from uplift to orogen-parallel transport in a late-Acadian, upper amphibolite- to granulite-facies shear zone, south-central Massachusetts

Dome-stage or backfold-deformation resulted in the formation of several structural features of the small-scale Acadian. Two stages of shearing existed in the Bronson Hill anticlinorium and the eastern side of the Monson Gneiss. Peak metamorphism preceded late-stage deformation during Acadian orogeny. There was a shift into orogen-parallel extension during this deformation. There may be a variation in the orientation of the direction of maximum extension at the backfold-stage uplift, from near vertical to near parallel and horizontal to the orogen at the stage of dome-formation.