Deformation and metamorphism on the east side of the Green Mountain massif in southern Vermont

North-plunging F (sub 1) folds overturned to the west with an axial-planar foliation, S (sub 1) . Motion on two major thrust faults juxtaposed three similar but distinctive cover-rock sequences after or late in F (sub 1) folding. Smaller-scale F (sub 2) folds deformed F (sub 1) fold limbs and the thrust faults and have an axial-planar crenulation cleavage, S (sub 2) . In the structurally higher central and eastern cover-rock sequences, an early stage of garnet growth began late in S (sub 1) development or after it. A retrogression partially resorbed first-stage garnet and was followed by a second prograde stage of garnet growth late in (or after) S (sub 2) development. This metamorphic history resulted in distinctive textural unconformities and zoning anomalies in garnet. The western cover-rock sequence lacks evidence for a major retrogression. F (sub 1) folding and F (sub 2) folding approximately bracket both the motion on the thrust faults and the retrogression. The second prograde metamorphism and the younger deformation are Acadian. Tentative correlation of the first garnet growth stage with Ordovician metamorphism recognized in western New England and of motion on the thrust faults with Taconian synmetamorphic thrusts in the region suggests that these early thermal and tectonic events occurred in the Ordovician.--Modified journal abstract.