Tectono-metamorphic evolution of western Maine, Northern Appalachians, USA

TL;DRAbstract

Section A: Multiply-deformed schists in Western Maine were multiply metamorphosed under lower-amphibolite-facies conditions during the Acadian orogeny. Most of the many deformations were partitioned on a regional scale into zones dominated by coaxial bulk shortening and surrounded by anastomosing zones of non-coaxial shortening and shearing. Protection provided by plutons emplaced at different times during this history resulted in the matrix foliation orientation varying with respect to pluton proximity as well as to the regional-scale structures. Garnet and staurolite porphyroblasts grew episodically many times as deformation was partitioned and repartitioned during successive tectonic events. A succession of five FIAs trending ESE-WNW, N-S, E-W, ENE-WSW and NE-SW were measured from both garnet and staurolite porphyroblasts. Thus at least five periods of growth are inferred for these phases, in contrast with only two periods of growth as was previously believed. Pitch measurements of

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