34 Paleozoic Tectonics of the Northern Appalachian Mountains: New Insights and Persistent Problems: First Annual NETectonics Symposium (Posters)
STRAIN PARTITIONING OF D1 ACADIAN DEFORMATION IN THE PRESIDENTIAL RANGE, NEW HAMPSHIRE
Paper number: 34-6
Program: SYMPOSIA
Authors
Abstract
L1 mineral lineations composed of pseudomorphed andalusites are common. L1 is sub-parallel to F1 hinge lines and never seen in the principal stretching direction, perpendicular to the hinge lines. Reverse refraction of S1 schistosity in andalusite bearing schists suggests that andalusite growth occurred prior to the main phase of D1 deformation. Outcrop scale stratigraphic/rheological variations control whether L1 develops. In thick (> 10 cm) massive schists, peudoandalusites are unaligned within the S1 schistosity, whereas lithologies where original sedimentary bedding, S0, is characterized by thin beds (< 10 cm) of alternating schist and quartzite, the L1 mineral lineation is well defined. L1 and F1 hinge lines vary in orientation along the length of the D1 macroscopic axial traces reflecting the non--cylindrical, sheath-like fold geometry for D1 nappes. As such, the concentration of L1 lineations, which trend shallowly to moderately WSW, record the ENE transport direction of the easterly facing nappes.