MULTIPLE FOLIATIONS IN DIANA SYENITE, CARTHAGE-COLTON MYLONITE ZONE, ADIRONDACKS: MAGNETOFABRIC AND PETROFABRIC EVIDENCE AND IMPLICATIONS

The Diana Syenite is a large body along and within the southwest Carthage-Colton Mylonite Zone, a major terrane boundary in the southeast Grenville Province. Multiple generations of foliations though the central portion of that body were investigated by magnetic and microscopic methods. Magnetic fabrics were characterized by analyses of anisotropy of magnetic susceptibility (AMS) in oriented cores. Planar and linear features indicated by the AMS patterns were investigated using precisely oriented thin-sections in optimal orientations. A modified universal stage and a custom jig were used to control the thin sections taken. Our results show three generations of foliations, two of which can be correlated with the second and third deformation fold-axial-plane foliations of Wiener (1983)* formed during Grenville orogenesis. A third foliation post-dates the other foliations. These results suggest that the penetrative and defining fabric of the Carthage-Colton Mylonite Zone does not show a large structural discontinuity across the southern portion of the zone. We conclude that certain structures, which cross-cut the foliations, may have accommodated large-scale terrane movements. *Wiener, R.W., 1983, G.S.A. Bull. 94, 1081 - 1108.