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Deformation microstructures of Barre granite: An optical, Sem and Tem study

January 1, 1986

New scanning electron microscope techniques have been developed for characterizing ductile deformation microstructures in felsic rocks. In addition, the thermomechanical history of the macroscopically undeformed Barre granite (Vermont, U.S.A.) has been reconstructed based on examination of deformation microstructures using optical microscopy, scanning electron microscopy, and transmission electron microscopy. The microstructures reveal three distinct events: 1. (1) a low-stress, high-temperature event that produced subgrains in feldspars, and subgrains and recrystallized grains in quartz; 2. (2) a high-stress, low-temperature event that produced a high dislocation density in quartz and feldspars; and 3. (3) a lowest-temperature event that produced cracks, oriented primarily along cleavage planes in feldspars, and parallel to the macroscopic rift in quartz. The first two events are believed to reflect various stages in the intrusion and cooling history of the pluton, and the last may be related to the last stages of cooling, or to later tectonism. ?? 1986.

Publication Year 1986
Title Deformation microstructures of Barre granite: An optical, Sem and Tem study
Authors A. Schedl, A. K. Kronenberg, J. Tullis
Publication Type Article
Publication Subtype Journal Article
Series Title Tectonophysics
Index ID 70014949
Record Source USGS Publications Warehouse