Using the 'crystal signature' of mylonites to demarcate the Main Central Thrust (Alaknanda region, Garhwal Himalaya)

Nicholas JR Hunter, Roberto F Weinberg, C J L Wilson, V Luzin

Research output: Contribution to conferenceAbstract


During plastic deformation, quartz typically develops a crystallographic preferred orientation (CPO), which reveals information about the stress, temperature, strain and key deformation mechanisms associated with shear zone mechanics. Such information is critical for understanding major tectonic processes and the rheological weakening of the crust, and therefore comprehensive CPO analyses are of particular importance to a complete understanding of deformation processes during the Himalayan orogeny. An additional and particularly remarkable aspect of CPOs is their ability to reveal information even in rocks where there is no visible appearance of deformation. Because deformation fabrics are typically recognized based on the juxtapositions between two or more phases, evidence of strong shearing in monomineralic rocks, such as quartzites, can be difficult to observe in the field and under petrographic microscope. When analyzed using crystallographic diffraction techniques, however, they can reveal stron CPOs associated with plastic deformation.
Original languageEnglish
Number of pages3
Publication statusPublished - 2015
EventHimalaya-Karakoram-Tibet Workshop, 2015 - Dehradun, India
Duration: 6 Oct 20158 Oct 2015
Conference number: 30th


ExhibitionHimalaya-Karakoram-Tibet Workshop, 2015

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