37 Tectonics

Wednesday, 11 March 2026
8:30 AM - 10:00 AM
RCC, 106

Overcoming the Challenges of Multiphase Mylonitic Rocks via Recent Advances in EBSD Software Algorithms

Paper number: 37-1
Program: Technical Sessions
Time: 8:45 AM – 9:00 AM

Authors

Abstract

Mylonites can be difficult for traditional EBSD data processing methods as they contain a litany of problems for these methods. Mylonites are often comprised of multiphase, low symmetry heavily deformed minerals that vary widely in grain size, while at the same time being crystallographically textured. Each of these features by itself can be a problem and being combined together can be difficult to overcome. 

Recent advances in Electron Backscatter Diffraction (EBSD) software algorithms, including Neighbor Pattern Averaging and Reindexing (NPAR), its non-local extension (NLPAR), Spherical Indexing, and enhanced background processing, have significantly improved the ease of collecting high quality datasets from multiphase mylonites. 

While each of these advances alone are significant, in combination, tough samples like multiphase mylonites can be routinely sampled. Data will be presented on a 7 phase (Garnet, Hornblende, Plagioclase, Scapolite, Clinopyroxene, Quartz, and Titanite) highlighting the difficulties encountered and how tools like SI and NPAR improved both the data quality and the learning curve to get the data. 

Geological Society of America Abstracts with Programs. Vol. 58, No. 1

doi: 10.1130/abs/2026SE-411575

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