The recrystallized grain size piezometer for quartz: An EBSD‐based calibration

• Published in: Geophysical research letters 2017-07, Vol.44 (13), p.6667-6674
• Main Authors: Cross, A. J., Prior, D. J., Stipp, M., Kidder, S.
• Format: Article
• Language: English
• Subjects: Alloys; Backscatter; Calibration; Deformation; Diffraction; Dislocation; Dislocation density; Distortion; EBSD; Electron backscatter diffraction; Empirical analysis; Grain orientation; Grain size; Grains; High temperature; Light microscopy; Lithosphere; lithospheric stress; Microscopy; Microstructural analysis; Optical microscopy; Particle size; piezometer; Piezometers; Quartz; Recrystallization; Resolution; Rock; Rocks; Sliding; Slumping; Solifluction; Stresses; Tectonics; Temperature; Temperature effects
• ISSN: 0094-8276; 1944-8007
• DOI: 10.1002/2017GL073836

We have reanalyzed samples previously used for a quartz recrystallized grain size paleopiezometer, using electron backscatter diffraction (EBSD). Recrystallized and relict grains are separated using their grain orientation spread, which acts as a measure of intragranular lattice distortion and a proxy for dislocation density. For EBSD maps made with a 1 μm step size, the piezometer relationship is D = 103.91 ± 0.41 ∙ σ−1.41 ± 0.21 (for root‐mean‐square mean diameter values). We also present a “sliding resolution” piezometer relationship, D = 104.22 ± 0.51 ∙ σ−1.59 ± 0.26, that combines 1 μm step size data at coarser grain sizes with 200 nm step size data at finer grain sizes. The sliding resolution piezometer more accurately estimates stress in fine‐grained (