Articles | Volume 8, issue 5
Solid Earth, 8, 1071–1093, 2017
https://doi.org/10.5194/se-8-1071-2017

Special issue: Analysis of deformation microstructures and mechanisms on...

Solid Earth, 8, 1071–1093, 2017
https://doi.org/10.5194/se-8-1071-2017

Research article 17 Oct 2017

Research article | 17 Oct 2017

The grain size(s) of Black Hills Quartzite deformed in the dislocation creep regime

Renée Heilbronner and Rüdiger Kilian Renée Heilbronner and Rüdiger Kilian
  • Department of Environmental Sciences Geological Institute, Bernoullistrasse 32, 4056 Basel, Switzerland

Abstract. General shear experiments on Black Hills Quartzite (BHQ) deformed in the dislocation creep regimes 1 to 3 have been previously analyzed using the CIP method (Heilbronner and Tullis, 2002, 2006). They are reexamined using the higher spatial and orientational resolution of EBSD. Criteria for coherent segmentations based on c-axis orientation and on full crystallographic orientations are determined. Texture domains of preferred c-axis orientation (Y and B domains) are extracted and analyzed separately. Subdomains are recognized, and their shape and size are related to the kinematic framework and the original grains in the BHQ. Grain size analysis is carried out for all samples, high- and low-strain samples, and separately for a number of texture domains. When comparing the results to the recrystallized quartz piezometer of Stipp and Tullis (2003), it is found that grain sizes are consistently larger for a given flow stress. It is therefore suggested that the recrystallized grain size also depends on texture, grain-scale deformation intensity, and the kinematic framework (of axial vs. general shear experiments).

Short summary
The crystallographic texture of experimentally sheared samples of dynamically recrystallized quartzite have been reanalyzed using EBSD. Detailed grain size analysis reveals that the recrystallized grain size depends not only on stress, as assumed in the recrystallized quartz piezometer of Stipp and Tullis (2003), but also on texture, grain-scale deformation intensity, and the kinematic framework of axial versus general shear experiments.