The grain size(s) of Black Hills Quartzite deformed in the dislocation creep regime
Renée Heilbronner1,2 and Rüdiger Kilian11Geological Institute, Basel University, Bernoullistrasse 32, CH_4056 Basel, Switzerland 2Institutt for geovitenskap, UiT Norges arktiske universitet, Dramsveien 201, N-9037 Tromsø, Norway
Received: 16 Mar 2017 – Accepted for review: 16 Mar 2017 – Discussion started: 20 Mar 2017
Abstract. A number of general shear experiments on Black Hills Quartzite (BHQ) in the dislocation creep regime, 5 of which have been analyzed previously using the CIP method (Heilbronner & Tullis, 2002 and 2006), are (re-)examined using the higher spatial and orientational resolution of EBSD. Segmentations based on c-axis orientation and on full crystallographic orientations are compared. Texture domains of preferred c-axis orientation are extracted and analyzed separately. Subdomains are recognized and their shape and size is related the kinematic framework and the original grains in the BHQ. Grain size analysis using a segmentation based on c-axis orientations is carried out for all, high and low strain samples of all regimes, and for a number of texture domains. The results are compared to the recrystallized quartz piezometer of Stipp & Tullis (2003), returning consistently higher values for stress or grain size. Possible causes for the discrepancy are texture dependence, grain scale strain, and dependence on the kinematic framework (in axial versus general shear experiments).
Heilbronner, R. and Kilian, R.: The grain size(s) of Black Hills Quartzite deformed in the dislocation creep regime, Solid Earth Discuss., doi:10.5194/se-2017-30, in review, 2017.