A dynamic atlas of interference patterns in superimposed, opposite sense ductile shear zones

Finch, M.A., Bons, P.D., Weinberg, R.F., Llorens, M.G., Griera, A., and Gomez-Rivas, E. (2022) A dynamic atlas of interference patterns in superimposed, opposite sense ductile shear zones. Journal of Structural Geology, 165. 104739.

[img] PDF (Published Version) - Published Version
Restricted to Repository staff only

View at Publisher Website: https://doi.org/10.1016/j.jsg.2022.10473...


Ductile shear zones that reactivate a coplanar shear zone with opposite shear sense are known from a variety of tectonic environments. Recognition of reactivation requires understanding the interference patterns that form when microstructures produced in the first event (D1) are modified by the second event (D2). We use numerical modelling to demonstrate the effect of D1 structures on the development of shear zone interference patterns during a coplanar, opposite sense D2 ductile shearing event. Seven models were generated from increasing D1 dextral simple shear strains (γdextral = 2–14) and we then superimposed D2 sinistral shearing (γsinistral = 10). The interference patterns produced are highly variable with geometric relationships between weak layers and strong lithons determining deformation style. Shear zones with high D1 strain can more easily accommodate D2 strain because more strain is localised into long, weak phase C planes, which are readily inverted and reused during sinistral shear. Interference structures in models and naturally deformed rocks include rotated σ-clasts, folded D1 S planes, disharmonic and hook folds, and cuspate layers of weak phase. We present a dynamic atlas of interference patterns produced due to overprinting shear zones to facilitate identification of these zones in nature.

Item ID: 76884
Item Type: Article (Research - C1)
ISSN: 1873-1201
Copyright Information: © 2022 Elsevier Ltd. All rights reserved.
Funders: Australian Research Council (ARC)
Projects and Grants: ARC DP220101198
Date Deposited: 29 Nov 2022 23:27
FoR Codes: 37 EARTH SCIENCES > 3705 Geology > 370511 Structural geology and tectonics @ 100%
SEO Codes: 28 EXPANDING KNOWLEDGE > 2801 Expanding knowledge > 280107 Expanding knowledge in the earth sciences @ 100%
Downloads: Total: 1
More Statistics

Actions (Repository Staff Only)

Item Control Page Item Control Page