Abstract
We present results from a natural deformed shear zone in the Turon de Técouère massif of the French Pyrenees that directly addresses the processes involved in strain localization, a topic that has been investigated for the last 40 years by structural geologists. Paleopiezometry indicates that differential stresses are variable both spatially across the zone, and temporally during exhumation. We have, however, also calculated strain rate, which remains constant despite changes in stress. This result appears to be at odds with recent experimental deformation on monophase (olivine) rocks, which indicate that strain localization occurs dominantly as a result of constant stress. We hypothesize that in the Turon de Técouère massif—and many natural shear zones—strain localization occurs as a result of reactions, which decrease the grain size and promote the activation of grain size sensitive deformation mechanisms. From a tectonics perspective, this study indicates that the deformation rate in a particular plate boundary is relatively uniform. Stress, however, varies to accommodate this deformation. This viewpoint is consistent with deformation at a plate boundary, but it is not the typical way in which we interpret strain localization.
Original language | English |
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Article number | 1351 |
Pages (from-to) | 1-25 |
Number of pages | 25 |
Journal | Minerals |
Volume | 11 |
Issue number | 12 |
Early online date | 30 Nov 2021 |
DOIs | |
Publication status | Published - Dec 2021 |
Bibliographical note
Special Issue: Mantle Strain Localization—How Minerals Deform at Deep Plate Interfaces.Funding Information:
Funding: This research was funded by a NWO‐Pionier subsidy to M.R.D.; U.S. National Science Foundation grant EAR‐1629840 awarded to B.T. and V.C.; and a Marie Curie International Outgoing Fellowship (PIOF‐GA‐2012–329183) and a research support grant from the University of Sydney (Australia) awarded to V.C.
Funding Information:
This research was funded by a NWO?Pionier subsidy to M.R.D.; U.S. National Science Foundation grant EAR?1629840 awarded to B.T. and V.C.; and a Marie Curie International Outgoing Fellowship (PIOF?GA?2012?329183) and a research support grant from the University of Sydney (Australia) awarded to V.C.
Publisher Copyright:
© 2021 by the authors. Licensee MDPI, Basel, Switzerland.
Keywords
- Mylonite
- Peridotite
- Pyrenees
- Strain localization
- Strain rate
- Stress