HAL will be down for maintenance from Friday, June 10 at 4pm through Monday, June 13 at 9am. More information
Skip to Main content Skip to Navigation
Journal articles

Porosity induced by dislocation dynamics in quartz-rich shear bands of granitic rocks

Abstract : The production of micro-pores is a driving mechanism for fluids to interact with deep environment and influence rock properties. Yet, such a porosity still remains misunderstood to occur in viscous rocks and may be attributed to either grain boundary sliding (GBS), dissolution effects or sub-grain rotation. Here we focus on quartz-rich shear bands across the Naxos western granite (Aegean Sea, Greece), where we document sub-micron pores at quartz boundaries. While most of these pores are observed along grain boundaries, some of them occur at intra-grain boundaries, which excludes dissolution or GBS to produce them, but instead involves the dynamic of dislocations. We then confirm that quartz is dominated by dislocation creep with evidence of a moderate to strong lattice-preferred orientation (LPO) and numerous tilt/twist boundaries, including at the pluton margin where rocks embrittled. These features coincide with (1) randomly oriented 'inclusion' quartz grains along tilt/twist boundaries and (2) a partial dependency of the LPO strength on grain size. Our findings suggest that pores arise from coalescing dislocations at boundaries of rotating sub-grains, providing nucleation sites for new grains to be precipitated during plastic flow. Fluid infiltration, rock embrittlement and related implications are also expected through pores accumulation with increasing strain.
Document type :
Journal articles
Complete list of metadata

https://hal-univ-paris.archives-ouvertes.fr/hal-03663782
Contributor : Equipe Hal Université Paris Cité Connect in order to contact the contributor
Submitted on : Tuesday, May 10, 2022 - 2:07:21 PM
Last modification on : Friday, May 13, 2022 - 3:32:48 AM

File

Porosity induced.pdf
Publisher files allowed on an open archive

Licence


Distributed under a Creative Commons Attribution 4.0 International License

Identifiers

Citation

Jacques Précigout, Estelle Ledoux, Laurent Arbaret, Charlotte Spriet. Porosity induced by dislocation dynamics in quartz-rich shear bands of granitic rocks. Scientific Reports, Nature Publishing Group, 2022, 12 (1), pp.6141. ⟨10.1038/s41598-022-10053-x⟩. ⟨hal-03663782⟩

Share

Metrics

Record views

0

Files downloads

0