Influence of pore fluid pressure and differential stress on gypsum dehydration and rock texture revealed by 4D synchrotron X-ray tomography

May 27, 2022

Roberto Rizzo (1), Florian Fusseis(1), Ian Butler(1), Sohan Seth (2), John Wheeler (3), Oliver Plümper(4), Hamed Amiri (4), Alireza Chogani (4),Christian Schlepütz (5), Federica Marone (5), and Edward Ando (6)
EGU General Assembly. (23-27 May 2022). DOI:


Tectonic-scale features happening at convergent plates are ultimately the outcome of microscopic, grain scale processes. In collision zones, prograde metamorphism occurs by gradual increase of pressure and temperature [1; 2]. Among the most important prograde mineral reactions are dehydration reactions, which are characterized by solid volume reduction, porosity creation, fluid release and high pore fluid pressures [3]. Most models linking dehydration and mechanical instabilities [4-6] involve feedback loops between coupled chemical, hydraulic and mechanical processes. Feedbacks control pore fluid pressure build-up and drainage, and provide efficient pathways for the transport of chemical components. Gypsum dehydration is crucial in the formation of detachment faults thin-skinned tectonics [7]. It is also used as a proxy for serpentine dehydration and the generation of intermediate depth seismic events/aseismic slip activity [8].

How Our Software Was Used

A Dragonfly deep-learning algorithm was applied to derive data on mineral phase transformation and formation of pore networks.

Author Affiliation

(1) The University of Edinburgh, School of Geosciences, Edinburgh , United Kingdom of Great Britain – England, Scotland, Wales
(2) Institute for Adaptive and Neural Computation, School of Informatics, University of Edinburgh, United Kingdom of Great Britain
(3) Department of Earth Sciences, Liverpool University, Liverpool L69 7GP, United Kingdom of Great Britain
(4) Department of Earth Sciences, Utrecht University, 3584 CD Utrecht, The Netherlands
(5) Swiss Light Source, Paul Scherrer Institut, Villigen, Switzerland
(6) 3SR - Laboratoire sols, solides, structures - risques, Grenoble, France