The critical role of stored energy in metamorphism
Abstract
The mechanical behaviour of the Earth is widely assumed to change with increasing timescale as rocks progressively relax imposed stresses [1]. On short timescales, elasticity dominates and its release drives earthquakes [2]; at intermediate timescales, viscoelastic relaxation facilitates processes such as glacial rebound [3]; whereas over geological timescales viscous deformation dominates, allowing the mantle to flow [4]. Energetically, this progression implies that mechanically stored potential energy becomes increasingly irrelevant to long-term geological processes such as metamorphism. Here we challenge this assumption using time-resolved deformation experiments that isolate changes in stored energy during metamorphic reaction. We show that increasing stored energy causes reaction to occur sooner and faster, increases nucleation density and reduces product grain size. Comparison with experiments from crustal and mantle materials shows that this influence persists across different reactions and deformation regimes. These results demonstrate that stored energy can exert a first-order control on geological transformation despite its comparatively small contribution to the total energy budget. Because stress and stored energy are heterogeneous across materials and scales, our results place stored energy alongside water as a driver of metamorphic change and provide experimental support for a view of the Earth in which changes in Helmholtz energy influence the emergence of material instabilities [5-8].
Related
- Avalanches can increase stored energy in a granular fault
- Magma-induced midcrustal flow and high-temperature metamorphism: Insights from the early Mesozoic Yunkai massif (South China) and tectonic implications
- An overlooked pool of hydrogen stored in humic matter revealed by isotopic exchange: implication for radioactive ³H contamination
- Unraveling critical paths and inequalities in the tourism industry: An integrated water-energy-carbon nexus approach for China
- Indoor environmental quality assessment in the built environment: A critical synthesis of methodologies and energy integration practices
BibTeX
@misc{gilgannon2026critical,
title = {{The critical role of stored energy in metamorphism}},
author = {James Gilgannon and Damien Freitas and Eilidh Vass Payne and Roberto Emanuele Rizzo and Ian Butler and Danielle Duggins and Simon Hunt and Andrew King and Christian M. Schlepütz and Dominik Daisenberger and Neil Bourne and Florian Fusseis},
howpublished = {EarthArXiv},
year = {2026},
month = oct,
doi = {10.31223/x5wc08},
url = {https://eartharxiv.org/repository/view/15429/},
note = {CC BY 4.0},
}
RIS
TY - UNPB
TI - The critical role of stored energy in metamorphism
AU - James Gilgannon
AU - Damien Freitas
AU - Eilidh Vass Payne
AU - Roberto Emanuele Rizzo
AU - Ian Butler
AU - Danielle Duggins
AU - Simon Hunt
AU - Andrew King
AU - Christian M. Schlepütz
AU - Dominik Daisenberger
AU - Neil Bourne
AU - Florian Fusseis
PY - 2026
DA - 2026/10/09
PB - EarthArXiv
DO - 10.31223/x5wc08
UR - https://eartharxiv.org/repository/view/15429/
AB - The mechanical behaviour of the Earth is widely assumed to change with increasing timescale as rocks progressively relax imposed stresses [1]. On short timescales, elasticity dominates and its release drives earthquakes [2]; at intermediate timescales, viscoelastic relaxation facilitates processes such as glacial rebound [3]; whereas over geological timescales viscous deformation dominates, allowing the mantle to flow [4]. Energetically, this progression implies that mechanically stored potential energy becomes increasingly irrelevant to long-term geological processes such as metamorphism. Here we challenge this assumption using time-resolved deformation experiments that isolate changes in stored energy during metamorphic reaction. We show that increasing stored energy causes reaction to occur sooner and faster, increases nucleation density and reduces product grain size. Comparison with experiments from crustal and mantle materials shows that this influence persists across different reactions and deformation regimes. These results demonstrate that stored energy can exert a first-order control on geological transformation despite its comparatively small contribution to the total energy budget. Because stress and stored energy are heterogeneous across materials and scales, our results place stored energy alongside water as a driver of metamorphic change and provide experimental support for a view of the Earth in which changes in Helmholtz energy influence the emergence of material instabilities [5-8].
ER -