Skip to Main content Skip to Navigation
New interface
Journal articles

Metamorphic record of catastrophic pressure drops in subduction zones

Philippe Yamato 1, * Jean-Pierre Brun 1 
* Corresponding author
Abstract : When deeply buried in subduction zones, rocks undergo mineral transformations that record the increase of pressure and temperature. The fact that high-pressure metamorphic parageneses are found at the Earth’s surface proves that rock burial is followed by exhumation. Here we use analysis of available data sets from high-pressure metamorphic rocks worldwide to show that the peak pressure is proportional to the subsequent decompression occurring during the initial stage of retrogression. We propose, using a simple mechanical analysis, that this linear relationship can be explained by the transition from burial-related compression to extension at the onset of exhumation. This major switch in orientation and magnitude of principal tectonic stresses leads to a catastrophic pressure drop prior to actual rock ascent. Therefore, peak pressures are not necessarily, as commonly believed, directly dependent on the maximum burial depth, but can also reflect a change of tectonic regime. Our results, which are in agreement with natural data, have significant implications for rock rheology, subduction zone seismicity, and the magnitudes of tectonic pressures sustained by rocks. Current views of subduction dynamics could be reconsidered in that perspective.
Document type :
Journal articles
Complete list of metadata
Contributor : Isabelle Dubigeon Connect in order to contact the contributor
Submitted on : Tuesday, December 6, 2016 - 8:17:01 AM
Last modification on : Thursday, June 2, 2022 - 2:48:13 PM



Philippe Yamato, Jean-Pierre Brun. Metamorphic record of catastrophic pressure drops in subduction zones. Nature Geoscience, 2017, 10 (1), pp.46-50. ⟨10.1038/ngeo2852⟩. ⟨insu-01409600⟩



Record views