Memory and jamming in fault zone sediments

Jhardel Dasent

doi:10.1038/s43247-025-02952-4

Memory and jamming in fault zone sediments

2025-12-09

0

OA

AI

DOI：10.1038/s43247-025-02952-4

Original

Original request for help

Save

Abstract

En 中文

Many subsurface processes involve transitions in granular material states, from arrested to creeping to flowing. Experiments and frameworks for idealized systems reveal that granular fabrics develop during shearing, co-evolve with applied stress, and govern such transitions. We use microtomography to test whether fabrics at two San Andreas fault sites reflect slip history and whether idealized frameworks extend to nature. Near-surface sediments within the fault zone transition between deformation patterns over the seismic cycle, including bulk/localized grain re-arrangements, individual grain fracturing, and localized zones of fracturing. Aseismic and co-seismic shearing produce distinct preferred grain orientations. Co-seismic fabrics can be preserved after centuries of aseismic strain, aseismic fabrics may be overprinted, and grain size and coordination number influence the fabrics. Idealized frameworks, namely anisotropic critical state theory, frictional jamming, and material memory, can explain our observations, and fault zone sediments likely undergo cycles of memory creation and erasure that influence rigidity spatiotemporally. Creep and earthquakes produce distinct microstructural fabrics, representing a form of material memory that can be created and erased through the seismic cycle, according to X-ray microtomography of sediments within the San Andreas fault zone.

Memory and jamming in fault zone sediments

Abstract

Journal

Organization