Quantification of plastic deformation in anorthite using micropillar compression

Sarah Incel; Chunhua Tian; Anja Schreiber; Vladimir Roddatis; Sandra Korte-Kerzel

Home/Archive/arXiv

arXiv · 2610.10081

Quantification of plastic deformation in anorthite using micropillar compression

Sarah Incel·Chunhua Tian·Anja Schreiber·Vladimir Roddatis·Sandra Korte-Kerzel

View original source ↗Read source document ↗Export metadata ↓

Abstract

Plagioclase is the most abundant mineral group of the crust and will therefore either control or strongly influence crustal rheology. Yet, we still know little about crystal plasticity in plagioclase as brittle deformation dominates under most laboratory conditions. To overcome past challenges in quantifying crystal plastic deformation in plagioclase, we used micropillar compression to quantify the strength of specific slip systems as well as the stresses necessary for mechanical twinning in anorthite. Pillars with diameters of around 1 micrometre were milled from three differently oriented cuts of the same anorthite single crystals using focused-ion beam. Uniaxial deformation of 36 pillars in total was then conducted inside a scanning-electron microscope under either 25, 300, or 800 degrees Celsius. Most pillars were deformed with a constant displacement rate that corresponds to a strain rate of around 0.001 1/s on the pillars. We find that the critical resolved shear stress (CRSS) for mechanical (pericline) twinning lies at around 300 MPa and is, as expected from previous studies on other materials, insensitive to changes in temperature or strain rate. Pillar deformation in crystals oriented to activate slip exhibit a strong decrease in yield stress with increasing temperature. Among the deformation mechanisms active during pillar deformation, twinning is the easiest under the applied conditions, followed by slip on (011)[100] regardless of temperature. Slip on (011)[0-11] or (0-11)[011] is consistently the hardest mechanism to activate in our anorthite pillars.

Explore related subjects

physics.geo-ph cond-mat.mtrl-sci

Keep this discovery

Explore connections, maps & timelines

BibTeX RIS

Sarah Incel, Chunhua Tian, Anja Schreiber, Vladimir Roddatis, Sandra Korte-Kerzel. 2026-10-07. Quantification of plastic deformation in anorthite using micropillar compression. https://arxiv.org/abs/2610.10081

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related papers

arXiv2026

Effects of microstructural heterogeneity on the macroscopic spectrum of elastically accommodated grain-boundary sliding

Elastically accommodated grain-boundary sliding (EAGBS) is a plausible source of upper-mantle seismic attenuation and dispersion, yet classical theory predicts a localized Debye-like peak that is absent or only weakly expressed in dry olivine experiments. Here we test whether microstructural heterogeneity can explain this discrepancy using 2-D finite-element simulations on periodic Voronoi tessellations. We find that irregular grain geometry changes the baseline EAGBS response relative to the regular hexagonal benchmark, but increasing grain-size variance alone produces only modest changes in modulus and peak height, with little spectral broadening. In contrast, a broad distribution of grain-boundary viscosities progressively suppresses and broadens the Debye-like loss peak into a weak background spanning a wide frequency interval. This broadening arises from the superposition of many localized relaxation processes with distinct characteristic timescales and motivates a reduced-order 0-D description of the aggregate response. These results suggest that the absence of a pronounced EAGBS peak in dry olivine does not necessarily imply the absence of EAGBS mechanism itself. If grain boundaries sample a sufficiently broad viscosity distribution, the macroscopic EAGBS contribution may appear experimentally only as part of a broad attenuation background, while still remaining relevant for upper-mantle seismic attenuation and velocity dispersion.

physics.geo-ph↗

arXiv2026

Escaping Geological Generative Prior Distributions in Bayesian Travel Time Tomography

Solutions to geophysical inverse problems are generally non-unique, and greatly benefit from additional geological prior information. Generative Neural Networks (GNNs) are commonly used to parametrise such information, typically restricting solutions to a lower-dimensional latent space. The final inversion result is obtained by mapping the latent space parameters to the original higher-dimensional model space using the GNNs. However, solutions then remain confined to a low-dimensional geological generative manifold; if the true Earth model lies outside of this manifold, standard latent space inversion fails. We propose a Bayesian model space inversion method that uses the generative manifold as a guide to find the solutions that lie outside this manifold. We validate our approach in non-linear travel-time tomography experiments on both simple and more geological structures. By comparing our method with model space inversion using uniform prior probabilities and standard latent-space inversion, we demonstrate that the less informative uniform prior fails to constrain the solution, while the latent space approach fails when the true Earth model lies outside of the generative manifold. Conversely, our new model-space inversion method successfully recovers complex off-manifold geological features while maintaining low solution uncertainty.

physics.geo-ph↗

arXiv2026

Bridge Vibrations as Persistent Seismic Sources for Time-lapse Imaging of River Corridors with Distributed Acoustic Sensing

Fluvial corridors mediate dynamic river-groundwater exchanges and support major transportation infrastructure, yet continuous subsurface monitoring remains limited by sparse point sensors and infrequent time-lapse surveys. Addressing this observational gap is critical during extreme flood events, when transient saturation, pore-pressure buildup, and structural scour drive complex hydro-mechanical changes that threaten both riparian slope stability and bridge foundations. Here, we demonstrate that traffic-excited highway bridges act as persistent, spatially fixed seismic sources; their vibrations, recorded on roadside telecommunication fiber with Distributed Acoustic Sensing (DAS), enable time-lapse imaging of river corridors. We evaluate this approach using dark fiber recordings along South Korea's Gyeongbu Expressway during a record monsoon flood in July 2025, targeting a 430 m multi-span bridge crossing the Miho River. Vehicle impacts excite flexural resonances of the bridge deck, generating a discrete spectral comb of fundamental-mode Rayleigh waves in the surrounding ground; these 3-6 Hz waves propagate beyond 400 m across both riverbanks to image the alluvial section down to bedrock. Because bridge-structure geometry constrains the source location and dominant modal frequencies, virtual source gathers achieve rapid convergence within 5 min of ballistic wave stacking with high waveform repeatability over the recording period. Relative seismic velocity (dv/v) monitoring resolves velocity drops up to 1.0% during flood passage associated with heavy precipitation and river stage rise, consistent with hydrological softening of the riparian sediments. These results demonstrate that traffic-excited bridges provide persistent, repeatable seismic illumination, turning roadside telecommunication cables into dense arrays for both hydrogeophysical and civil infrastructure applications.

physics.geo-ph↗