Journal of Geophysical Research: Solid Earth最新文献

{"title":"Cambrian Stage 3 Paleomagnetism of the South China Block: Implications for Early Paleozoic Gondwana Reconstructions","authors":"Dongmeng Zhang,&nbsp;Xin Cheng,&nbsp;Vadim A. Kravchinsky,&nbsp;Mengting Zhong,&nbsp;Bitian Wei,&nbsp;Nan Jiang,&nbsp;Longyun Xing,&nbsp;Shuqi Lan,&nbsp;Weijie Zhang,&nbsp;Jiahui Zhang,&nbsp;Chao Chang,&nbsp;Wei Liu,&nbsp;Yanan Zhou,&nbsp;Xingliang Zhang,&nbsp;Hanning Wu","doi":"10.1029/2026JB035049","DOIUrl":"https://doi.org/10.1029/2026JB035049","url":null,"abstract":"<p>The paleogeographic position of the South China Block (SCB) during the early Paleozoic and its affiliation with Gondwana remain debated. We report new high-quality paleomagnetic data from sandstone-dominated Cambrian Stage 3 strata correlated with the Yu'anshan–Hongjingshao succession collected along the southwestern margin of the SCB (Guliancun section). Systematic demagnetization combined with detailed rock-magnetic analyses identifies a dual-polarity characteristic remanent magnetization primarily carried by single-domain to vortex-state detrital magnetite. The magnetization yields a positive fold test, passes reversal tests after tilt correction, exhibits negligible tectonic overprinting or inclination shallowing, and yields a paleopole that effectively averages secular variation. After applying a ∼20° clockwise rotation correction consistent with regional Cenozoic tectonics, the paleopole GY' (<i>Λ</i>_<i>p</i> = −51.8°N, <i>Φ</i>_<i>p</i> = 182.8°E, <i>A</i>₉₅ = 3.21°, <i>N</i> = 29 sites) positions the SCB at low southern paleolatitudes (∼13.6°S) at ∼518 Ma. This age assignment is based on correlations with the Chengjiang Biota-bearing interval and detrital-zircon maximum depositional ages. Paleogeographic reconstructions illustrate the SCB's close spatial relationship with East Gondwana during Cambrian Stage 3, supporting a coherent configuration with a southwest-facing margin. Apparent polar wander path fitting supports a sustained link between the SCB and East Gondwana from the Early Cambrian to Early Devonian (520–405 Ma). This linkage is further reinforced by independent paleobiogeographic and provenance evidence. Collectively, our results provide robust new constraints on Cambrian paleogeography, clarifying the SCB's role in Gondwana assembly.</p>","PeriodicalId":15864,"journal":{"name":"Journal of Geophysical Research: Solid Earth","volume":"131 10","pages":""},"PeriodicalIF":4.0,"publicationDate":"2026-10-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1029/2026JB035049","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149205924","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Combining Borehole Seismic Data and Deep-Learning Methods to Monitor Seismic Sequences in the Istanbul-Marmara Region, NW Türkiye","authors":"Oliver Fabisch,&nbsp;Marco Bohnhoff,&nbsp;Patricia Martínez-Garzón","doi":"10.1029/2026JB034241","DOIUrl":"https://doi.org/10.1029/2026JB034241","url":null,"abstract":"<p>The North Anatolian Fault Zone beneath the Sea of Marmara in NW Türkiye displays a 50% probability of an <span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 <mi>M</mi>\u0000 <mo>≥</mo>\u0000 <mn>7</mn>\u0000 </mrow>\u0000 <annotation> $mathrm{M}ge 7$</annotation>\u0000 </semantics></math> earthquake within the next decades. The proximity of the fault to the Istanbul megalopolis highlights the need for high-resolution microseismicity monitoring to identify seismicity transients including pre-mainshock clustering. We analyze six 4.0 <span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 <mo>≤</mo>\u0000 </mrow>\u0000 <annotation> ${le} $</annotation>\u0000 </semantics></math> M_L <span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 <mo>≤</mo>\u0000 </mrow>\u0000 <annotation> ${le} $</annotation>\u0000 </semantics></math> 5.8 earthquake sequences in the eastern and central Marmara region from 2016 to 2023 and focus on the occurrence of seismicity immediately prior to the mainshocks. We combine borehole and surface seismic waveform data with deep-learning phase picking, automated phase association, and non-linear relocation to compile a comprehensive seismicity catalog. Compared with conventional processing, our workflow allows us to detect about eight times more events in time windows around the mainshocks in the area instrumented with borehole sensors. We then apply waveform cross-correlation, refined location techniques, and template matching to quantify waveform similarity and characterize seismic activity preceding moderate events. We observe a strong increase in waveform similarity and decrease in inter-event distance prior to a 2016 M_L 4.5 event in the Çınarcık Basin, consistent with earlier results from manual processing, and identify additional highly similar events preceding the mainshock. The 2019 M_L 5.8 Silivri sequence shows increased waveform similarity but more heterogeneous spatial clustering. We demonstrate that borehole seismic arrays are critical for resolving these subtle signals due to higher signal-to-noise ratios. Our workflow provides a robust basis towards near-real-time microseismic monitoring in the Istanbul-Marmara region and systematically identifying seismicity transients and localization processes.</p>","PeriodicalId":15864,"journal":{"name":"Journal of Geophysical Research: Solid Earth","volume":"131 10","pages":""},"PeriodicalIF":4.0,"publicationDate":"2026-10-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1029/2026JB034241","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149206145","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A Simple Discrete Elastic Model Exhibits Both the Statistical Properties and Migration Patterns of Slow Slip","authors":"Ling Xia,&nbsp;Allan M. Rubin","doi":"10.1029/2026JB034106","DOIUrl":"https://doi.org/10.1029/2026JB034106","url":null,"abstract":"&lt;p&gt;More than 20 years after their discovery, the physical mechanisms of slow earthquakes remain enigmatic. Here, we develop a simple quasi-static elastic model that reproduces both the migration patterns of elastic/frictional models, and the statistical properties of Brownian models. Fault elements are either slipping or locked, with locked elements having either a fully healed static strength &lt;span&gt;&lt;/span&gt;&lt;math&gt;\u0000 &lt;semantics&gt;\u0000 &lt;mrow&gt;\u0000 &lt;msub&gt;\u0000 &lt;mi&gt;τ&lt;/mi&gt;\u0000 &lt;mi&gt;p&lt;/mi&gt;\u0000 &lt;/msub&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;annotation&gt; ${tau }_{p}$&lt;/annotation&gt;\u0000 &lt;/semantics&gt;&lt;/math&gt;, or a reduced static strength if they slipped recently. By adjusting &lt;span&gt;&lt;/span&gt;&lt;math&gt;\u0000 &lt;semantics&gt;\u0000 &lt;mrow&gt;\u0000 &lt;msub&gt;\u0000 &lt;mi&gt;τ&lt;/mi&gt;\u0000 &lt;mi&gt;p&lt;/mi&gt;\u0000 &lt;/msub&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;annotation&gt; ${tau }_{p}$&lt;/annotation&gt;\u0000 &lt;/semantics&gt;&lt;/math&gt;, the fixed slip speed &lt;span&gt;&lt;/span&gt;&lt;math&gt;\u0000 &lt;semantics&gt;\u0000 &lt;mrow&gt;\u0000 &lt;msub&gt;\u0000 &lt;mi&gt;V&lt;/mi&gt;\u0000 &lt;mi&gt;slip&lt;/mi&gt;\u0000 &lt;/msub&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;annotation&gt; ${V}_{mathit{slip}}$&lt;/annotation&gt;\u0000 &lt;/semantics&gt;&lt;/math&gt;, and the grid spacing &lt;span&gt;&lt;/span&gt;&lt;math&gt;\u0000 &lt;semantics&gt;\u0000 &lt;mrow&gt;\u0000 &lt;mi&gt;Δ&lt;/mi&gt;\u0000 &lt;mi&gt;x&lt;/mi&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;annotation&gt; ${Delta }x$&lt;/annotation&gt;\u0000 &lt;/semantics&gt;&lt;/math&gt;, the model can generate characteristic events with recurrence intervals of about 1 year and propagation speeds of about 10 km/day, consistent with observations and with analytical estimates derived from fracture mechanics. The simulated events also exhibit a proportionality between squared moment acceleration&lt;span&gt;&lt;/span&gt;&lt;math&gt;\u0000 &lt;semantics&gt;\u0000 &lt;mrow&gt;\u0000 &lt;mfenced&gt;\u0000 &lt;mrow&gt;\u0000 &lt;msubsup&gt;\u0000 &lt;mover&gt;\u0000 &lt;mi&gt;M&lt;/mi&gt;\u0000 &lt;mrow&gt;\u0000 &lt;mo&gt;̈&lt;/mo&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;/mover&gt;\u0000 &lt;mn&gt;0&lt;/mn&gt;\u0000 &lt;mn&gt;2&lt;/mn&gt;\u0000 &lt;/msubsup&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;/mfenced&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;annotation&gt; $left({ddot{M}}_{0}^{2}right)$&lt;/annotation&gt;\u0000 &lt;/semantics&gt;&lt;/math&gt; and moment rate&lt;span&gt;&lt;/span&gt;&lt;math&gt;\u0000 &lt;semantics&gt;\u0000 &lt;mrow&gt;\u0000 &lt;mfenced&gt;\u0000 &lt;mrow&gt;\u0000 &lt;msub&gt;\u0000 &lt;mover&gt;\u0000 ","PeriodicalId":15864,"journal":{"name":"Journal of Geophysical Research: Solid Earth","volume":"131 10","pages":""},"PeriodicalIF":4.0,"publicationDate":"2026-10-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1029/2026JB034106","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149205726","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Radial-Component Predominant-Mode Inversion of Rayleigh Waves: Application to DAS-Based Site Characterization","authors":"Mrinal Bhaumik,&nbsp;Brady R. Cox","doi":"10.1029/2026JB034811","DOIUrl":"https://doi.org/10.1029/2026JB034811","url":null,"abstract":"&lt;p&gt;Distributed Acoustic Sensing (DAS) has emerged as a transformative technology for near-surface site characterization. When a vertical source is activated along the fiber, DAS measures only the in-line (radial) component of Rayleigh-wave motion, whereas conventional surface-wave methods primarily measure the vertical component. Dispersion data extracted from radial-component waveforms may differ from those obtained from vertical-component measurements, particularly under complex stratigraphic conditions. Hence, a component-consistent forward problem is desired when inverting radial-component DAS dispersion data to retrieve accurate shear wave velocity (&lt;span&gt;&lt;/span&gt;&lt;math&gt;\u0000 &lt;semantics&gt;\u0000 &lt;mrow&gt;\u0000 &lt;msub&gt;\u0000 &lt;mi&gt;V&lt;/mi&gt;\u0000 &lt;mi&gt;s&lt;/mi&gt;\u0000 &lt;/msub&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;annotation&gt; ${V}_{s}$&lt;/annotation&gt;\u0000 &lt;/semantics&gt;&lt;/math&gt;) profiles. This study presents a radial-component predominant-mode (RCPM) inversion framework designed for DAS-based surface-wave analysis that explicitly accounts for source–receiver directivity and modal sensitivity of the Rayleigh-wave radial component. The proposed approach matches measured dominant radial dispersion trends with the theoretical mode exhibiting the maximum modal participation. As a result, the RCPM framework eliminates the need for explicit modal indexing, provides a component-consistent interpretation of radial-component dispersion data, and substantially reduces reliance on subjective analyst-driven modal interpretations. The RCPM approach is systematically evaluated using three synthetic ground models and two field DAS data sets. The synthetic results demonstrate that modal energy distribution differs significantly between vertical and radial components in the presence of strong velocity contrasts and velocity reversals, and that conventional inversion approaches may misinterpret modal behavior, resulting in less accurate &lt;span&gt;&lt;/span&gt;&lt;math&gt;\u0000 &lt;semantics&gt;\u0000 &lt;mrow&gt;\u0000 &lt;msub&gt;\u0000 &lt;mi&gt;V&lt;/mi&gt;\u0000 &lt;mi&gt;s&lt;/mi&gt;\u0000 &lt;/msub&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;annotation&gt; ${V}_{s}$&lt;/annotation&gt;\u0000 &lt;/semantics&gt;&lt;/math&gt; profiles. In contrast, the RCPM method consistently captures the correct modal response and yields reliable &lt;span&gt;&lt;/span&gt;&lt;math&gt;\u0000 &lt;semantics&gt;\u0000 &lt;mrow&gt;\u0000 &lt;msub&gt;\u0000 &lt;mi&gt;V&lt;/mi&gt;\u0000 &lt;mi&gt;s&lt;/mi&gt;\u0000 &lt;/msub&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;annotation&gt; ${V}_{s}$&lt;/annotation&gt;\u0000 &lt;/semantics&gt;&lt;/math&gt; profiles. Application to two field DAS data sets further demonstrates good agreement between the inverted &lt;span&gt;&lt;/span&gt;&lt;math&gt;\u0000 &lt;semantics&gt;\u0000 &lt;mrow&gt;\u0000 &lt;msub&gt;\u0000 &lt;mi&gt;V&lt;/mi&gt;\u0000 &lt;mi&gt;s&lt;/mi&gt;\u0000 &lt;/msub&gt;\u0000 &lt;/mro","PeriodicalId":15864,"journal":{"name":"Journal of Geophysical Research: Solid Earth","volume":"131 10","pages":""},"PeriodicalIF":4.0,"publicationDate":"2026-10-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149205803","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"EBSD-Based Calibration of Differential Stress in Experimentally Deformed Quartzite: An All-Grain Perimeter-Density Piezometer","authors":"Scott E. Johnson,&nbsp;Won Joon Song,&nbsp;Walter A. Sullivan,&nbsp;Michael Stipp","doi":"10.1029/2026JB034882","DOIUrl":"https://doi.org/10.1029/2026JB034882","url":null,"abstract":"&lt;p&gt;We use electron backscatter diffraction maps to calibrate an all-grain perimeter-density piezometer for quartz from nine experimentally deformed Black Hills quartzite samples spanning differential stresses &lt;span&gt;&lt;/span&gt;&lt;math&gt;\u0000 &lt;semantics&gt;\u0000 &lt;mrow&gt;\u0000 &lt;mrow&gt;\u0000 &lt;mo&gt;(&lt;/mo&gt;\u0000 &lt;mi&gt;σ&lt;/mi&gt;\u0000 &lt;mo&gt;)&lt;/mo&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;annotation&gt; $(sigma )$&lt;/annotation&gt;\u0000 &lt;/semantics&gt;&lt;/math&gt; of 34 &lt;span&gt;&lt;/span&gt;&lt;math&gt;\u0000 &lt;semantics&gt;\u0000 &lt;mrow&gt;\u0000 &lt;mrow&gt;\u0000 &lt;mo&gt;±&lt;/mo&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;annotation&gt; $pm $&lt;/annotation&gt;\u0000 &lt;/semantics&gt;&lt;/math&gt; 16 to 189 &lt;span&gt;&lt;/span&gt;&lt;math&gt;\u0000 &lt;semantics&gt;\u0000 &lt;mrow&gt;\u0000 &lt;mrow&gt;\u0000 &lt;mo&gt;±&lt;/mo&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;annotation&gt; $pm $&lt;/annotation&gt;\u0000 &lt;/semantics&gt;&lt;/math&gt; 30 MPa. The number-weighted mean perimeter density, &lt;span&gt;&lt;/span&gt;&lt;math&gt;\u0000 &lt;semantics&gt;\u0000 &lt;mrow&gt;\u0000 &lt;mrow&gt;\u0000 &lt;mo&gt;〈&lt;/mo&gt;\u0000 &lt;mrow&gt;\u0000 &lt;mi&gt;P&lt;/mi&gt;\u0000 &lt;mo&gt;/&lt;/mo&gt;\u0000 &lt;mi&gt;A&lt;/mi&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;mo&gt;〉&lt;/mo&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;mo&gt;=&lt;/mo&gt;\u0000 &lt;mrow&gt;\u0000 &lt;mo&gt;(&lt;/mo&gt;\u0000 &lt;mrow&gt;\u0000 &lt;mn&gt;1&lt;/mn&gt;\u0000 &lt;mo&gt;/&lt;/mo&gt;\u0000 &lt;mi&gt;N&lt;/mi&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;mo&gt;)&lt;/mo&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;msub&gt;\u0000 &lt;mo&gt;∑&lt;/mo&gt;\u0000 &lt;mi&gt;i&lt;/mi&gt;\u0000 &lt;/msub&gt;\u0000 &lt;msub&gt;\u0000 &lt;mi&gt;P&lt;/mi&gt;\u0000 &lt;mi&gt;i&lt;/mi&gt;\u0000 &lt;/msub&gt;\u0000 &lt;mo&gt;/&lt;/mo&gt;\u0000 &lt;msub&gt;\u0000 &lt;mi&gt;A&lt;/mi&gt;\u0000 &lt;mi&gt;i&lt;/mi&gt;\u0000 &lt;/msub&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;annotation&gt; $langle P/Arangle =(1/N){sum }_{i}{P}_{i}/{A}_{i}$&lt;/annotation&gt;\u0000 &lt;/semantics&gt;&lt;/math&gt;, scales nearly linearly with differential stress, where each grain &lt;span&gt;&lt;/span&gt;&lt;math&gt;\u0000 &lt;semantics&gt;\u0000 &lt;mrow&gt;\u0000 &lt;mrow&gt;\u0000 &lt;mi&gt;i&lt;/mi&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;annotation&gt; $i$&lt;/annotation&gt;\u0000 &lt;/semantics&gt;&lt;/math&gt; has perimeter &lt;span&gt;&lt;/span&gt;&lt;math&gt;\u0000 &lt;semantics&gt;\u0000 &lt;mrow&gt;\u0000 &lt;mrow&gt;\u0000 &lt;msub&gt;\u0000 &lt;mi&gt;P&lt;/mi&gt;\u0000 &lt;mi&gt;i&lt;/mi&gt;\u0000 &lt;/msub&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;annotation&gt; ${P}_{i}$&lt;/annotation&gt;\u0000 &lt;/semantics&gt;&lt;/math&gt; and area &lt;span&gt;&lt;/span&gt;&lt;math&gt;\u0000 &lt;semantics","PeriodicalId":15864,"journal":{"name":"Journal of Geophysical Research: Solid Earth","volume":"131 10","pages":""},"PeriodicalIF":4.0,"publicationDate":"2026-10-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149205943","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A Global Lithospheric Magnetic Field Model Derived From Multi-Satellite Gradient Observations and Regional Aeromagnetic Data","authors":"Yuxuan Lin,&nbsp;Yan Feng,&nbsp;Jiaxuan Zhang,&nbsp;Pan Zhang,&nbsp;Xinwu Li,&nbsp;Ya Huang","doi":"10.1029/2026JB033783","DOIUrl":"https://doi.org/10.1029/2026JB033783","url":null,"abstract":"<p>Using gradient data from the Macau Science Satellite-1 (MSS-1), CHAMP, Swarm-A, and Swarm-C satellites, together with aeromagnetic model data from China, we built the China-specific Global Gradient Lithospheric Magnetic Model (CGGLM). The new model reaches spherical harmonic degree 140 and uses the Iteratively Re-weighted Least-Squares method with L2 regularization. To obtain cleaner modeling data, we removed the influences of the core field, large-scale external fields, the ocean tide field, the ocean circulation field, and weak current systems (Polar Electrojet and Equatorial Electrojet). Power spectrum and correlation analyses, together with comparisons between CGGLM and other models such as LCS-1 and MF7, show good agreement. The correlation coefficient (<span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 <msub>\u0000 <mi>ρ</mi>\u0000 <mi>n</mi>\u0000 </msub>\u0000 </mrow>\u0000 <annotation> ${rho }_{n}$</annotation>\u0000 </semantics></math>) is greater than 0.75 for <i>N</i> ≤ 100. Above degree 120, the coefficients change somewhat due to the influence of near-surface data, but the correlation remains acceptable. CGGLM also shows improved regional consistency with aeromagnetic observations. Compared with LCS-1, the new model captures more medium- to small- scale magnetic anomalies in China, particularly in southwestern Tibet and southern China.</p>","PeriodicalId":15864,"journal":{"name":"Journal of Geophysical Research: Solid Earth","volume":"131 10","pages":""},"PeriodicalIF":4.0,"publicationDate":"2026-10-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1029/2026JB033783","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149146714","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Lithospheric Delamination of the Pamir Driven by the Underthrusting Indian Plate as Inferred From Seismic Observations","authors":"Kecheng Zhou,&nbsp;Xuewei Bao,&nbsp;Bingfeng Zhang,&nbsp;Hanlin Chen,&nbsp;Yang Pan,&nbsp;Yingkai Wu","doi":"10.1029/2026JB034957","DOIUrl":"https://doi.org/10.1029/2026JB034957","url":null,"abstract":"<p>The tectonic evolution and deformation mechanisms of the Pamir remain controversial, partly because the crustal response to deep lithospheric geodynamic processes is insufficiently constrained. Two competing lithospheric tectonic models are under consideration: subduction of the Asian slab and delamination of Pamir lithosphere, each of which predicts distinct crustal anisotropic signatures. Here, we use shear-wave splitting of Moho P-to-S converted-phases from receiver functions recorded at 198 seismic stations to map crustal anisotropy across the Pamir and the surrounding regions, thereby providing direct constraints on crustal deformation styles. We further determine crustal thicknesses and Vp/Vs ratios using H-κ-c stacking. Crustal thickness correlates positively with surface elevation and negatively with Bouguer gravity anomalies, indicating that crustal thickening provides the dominant first-order support for the high topography. More importantly, Pms splitting measurements reveal strong crustal anisotropy, with a mean delay time of ∼0.66 s, and a systematic rotation of fast-polarization orientations across the intermediate-depth seismicity belt. In the southern Pamir, convergence-parallel fast directions record N-S-oriented basal shear imposed by the indented Indian lithospheric mantle, which has likely promoted Quaternary extension of southern Pamir. Conversely, to the north of this belt, orogen-parallel fast-directions signify pure-shear thickening of the Pamir lithosphere. Together with low crustal Vp/Vs ratios of 1.60–1.72 beneath the southern Pamir, which are consistent with a felsic bulk crust and removal of mafic lower crust, these observations favor Indian-lithosphere-induced delamination of the Pamir lithosphere rather than a model dominated by uniform southward subduction of Asian lithosphere.</p>","PeriodicalId":15864,"journal":{"name":"Journal of Geophysical Research: Solid Earth","volume":"131 10","pages":""},"PeriodicalIF":4.0,"publicationDate":"2026-10-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149146282","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Deep Learning Based Upscaling for Predicting Relative Permeabilities Directly From Sub-Volume Images","authors":"Jingwei Zhu,&nbsp;Yuntao Jia,&nbsp;Hang Deng,&nbsp;Ke Xu,&nbsp;Chiyu Xie,&nbsp;Martin J. Blunt","doi":"10.1029/2026JB034450","DOIUrl":"https://doi.org/10.1029/2026JB034450","url":null,"abstract":"<p>Relative permeability (RP) controls multiphase flow in porous media and is therefore central to subsurface applications such as CO₂ sequestration and underground energy storage. Although deep learning has recently enabled RP prediction from digital rocks, direct inference for cm-scale samples is often impractical because high-resolution imaging is costly and has a limited field of view. Here we propose a physics-informed deep learning framework, a three-dimensional (3D) spatial pyramid pooling convolutional upscaling network (3DSPPConvUpNet), that predicts whole-sample RPs from small images together with wettability descriptors. The network embeds scale and geometry information (resolution, sub-volume location, and size proportion) and enforces key physical constraints in the loss function. Across multiscale sandstone data sets, the proposed model achieves high predictive skill (testing <span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 <mtext>MAE</mtext>\u0000 <mo>&lt;</mo>\u0000 <mn>4</mn>\u0000 <mo>%</mo>\u0000 </mrow>\u0000 <annotation> $text{MAE}&lt; 4mathit{%}$</annotation>\u0000 </semantics></math>) and reproduces experimental core-scale RPs for two unseen sandstones using only 1/16 and 1/12 of their full-rock structures, respectively. These results demonstrate a practical new route to data-driven RP upscaling when full-core imaging is unavailable.</p>","PeriodicalId":15864,"journal":{"name":"Journal of Geophysical Research: Solid Earth","volume":"131 10","pages":""},"PeriodicalIF":4.0,"publicationDate":"2026-10-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149146369","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"BaSIC: A Bayesian Inversion Model for Basalt Source Investigation and Characterization","authors":"E. H. Cunningham,&nbsp;S. Lambart,&nbsp;E. L. Brown","doi":"10.1029/2026JB034659","DOIUrl":"https://doi.org/10.1029/2026JB034659","url":null,"abstract":"<p>We present BaSIC: Basalt Source Investigation and Characterization, an open-source Python based Bayesian inversion method to constrain the source mineralogy of basalts. Using bulk rock geochemistry, the model takes the averages and standard deviations of six elemental ratios (Mn/Fe, Zn/Fe, Mn/Zn, Sc/Zn, Co/Fe, and Ga/Sc) for a given basalt suite and inverts for the most likely source mineral assemblage and melt fraction. When applied to a global suite of ocean island basalts, BaSIC reveals a strong tectonic control on apparent source mineralogy. Isolated oceanic islands situated above thick lithosphere yield source assemblages that are systematically poorer in olivine and richer in garnet than islands located near spreading centers or above thinner lithosphere. We attribute this result to preferential sampling of fertile lithologies (rather than cryptic mineralogical variations) in the deeper regions of the melting column. We further test our model using basalts from the recent (2021–2024) eruptions on Iceland's Reykjanes Peninsula. BaSIC detects a progressive pyroxene enrichment in the source and decrease of the bulk melt fraction with successive eruptions, consistent with isotopic studies that show recently erupted lavas are more enriched and isotopically variable than the most recent eruptions (Reykjanes Fires, ∼800 years ago) prior to the new cycle. Together, these results demonstrate that BaSIC can resolve both regional-scale variations across ocean island systems and time-evolving source changes within a single volcanic system.</p>","PeriodicalId":15864,"journal":{"name":"Journal of Geophysical Research: Solid Earth","volume":"131 10","pages":""},"PeriodicalIF":4.0,"publicationDate":"2026-10-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1029/2026JB034659","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149146064","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Reaction-Driven Crack Propagation Controlled by Vein Extension in a Dilute Fracture System","authors":"Rui Feng,&nbsp;John Rudnicki","doi":"10.1029/2026JB034377","DOIUrl":"https://doi.org/10.1029/2026JB034377","url":null,"abstract":"&lt;p&gt;Permanent mineral trapping of &lt;span&gt;&lt;/span&gt;&lt;math&gt;\u0000 &lt;semantics&gt;\u0000 &lt;mrow&gt;\u0000 &lt;msub&gt;\u0000 &lt;mtext&gt;CO&lt;/mtext&gt;\u0000 &lt;mn&gt;2&lt;/mn&gt;\u0000 &lt;/msub&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;annotation&gt; ${text{CO}}_{2}$&lt;/annotation&gt;\u0000 &lt;/semantics&gt;&lt;/math&gt; in ultramafic rocks can be accelerated if carbonate precipitation wedges open microcracks and sustains crack growth, thereby increasing permeability and reactive surface area. We develop a vein-extension controlled model for carbonation reaction-driven cracking in a dilute fracture system that couples (a) a singular integral equation for crack opening, (b) crystallization pressure-limited precipitation kinetics for vein thickening, (c) a growth law for the mineralized vein length &lt;span&gt;&lt;/span&gt;&lt;math&gt;\u0000 &lt;semantics&gt;\u0000 &lt;mrow&gt;\u0000 &lt;mi&gt;b&lt;/mi&gt;\u0000 &lt;mrow&gt;\u0000 &lt;mo&gt;(&lt;/mo&gt;\u0000 &lt;mi&gt;t&lt;/mi&gt;\u0000 &lt;mo&gt;)&lt;/mo&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;annotation&gt; $b(t)$&lt;/annotation&gt;\u0000 &lt;/semantics&gt;&lt;/math&gt;, and (d) a propagation criterion based on the critical stress intensity factor. The growth law for &lt;span&gt;&lt;/span&gt;&lt;math&gt;\u0000 &lt;semantics&gt;\u0000 &lt;mrow&gt;\u0000 &lt;mi&gt;b&lt;/mi&gt;\u0000 &lt;mrow&gt;\u0000 &lt;mo&gt;(&lt;/mo&gt;\u0000 &lt;mi&gt;t&lt;/mi&gt;\u0000 &lt;mo&gt;)&lt;/mo&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;annotation&gt; $b(t)$&lt;/annotation&gt;\u0000 &lt;/semantics&gt;&lt;/math&gt; captures the competition between diffusive supply and reaction rate, reduced when reactant residence time is insufficient for precipitation, providing a minimal representation of the non-collocated nature of carbonation. Non-dimensionalization identifies three governing controls: a Damköhler-type number quantifying the competition between precipitation kinetics and diffusion, a chemical supply strength characterizing solute availability relative to host stiffness, and a normalized fracture toughness. Semi-analytical solutions reproduce a prolonged initiation stage during which stress intensity builds while crack length remains fixed, followed by stable wedge-loaded propagation once toughness is reached. Initiation time and onset propagation speed depend nonmonotonically on transport conditions, producing an optimum region (e.g., near Damköhler number &lt;span&gt;&lt;/span&gt;&lt;math&gt;\u0000 &lt;semantics&gt;\u0000 &lt;mrow&gt;\u0000 &lt;mi&gt;λ&lt;/mi&gt;\u0000 &lt;mo&gt;∼&lt;/mo&gt;\u0000 &lt;mn&gt;1&lt;/mn&gt;\u0000 &lt;msup&gt;\u0000 &lt;mn&gt;0&lt;/mn&gt;\u0000 &lt;mrow&gt;\u0000 &lt;mo&gt;−&lt;/mo&gt;\u0000 &lt;mn&gt;3&lt;/mn&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;/msup&gt;\u0000 &lt;/mrow&gt;\u0000 ","PeriodicalId":15864,"journal":{"name":"Journal of Geophysical Research: Solid Earth","volume":"131 10","pages":""},"PeriodicalIF":4.0,"publicationDate":"2026-10-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1029/2026JB034377","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149146065","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}