The potential for strong induced earthquakes in industrial production fields is largely controlled by the spatial arrangement of pre-existing faults shaped by regional tectonics. The 2021 Ms 6.0 Luxian earthquake in the southern Sichuan basin is an unusual case in which the seismogenic fault geometry deviates from the prevailing regional stress field and geological framework. To date, the seismogenic environment and the tectonic processes responsible for this destructive event remain poorly understood. In this study, we present a sedimentary shearwave velocity model and eleven moment tensor solutions across the Luxian shale gas field, derived using data collected by our newly deployed seismic network. Our results reveal previously unrecognized, nearly reversed lateral variations in the amplitudes of synclinal low-velocity anomalies between terrestrial and marine strata, in addition to a first-order velocity contrast that correlates with the regional anticline-syncline architecture. The central Yujiasi syncline exhibits weaker low-velocity anomalies in the shallow terrestrial strata than areas to the north and south, reflecting lower strain intensity likely influenced by shallower decollement layers. Detected seismicity and anomalous reverse-faulting events with fold-parallel P-axes (including the Ms 6.0 earthquake) cluster mainly within two strain transition zones of the Yujiasi syncline, where stress is expected to concentrate and form fold-normal fault planes. These observations provide direct evidence that heterogeneous folding regulates the spatial distribution of induced seismicity in the southern Sichuan basin. They also help identify areas susceptible to induced seismic hazards and provide guidance for planning hydraulic fracturing operations in the region.

Tectonic regionalization characterizes the primary variation of Earth’s lithosphere and is critical for the quantitative investigation of geodynamic evolution. Although classification of lithospheric blocks based on crustal rock types has been successful, tectonic regionalization with information on deep crustal and mantle structures could provide an alternative perspective due to the addition of mantle structure information. Rayleigh-wave phase velocity dispersion data quantify crustal and upper mantle structures and are thus suitable for deep tectonic regionalization. Here, we used a variational autoencoder (VAE), an unsupervised machine learning method, to classify Rayleigh-wave dispersion maps at 8–120 s in China and its surrounding regions. VAE can compress high-dimensional and nonlinear data to a minimal set of latent variables, which allows a quantitative tectonic regionalization. We found that two latent variables are sufficient to represent the general variations of the dispersion maps. The two latent variables are spatially correlated with topography and the effective elastic thickness of the lithosphere. By generating dispersion curves using even samples from the latent space, we can categorize the continental lithosphere in and around China into four distinct types visually, potentially reflecting different lithospheric activities (e.g., magmatic activities) and composition states related to the physical properties of the lithosphere. We also find that dispersion curves with large reconstruction loss are indicative of regions with relatively poor data resolution. The information extracted from dispersion curves enables us to better understand the integral lithospheric structure from shallow to deep.

Abstract The Pamir, located at the northwestern margin of the Tibetan Plateau, is undergoing E–W extension within its interior, accommodated by micro‐block motions along major fault systems; however, the mechanisms governing this modern block kinematics remain elusive. Here, we present an updated crustal shear‐wave velocity model of the region, developed via adjoint‐state surface‐wave traveltime tomography. The Rayleigh‐wave dispersion data set is compiled from teleseismic and regional earthquakes, as well as ambient noise; for the latter, three‐station interferometry was employed to incorporate asynchronous records. The resulting model reveals distinct middle‐to‐lower crustal low‐velocity zones (LVZs) that spatially align with the major active faults bounding the micro‐blocks. Although the estimated melt fractions within these LVZs fall below the rheological threshold required to sustain large‐scale flow, rock strength is drastically reduced within these zones. This melt‐induced weakening focuses deep‐seated strain and promotes fault development, thereby regulating the modern crustal kinematics of the Pamir.

Central Mongolia, recording Phanerozoic accretion and continental growth, has experienced varying intracontinental deformation since the Cenozoic. These include dome-like uplift of the Hangai Dome accompanied by diffuse normal faults with low seismicity, but shortening at its peripheries marked by significant strike-slip/thrust motions with intensive seismicity. Nevertheless, how this complex intracontinental deformation is accommodated by deep strain partitioning remains elusive. We present a new high-resolution 3-D radially anisotropic shear-wave velocity model of the lithosphere beneath central Mongolia using ambient noise tomography with data mainly from two dense seismic arrays. Specifically, in the mid-lower crust, the Hangai Dome shows weak anisotropy, indicating relatively weak deformation due to its cratonic basement, whereas the dome's peripheries feature strong positive radial anisotropy, suggesting intensive sub-horizontal ductile shear deformation. Additionally, we demonstrate the presence of the uppermost-mantle partial melting and further constrain the melt fraction and shape by radial anisotropy, which suggest a northeastward decrease in lithospheric strain across the Hangai Dome and its peripheries, likely due to the propagation and subsequent attenuation of NE-directed compressive stress from the India-Asia collision through central Mongolia. Considering the heterogenous lithospheric rheology, our findings provide novel insights into the lithospheric strain partitioning below the complex intracontinental deformation field in central Mongolia.

The mechanisms responsible for intracontinental basaltic volcanism are not well understood. The Cenozoic long-lived (similar to 30 Myr) and diffuse intraplate volcanism in central Mongolia is an ideal natural lab to address this issue. Here we present a high-resolution lithospheric 3-D shear-wave velocity model using ambient noise tomography with data mainly from two dense seismic arrays. Our model shows strong lithospheric heterogeneities beneath central Mongolia, correlating well with the occurrence of Cenozoic basaltic volcanism. Specifically, relatively thick, high-velocity lithospheric mantle is imaged beneath the central Hangai Dome and the H & ouml;vsg & ouml;l region where Precambrian basements have been suggested to exist, which likely represent relicts of old cratonic lithosphere. Step changes in lithospheric thickness formed at their peripheries due to heterogenous lithospheric thinning or modification likely caused by recent deep mantle upwelling. More interestingly, most basaltic volcanism in central Mongolia is located at or near these strong lateral gradients of lithospheric thickness, suggesting the important role of small-scale convection in their formation due to lithospheric thickness undulations. Taken together, the Cenozoic intraplate volcanism in central Mongolia was likely controlled by inherited lithospheric heterogeneities and mantle upwelling.

Understanding whether and how dense rocks in continental crust are recycled back to mantle depths is crucial to deciphering the evolution of the Earth. Viscous drainage of the eclogitic layer in the lower thickened crust has been proposed as a mechanism that predates plate tectonics, but it has not been confirmed by observations. Specifically, it remains unclear whether this mechanism operated during orogenesis driven by modern plate tectonics. The Pamir Plateau lies at the western end of the active Himalayan-Tibetan orogen in the India-Asia collision zone. Here, we present a three-dimensional resistivity model constructed by inverting magnetotelluric data from the eastern Pamir and its surroundings. The mid-crustal conductors are interpreted as trapped aqueous fluids from eclogitization reactions in the lower thickened crust. Three-dimensional resistivity modeling supports the hypothesis of a nearly vertical collision mechanism between the East Pamir crust and the Tarim crust. In addition, the resistivity and velocity structures, as well as the characteristics of intermediate-depth earthquakes, can be well explained by viscous drainage followed by dripping of the eclogitic layer based on the petrophysical properties and rheological behavior. We argue that viscous drainage and dripping have initiated and are ongoing in the eastern Pamir, potentially representing the early-stage of stabilization in the orogen.

Abstract In the northwestern India‐Asia collision zone, intensive tectonic deformation (e.g., orogenic uplift and crustal exhumation) is observed, but its relationships with deep mantle dynamics remain controversial. Here, we construct a 3D P‐wave velocity model of the upper mantle beneath the Pamir, Tianshan, and adjacent regions using teleseismic tomography with seismic data from 353 stations and 3,321 teleseismic events. Our tomographic model reveals a striking subvertical boundary between the low‐velocity central Tianshan and the high‐velocity Tarim lithosphere beneath the southern Tianshan fault system, indicating that the Tarim lithosphere has been sub‐horizontally compressing the central Tianshan lithosphere. Furthermore, a high‐velocity anomaly is observed in the upper mantle beneath the central Tianshan, which is interpreted as the delaminated Tianshan lithosphere due to the compression of the Tarim. In the Pamir‐Hindu Kush region, a slab‐like high‐velocity anomaly extends into the mantle transition zone (MTZ) beneath the Hindu Kush. This, along with our imaged flat high‐velocity anomaly beneath the Pamir, suggests that the Indian lithosphere is steeply subducting beneath the Hindu Kush and sub‐horizontally underthrusting beneath the Pamir. Additionally, the underthrusting Indian lithosphere may force the Tajik lithosphere to delaminate beneath the western Pamir, as suggested by a steeply dipping high‐velocity anomaly. A large‐scale high‐velocity anomaly is imaged near the base of the MTZ beneath the Pamir and Karakoram, which likely represents the detached Indian lithosphere due to the breakoff of the Indian slab ∼20 Ma.

Abstract The Hangai Dome in central Mongolia represents one of the most prominent intracontinental uplifts, yet the relative contributions of crustal and mantle dynamics in sustaining its high topography remain unresolved. Here we jointly invert Rayleigh wave dispersion and receiver function data to constrain crustal and uppermost mantle structures, including Moho and lithosphere‐asthenosphere boundary (LAB) architecture, crustal Vp/Vs ratios and Vs. Our results reveal the significantly thickened crust (50–53 km) and thinned lithosphere (65–70 km) beneath the Hangai Dome, with pronounced lateral variations indicating presence of fluids and volatiles in the lower crust beneath the eastern Hangai Dome that generates low‐velocity zone and promotes rapid ascent of mantle‐derived melts. Furthermore, surface elevation exhibits strong linear correlations with crustal thickness and Bouguer gravity anomalies, consistent with near‐isostatic equilibrium. Our results indicate a leading role of inherited thickened crust in controlling topographic uplift of the Hangai Dome, whereas asthenospheric upwelling likely exerts a secondary influence.

Probing the deep lithosphere is a frontier in solid Earth science. Present-day lithospheric architecture is a time-integrated configuration shaped by long-term geological processes, with magmatism playing a pivotal role. Although petrological inference has long been incorporated into lithospheric investigations and integrated with advanced geophysical methods, the full potential of surface-exposed magmatic rocks remains underexploited, particularly in ancient orogens. Here, we investigate Late Carboniferous to Middle Permian magmatic rocks in the West Tianshan, SW Central Asian Orogenic Belt, using multi-proxy isotopic and elemental spatial imaging together with thermodynamic phase-equilibrium modeling. Radiogenic (Hf-Nd) isotopic mapping reveals two distinct domains: an isotopically depleted domain (IDD) in the north and an isotopically enriched domain (IED) in the south. The lower crust beneath IDD was built through magmatic differentiation of intermediate magmas sourced from an oceanic subduction-modified mantle. In contrast, the lower crust beneath IED formed via the differentiation of sanukitoid magmas derived from an ancient crust-metasomatized mantle, with variable involvement of Tarim supracrustal relaminant. Domain-scale contrasts in Bouguer gravity anomaly and Vs velocity structure indicate marked differences in the modern lower crust’s physical properties. Given the insignificant Mesozoic-Cenozoic lithospheric modification, the systematic spatial correspondence between geochemical proxies and lower-crustal Vs velocity structure links modern lithospheric architecture directly to Late Paleozoic magmatism. Our study provides a reproducible workflow that integrates geochemical information from surface-exposed, deep-time magmatic rocks with geophysical observations to explore lithospheric architecture and its genesis beneath ancient orogens.

Postcollisional downgoing of the Indian plate has absorbed large amounts of the Cenozoic India-Asia convergence and is a key process governing the Tibetan Plateau's evolution and growth; however, to date, whether the Indian slab is currently subducting or underthrusting is still controversial. Here, we present new constraints on the nature of seismic anisotropy within the crust of the eastern Lhasa terrane and the adjacent areas by exploiting the splitting phenomenon of P-to-S converted phases from the Moho. A crustal seismic anisotropy dataset in the main collisional belt of Tibet is then assembled by incorporating the newly obtained and published measurements. Our results highlight the systematic changes in preferred orientation of deep-crust anisotropic minerals along the perpendicular direction of the Himalayan arc, with a sharp northward transition from convergence-parallel to orogen-parallel directions occurring at similar to 450 to 500 km north of the Main Frontal thrust. The latter observation provides an estimate of the northern frontier of the Indian lower crust from the perspective of seismic anisotropy and indicates overall and long-distance underthrusting of the Indian plate under Tibet.

On 7 January 2025, a M w 7.1 normal-faulting earthquake occurred in the Dinggye Rift zone, southern Tibetan plateau. In this study, we present high-resolution crustal S-wave isotropic and P-wave azimuthally anisotropic velocity models around the source region of this earthquake, constructed using novel adjoint-state traveltime tomography techniques. We find that the high-slip zone of the mainshock rupture coincides with a high-strength asperity (Lhagai gneiss dome) characterized by negligible seismic anisotropy. The source region is subject to basal shear imposed by the underthrusting Indian slab and impinging fluid flow through a slab window, as evidenced by the observations of convergence-parallel anisotropy and pronounced low-velocity anomalies below the hypocenter. These tectonic forces collectively reconfigure the local stress field to favor normal faulting by counteracting the convergence-induced compression, and together with the high elastic strain accumulation facilitated by the fault asperity, contributes to the generation of this high-magnitude normal-faulting continental earthquake.

To decipher the mechanism by which the Phanerozoic accretionary terranes collaged with the Tarim Craton, we constructed a three-dimensional (3-D) lithospheric resistivity model using magnetotelluric data and inversion with testing. The model covers the area across the northern Tarim Craton in the south and the southern Altaids in the north and shows five tectonic-related low-resistivity regions. The low resistivity in East Junggar highlights a Permian rifting zone. The southwest Tianshan low-resistivity anomalies mark asthenospheric upwellings and are related to present-day orogenesis. The intra-crustal low-resistivity area in the northern Tarim Craton could be attributed to metamorphic products from the layered underplating coeval within the Tarim large igneous event. The relatively weak low-resistivity anomalies in Central Tianshan may represent fossil suturing zones. Beneath western Junggar and Chinese North Tianshan (NTS), a large low-resistivity anomaly is continuously distributed in the upper mantle, but spatial correspondence was not shown with the overlying resistivity structure, which could be attributed to the movement of the shallow lithosphere decoupled from the lower lithospheric mantle. We argue that the Yili-Central Tianshan terrane moved northeastward to collage with the Junggar terrane, driving the Junggar terrane rotation and shallow buckling of West Junggar, which constructed the thin-skinned Chinese NTS. The closure of the South Tianshan back-arc basin, associated with southward subduction, completed the amalgamation of peripheral accretionary terranes with the Tarim Craton after the Late Permian. The present study supplies a typical example of the amalgamation of accretionary terranes with a core, thus improving the understanding of continental growth.

Systematical investigation of deep mantle structure beneath the Pamir Plateau, western Tian Shan and their surroundings is of great significance to understand dynamics of continental collision, intracontinental orogenesis and deformation in response to the Indo-Eurasian collision. In this research, we imaged the mantle transition zone (MTZ) structure beneath these regions using 42,560 P-wave receiver functions obtained from 352 seismic stations and 6,173 teleseismic events. Our results reveal significant 15-20 km depression of the 410-km discontinuity (d410) mainly beneath the southern Kazakh Shield, which is consistent with the low-velocity anomaly in tomographic models and thus attributed to the mantle upwelling from the MTZ, providing evidence for the fossil Tian Shan plume responsible for the Late Cretaceous-Paleocene basaltic magmatism (74-52 Ma) at the western Tian Shan. Considering that the d410 is slightly depressed by similar to 8 km beneath the western Tian Shan, deep subduction of the Tarim lithosphere is likely excluded and its subhorizontal indentation into the Tian Shan is preferred. As a result, segments of thickened Tian Shan lithosphere delaminated and accumulated near the 660-km discontinuity (d660), which induce small-scale upwelling across the d410 there. The d410 is depressed by similar to 10-15 km beneath Tarim, which is interpreted to be caused by the mantle upwelling originating from beneath the d410. The d660 below the central Hindu Kush is extremely depressed by 25-30 km, providing direct evidence for the deep subduction of Indian lithosphere into the bottom of the MTZ and suggesting different mechanisms for continental collision between the Hindu Kush and Pamir Plateau. Intensive tectonic activities are ongoing in the Pamir Plateau, western Tian Shan and their surroundings, whereas the deep mantle structure and related dynamical processes are poorly constrained by independent seismological observations. Here we mapped the detailed mantle transition zone (MTZ) structure utilizing large data sets of seismic data by imaging the 410-km (d410) and 660-km (d660) discontinuities. Our results show prominent depression of d410 (15-20 km) below the southern Kazakh Shield in agreement with the tomography-derived low-velocity anomalies, which we interpret as mantle upwelling from the MTZ likely associated with the fossil Tian Shan plume and the eruption of basaltic magmatism (74-52 Ma) in the western Tian Shan. Furthermore, the subhorizontal indentation of Tarim lithosphere into western Tian Shan is supported by slightly depressed d410 (similar to 8 km) there, followed by the delamination of thickened Tian Shan lithosphere into the bottom of the MTZ. Furthermore, mantle upwelling from the MTZ beneath the Tarim Basin is indicated by the depressed d410 there (similar to 10-15 km). While the Indian slab underthrusts northward beneath the Pamir Plateau, it subducts deep into the bottom of the MTZ beneath the central Hindu Kush. The mantle transition zone structure beneath the Pamir Plateau and western Tian Shan and adjacent regions are imaged with great detail The 15-20 km depression of the 410-km discontinuity beneath southern Kazakh Shield is likely associated with the fossil Tian Shan plume Significant depression of the 660-km discontinuity (25-30 km) suggests deep subduction of the Indian slab beneath the central Hindu Kush

Syncontractional extension is prominent in present-day Tibet, but its origin remains vigorously debated. Several deep-seated geodynamic processes (e.g., Indian underthrusting, horizontal flow, and mantle upwelling) have been linked to Tibetan rifting. Indian underthrusting is a good candidate because it can well explain why surface rifts are more prominent south of the Bangong-Nujiang suture; however, how Indian underthrusting causes extension is not well understood and lacks observational constraints. Seismic anisotropy, measured by exploiting the birefringence effect of shear waves, can be indicative of the deformation styles within the crust. Here, we unveil the dominant convergence-parallel alignment of anisotropic fabrics in the deep crust of the southern Tibetan rifts using seismic recordings collected from our recently deployed and existing seismic stations. This finding suggests that the strong north-directed shearing exerted by the underthrusting Indian plate is key to enabling present-day extension in southern Tibet.

Erythro-myeloid progenitors of the yolk sac that originates during early embryo development has been suggested to generate tissue-resident macrophage, mast cell, and even endothelial cell populations from fetal to adult stages. However, the heterogeneity of erythro-myeloid progenitors (EMPs) is not well characterized. Here, we adapt single-cell RNA sequencing to dissect the heterogeneity of EMPs and establish several fate-mapping tools for each EMP subset to trace the contributions of different EMP subsets. We identify two primitive and one definitive EMP subsets from the yolk sac. In addition, we find that primitive EMPs are decoupled from definitive EMPs. Furthermore, we confirm that primitive and definitive EMPs give rise to microglia and other tissue-resident macrophages, respectively. In contrast, only Kit+ Csf1r- primitive EMPs generate endothelial cells transiently during early embryo development. Overall, our results delineate the contribution of yolk sac EMPs more clearly based on the single-cell RNA sequencing (scRNA-seq)-guided fate-mapping toolkit.

This project contains the datasets needed to produce the crustal and upper-mantle shear-wave velocity model in a manuscript submitted for publicaiton with Journal of Geophysicsl Research - Solid Earth. The folders contains the final stacked Rayleigh-wave CCFs in SAC format between all available station pairs.

Abstract The mechanisms of surface uplift of Hangai Dome (>2 km) and formation of Cenozoic intraplate volcanism in central Mongolia remain vigorously debated. Here we directly investigate the mantle transition zone (MTZ) structure beneath central Mongolia to explore whether the deep mantle geodynamical processes have played a role. Our results reveal significant MTZ thinning of 8–13 km in three subareas mainly caused by the uplifted 660‐km discontinuity (∼10 km). In addition, the 410‐km discontinuity is depressed beneath the Hangai Dome (∼6 km) and the northern portion of the study area (10–15 km). These observations provide direct evidences for intracontinental mantle upwellings from the lower to the upper mantle, causing the Cenozoic uplift and basaltic volcanism of central Mongolia. Furthermore, these mantle upwellings are relatively sluggish compared to canonical mantle plumes based on the small magnitude of MTZ thinning and thus relatively moderate thermal anomaly within the MTZ (62–100 K).

The mechanisms causing the uplifting of the Tien Shan, one of the largest and most active intracontinental orogenic belts on Earth, have been vigorously debated for decades. Seismic investigation is a fundamental tool used for deep structural exploration and is key to understanding continental geodynamics. As such, in this study, we reviewed the recent research progress on the crustal and upper-mantle structures of the Tien Shan and the remaining controversies. The results showed that the Tien Shan and adjacent basins exhibit contrasting structural and physical properties from the crust down to the upper mantle in various aspects, such as crustal thickness, Moho morphology, mantle transition-zone thickness, seismic velocity, and seismic attenuation. The mountainous areas have complex crustal seismic anisotropy patterns, whereas orogen-parallel anisotropic fabrics dominate at upper mantle depths. Low-velocity anomalies pervasively exist in the mid-lower crust and uppermost mantle of Tien Shan. Taken together, these observations provide evidence of the important roles played by intracontinental subduction and mantle upwelling in Cenozoic orogenesis of the Tien Shan. However, further development of our understanding of the geodynamics in Tien Shan has been hindered by the low imaging resolution of seismic anisotropy, lithosphere-asthenosphere boundary, and mantle transition zone in eastern Tien Shan. And some important geophysical parameters and their implications are still far from being well-understood. Future deployment of dense temporary seismic arrays in the eastern Tien Shan and joint inversion of multiple and complementary geophysical data will considerably increase the resolution of seismic models and ultimately enhance our knowledge of geodynamic evolution in compressional intracontinental orogens.