Global observations reveal faults respond to earthquake ruptures through localized on-fault slip and distributed off-fault deformation (OFD). Deformation becomes increasingly delocalized along faults that are immature or geometrically complex, rupture slowly, or propagate through sediment-rich regions. However, the physical processes by which sediments control this delocalization remain largely unresolved. Here we utilize high-resolution optical imagery to characterize surface rupture and OFD of the 2025 Mw 7.8 Myanmar earthquake, a supershear rupture event on a mature fault topping with thick sediments including the Quaternary alluvium and Irrawaddy Formation. Our results show averaging 32% OFD, far exceeding 13-19% expectation from global observations of such mature faults with simple geometry and supershear rupture speeds. Sediment-rich terrains along this rupture significantly amplify OFD to ~31-42%, nearly double the 19% observed in bedrock, and generate two highly diffused deformation sections lacking clear surface rupture. Dynamic rupture simulations incorporating variations in shear-wave velocity and frictional properties reproduce the observed OFD spectrum (from localized to fully delocalized deformation, revealing that plastic yielding of sediments dramatically delocalizes fault strain in the uppermost few hundreds of meters. We suggest such process should be integrated into models of shallow faulting and seismic hazard assessment in sediment-rich regions worldwide.

The 2025 Myanmar earthquake caused heavy casualties and economic losses in Myanmar and surrounding regions. The mechanism of the unexpectedly long rupture and the effect of sediments on its rupture dynamics remain unclear. Here we integrate seismic and geodetic observations with kinematic inversions and dynamic rupture simulations, revealing that the rupture extended ~450 km with a maximum slip of 6.9 m concentrated within the top 10 km of the upper crust. The rupture propagated ~70 km northward (subshear to supershear) and ~380 km southward (subshear to supershear and back to subshear). The long southward-propagating supershear rupture created a highly energetic front that resulted in an unexpectedly long surface rupture. Moreover, we find the coexistence of shallow subshear and deep supershear around station NPW due to the influence of sediments. Our results highlight the importance of combining data-driven inversions and physics-based modeling to decipher the rupture dynamics of large earthquakes. Integrating geodetic and seismic data with kinematic and dynamic modeling suggests that the 2025 Mw 7.7 Myanmar rupture transitioned between subshear and supershear speeds in both directions and was strongly influenced by thick sediments.

The MW 8.8 Kamchatka earthquake in Russia's Kamchatka Peninsula is one of the top ten largest earthquakes worldwide since 1900. This event occurred in a tectonically active Kurile–Kamchatka subduction zone where several large earthquakes (M ​> ​8) have occurred over the past 100 years. Here, we combine the teleseismic vertical-component P-wave back-projection method and finite fault inversion with teleseismic P and SH waveforms to investigate the kinematic features of this earthquake. The results indicate that the ruptured area spans approximately 600 ​km in length and 175 ​km in width, with a total source duration of about 220 ​s. Moreover, the coseismic slip occurred mainly within the subducting interface away from the trench, reaching a maximum slip of about 8 ​m. Notably, the rupture propagated approximately 500 ​km southwestward from the hypocenter, consistent with the aftershock distribution. These results imply that the rupture zone of this earthquake might spatially overlap with that of the 1952 MW 8.8–9.0 Kamchatka earthquake. Furthermore, the smaller than anticipated tsunami generated by this megathrust event could be attributed to its limited shallow slip near the trench. This study provides preliminary kinematic insights into this event and lays a certain foundation for subsequent in-depth studies.

[Objective]The West Kunlun Orogenic Belt,located on the northwestern margin of the Tibetan Plateau,is a key area for studying the tectonic uplift and expansion of the plateau.However,the Cenozoic uplift of the West Kunlun Orogenic Belt is still controversial.[Methods]This study focuses on the well-exposed Late Cenozoic sediments on the Puska Anticline,West Kunlun foreland.High-resolution magnetostratigraphy was applied to constrain the age of the lower boundary of the growth strata,providing insight into the uplift timing of the West Kunlun Orogenic Belt from the per-spective of mountain-basin coupling.[Results]Magnetic analysis indicates that hematite and magnetite are the dominant remanence carriers.The high-resolution magnetostratigraphy reveals an age range of～6.8 to 2.4 Ma for the Puska Section,and the base age of the growth strata is～5.3 Ma,indicating that the deformation of this anticline was initiated at～5.3 Ma.[Conclusions]Integrating previously published results of sedimentation,tectonics,and low-temperature thermochrono-logy in the West Kunlun foreland,this study proposes that the West Kunlun Orogenic Belt has undergone an episode of intensive uplift since～5.3 Ma.This suggests that the Tibetan Plateau has experienced significant uplift since the beginning of the Pliocene,with tectonic strain beginning to propagate toward the Tarim Basin.[Significance]This study provides new perspectives and evidence for understanding the complex relationship between the uplift of the Tibetan Plateau and the sedimentary responses in its periphery,contributing to further unraveling the comprehensive impact of the Tibetan Plateau.

Pre-seismic turbidity and salinity anomalies in groundwater were documented at HS04 and HS14 monitoring wells and/or springs along the East Anatolian Fault Zone (EAFZ) following the 2023 Kahramanmara & scedil; Earthquake Doublet (Mw 7.8 and Mw 7.6). By synthesizing hydrogeochemical datasets (2013-2023) with post-seismic responses, we unravel fault-segmented groundwater evolution: Northern Na-Cl and Na-HCO3 type waters result from mixing of mantle-derived magmatic fluids (0 %-7 % contribution) with shallow groundwater, governed by volcanic rock-carbonate dissolution. Central-southern Ca-HCO3 and Ca-Na-HCO3 systems reflect shallow circulation with localized inputs from evaporites (increased SO concentration caused by dissolution of anhydrite), ophiolites (Mg2+ anomalies) and seawater. PHREEQC simulation shows that the dissolution-precipitation equilibrium of anhydrite is sensitive to the variation of water-rock reaction intensity in the central-southern segments of the EAFZ. Coseismic permeability changes disrupt the solubility equilibria of anhydrite, driving hydrochemical anomalies. We propose that seismic stress redistribution induces fracture network reorganization, thereby disrupting anhydrite solubility equilibria. Given its tectonic sensitivity and widespread occurrence, anhydrite dissolution dynamics emerge as a potential tracer for hydrogeochemical monitoring in active fault zones. We propose a novel research paradigm wherein regional hydrogeological surveys identify applicable target indicator horizons, enabling continuous monitoring and establishment of region-specific evaluation metrics to ultimately achieve early warning capabilities for geohazard precursors.

Establishing fault slip rates can help resolve the long‐standing question of whether continental deformation focuses along major block boundaries or is distributed more evenly across diffuse fault networks. In the northeastern Tibet Plateau, the ESE‐trending Haiyuan and Kunlun sinistral strike‐slip faults have well‐established slip rates of ∼4–8 mm/yr and ∼10–12 mm/yr, respectively, but the relative importance of intervening NNW‐trending dextral strike‐slip and E–W thrust faults is still controversial. We investigate late Quaternary activity along one of the most prominent of these faults, the NNW‐trending, multi‐segmented South Riyueshan fault (SRYSF). By quantifying geomorphic offsets using remotely sensed digital topography and dating them with Optically Stimulated Luminescence and Radiocarbon, we establish minimum slip rates of ∼3.6 mm/yr for the northern Guide segment and ∼1.7 mm/yr for the southern Duohemao segment. North of 35ºN, magnetotelluric data show the Guide segment and western Waligong segment terminating northwards into the Qinghai Nanshan and West Qinling thrusts, implying a lack of connectivity with the North Riyueshan fault (NRYSF). These multi mm/yr slip rates suggest an important role for NNW‐trending dextral strike‐slip faults in NE Tibet, accommodating shear between the Kunlun and Haiyuan faults by rotating counterclockwise about vertical axes. However, slip rate variations along the SRYSF (∼1.7–3.6 mm/yr) and NRYSF (∼1.1–2.4 mm/yr) caution that regions between these NNW‐trending faults are internally deforming. As well as highlighting limitations to block‐like deformation of NE Tibet, our work emphasizes the importance of measuring fault slip rates at multiple locations to account for variations both along strike and between parallel strands.

Strong earthquakes rank among the most devastating natural disasters, with the potential to inflict catastrophic damage on communities and critical infrastructure worldwide. The structural geological and geophysical study of seismogenic features remains a cornerstone of earthquake research, providing essential insights into the dynamic processes driving these powerful events. High-resolution investigations in geomorphology, stratigraphy, and structural geology allow for a detailed understanding of the spatial and temporal characteristics of seismic deformations, encompassing co-seismic, post-seismic, and inter-seismic stages, potentially spanning multiple earthquake cycles. The integration of cutting-edge techniques—such as high-resolution data from Light Detection and Ranging (LiDAR), Structure from Motion (SfM), geophysical surveys, drilling, and frictional laboratory experiments—coupled with precise dating methods, enables quantitative analysis at high spatial resolutions across diverse temporal ranges, from years to millions of years. Recent advancements in frictional experimental techniques and numerical modeling have also significantly refined our understanding of deformation processes within seismogenic structures. This special issue compiles research on tectonic activities related to seismogenic structures from varied global tectonic setting, with a focus on leveraging high-resolution spatial data and sophisticated dating techniques. The contributions aim to deepen our understanding of the dynamics underlying strong earthquakes and improve our capacity for seismic hazard assessment.

High-resolution three-dimensional (3D) data is pivotal for capturing the intricacies of fault geometry and the subtleties of offset geomorphic markers, providing essential constraints for delineating the spatial characteristics of active faults. By integrating various techniques, we can harness the full spectrum of advantages they offer in acquiring high-resolution topographic information, thereby enhancing our ability to discern and interpret the complex architecture of fault systems. The geometric structure, and segmentation characteristics of the Elashan fault, located between the Haiyuan and Eastern Kunlun faults, are not yet fully understood, which impeded our comprehensive understanding of the plateau's expansion and deformation process. We use high-resolution, multi-scale topographic data to decipher the geometric kinematics of the Elashan fault. We conclude that diverse contractional structures, such as leading and trailing contractional imbricate fans, a contractional duplex, and a dextral left-stepping restraining bend develop along different segments of the Elashan fault. The geometric and kinematic model of the Elashan fault aligns with that of a typical strike-slip contractional duplex, accommodating the differences in north-south crustal shortening on the northeastern margin of the Tibetan Plateau, thus forming a diverse array of strike-slip compressional tectonic deformation features. We also re-estimated the slip rate of the Elashan fault in the Xianquan segment to be 2.3-2.9 mm/yr, higher than the result of 1.1 +/- 0.3 mm/yr by Yuan et al. (2011), (). The significant slip rate on the dextral strike-slip fault, coupled with the nearly EW-trending thrust faults, implies substantial interaction within the Haiyuan-Kunlun "block."

The timing and surface rupture length of large earthquakes are key parameters for seismic hazard studies in the Tanlu fault zone (TLFZ). Existing studies suggest that the M 81/2 Tancheng earthquake in A.D. 1668 may have been generated by the cascading rupture of the Juxian-Tancheng fault (JTF) and the Anqiu-Juxian fault (AJF) in the TLFZ. The Anqiu earthquake in 70 B.C. near the AJF also shook eastern China; however, the latest surface rupturing event along the AJF has not been studied, thus the potential earthquake hazard has large uncertainties. In this study, we excavated three trenches along the AJF to determine the most recent surface rupturing events to address these problems. As evidenced by paleoseismic and chronological investigations, the latest seismic events occurred along the northern segment (S1) and middle segment (S2) at approximately A.D. 63-225 and 2148-48 B.C., respectively. Combined with previous studies and historical records, our study inferred that the Anqiu earthquake in 70 B.C. was generated by S1 and S2, with an estimated magnitude of Mw 7.5 +/- 0.2. The most recent event on S3 occurred just before 10297 +/- 53 yr B.P. Our study also revealed that the Tancheng M 81/2 earthquake was generated by the JTF alone without surface rupture of the AJF. Thus, the elapsed time of the latest large earthquake along the AJF is more than 2000 yr.

On February 6, 2023, a doublet earthquake sequence (two M7.8 earthquakes) occurred in southeastern Turkey. The first mainshock, the M7.8 Pazarcik earthquake, took place on the East Anatolian Fault (EAF), being one of the largest recorded seismic events on this fault. The comprehensive analysis of tectonic background of the seismogenic fault and historical earthquakes shows that this earthquake happened in the seismic gap of the EAF. Serving as one of the major active faults in Turkey, the EAF forms an similar to 580-km-long plate boundary between the Arabian and Anatolian plates. In contrast to the North Anatolian Fault (NAF) bounding the northern margin of the Anatolian plate and experiencing a series of destructive earthquakes, the EAF has only undergone small to moderate events in the past century. The northeast segment of this fault are distinguished by moderate earthquakes and responsible for the most destructive earthquakes in the past two hundred years. However, field investigations indicate that the surface ruptures of the M7.8 Pazarcik earthquake mainly occurred along the three segments of the southwestern EAF and a branch fault near the epicenter, with a total surface rupture length of approximately 300 km. The surface ruptures exhibit typical strike-slip faulting features, including right-stepping echelon cracks, scarps, moletracks, depressions, pressure ridges, and left-lateral offset linear landforms. Faulted landforms and striations on the fault plane indicate a predominant left-lateral strike-slip motion, with a maximum co-seismic left-lateral displacement of 6.4 m. The co-seismic surface rupture length and maximum horizontal displacement are the highest values recorded on this fault. Based on field geological surveys and combined with the existing seismological and geodetic observation data, it is determined that the M7.8 Pazarcik earthquake was initiated on a secondary fault (the Narli fault), triggering the main rupture of the EAF. This was a multi-segment rupture event, which shows typical rupture-cascading that one event brought several neighbouring fault segments to failure together. Overall, the EAF is a complex fault with activity differences between the north and south, attention should be paid to the northeastern part of this fault where a possibility that several segments can rupture together to form a large cascade event exists.

The spatial variation in slip rates of large-scale strike-slip faults provides crucial support for the conceptual models of continental collision. However, the reasons for the decrease in slip rate of the East Kunlun Fault at the eastern margin of the Qaidam Basin on the Tibetan Plateau are still unclear. At the eastern margin of the Qaidam Basin, we identified four active strike-slip faults-two NW-SE-orientated dextral (the Xiariha Fault and Yingdeerkang Fault) and two E-W-orientated sinistral (the Reshui-Taosituohe Fault and Taosituohenan Fault)-and determined their slip rates using uncrewed aerial vehicle-based topography and optically stimulated luminescence dating. For the Xiariha Fault, from north to south slip rates are 1.39 +0.51/-0.34 mm/ yr, 1.19 +0.15/-0.14 mm/yr, and 0.9 +0.19/-0.16 mm/yr. The Yingdeerkang Fault slips at 0.66 +0.08/-0.07 mm/yr. The Reshui-Taosituohe Fault, from west to east, slips at 0.95 +0.22/-0.19 mm/yr and 1.20 +0.11/ -0.09 mm/yr. The Taosituohenan Fault, west to east, slips at 0.62 +0.12/-0.12 mm/yr to 1.01 +0.21/-0.19 mm/yr and 1.21 +0.43/ -0.25 mm/yr. We believe that the gradual decrease in slip rate of the East Kunlun Fault at the Tuosuo Lake segment toward the east is influenced by the activity of the four active strike-slip faults with a slip rate of similar to 1 mm/ yr along the eastern margin of the Qaidam Basin and the Elashan Fault. The decrease in fault slip rate is not solely attributed to the diverse structural styles of the fault itself but also to the strain absorption by the development of differently oriented faults around its periphery.

The Nalun-Nalati-Hongliuhe suture zone, which constitutes the central axis of the Tianshan Orogenic Belt (TSOB), has been reactivated during the late Cenozoic. The Nalati fault, located within the suture zone, facilitates the investigation of the internal structural deformation of the TSOB. However, existing studies focus on the eastern segment of the Nalati fault, its western segment, located in the interior of the Tianshan Orogenic Belt, has received scant attention. Consequently, there remains a substantial gap in understanding the distribution, activity, and paleoseismic events associated with the Nalati fault. This study concentrates on the Tekes segment within the Ili Prefecture, utilizing remote sensing and comprehensive field surveys to delineate its geometric distribution and left-lateral strike-slip characteristics. Moreover, Through trench analysis and radiocarbon dating, we have identified four significant paleoseismic events. Utilizing the unmanned aerial vehicle mapping and the LaDiCaoz_v2.1 code, we measured approximately 3.0 m of horizontal displacement from a single seismic event. The application of OxCal age correction has enabled precise dating of these events with 95.4% confidence: Event 1 (1668-2040 years BP), Event 2 (5386-5911 years BP), Event 3 (5897-6651 years BP), and Event 4 (6740-7321 years BP). Our findings imply that the Tekes segment of the Nalati fault remains active during the Holocene, indicating the high seismic hazard of the region. The average left-lateral slip rate along the Tekes segment is over 1.5 mm/yr during the Holocene. The Nalati fault accommodates approximately 1/3 of the total left-lateral shear strain within the TSOB.

The Late Quaternary activity characteristics of faults are essential for understanding regional strain distribution and estimating seismic hazards. The Bayan Har block, located in the northern Tibetan Plateau, is a region with a high level of seismic hazard. Remarkably, over the past three decades, many strong earthquakes have occurred on the block boundary fault zones of the Bayan Har block. However, the 2021 Ms 7.4 Maduo earthquake and the 2022 Maerkang Ms 6.0 earthquake swarm were exceptions as they took place within the Bayan Har block, not on the boundary fault zones. The reason for the occurrence of these intraplate earthquakes presents an interesting research query. The Songgang Fault (SGF) is a NW-trending strike-slip fault within the Bayan Har block. The 2022 Maerkang Ms 6.0 earthquake swarm occurred 6 km northeast of the SGF. What role did the SGF play in the process of the earthquake swarm? Through utilizing high-resolution remote sensing image interpretation, detailed field geological and geomorphologic surveys, trench analysis, and dating technologies, we found that the SGF is a sinistral strike-slip active fault since the Late Pleistocene, exhibiting tectonic behavior conducive to the preparation and occurrence of moderately large earthquakes. OSL dating of dislocated stream channels reveals a left-lateral slip rate of the SGF yields 1.6-2.1 mm/yr since the Late Pleistocene. The SGF distributes and transmits the tectonic deformation within the Bayan Har block, accommodating southeastward lateral extrusion of the Bayan Har block materials and contributing to the kinematic mechanisms of the entire eastern margin of the Tibetan Plateau. Furthermore, the 2022 Ms 6.0 Maerkang earthquake swarm exhibits a conjugate rupture phenomenon in a complex tectonic zone where several secondary fault planes of the SGF converge. This main fault zone deserves attention as a potential source zone of future earthquakes.

High-resolution topographic and geomorphic data are important basic data for the study of active structures. Here, multisource remote sensing data were used to reinterpret the active faults in the northern segment of the Red River Fault (China). First, we obtained airborne light detection and ranging (LiDAR) data, high-resolution GaoFen-7 (GF-7) remote sensing image data, and historical aerial photographs, and a high-resolution digital elevation model (DEM) was generated based on the airborne LiDAR data and GF-7 data. According to the remote sensing interpretation, the main active faults were identified. We subsequently verified the faults in the field and constrained the geographic locations. The current activity was confirmed to be dominantly normal faulting, with some dextral strike-slip components, and the latest active age was the Late Holocene. It reflects the coordination of structural deformation between the rotation of the secondary block and the sliding of the boundary fault within the Sichuan–Yunnan Block. The results show that airborne LiDAR and GF-7 remote sensing data have a great application value in providing high-resolution topographic and geomorphologic data for the study of active structures. The comprehensive application of multisource remote sensing data can greatly improve the reliability of active fault interpretations and provide a reference for follow-up research within the study area.

Quantifying the geometrical and kinematic aspects of faults within the Tian Shan Mountain Range is crucial for investigating the tectonic deformation patterns in the region. Through remote sensing image analysis using GaoFen-7 (GF-7) data and field geological surveys, we determined the geometric distribution and fault properties of the Kalawenguquan fault. The newly discovered Kalawenguquan fault spans more than 400 km and mainly strikes in the NEE direction, with some localized segments in the NE direction. The fault plane dips southward at angles ranging from 55 degrees to 85 degrees . The Kalawenguquan fault is a recently discovered Holocene active fault in the Tian Shan and is a thrust and left-lateral strike-slip fault. Based on geological survey findings and sediment dating data from the late Quaternary, the Kalawenguquan fault has a vertical sliding rate of approximately 0.41 mm/a. The left-lateral strike-slip rate was calculated to be 0.6 - 1.4 mm/a. We detected that at least two paleoseismic events occurred on the fault since 5.4 +/- 0.4 ka. In the range of 41 degrees-45 degrees latitude, 45 % of the crustal shortening in the Tian Shan is absorbed by the internal structure.

Active tectonics is not only the manifestation of the latest crustal activity but also the leading cause of strong earthquakes. With its complex active tectonic system, China has become an area with particularly severe seismic activity and related hazards worldwide. Therefore, a deep understanding of active tectonic characteristics and the occurrence patterns of strong earthquakes in China can help scientifically prevent or mitigate the risk of seismic disasters in urban planning and major engineering construction projects. In order to timely exchange the latest achievements in the field of active tectonics and strong earthquakes, this special issue on Active Tectonics and Strong Earthquakes selected 12 representative papers, mainly covering six different fields, including the earthquake-controlling process of active tectonics, paleoearthquakes, surveying and detection of active faults, seismic geological hazards, application of remote sensing technology and reservoir-induced earthquakes. Based on the new achievements of this issue and the research trends in related fields at home and abroad, it is suggested that future research on active tectonics and strong earthquakes should focus on four aspects: (1) comprehensive understanding of regional seismic hazards from the perspective of active tectonic evolution and active fault systems; (2) quantitative and refined field investigations of active tectonics; (3) application of high-precision remote sensing and various dating techniques continuously expanding the scope and timing of paleoearthquake research; (4) human-induced earthquakes.

The formation age of the middle Yellow River and the existence of a northward-flowing river have been fiercely debated. The age distribution of detrital zircon varied spatiotemporally and produced contradictory provenance interpretations. The Jinshaan Gorge, the main part of the middle Yellow River and key to studying fluvial evolution and clarifying disputes, developed its topography during the late Cenozoic. In this study, we systematically review the Cenozoic tectonic evolution of the North China Craton, perform detrital zircon U-Pb dating in the Neogene-Quaternary sediments and investigate the topography along the Jinshaan Gorge, and the sedimentology and chronological framework of these sediments. We propose that the Gorge of the middle Yellow River could have developed since the Neogene, controlled by the tectono-geomorphologic evolution of the North China Craton in a dominantly extensional environment. No evidence supports a northward-flowing river during the Early Pleistocene or even earlier in the Jinshaan Gorge. We attribute the provenance variations of the Cenozoic sediments to detrital mixing of diverse geological units, local and distant, and especially highlight the systematic provenance shift between the Neogene and Quaternary sediments caused by bedrock downcutting and recycling aeolian sediments. The increased 1.5-0.33 Ga component of the lower Yellow River during the Early Pleistocene was likely caused by enhanced loess accumulation and should not be individually used as a proxy for the Yellow River formation. We emphasize the significance of a comprehensive study of river evolution. Three-quarters of the Yellow River channel is located on the North China Craton, but the formation and evolution of the Yellow River have been usually attributed to the upper reaches due to the growth of the Tibetan Plateau. Geological units, such as aeolian deposits have a significant impact on the fluvial sediments of the Yellow River, and only systematic work can help unraveling their provenance and potential recycling. We have found that the tectonic evolution of the North China Craton between the rigid Ordos Block and the Lvliang Shan controlled the initial entrenchment of the Jinshaan Gorge in the middle Yellow River since the late or maybe the early Miocene. We have also revealed the complex spatial provenance changes of the fluvial sediments along the Yellow River and the systematic provenance shift between the Neogene and Quaternary sediments. At the same time, we emphasize the significance of an integrated study combining tectono-geomorphic features, sedimentology and quantitative analysis, such as provenance, for the reconstruction of the river geological evolution. The middle Yellow River has developed under the extensional tectonic evolution of the North China Craton since the Cenozoic Systematic provenance shift between the Neogene and Quaternary sediments was caused by bedrock downcutting and aeolian deposition Detrital signal from the Tibetan Plateau cannot be transported to and detected in the lower Yellow River

The Xianshuihe fault is one of the most active intra-continental fault in China with high frequency of large earthquakes. However, fault rocks and geodetic studies have shown that it has extensively creeping behavior. Understanding the geometrics and deformation behavior along and within the Xianshuihe fault is essential to investigate its deformation mechanism and assess its earthquake hazard. Here, we focus on the geometrics, fault rock physical characteristics within the northern Lahuo segment of the fault. Optical microscopy, scanning electron microscopy, and powder X-ray diffraction (XRD) are used to analyze the mineral composition and deformation behavior. There, the current location of the fault plane is located along the eastern boundary of the fault deformation zone with N110 degrees-striking, 50 degrees-dipping (to the NE) and sinistral/normal motion. Fault gouge in the fault core is mostly brown (3cm-thick) and black (20-30cm-thick) upstream and downstream from the main fault, respectively. It mainly consists of clay minerals and quartz, as well as 70% of strong minerals. The gravels in the fault gouge are mainly angular and long with the phenomenon of being sliced to form flat, straight planes, suggesting that the fault is dominated by stick-slip deformation due to large earthquakes. What's more, the fault gouge lenticle in fault zone is mainly consists of clay minerals (60%) with dense foliations, clearly oriented and the enrichment of Al and K elements, which indicate the creeping behavior. Then we got that the northern Lahuo segment of the Xianshuihe fault has obvious stick-slip deformation after creeping Our results are different with those previously published, which argued that the Xianshuihe fault is a steeply dipping sinistral fault with extensive creeping deformation. Our new data show that the spatial distribution of deformation behavior varies along various segments of the Xianshuihe fault. It can be due to the host rocks and fluid, as well as the geometry of fault branches. Our new results help to better understand the deformation behavior, seismogenic mechanism and strong earthquake risk in the future along huge strike-slip fault system.

Quantitatively characterizing the geometry, kinematics, and deformation rate of fold-thrust belts in intermontane basins is the key to understanding strain partitioning within the Tian Shan range. This work focuses on the Bayin anticline in the Youludusi Basin, a typical intermontane basin located within the eastern Tian Shan. The Kaidu River cuts through the Bayin anticline and has developed three levels of terraces (T-1-T-3) across the structure. By using cosmogenic nuclide and optically stimulated luminescence dating methods, the formation ages of terraces T-1 and T-3 are constrained to 11.54 +/- 0.55 ka and 42 + 7.0/-7.1 ka, respectively. When applying a listric thrust fault model to the Bayin anticline and using terraces as references, the vertical displacements are estimated to be 16.45 + 6.46/-3.19 m (T-1), 32.08 + 12.85/-6.19 m (T-2), and 95.93 + 38.94/-18.6 m (T-3), and the shortening amounts are 10.56 + 8.33/-5.04 m (T-1), 20.46 + 16.68/-9.64 m (T-2), and 61.24 + 50.22/-28.93 m (T-3). Based on this listric thrust fault model and terrace T-1-T-3 ages, the rate of fault slip controlling the growth of the Bayin anticline is determined to be 1.6 +/- 1.0 mm/yr, and the crustal shortening rate of the anticline is 1.0 + 0.7/-0.6 mm/yr. The estimated crustal shortening deformation of the Bayin anticline accounts for similar to 12 % of the total deformation in the Youludusi Basin. In terms of the entire orogenic belt, the crustal shortening absorbed in the southern, central, and northern parts accounts for 24 %-56 %, 46 %-71 %, and 19 %-74 %, respectively, of the total strain across the eastern Tian Shan. Therefore, we believe that the Eastern Tianshan undergoes uniform deformation.

The Red River Fault Zone is a large-scale right-lateral strike-slip fault zone with relatively strong activity during the Quaternary Period. This fault, located on the southeastern margin of the Qinghai-Tibetan Plateau, plays a key role in the extrusion, rotation and escape of the continental blocks constituting the Qinghai-Tibetan Plateau. Furthermore, this fault represents the southwestern boundary of the Sichuan-Yunnan Block, which has experienced strong deformation and frequent seismic activity. The northern segment of the Red River Fault Zone is the most active part of the whole fault. However, surface erosion and vegetation coverage have obscured the activity of the northern segment; therefore, the study of its activity has obviously been insufficient. There is still controversy over whether all the secondary faults on the northern segment are active Holocene faults. Studying the activity characteristics of the northern segment, which is densely populated, is particularly important for seismic risk prevention in this area. Based on remote sensing interpretations and field geological surveys, this paper describes the latest activity characteristics of the Cangshan Piedmont Fault, Fengyi-Dingxiling Fault and Midu Basin Margin Fault, including their spatial distributions and kinematic characteristics. According to the ages of the offset strata in profiles, the above three secondary faults were all active in the late Holocene. The latest active age of the Cangshan Piedmont Fault was later than 543-494 cal BP, and two palaeoseismic events that occurred in this section during the Holocene occurred at 2700 and 473 cal BP. The latest active age of the Fengyi-Dingxiling Fault was later than 2760-2700 cal BP; in this section, one Holocene palaeoseismic event occurred between 1777 cal BP and 2730 cal BP, another occurred between 2730 cal BP and 5664 cal BP, and the third occurred between 6449 cal BP and 8360 cal BP. The latest active age of the Midu Basin Margin Fault was later than 558-510 cal BP, and two Holocene palaeoseismic events occurred later than 2318-2114 cal BP and 558-510 cal BP. Based on the results of this paper and previous studies, we believe that the Fengyi-Dingxiling Fault on the northern segment of the Red River Fault Zone is at risk for future strong earthquakes. Additionally, abundant geological and geomorphologic evidence suggests that the northern segment is dominated by normal faults, reflecting the local strain response to secondary clockwise rotation of the Sichuan-Yunnan Block along the boundary fault. This finding is in line with the eastwards extrusion and escape of materials on the QinghaiTibetan Plateau caused by the northwards and northeastwards pushing of the Indian Plate. To a certain extent, these observations reflect the tectonic deformation coordination between block rotation and boundary fault slip in the Sichuan-Yunnan Block in the context of continental block extrusion on the Qinghai-Tibetan Plateau.