Hasil untuk "Dynamic and structural geology"

P. DeCelles

D. Rickenmann, D. Rickenmann

<p>This study investigates spatial and temporal variability of bedload transport in four Swiss mountain streams using continuous Swiss Plate Geophone (SPG) monitoring. This surrogate measuring system had been calibrated in previous studies to produce reliable estimates of bedload transport rates. The measurements were analysed at two different time scales: short-term transport events typically covering a duration of a few weeks and multi-year annual transport totals. Power-law relations between dimensionless transport intensity and shear stress were derived to evaluate the temporal variability in the steepness of transport relations and in the reference shear stress. Results were compared with predictive equations developed for mountain streams. Findings show substantial variability both within and across sites, likely reflecting the influence of sediment availability, stream slope, streambed texture and flow history. Overall, continuous monitoring highlights the strong role of temporal spatial variability on bedload transport levels, possibly due to changing sediment availability and bed surface composition, and with implications for predictive modelling and river management.</p>

Jawid Ahmad Baktash, Mursal Dawodi, Nadira Ahmadi

We introduce AFSTRESS, the first multi-label corpus of self-reported stress narratives in Dari (Eastern Persian), comprising 737 responses collected from Afghan individuals during an ongoing humanitarian crisis. Participants describe experienced stress and select emotion and stressor labels via Dari checklists. The dataset enables analysis at three levels: computational (multi-label classification), social (structural drivers and gender disparities), and psychological (learned helplessness, chronic stress, and emotional cascade patterns). It includes 12 binary labels (5 emotions, 7 stressors), with high label cardinality (5.54) and density (0.462), reflecting complex, multi-dimensional stress. Structural stressors dominate: uncertain future (62.6 percent) and education closure (60.0 percent) exceed emotional states, indicating stress is primarily structurally driven. The strongest co-occurrence is between hopelessness and uncertain future (J = 0.388). Baseline experiments show that character TF-IDF with Linear SVM achieves Micro-F1 = 0.663 and Macro-F1 = 0.651, outperforming ParsBERT and XLM-RoBERTa, while threshold tuning improves Micro-F1 by 10.3 points. AFSTRESS provides the first Dari resource for computational analysis of stress and well-being in a crisis-affected population.

Ryotaro Sahashi, Po-Yen Chen, Teruyasu Mizoguchi

Among wurtzite-type ferroelectrics, scandium-doped aluminum nitride (ScAlN) has emerged as a leading candidate for CMOS-compatible low-voltage memory, combining strong spontaneous polarization with process compatibility. A remarkable feature of this system is the pronounced reduction of the coercive field (Ec) with increasing Sc concentration; however, its microscopic origin remains poorly understood at the atomic scale, particularly under finite temperature and applied electric fields. Here, we integrate a density-functional-theory-accurate machine-learning force field with an equivariant neural-network-based Born effective charge model to perform large-scale electric-field-driven molecular dynamics simulations at near-first-principles accuracy. The framework correctly reproduces the experimentally observed qualitative trends in key experimental trends, including the decrease in the c/a ratio and the monotonic reduction of Ec with increasing Sc content. Beyond static structural softening, we uncover a dynamic mechanism underlying Ec reduction. Sc atoms exhibit larger thermal vibrations and undergo preceding displacements during switching, acting as dynamic triggers for polarization reversal. Moreover, the displacement correlation between Sc and Al atoms evolves systematically with composition, enhancing cooperative atomic rearrangements and lowering the effective switching barrier. These results demonstrate that Ec reduction in ScAlN arises from the synergy of structural softening and dynamic correlation evolution, providing a new perspective for designing hexagonal ferroelectrics.

Andrzej Skumiel

This article describes systems generating high-frequency rotating magnetic fields for magnetic hyperthermia treatments. It covers two- and three-phase device systems powered by rectangular signals. A passive bandpass filter tuned to a specific frequency (100 kHz) is placed between the magnetic circuits and the DC power source powering the device. The paper compares the electrical parameters of both solutions, including the supply voltage, magnetic field strength amplitude <i>H</i>, and magnetizing current <i>I</i>_L as a function of the supply voltage (<i>U</i>_dc). At a fixed supply voltage <i>U</i>_dc, the magnetizing current <i>I</i>_L and the rotating magnetic field strength amplitude <i>H</i> are approximately twice as large for the three-phase system as for the two-phase system. The relationships between the magnetizing currents <i>I</i>_L and the magnetic field strength amplitude <i>H</i> as a function of the supply voltage <i>U</i>_dc are linear.

Tyler J. Oathes, Ross W. Boulanger

Two-dimensional viscoplastic nonlinear analyses of the 2019 Feijão Dam 1 failure are performed using the finite difference program FLAC 8.1 with the user-defined constitutive models PM4SiltR and PM4Sand to assess how a series of commonly used engineering approaches can approximate the observed failure. A brief history of Feijão Dam 1, its failure, and the findings from two previous independent failure investigations are summarized. The present study uses the site characterization from those prior studies to develop the dam cross section, obtain material index properties, and establish groundwater conditions but uses alternative techniques for characterizing undrained shear strengths. The simulations show that the dam was marginally stable against long-term consolidated, undrained conditions and that modest loading changes were sufficient to trigger failure with deformation patterns consistent with the observed failure. The simulations further show that the collapse could have been triggered by a modest wetting event, ongoing drilling activities, or a combination of both mechanisms. Result sensitivity to choices in the calibration process and the numerical solution scheme are evaluated. The implications of these results on the use of commonly used engineering approaches for system-level time-dependent analyses and on long-term slope stability assessment procedures in practice are discussed. The results of this study provide support for the use of these analysis methods and engineering procedures in practice despite their simplifications and associated limitations.

Arvind Saini, Rajiblochan Sahoo, Rajarshi Chakrabarti et al.

Heteropolymers are ubiquitous in both synthetic systems, such as block copolymers, and biological macromolecules, including proteins and nucleic acids. Beyond their chemical composition, these polymers often exhibit spatial variations in physical properties. For instance, in biopolymers such as chromatin, stiffness heterogeneity arises from inherent molecular features as well as extensile or contractile active forces. In this letter, we develop a theoretical framework that extends the physics of flexible polymers, a widely used tool to describe biopolymer dynamics, to incorporate spatially varying stiffness. Using this approach, we specifically analyze the structure and dynamics of flexible heteropolymers with periodic stepwise stiffness profiles. We find that stiffness heterogeneity leads to qualitative deviations in dynamical observables such as mean squared displacement while also increasing structural anisotropy. Altogether, this framework provides a platform to interpret stiffness heterogeneity from experimental data especially for biopolymers as well as to design heteropolymers with tailored structural and dynamic properties.

Maggie A. Thompson, Paolo A. Sossi, Dan J. Bower et al.

Rocky planet atmospheres form and evolve through interactions between the planet's surface and interior. If a growing rocky planet acquires enough mass prior to the dissipation of the nebular gas disk, it can gravitationally capture a `primary' atmosphere dominated by H2. At the same time, these young, rocky bodies are likely to have partial or global magma oceans as a result of the heat from accretion, core formation and radioactive decay of short-lived major element isotopes. During this magma ocean stage, the dissolution of volatile, life-essential elements, such as hydrogen in the form of water or H2, into the magma is critical in determining the extent to which a rocky planet can maintain these elements over time. However, our ability to quantify the amount of hydrogen dissolved in the magma oceans of rocky planets is limited by the lack of experimental constraints on H-bearing species' solubilities at relevant pressure and temperature conditions, including those expected for the early Earth. Here we experimentally determine the solubility of water in silicate melts of various compositions in the Ca-Mg-Al-Si-Fe-O system at a total pressure of 1 bar and temperatures from 1673-1823 K, synthesized in a H2-CO2 gas-mixing furnace. We use Bayesian parameter estimation to derive a robust water solubility law that includes the effects of melt composition and temperature. Using this solubility law, we estimate that ~100 ppm of hydrogen can dissolve into a 1 MEarth planet with a surface pressure of ~300 bars set by accretion of solar-like nebular gas. For rocky planets in general, ingassing of a primary atmosphere may be an important source and initial storage mechanism for hydrogen-bearing species in a planet's interior, provided it grew to a sufficient mass within the lifetime of the solar nebula.

Vinayak Shantaram Bhat, M. Benjamin Jungfleisch

Investigating the emergence of complexity in disordered interacting systems, central to fields like spin glass physics, remains challenging due to difficulties in systematic experimental tuning. We introduce a tunable artificial spin lattice platform to directly probe the connection between controlled structural disorder and collective spin-wave dynamics. By precisely varying positional and rotational randomness in Ni81Fe19 nanobar arrays from periodic to random, we map the evolution from discrete spectral modes to a complex, dense manifold. Crucially, we establish a quantitative correlation between information-theoretic measures of static disorder and the dynamic spectral complexity derived from the GHz spin-wave response. This correlation provides a dynamic fingerprint of an increasingly complex energy landscape resulting from tuned disorder. Furthermore, thermal probe via thermal Brillouin light scattering reveal significantly richer microstates diversity in disordered states than driven probe using broadband ferromagnetic resonance. Our work presents a unique experimental testbed for studying how the ingredients of glassy physics manifest in high-frequency dynamics, offering quantitative insights into the onset of complexity in interacting nanomagnet systems.

Md. Saiful Bari Siddiqui, Md Mohaiminul Islam, Md. Golam Rabiul Alam

Overfitting remains a significant challenge in deep learning, often arising from data outliers, noise, and limited training data. To address this, the Divide2Conquer (D2C) method was previously proposed, which partitions training data into multiple subsets and trains identical models independently on each. This strategy enables learning more consistent patterns while minimizing the influence of individual outliers and noise. However, D2C's standard aggregation typically treats all subset models equally or based on fixed heuristics (like data size), potentially underutilizing information about their varying generalization capabilities. Building upon this foundation, we introduce Dynamic Uncertainty-Aware Divide2Conquer (DUA-D2C), an advanced technique that refines the aggregation process. DUA-D2C dynamically weights the contributions of subset models based on their performance on a shared validation set, considering both accuracy and prediction uncertainty. This intelligent aggregation allows the central model to preferentially learn from subsets yielding more generalizable and confident edge models, thereby more effectively combating overfitting. Empirical evaluations on benchmark datasets spanning multiple domains demonstrate that DUA-D2C significantly improves generalization. Our analysis includes evaluations of decision boundaries, loss curves, and other performance metrics, highlighting the effectiveness of DUA-D2C. This study demonstrates that DUA-D2C improves generalization performance even when applied on top of other regularization methods, establishing it as a theoretically grounded and effective approach to combating overfitting in modern deep learning. Our codes are publicly available at: https://github.com/Saiful185/DUA-D2C.

Anand Sharma, Chen Liu, Misaki Ozawa

We investigate numerically the identification of relevant structural features that contribute to the dynamical heterogeneity in a model glass-forming liquid. By employing the recently proposed information imbalance technique, we select these features from a range of physically motivated descriptors. This selection process is performed in a supervised manner (using both dynamical and structural data) and an unsupervised manner (using only structural data). We then apply the selected features to predict future dynamics using a machine learning technique. Finally, we discuss the potential applications of this approach in identifying the dominant mechanisms governing the glassy slow dynamics.

Noah Toyonaga, L Mahadevan

The dynamics of many macromolecular machines is characterized by chemically-mediated structural changes that achieve large scale functional deployment through local rearrangements of constitutive protein sub-units. Motivated by recent high resolution structural microscopy of a particular class of such machines, contractile injection systems (CIS), we construct a coarse grained semi-analytical model that recapitulates the geometry and bistable mechanics of CIS in terms of a minimal set of measurable physical parameters. We use this model to predict the size, shape and speed of a dynamical actuation front that underlies contraction. Scaling laws for the velocity and physical extension of the contraction front are consistent with our numerical simulations, and may be generally applicable to related systems.

Yang Wang, Yuejun Wang, Peizhen Zhang et al.

Qianhao Tang, Ivan Gratchev, Sinnappoo Ravindran

This paper seeks to investigate the effect of rainfall intensity on the occurrence of shallow landslides by means of a series of flume tests. Coarse-grained material was used to build a slope, and several rainfall events with an intensity of either 40 mm/h, 70 mm/h, or 100 mm/h were simulated to initiate slope failure. A set of pore water pressure and moisture content sensors was installed in the slope to monitor changes in the water conditions during each test. Different initial moisture contents of 5% and 10% of the soil mass were used to better understand the effect of moisture on slope stability during rainfall. It was found that the slope failed when intensities of 70 mm/h and 100 mm/h were used; however, no failure was observed with a rainfall intensity of 40 mm/h. The failure patterns were found to be similar, with progressive slides occurring as more water infiltrated the slope. A numerical procedure to estimate the factor of safety over the period of the rainfall event was proposed and validated against the laboratory data. The results of the numerical analysis yielded the failure time, which was close to the time observed in the flume tests.

R. Ott, R. Ott, S. F. Gallen et al.

<p>Carbonate rocks are highly reactive and can have higher ratios of chemical weathering to total denudation relative to most other rock types. Their chemical reactivity affects the first-order morphology of carbonate-dominated landscapes and their climate sensitivity to weathering. However, there have been few efforts to quantify the partitioning of denudation into mechanical erosion and chemical weathering in carbonate landscapes such that their sensitivity to changing climatic and tectonic conditions remains elusive. Here, we compile bedrock and catchment-averaged cosmogenic calcite–<span class="inline-formula">³⁶Cl</span> denudation rates and compare them to weathering rates derived from stream water chemistry from the same regions. Local bedrock denudation and weathering rates are comparable, <span class="inline-formula">∼20</span>–40 <span class="inline-formula">mm ka⁻¹</span>, whereas catchment-averaged denudation rates are <span class="inline-formula">∼2.7</span> times higher. The discrepancy between bedrock and catchment-averaged denudation is 5 times lower compared to silicate-rich rocks, illustrating that elevated weathering rates make denudation more spatially uniform in carbonate-dominated landscapes. Catchment-averaged denudation rates correlate well with topographic relief and hillslope gradients, and moderate correlations with runoff can be explained by concurrent increases in weathering rates. Comparing denudation rates with weathering rates shows that mechanical erosion processes contribute <span class="inline-formula">∼50</span> % of denudation in southern France and <span class="inline-formula">∼70</span> % in Greece and Israel. Our results indicate that the partitioning between largely slope-independent chemical weathering and slope-dependent mechanical erosion varies based on climate and tectonics and impacts the landscape morphology. This leads us to propose a conceptual model whereby in humid, slowly uplifting regions, carbonates are associated with low-lying, flat topography because slope-independent chemical weathering dominates denudation. In contrast, in arid climates with rapid rock uplift rates, carbonate rocks form steep mountains that facilitate rapid, slope-dependent mechanical erosion required to compensate for inefficient chemical weathering and runoff loss to groundwater systems. This result suggests that carbonates represent an end member for interactions between climate, tectonics, and lithology.</p>

Samantha M. Webster, Mira B. May, Barrett M. Powell et al.

Throughout the history of electron microscopy, ribosomes have served as an ideal subject for imaging and technological development, which in turn has driven our understanding of ribosomal biology. Here, we provide a historical perspective at the intersection of electron microscopy technology development and ribosome biology and reflect on how this technique has shed light on each stage of the life cycle of this dynamic macromolecular machine. With an emphasis on prokaryotic systems, we specifically describe how pairing cryo-EM with clever experimental design, time-resolved techniques, and next-generation heterogeneous structural analysis has afforded insights into the modular nature of assembly, the roles of the many transient biogenesis and translation co-factors, and the subtle variations in structure and function between strains and species. The work concludes with a prospective outlook on the field, highlighting the pivotal role cryogenic electron tomography is playing in adding cellular context to our understanding of ribosomal life cycles, and noting how this exciting technology promises to bridge the gap between cellular and structural biology.

Jun-Hyung Park, Yeachan Kim, Junho Kim et al.

Structure pruning is an effective method to compress and accelerate neural networks. While filter and channel pruning are preferable to other structure pruning methods in terms of realistic acceleration and hardware compatibility, pruning methods with a finer granularity, such as intra-channel pruning, are expected to be capable of yielding more compact and computationally efficient networks. Typical intra-channel pruning methods utilize a static and hand-crafted pruning granularity due to a large search space, which leaves room for improvement in their pruning performance. In this work, we introduce a novel structure pruning method, termed as dynamic structure pruning, to identify optimal pruning granularities for intra-channel pruning. In contrast to existing intra-channel pruning methods, the proposed method automatically optimizes dynamic pruning granularities in each layer while training deep neural networks. To achieve this, we propose a differentiable group learning method designed to efficiently learn a pruning granularity based on gradient-based learning of filter groups. The experimental results show that dynamic structure pruning achieves state-of-the-art pruning performance and better realistic acceleration on a GPU compared with channel pruning. In particular, it reduces the FLOPs of ResNet50 by 71.85% without accuracy degradation on the ImageNet dataset. Our code is available at https://github.com/irishev/DSP.

W. McKinnon, D. Richardson, J. Marohnic et al.

Examining Arrokoth The New Horizons spacecraft flew past the Kuiper Belt object (486958) Arrokoth (also known as 2014 MU69) in January 2019. Because of the great distance to the outer Solar System and limited bandwidth, it will take until late 2020 to downlink all the spacecraft's observations back to Earth. Three papers in this issue analyze recently downlinked data, including the highest-resolution images taken during the encounter (see the Perspective by Jewitt). Spencer et al. examined Arrokoth's geology and geophysics using stereo imaging, dated the surface using impact craters, and produced a geomorphological map. Grundy et al. investigated the composition of the surface using color imaging and spectroscopic data and assessed Arrokoth's thermal emission using microwave radiometry. McKinnon et al. used simulations to determine how Arrokoth formed: Two gravitationally bound objects gently spiraled together during the formation of the Solar System. Together, these papers determine the age, composition, and formation process of the most pristine object yet visited by a spacecraft. Science, this issue p. eaay3999, p. eaay3705, p. eaay6620; see also p. 980 Simulations show that Arrokoth (2014 MU69) formed by the gentle inspiral of a binary system in the early Solar System. INTRODUCTION The close flyby of the Kuiper Belt object (486958) Arrokoth (formerly 2014 MU69) by NASA’s New Horizons spacecraft revealed details of the body’s structure, geology, and composition. Arrokoth is a member of the cold classical component of the Kuiper Belt, a population of dwarf planets and smaller bodies thought to be only modestly dynamically or collisionally disturbed, unlike the asteroids of the inner Solar System, comets, or other groups of Kuiper Belt objects. Data from this flyby provides the opportunity to observe the results of primordial planetesimal accretion, largely unobscured by later geological or dynamical processes. RATIONALE Planetesimal formation is an unsolved problem in planetary science. Many mechanisms have been proposed in which small solid particles (dust and pebbles) agglomerate into planetesimals and ultimately into planets. The flyby of Arrokoth provides data that constrain planetesimal formation theories and allow us to construct models of Arrokoth’s specific physical characteristics. The accretion processes that operated in the cold classical region of the Kuiper Belt during the formation of the Solar System are expected to have also occurred elsewhere in the protosolar nebula. Arrokoth is a contact binary about 35 km long composed of two unequally sized lobes. Each lobe is flattened or lenticular in shape, and the planes of flattening of both (determined from their principal axes) are closely aligned, to within 5°. The smaller lobe is slightly oblong, with its long axis pointing down the long axis of the binary as a whole (to within 5°). The surface and overall structure of Arrokoth do not display any obvious signs of catastrophic or subcatastrophic collision, and the join or neck between the two lobes is narrow. Each lobe is compositionally similar to within the precision of spectral measurements. RESULTS We show that stresses in the neck region today are compatible with the structural integrity of Arrokoth for densities (several 100 kg m−3) and material strengths (a few kilopascals) similar to those observed in comets, but at mass scales ~1000 times the mass of typical cometary nuclei. We performed numerical simulations of collisions between two bodies on the scale of the two lobes of Arrokoth, assuming those density and strength parameters. We found that impacts at or greater than their mutual escape speed (a few meters per second) would have been highly damaging. The close geometric alignment of the lobes is highly unlikely to the be the result of a chance collision alone but can be readily understood as the result of tidal evolution of a tight, co-orbiting binary. This requires a mechanism to extract angular momentum from the binary orbit, causing the orbit to shrink, and the two components to gently merge. Numerical models show that overdense concentrations of particles in the protosolar gas nebula can become gravitationally unstable and collapse to form planetesimals. The angular momentum in the simulated pebble clouds is high enough that formation of co-orbiting binaries is efficient and with binary characteristics that are a good match to binaries observed in the Kuiper Belt today. We examined a range of mechanisms to extract or transfer angular momentum from a co-orbiting binary and drive an ultimate merger, including mutual tides, tidal effects of the Sun (Kozai-Lidov oscillations), collisions with smaller Kuiper Belt objects, the ejection of third bodies, asymmetric radiation forces, and gas drag. We found that for bodies the size of Arrokoth, gas drag may be most effective in this merger process over the lifetime of the protosolar nebula. CONCLUSION We show that models of Arrokoth’s formation and evolution support accretion of the binary through the gravitational collapse of an overdense pebble cloud in the presence of protosolar nebular gas, either as a contact binary initially or as a co-orbiting binary that later inspiraled and gently merged. Similar accretional processes and binary planetesimal formation likely occurred throughout the early Solar System. Simulated maximum accelerations experienced by particles during low-velocity impact of two spheres, approximating the scale of the two lobes of Arrokoth. Spheres are modeled as granular aggregates with bulk densities of 500 kg m−3 and an impact speed of 2.9 m s−1 at a tangent angle of 80°; such gentle collisional conditions are necessary to preserve Arrokoth’s overall undamaged shape. Extreme reds and blues correspond to the greatest and least maximum accelerations experienced, respectively. The maximum disturbance is concentrated in the narrow contact area, or neck, between the two bodies. The New Horizons spacecraft’s encounter with the cold classical Kuiper Belt object (486958) Arrokoth (provisional designation 2014 MU69) revealed a contact-binary planetesimal. We investigated how Arrokoth formed and found that it is the product of a gentle, low-speed merger in the early Solar System. Its two lenticular lobes suggest low-velocity accumulation of numerous smaller planetesimals within a gravitationally collapsing cloud of solid particles. The geometric alignment of the lobes indicates that they were a co-orbiting binary that experienced angular momentum loss and subsequent merger, possibly because of dynamical friction and collisions within the cloud or later gas drag. Arrokoth’s contact-binary shape was preserved by the benign dynamical and collisional environment of the cold classical Kuiper Belt and therefore informs the accretion processes that operated in the early Solar System.

S. Balovtsev

The steady trend of complication of mining and geological factors in underground coal mining and at the same time the processes of mining intensification cause growth of dynamic manifestations of natural factors of mining, such as sudden coal and gas outbursts, rock bursts, rock collapses, leading to gas and dust explosions and fires. This requires developing the models of different phenomena manifestation risks, which enable improving the process safety of a mining enterprise. In this study, based on the methodology of aerological risk assessment in coal mines, a structural analysis of aerological risks was carried out. The criteria of hazard of mining-geological and mine engineering factors and vulnerability of schemes and methods of ventilation, ventilation facilities, and main fans were developed. A hierarchical structure of aerological risks of higher ranks was developed. The presented risk structure allows determining the area of superposition of hazards of coal mining and vulnerability of ventilation systems for each mine and its individual facilities, as well as quantifying these areas in the form of aerological risks. The ranges of aerological risk values of higher ranks for super-category mines and mines hazardous by sudden coal and gas outbursts for different ventilation modes were established. The presented methodology enables forecasting and reducing aerological risks in course of designing, operation, liquidation, and conservation of coal mines.

Xiangyang Yang, Yunpeng Dong, Yanbo Feng et al.

The Bayanwula Tectonic Belt (BTB) is located between the Alxa Massif and the Ordos Basin in the northwestern North China Craton (NCC). The Mid‐Mesozoic to Cenozoic deformation characteristics of the BTB is crucial for understanding the tectonic processes of eastern Asia during that time. Together with the regional geology, our field observation and structural analysis reveal that the BTB has undergone three phases of deformation since the Late Jurassic. The first phase of deformation (D1) is represented by NE–SW‐striking thrust faults involved in the Jurassic strata, indicating a phase of NW–SE shortening deformation. Based on the combination of angular unconformity between the Upper Jurassic and Lower Cretaceous strata, the timing of D1 is constrained at the end of Jurassic and dynamically related to the westward subduction of the Palaeo‐Pacific Plate during the end of the Jurassic. The second one (D2) is characterized by the ~NE–SW‐striking normal faults and Lower Cretaceous syn‐sedimentary strata on both sides of the BTB, which show that a phase of ~NW–SE extension deformation occurred in the Early Cretaceous, dynamically related to the rollback of the Palaeo‐Pacific Plate in the Early Cretaceous. The third stage of deformation (D3) is represented by the NW–SE‐striking folds that involved the Pliocene strata, as well as dextral strike‐slipping of the East Bayanwula Fault and the West Helanshan Fault, indicating a phase of NE–SW shortening at the end of the Pliocene. Dynamically, the D3 is related to the outward expansion of the Tibetan Plateau.