Geoscience frontiers最新文献

{"title":"A first-principles molecular dynamics study of molecular hydrogen diffusion in Fe-free olivine","authors":"Haibo Liu ,&nbsp;Baohua Zhang ,&nbsp;Hongzhan Fei ,&nbsp;Lei Liu","doi":"10.1016/j.gsf.2024.101926","DOIUrl":"10.1016/j.gsf.2024.101926","url":null,"abstract":"<div><div>Molecular hydrogen (H₂) may be an important form of water in nominally anhydrous minerals in the Earth’s mantle and plays a critical role in mantle water cycle, but the transport properties of H₂ remain unclear. Here, the diffusion of H₂ in Fe-free olivine lattice is investigated at pressures of 1–13 GPa and temperatures of 1300–1900 K by first-principles molecular dynamics. The activation energy and activation volume for H₂ diffusion in Fe-free olivine are determined to be 55 ± 8 kJ/mol and 3.6 ± 0.2 cm³/mol, respectively. H₂ diffusion in Fe-free olivine is faster than H⁺ by 1–4 orders of magnitude and therefore it is more favorable for hydrogen transportation under upper mantle conditions. H₂ can be carried to the mantle transition zone by subducting slabs without releasing to the surrounding mantle. The upper mantle may act as a lid, preventing the releasing of H₂ produced in the deep mantle to the surface.</div></div>","PeriodicalId":12711,"journal":{"name":"Geoscience frontiers","volume":"16 1","pages":"Article 101926"},"PeriodicalIF":8.5,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142256608","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A first-principles study of helium diffusion in aragonite under high pressure up to 40 GPa","authors":"Yu Huang ,&nbsp;Mingqiang Hou ,&nbsp;Hong Liu","doi":"10.1016/j.gsf.2024.101931","DOIUrl":"10.1016/j.gsf.2024.101931","url":null,"abstract":"<div><div>Helium diffusion in carbonates under mantle pressure is crucial for understanding thermal and chemical evolution of mantle. Based on the density functional theory (DFT) and the the climbing image nudged elastic band (CI-NEB) method, we performed first-principles calculations of diffusion characteristics of helium in perfect aragonite crystal under high pressure to 40 GPa. Our results show that He diffusion behaviors are controlled by pressure, temperature and crystal size. The activation energy increases, and the diffusion coefficients decrease significantly under high pressure. E_a[1<!--> <!-->0<!--> <!-->0] increases from 176.02 kJ/mol to 278.75 kJ/mol, and E_a[0<!--> <!-->0<!--> <!-->1] increases from 195.89 kJ/mol to 290.43 kJ/mol, with pressure increasing from 20 GPa to 40 GPa. At 700 K, the diffusion coefficients at 40 GPa is 7 orders of magnitude lower than that at 20 GPa; and at 1000 K it decrease 5 orders of magnitude. To ensure that at least 90% helium is not lost, we synthesized the temperature obtained from cooling and heating processes and derive the 'stable temperature range' for helium in aragonite. The obtained results show that the stable temperature range is 22–76 ℃ at 0 GPa and 641–872 °C at 40 GPa, for the crystal of 100–2000 μm size. Besides, the travel time of helium in aragonite under high pressure increases rapidly with pressure increasing. Our calculations indicate that helium can be quantitatively retained in aragonite in the deep mantle as long as the temperature is in the 'stable temperature range'. These results have certain implications for exploring the evolution of mantle and the storage of helium within it.</div></div>","PeriodicalId":12711,"journal":{"name":"Geoscience frontiers","volume":"16 1","pages":"Article 101931"},"PeriodicalIF":8.5,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143172716","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Equation of state and thermodynamic properties of liquid Fe-O in the Earth’s outer core","authors":"Miaoxu Xie ,&nbsp;Jie Fu ,&nbsp;Anatoly B. Belonoshko","doi":"10.1016/j.gsf.2024.101847","DOIUrl":"10.1016/j.gsf.2024.101847","url":null,"abstract":"<div><div>Equation of state (EoS) plays a crucial role in the prediction of the composition of the outer core. Here, we calculated pressure (<em>P</em>)-volume (<em>V</em>)-temperature (<em>T</em>) data of liquid iron-oxygen alloys (Fe-<em>X</em> wt.% O, <em>X</em> = 0, 2.8, 6.1, and 9.9) under the outer core conditions (∼136–330 GPa, 4000–6000 K) by first-principles molecular dynamics simulations. We established an EoS for liquid Fe-O alloys with parameters including <em>P</em>, <em>T</em>, <em>V</em>, and O concentrations. Consequently, thermodynamic properties of liquid Fe-O alloys such as density (<em>ρ</em>), thermal expansion coefficient, isothermal and adiabatic bulk modulus, and sound velocity (<em>V_P</em>) are calculated. To constrain the O content, we predicted the <em>ρ</em>-<em>P</em> and <em>V_P</em>-<em>P</em> profiles along the geotherm and compared them with data from the Preliminary Reference Earth Model (PREM). We conclude that the adiabatic <em>T</em> profile as a function of depth affects the prediction of O content dramatically. With several anchored <em>T</em>_ICB, the composition of Fe-6.1 wt.% O matches the PREM data with an acceptable range of error. But strictly speaking, the distribution in the outer core is probably uneven. In such case, we state that the O content in the outer core cannot be higher than approximately 6.1 wt.%.</div></div>","PeriodicalId":12711,"journal":{"name":"Geoscience frontiers","volume":"16 1","pages":"Article 101847"},"PeriodicalIF":8.5,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140771491","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Viscosities of hcp iron alloys under Earth’s inner core conditions","authors":"Yunfan Xu ,&nbsp;Yu He ,&nbsp;Shichuan Sun ,&nbsp;Wei Zhang ,&nbsp;Weiru Dai ,&nbsp;Duck Young Kim ,&nbsp;Heping Li","doi":"10.1016/j.gsf.2024.101935","DOIUrl":"10.1016/j.gsf.2024.101935","url":null,"abstract":"<div><div>Viscosity is critical for controlling the dynamics and evolution of the Earth’s inner core (IC). The viscosities of hexagonal close-packed (hcp) and body-centred cubic (bcc) Fe were studied experimentally and theoretically under Earth's core conditions. However, Earth’s inner core is mainly composed of Fe-Ni alloys with some light element impurities (Si, S, C, H, O), and the influence of impurities (Ni, Si, S, C, H, and O) on viscosity is still unknown. In this study, the diffusion coefficients of Fe, Ni, Si, S, C, H, and O were calculated under IC conditions using ab initio molecular dynamics (AIMD) and deep learning molecular dynamics (DPMD) methods. Among them, C, H, and O are highly diffusive like liquids in the lattice, while Fe, Ni, Si, and S diffuse through Fe site vacancies. In binary alloys, the influence of these impurities (Ni: 12.5%, S: 3.6%, Si: 3.1%, C: 1.3%, O: 1.7%, H: 0.4% by weight) on viscosity is insignificant. Based on the dislocation creep mechanism, the predicted viscosities of the hcp Fe alloys are 1 × 10¹⁴–2 × 10¹⁶ Pa·s, which is consistent with the values predicted by free inner core nutation and seismic wave attenuation observations.</div></div>","PeriodicalId":12711,"journal":{"name":"Geoscience frontiers","volume":"16 1","pages":"Article 101935"},"PeriodicalIF":8.5,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143172718","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Wave velocities and anisotropy of rocks: Implication for origin of low velocity zone of the Qinling Orogenic Belt, China","authors":"Lei Liu ,&nbsp;Ying Li ,&nbsp;Tingting Li ,&nbsp;Hanyu Wang ,&nbsp;Shasha Liu ,&nbsp;Panpan Zhao ,&nbsp;Gerile Naren ,&nbsp;Li Yi ,&nbsp;Hong Liu ,&nbsp;Fengxia Sun ,&nbsp;Jianguo Du","doi":"10.1016/j.gsf.2024.101939","DOIUrl":"10.1016/j.gsf.2024.101939","url":null,"abstract":"<div><div>Structure and composition of Earth are fundamental importance in exploring the dynamic evolution of the crust and mantle. The Qinling Orogenic Belt (QOB) is located between the North China plate and the South China Plate, and is one of the main orogenic belts in China. To explore the composition and origin of anisotropy and the low wave velocity zone of the QOB, ten rock samples (gneiss and schist) were collected from the five sites of the QOB and the <em>P</em>- and <em>S</em>-wave velocities of these samples were measured under 0.6 to 2.0 GPa and 100 to 550 °C. The wave velocities increase with increasing pressure and decreasing temperature. The <em>V</em>_P and <em>V</em>_S of the schist and gneiss match the velocity of the middle and lower crust of the QOB, indicating that schist and gneiss are important component of the QOB. All the schist and gneiss samples exhibit obvious seismic anisotropy with 1.64%–17.42% for <em>V</em>_S and 2.93%–14.78% for <em>V</em>_P under conditions of crust and upper mantle. The CPO/LPO and layering distribution of mica in rock samples are the main reasons for this anisotropy. The <em>V</em>_S structures below the five sampled sites from seismic ambient noise tomography were built to explore the effect of schist and gneiss on the composition and structure of the QOB. The results indicate that orientation-arranged gneiss and schist driven by the tectonic stresses might be a new origin of the character of <em>V</em>_P/<em>V</em>_S, seismic anisotropy, and the low velocity zone in the QOB.</div></div>","PeriodicalId":12711,"journal":{"name":"Geoscience frontiers","volume":"16 1","pages":"Article 101939"},"PeriodicalIF":8.5,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143172719","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Polycyclic aromatic compounds in crude oil as proxies for Permian Tarim large igneous province activities","authors":"Rongzhen Qiao ,&nbsp;Meijun Li ,&nbsp;Donglin Zhang ,&nbsp;Hong Xiao ,&nbsp;Wenqiang Wang","doi":"10.1016/j.gsf.2024.102000","DOIUrl":"10.1016/j.gsf.2024.102000","url":null,"abstract":"<div><div>Large igneous provinces (LIPs), a critical area in Earth science, are closely related to paleoenvironmental evolution and biodiversity. The Permian Tarim large igneous province (TLIP) provides an ideal laboratory for correlational research. Previous reports show that the TLIP formed ∼300–262 Ma. Based on igneous lithology and the upper limit of single magmatic activity (&lt;5 Ma), the TLIP can be divided into five main magmatic episodes. Core logging, seismic sections, lithofacies observations, and in-situ calcite U-Pb dating indicate diabase intrusions and a hydrothermal upwelling event (∼295.9–273 Ma) resulted from TLIP magmatic activity. The results indicate that polycyclic aromatic compounds (PACs) in oil are powerful proxies of magmatic intrusion and hydrothermal activity in the Permian TLIP. The existing diabase intrusion (EDI) samples show a higher concentration of high-molecular-weight (HMW) PACs (≥5-ring PACs) and greater combustion-derived PAC ratios. The distribution coupling between the diabase intrusion and PACs indicates that the HMW PACs are mainly derived from the cycloaddition reactions by the pyrogenic source (i.e., diabase intrusion). The conversion of phenanthrene (Phe), biphenyl (Bp), and dibenzothiophene (DBT) series compounds indicates that the oil is altered by hydrothermal activity. The hydrogenium and sulfur carried by the hydrothermal upwelling process promote the heteroatom incorporation of PACs. The cycloaddition and heteroatom incorporation reactions of PACs during the formation of LIPs offer a new perspective for evaluating their impact. PACs serve as effective proxies for LIPs and may also contribute to biological crises associated with LIPs.</div></div>","PeriodicalId":12711,"journal":{"name":"Geoscience frontiers","volume":"16 2","pages":"Article 102000"},"PeriodicalIF":8.5,"publicationDate":"2024-12-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143145888","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A comparative study of various combination strategies for landslide susceptibility mapping considering landslide types","authors":"Lanbing Yu ,&nbsp;Biswajeet Pradhan ,&nbsp;Yang Wang","doi":"10.1016/j.gsf.2024.101999","DOIUrl":"10.1016/j.gsf.2024.101999","url":null,"abstract":"<div><div>Landslide susceptibility mapping (LSM) assists planners, local administrations, and decision-makers in preventing, mitigating and managing associated risks. This study proposes a novel DES-based framework that effectively captures the spatial developmental patterns of different landslide types, leading to higher precision LSM. The Wanzhou district (administrative division) of Chongqing Province, southwestern China, was selected as the test area, encompassing 881 landslides classified into rockfalls, reservoir-affected (RA) landslides, and non-reservoir-affected (NRA) landslides. Subsequently, three inventory maps and sixteen environment factors were used as inputs, with multicollinearity and importance analyses used to select the best factor combination for three types of landslides. Finally, the susceptibilities of rockfalls, RA and NRA landslides were combined by six combination strategies: Maximum, Mean, Probability, Voting, Stacking, and Dynamic Ensemble Selection (DES) models, and the optimal strategy was identified by area under the receiver operating characteristic curves (AUC), confusion matrix, and landslide distribution statistic. For LSM of individual landslide types, ResNet consistently outperformed traditional machine learning models, achieving testing AUC values of 0.8925, 0.9427, and 0.6754 for rockfalls, RA, and NRA landslides, respectively. The evaluation of the combination strategies revealed that the DES model achieved the highest testing AUC value of 0.8779, followed by Stacking (0.8728), Maximum (0.8704), Probability (0.8669), and Voting (0.8653), whereas the widely-used Mean method performed the worst (0.8503), even lower than the non-classified LSM (0.8587). The findings offer a robust approach for mitigating future landslide risks and minimizing their adverse impacts, providing valuable insights for geohazard management and decision-making.</div></div>","PeriodicalId":12711,"journal":{"name":"Geoscience frontiers","volume":"16 2","pages":"Article 101999"},"PeriodicalIF":8.5,"publicationDate":"2024-12-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143145886","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Multi-mechanism REYs enrichment in early Cambrian phosphorites within inner-shelf: Constraints from the geochemistry characteristics of francolite in Kunyang, Yangtze Block","authors":"Pei Liang ,&nbsp;Junyi Wang ,&nbsp;Li Chen ,&nbsp;Yuling Xie ,&nbsp;Bingbing Zhao","doi":"10.1016/j.gsf.2024.101996","DOIUrl":"10.1016/j.gsf.2024.101996","url":null,"abstract":"<div><div>Middle and heavy rare earth elements and yttrium (MHREYs) are critical to the high-tech and green-energy industries, generating tremendous supply risk in recent decades. Recently, sedimentary phosphorites have been identified as a new resource for MHREYs. The Early Cambrian is considered one of the critical large-scale phosphorus-forming periods in China and globally. During this period, widespread large-scale phosphorites mainly occurred at shelf, while small-scale phosphate concretions predominantly existed in near-slope settings on the Yangtze Block, South China. However, multi controls for ore-forming mechanism of extraordinary REYs enrichment in phosphorites have not been well constrained, limiting the understanding of the formation of large-scale phosphorites at shelf. To better understand the REYs enrichment in phosphorite, the REYs-rich Kunyang phosphorite, the largest phosphorite in shelf environment on the Yangtze Block, was investigated through mineralogy, in-situ geochemistry of major and trace elements in francolites. Based on the mineral characteristics, four types of phosphorite and four types of wall rocks were divided, which can be grouped into high-REYs (435–717 ppm) and low-REYs (224–282 ppm) categories. Comparing the geochemical characteristics of high-REYs and low-REYs groups, multi-mechanisms of REYs enrichment can be supposed. Frequent Fe redox cycling and related suboxic conditions may be responsible for the extraordinary REYs enrichment in phosphorites. In high-energy hydrodynamic systems with a low sedimentation rate, prolonged deposition of francolite enhanced the effects of adsorption and substitution in the early and late diagenetic stages, respectively, significantly increasing REYs uptake. Moreover, in the inner-shelf environment, wave fluctuations and storm effects are significant, leading to extensive diagenetic reworking, which form extremely high REYs contents in the altered rims of francolite. The negative Eu anomalies in the high-REYs group also indicate a positive influence of porewater on REYs enrichment. Regarding the sources of REYs, both seawater and terrigenous detrital material contribute to REYs in phosphorite at the shelf environment. The sedimentary high-REYs group indicate that terrigenous detrital material may enhance REYs content in seawater, which is then transferred to francolite during diagenesis. Consequently, multiple mechanisms controlled the REYs enrichment, leading to the formation of large-scale phosphorite in the inner-shelf.</div></div>","PeriodicalId":12711,"journal":{"name":"Geoscience frontiers","volume":"16 2","pages":"Article 101996"},"PeriodicalIF":8.5,"publicationDate":"2024-12-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143145889","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Non-arc setting for “Cadomian” magmatism in Iran and Anatolia","authors":"Yousef Zoleikhaei ,&nbsp;Peter A. Cawood ,&nbsp;Jacob A. Mulder","doi":"10.1016/j.gsf.2024.101995","DOIUrl":"10.1016/j.gsf.2024.101995","url":null,"abstract":"<div><div>Establishing the type and position of plate boundaries is crucial for paleogeographic reconstructions. The northern margin of Gondwana (NMG) is inferred to have been a convergent, Andean-style, plate margin for much the late Neoproterozoic to early Paleozoic (i.e., the Avalonian-Cadomian Orogen), based largely on the presence of igneous rocks with arc-related geochemical affinities. However, a major segment of the margin that fringed the Arabian Plate includes bimodal Ediacaran–middle Cambrian (ca. 600–500 Ma) igneous rocks, more typical of continental rift settings, which has led to ambiguous and contradictory interpretations of magma tectonogenesis. Here, we employ an alternative approach to investigate the tectonic setting of the NMG by studying the evolution of sedimentary basins that developed in Iran, Anatolia, and the Arabian Plate simultaneously with the ca. 600–500 Ma magmatism. The Ediacaran–middle Cambrian successions in this segment of the NMG consist of laterally continuous siliciclastic and carbonate sequences, which have been broadly correlated across the region. The consistent northward and eastward paleocurrent directions and decrease in clastic sediment grain-size from proximal (the Arabian Plate) to distal (Iran and Anatolia) successions suggest a northward and eastward deepening basin with relatively flat topography. The new detrital zircon (<em>n</em> = 2870) and apatite (<em>n</em> = 1178) U-Pb ages from the Ediacaran–middle Cambrian siliciclastic strata of Iran are mostly older than 600 Ma. Detrital apatite trace element compositions indicate that most grains are sourced from I-type granitoids and mafic igneous rocks, low- and high-grade metamorphic rocks, with a minority from ultramafic rocks. Together with published detrital zircon U-Pb age data from correlative strata in Anatolia and the Arabian Plate, these data suggest the pre-existing Arabian-Nubian Shield as the main source. Importantly, detrital zircon and apatite grains with ages &lt; 600 Ma are rare in these strata, suggesting that they received little input from contemporaneous Ediacaran–middle Cambrian (ca. 600–500 Ma) igneous rocks. We suggest that the very small sediment contribution from the ca. 600–500 Ma igneous rocks argues against the tectonic model that considers the development of a large Andean-style magmatic arc at this segment of the NMG. Integrating these constraints from the sedimentary record with geochemical data from the ca. 600–500 Ma igneous rocks in Iran and Anatolia favors an extensional continental margin setting that may be related to escape tectonics or post-collisional relaxation during Ediacaran–Cambrian following Gondwana assembly.</div></div>","PeriodicalId":12711,"journal":{"name":"Geoscience frontiers","volume":"16 2","pages":"Article 101995"},"PeriodicalIF":8.5,"publicationDate":"2024-12-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143145887","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Lithospheric deformation and seismotectonics in the southeastern Tibetan Plateau: A holistic perspective from joint inversion of multi-geophysical data","authors":"Feiyu Zhao ,&nbsp;Sanzhong Li ,&nbsp;Yanhui Suo ,&nbsp;Juzhi Deng ,&nbsp;Mengxue Dai ,&nbsp;Xiao Chen ,&nbsp;Bin Hu ,&nbsp;Yanguo Wang ,&nbsp;Yaping Hu","doi":"10.1016/j.gsf.2024.101994","DOIUrl":"10.1016/j.gsf.2024.101994","url":null,"abstract":"<div><div>The southeastern Tibetan Plateau (SETP) plays a pivotal role in accommodating the crustal deformation between the complex Tibet Plateau and the South China Block during the Cenozoic associated with the India-Asia Convergence. In this study, we establish a high-resolution 3-D lithospheric structure model of the SETP through joint inversion of observable multi-geophysical data, to understand its Cenozoic progressive deformation processes, deep seismotectonic environment, as well as regional geodynamic mechanism. We identify two low-density zones within the mid-lower crust that are separated by a pronounced high-density body beneath the inner zone of the Emeishan Large Igneous Province (ELIP). We also image an interconnected channel flow in the lower crust beneath the SETP. To further confirm the relationship between Cenozoic deformation propagation and deep lithospheric architecture, we adopt a holistic perspective from joint inversion of observable multi-geophysical data, coupled with integrated analysis on geometric-kinematic characteristics of major strike-slip fault zones and regional tectonics in the SETP. The results show that the mechanically weak mid-lower crust of the SETP is characterized by low effective elastic thickness (<em>Te</em>), high heat flow, low-density/velocity and low-viscosity, which might accommodate the ductile flow and provide an important channel for the lateral extrusion of crustal materials from the Tibetan Plateau, and ultimately contribute to the episodic lithospheric deformation of the SETP. We trace three main phases of deformation within the SETP during the Cenozoic: the Eocene-early Oligocene latitudinal crustal shortening and thickening, the late Oligocene-early Miocene clockwise rotation and lateral extrusion along major strike-slip faults, and the mid-late Miocene lower crustal flow accompanied with regional kinematic reversal. The lithospheric deformation, the invasion of fluids and the upwelling of deep molten materials are conducive to strain accumulation, which might also explain the occurrence of large earthquakes. Geodynamically, we consider that both the spatio-temporal variance of convergent rates, subduction angle, and processes of the India-Asia Convergence may be associated with episodic crustal deformation and intense seismicity in the SETP. The aqueous fluids in the weak mid-lower crust may have propagated outward due to the long-term gravitational driving forces and contributed to the lithospheric deformation and seismicity of the SETP. Furthermore, the retreat of the subducted Indian slab as well as the rollback and back-arc spreading of the western Pacific Plate also provided favorable conditions for the eastward extrusion of the Tibetan Plateau.</div></div>","PeriodicalId":12711,"journal":{"name":"Geoscience frontiers","volume":"16 2","pages":"Article 101994"},"PeriodicalIF":8.5,"publicationDate":"2024-12-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143145445","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}