Abstract:Mantle-derived magmas can serve as a"lithoprobe"for acquiring information about deep Earth materials.In this study,a newly discovered granite xenolith from the Late Ordovician(449 Ma)lamproite at Daping,East Guizhou,was investigated.Zircon U-Pb geochronology,Lu-Hf isotope,and trace element analyses were conducted on the granite xenolith.The results indicate that the concordant zircon U-Pb age of the granite xenolith is(833±2.6)Ma(MSWD=1.3,n=26).The εHf(t)values range from-11.4 to-2.30,and the depleted mantle model ages(TDM)vary from 2 457 to 1 893 Ma.The trace element compositions of zircon,including REEs,U,Th,Pb,Nb,and Hf,suggest that the granite xenolith is an S-type granite related to orogenic processes.The similarity in crystallization ages and Hf isotopic compositions between this granite xenolith and the Neoproterozoic granites exposed in the Fanjingshan region implies that they may collectively form a large granitic batholith at depth.This batholith provides crucial evidence for delineating the northern boundary of the western segment of the Jiangnan Orogen.It is proposed that the boundary between the northern side of the western Jiangnan Orogen and the Yangtze Block should be defined by the Zhangjiajie-Guiyang fault.

Abstract:Lijiang basin is a multi-plate confluence zone located in the southwestern margin of the Yangtze block.The study for the provenance of the Lower Triassic reveals the source-sink system of the southwestern Yangtze block and its spatio-temporal relationship with the western Gondwana arc basin system.Field observations and microscopic identification show that the sandstones of the Lamei Formation in Heqing region are mainly derived from the proximal transport of felsic volcanic rocks.The detrital zircons exhibit single age peaks of～254 Ma and～255 Ma,corresponding to the timing of felsic magmatic activity in the Emeishan Large Igneous Province(ELIP),and are consistent with interior/non-orogenic magmatic zircon trace element signatures,distinguishing them from those in arc orogenic belts.The εHf(t)values of the Lu-Hf isotopic analysis indicate the provenance of the sandstones of Lamei Formation are from the felsic rocks of the ELIP.Whole-rock geochemical data show that the Lamei Formation shares similar trace element characteristics with the Emeishan rhyolites,porphyries and syenites.A comprehensive analysis suggests that the materials of the Lamei Formation originate from the proximal transport of rhyolite,trachyte and syenite from ELIP.During the Early Triassic,the Lijiang basin functioned as a passive continental margin sedimentation area,primarily receiving materials from the ELIP,with no contributions from the western arc-basin system.

Abstract:The Yulong porphyry copper deposit is the only super-large porphyry deposit in the Yulong porphyry copper belt,and the previous research on this deposit is primarily focused on genesis,with limited emphasis on the significance of post-metallogenic transformation in formulating prospecting strategies.Thermochronological methods such as zircon U-Pb,apatite fission track,apatite and zircon(U-Th)/He were employed to date and conduct related thermal history inverse modellings.The results indicate that the zircon U-Pb concordant age of the monzogranite porphyry of the Yulong deposit is(41.7±0.5)Ma,with zircon(U-Th)/He age ranging from 34.9 Ma to 39.3 Ma,indicating that the magmatic-hydrothermal evolution process of the Yulong deposit may have lasted at least 5 Ma.The apatite fission track ages range from 34.7 Ma to 19.7 Ma,while apatite(U-Th)/He ages range from 20.7 Ma to 18.4 Ma.These sequentially decreasing ages are indicative of the timing of cooling and exhumation events.The inverse thermal history modelling indicates that the Yulong deposit has undergone a roughly three-stage cooling process,combined with the regional tectonic evolution data,and the relatively rapid cooling between 34 Ma and 30 Ma may be related to the rapid uplift of the Qinghai-Xizang Plateau,resulting from the ongoing collision between the India and Eurasian continents during this period.The relatively slow cooling observed between 30 Ma and 21 Ma could be linked to the weakening collision activity.The relatively rapid cooling between 21 Ma and 14 Ma may be associated with the crustal thickening event in the North Qiangtang terrane,triggered by tectonic shortening or magma inflation during this period.Utilizing the thermal history simulation method,the exhumation amount of Yulong deposit is 3.45 km,Considering the 4-5 km of metallogenic depth of Yulong deposit,there is still 0.5-1.5 km of prospecting space in the deep part of the deposit.

Abstract:The nickel isotope system serves as a crucial tool for investigating the sources,migration,transformation,and cycling processes of nickel in the ocean.Marine sediments play a vital role in the geochemical cycling of nickel,functioning both as a"source"and a"sink"for the element.The nickel isotopic composition can record key information about the nickel cycling process in seawater.In this paper it systematically summarizes the nickel isotopic compositions of seawater and major marine reservoirs,including riverine inputs,hydrothermal systems,and diverse marine sediments(iron-manganese oxide deposits,anoxic sediments,and carbonate sediments).It analyzes nickel isotopic compositions and their interrelationships,and delves into the fractionation mechanisms of nickel isotopes between sediments and seawater and their implications for reconstructing palaeoceanographic environments.The findings demonstrate that nickel isotope possesses unique advantages in tracing changes in palaeoceanographic productivity,sulfur-rich environmental evolution,and the mass balance of the global nickel cycle.

Abstract:Solid texture synthesis based on 2D samples(deep learning)is an important pathway for rock solid texture generation,which currently suffers from the inability of long distance dependence and color distortion.In this paper,it proposes an innovative method based on 3D coordinate attention generative adversarial network(3D-CA-GAN).By extending the coordinate attention mechanism to three-dimensional space(3D-CA)and combining the content-aware upsampling module and multi-scale discriminator,high-fidelity modeling of the spatial distribution of mineral particles is achieved.Experiments show that the method significantly outperforms existing techniques in terms of SSIM(0.773),PSNR(24.92%enhancement),and LPIPS(0.110 reduction),and ablation experiments further validate that the 3D-CA module improves the SSIM of directional textures by 14.69%.This study provides a new solution to texture synthesis with realism for geological modeling,and its 3D attention framework is useful for generic generation tasks.

Abstract:To find out a suitable equation for single-well pumping test in double-porosity aquifer,it takes wellbore storage effect into consideration and present the double-porosity non-Darian model with wellbore storage effect based on double-porosity non-Darcian model in this study.Taking a single-well pumping test as an example,the results show that the simulation curve has the highest accuracy when using the double-porosity non-Darcian model proposed in this study;taking non-Dacian effect into consideration is more suitable when the pumping rate is relatively large and the flow in aquifer shows non-Darcian property.When considering non-Darcian effect,we can have a better inversion of the instantaneous drawdown in early time;when regarding the aquifer as double-porosity,we can portray the weak to strong process of the water exchange in fracture and porosity media.In that case,the double-porosity non-Darcian model with wellbore storage effect presented in this study is suitable for single-well pumping test in double-porosity aquifer.

Abstract:As mineral exploration in China continues to advance,the search for concealed deposits in covered areas has become a crucial future direction.In this paper it systematically reviews the research progress in using gases as prospecting media for mineral exploration in covered terrains.It analyzes the principles,characteristics,sources,and migration mechanisms of mineralization-related gases used in exploration,summarizes the influence of environmental factors on their migration and enrichment.For different types of gases(such as CO2,hydrocarbon gases,sulfur-bearing gases,inert gases Rn and He,and mercury vapor(Hg)),it summarizes their application characteristics and challenges in mineral exploration,highlighting the advantages of multi-gas joint surveys specifically for metallic sulfide deposits.Although gas geochemical methods have demonstrated significant effectiveness in exploration practice,the genetic mechanisms,migration patterns,and influencing factors of various gases require further in-depth research,and the related theoretical framework needs refinement.Concurrently,there is an urgent need to establish a comprehensive system encompassing the detection,identification,tracing,and evaluation of gas geochemical anomalies to enhance the applicability and effectiveness of this method.

Abstract:Few studies focus on the change of debris flow hazard,although the change of disaster-pregnant factors would affect the hazard of debris flow.Taking the Chutou gully as an example,this study aims to discover the impact of disaster-pregnant factors on the development of debris flow hazard from 2007 to 2021 based on entropy method and multi-source monitoring data.A monitoring system of debris flow hazard is proposed.The findings are as follows:materials of debris flow increased 27 times after the Wenchuan earthquake,and then the materials continued to decrease and would return to the pre-earthquake levels by 2027.The critical rainfall of debris flow in 2019 increased by 12.97%compared with 2013 and the debris flow might occur if the conditions met the formula f(Ih,P)≥R(34.40 mm).The value of debris flow hazard increased after the earthquake,and hazard value would reach the peak(very high hazard)under extreme rainfall then relatively decrease.The Chutou gully would keep the high level of debris flow hazard after 2021.The monitoring system of debris flow hazard is proposed to find the high hazard area of debris flow,which could provide some new clues for prevention and control of debris flow.

Abstract:Integrating geological and drilling data,traditional geophysical techniques such as gravity,magnetic,and electrical surveys provide quantifiable constraints on density,magnetic susceptibility,resistivity and polarization,for locating concealed and deep-seated metallic ores.Since seismic exploration offers higher spatial resolution on strata and structural geometry,its combination with gravity,magnetic,and electrical methods can significantly enhance exploration accuracy of metallic ores.Due to the complex terrain and subsurface geological conditions encountered in metallic ore exploration,however,the traditional reflection seismic method faces two major challenges:high acquisition costs and multiplicity of only P-wave velocity tomography.Therefore,based on modern sensing,communication and computing technologies,in this paper it draws on the latest seismic techniques applied in engineering geology and fossil energy to address how to reduce the cost of seismic survey and improve the imaging accuracy in conditions of complex surface and subsurface geological structures of metallic ores.After thorough analysis of the challenges in metallic ore seismic exploration,it proposes several technical solutions,including the combined use of active and passive source seismic,artificial intelligence-based seismic acquisition technique to decrease the seismic acquisition cost substantially,multi-component seismic scattering imaging,and joint inversion for multiple physical parameters to improve accuracy of predicting ore deposits.Additionally,it discusses key issues that should be addressed in the future regarding the limitations of current seismic theories and techniques.

Abstract:The Southwest Yunnan Tin Belt is one of the most important tin metallogenic belts in China.The temporal and spatial distribution of granite-related tin deposits in the Southwest Yunnan Tin Belt has been summarized,but the relationship between the spatial distribution of tin deposits and the nature of the crust,as well as the reasons for its constraints on tin mineralization,are still unclear.In this paper,published zircon Hf isotope data of Early Paleozoic-Cenozoic granites in Southwest Yunnan are collected.Based on previous large-scale isotope mapping of the Sanjiang Tethys orogenic belt,the εHf(t)value and TDMC contour maps and two typical profiles in Southwest Yunnan are drawn by ArcGIS software.The mapping results show that the Changning-Menglian orogenic belt and Baoshan terrane are ancient crustal domains with low εHf(t)and high TDMC,while the Tengchong terrane has uneven isotopic distribution,and there are both ancient crustal regions with low εHf(t)and high TDMC,as well as newly formed crustal regions with high εHf(t)and low TDMC.The distribution of tin deposits in Southwest Yunnan is closely related to crustal properties.Tin deposits are all distributed in ancient crustal areas with low εHf(t)and high TDMC,while no tin deposits have been found in the newly formed crustal areas with high εHf(t)and low TDMC.The concentrated production of tin ore in ancient crustal regions may be related to ancient tin rich crust.The mixing of low tin and high oxygen fugacity mantle magma has an inhibitory effect on the enrichment of tin in granite,which may be the reason for the unclear tin mineralization in the newly formed crustal area.

Abstract:The Paleo-Tethyan Ocean,represented by the Jinshajiang River suture in eastern Tibetan Plateau,was consumed and closed in the Early-Middle Triassic,but the specific process after the oceanic crust demise is still poorly constrained.The potential for porphyry copper mineralization of magma generated in post-subduction setting remains unclear.In present study,geochronological and geochemical analyses were carried out on the Yarigong pluton in Batang area.Magmas were intruded in Late Triassic as corroborated by zircon U-Pb mean age of about 227 Ma.Rocks from this intrusion were characterized by high SiO2(65.5%to 67.6%)and Mg#(53 to 64),as well as high initial 87Sr/86Sr values(0.709 8 to 0.711 8)and low εNd(t)values(-7.4 to-8.0).Magma generation of the Yarigong pluton resulted from interaction between melts derived from continental crust and peridotite mantle,and partial melts of the continental crust was likely associated with the break-off of early subducted Paleo-Tethyan oceanic slab.Geochemical compositions of amphibole and zircon suggest high magma H2O contents(>5%),the oxygen fugacity of magma is lower than magma related to typical porphyry Cu deposits,and extremely low S in magma was indicated by consistent low SO3 in apatite.These conditions imply barren magma for porphyry Cu deposit formation.

Abstract:Quantitative research on the impact of urban underground space development on groundwater environment has important theoretical and practical significance for rational development and accurate management of urban underground space.In this paper it discusses the influence of urban underground space development on groundwater flow in Su-Xi-Chang area.Based on construction of the hydrogeological conceptual model of Su-Xi-Chang area,the groundwater flow numerical model was established.Based on the corrected groundwater flow numerical model,the influence of subway operation on groundwater flow was predicted.Due to the obstruction of underground runoff by subway,the upstream groundwater level increases by 0-0.4 m,while the backwater level decreases by 0-0.8 m,increasing the hydraulic gradient in the range of 17.56 km.After the subway is put into operation,the variation in groundwater level near the subway is larger in the first five years and smaller in the second five years.The direction of groundwater runoff changes locally,but the regional direction does not change significantly.

Abstract:The valley landslide disaster chain refers to a series of cascading hazardous events resulting from the complex interactions between landslide masses in river-adjacent areas and fluvial systems among the most common types are landslide-induced tsunami and landslide damming disaster chains.Research indicates that the uncertainties in valley landslide disaster chains mainly stem from three aspects:the uncertainty of disaster-triggering mechanisms,the dynamic unpredictability of the movement processes,and the coupling uncertainty in chain interactions.Current methods for disaster chain identification and susceptibility assessment primarily utilize remote sensing,spatial analysis,and machine learning techniques.However,these approaches often fail to adequately account for cascading effects and spatiotemporal evolution characteristics.Although qualitative,quantitative,and numerical simulation-based methods have been developed for risk assessment,limitations remain due to data scarcity and the lack of large-scale mechanistic analysis tools.Current methodologies often couple individual segments of the disaster chain,but fail to capture its systemic integrity and cascading interactions.Although combined structural and non-structural mitigation measures have been implemented,quantitative evaluations of chain-breaking effectiveness remain underdeveloped.Future research should focus on:developing multi-physics,cross-scale evolution theories of disaster chains;establish a large-scale,continuous multi-field monitoring and multi-source heterogeneous data fusion identification system;constructing a data-and physics-driven full-process risk assessment model for disaster chains;and strengthening precise early warning and systematic chain-breaking mitigation strategies.

Abstract:The landslide-tsunami is a typical multi-hazard coupled system,characterized by complex effects resulting from the transmedia transformation of hazards.In this paper it proposes a two-phase Riemann-SPH model for landslide-tsunami simulation that incorporates dynamic seepage and is validated against laboratory experiments.The incorporation of dynamic seepage effects enhances the completeness of the momentum exchange mechanism in the granular landslide-tsunami process,reducing the errors in the maximum wave amplitude(am)and maximum wave height(Hm)by at least 24.72%and 41.95%,respectively.The results reveal a synergistic regulation of tsunami characteristics by the sliding surface inclination(α)and the landslide leading edge inclination(β):as α increases,the am and Hm exhibit a single-peaked,nonlinear increase-then-decrease trend.The influence of β shows a distinct piecewise pattern:when α+β<90°,both am and Hm increase significantly with the angle.Beyond this threshold,non-monotonic variations appear,reflecting a competition between the increasing landslide volume and the decreasing effective impact area.Moreover,increasing α enhances seepage,turbulent and frictional dissipation effects,accelerating energy decay.These findings provide scientific support for the mitigation of landslide-tsunami hazards.

Abstract:This study aims to evaluate the applicability of existing seismic ground motion zoning maps in earthquake risk assessment for active fault zones under complex tectonic settings and improve the accuracy of seismic hazard analysis.Focusing on the affected area of the 2022 Ms 6.8 Luding earthquake in the Sichuan-Yunnan region,probabilistic seismic hazard analysis(PSHA)was conducted using the OpenQuake platform.Through seismic catalog processing,magnitude conversion,source parameter estimation,and fault modeling,a regional seismic model incorporating both background seismic sources and fault sources was established.Multiple ground motion prediction equations(GMPEs)suitable for active shallow crustal tectonics were selected to generate seismic motion parameter distribution maps and exceedance probability analysis results.The findings demonstrate that OpenQuake-simulated ground motion distributions align fundamentally with China's fifth-generation seismic ground motion zoning map,particularly showing enhanced accuracy in identifying high peak ground acceleration(PGA)zones.As PGA thresholds increase,high-exceedance probability areas gradually diminish and concentrate near major faults.By adopting 0.1 magnitude increments,this research avoids the underestimation of seismic moment release rates observed in the fifth-generation zoning map.Furthermore,results indicate concentrated strong earthquake risks in fault intersection zones,suggesting these areas should be prioritized for monitoring and protective measures.

Abstract:In order to investigate the microscopic damage mechanism of the degradation of the properties of freezing-thaw(F-T)damaged moraine soils,a method of simulating F-T damage of soils through water particle expansion is proposed based on the discrete element theory.Using the particle flow software PFC2D to simulate the triaxial compression test,combined with the comparative analysis of the test results,this method is accurate and reliable in modeling the changes in mechanical properties of moraine soils and reveals the evolution of microcrack;displacement field;force chain field and rupture characteristics of F-T moraine soils during the loading process.The results show follows(1)The microcracks in the F-T process show a trend of"cumulative evolution"that arises from the surrounding area and gradually expands to the middle,and the tensile microcracks are dominant;at 2-5 times of F-T processes,horizontal compression between particles dominated and a large number of tension microcracks inclined at 90° were developed.(2)The deterioration of moraine properties caused by F-T is particularly obvious in the early freeze-thaw period(2-5 times),the cohesion c decreases as a negative exponential function with the number of F-T cycles,while the internal friction angle φ shows a small fluctuation.(3)The specimen loaded process is dominated by shear cleavage,with the trend of"first slow,then steep,and finally slow"evolution,and the stress-strain curve is divided into four deformation stages according to the evolution characteristics.(4)When the sample is loaded after freeze-thaw,the transition point B of deceleration slope moves before the peak stress point C,indicating that point B can be used as a"precursor feature"in the process of microcrack expansion-through-formation failure;The specimen with 20 F-T cycles were more severely damaged when loaded and formed distinct shear zones.

Abstract:Aiming at the current problem of knowledge extraction and utilization from text reports in landslide prevention and control work,this study explores a set of methods for constructing and applying a knowledge graph based on geological disaster data and materials,promoting the transformation of geological disaster prevention from data management to knowledge management.Knowledge extraction and knowledge graph construction were conducted on basic data from 182 reports,22 specifications,5 literatures,4 668 landslide points,and 313 governance projects,as well as three years of historical disaster data,current landslide monitoring data,and forecasted weather data.Retrieval-augmented generation(RAG)technology was adopted to integrate and output multi-source knowledge.A knowledge graph system with 12 797 entities,34 873 relationships,and 9 658 chunks was established,enabling 10-day early warning for 4 518 landslides.Knowledge graph technology effectively extracts knowledge from text reports,and RAG technology efficiently integrates multiple knowledge sources,improving the accuracy of knowledge question-answering.

Abstract:The identification of geological structures and the quantification of uncertainties in strength parameters are crucial for assessing the stability of rock slopes.This study proposes a system reliability analysis method for multi-slip surface slopes based on geological structure detection.The method integrates multichannel analysis of Love waves(MALW)and first-arrival travel time tomography(FATT)to achieve complementary detection of weak layers and faults.Elastic wave velocities are used to reduce the strength parameters of weak layers,and their probabilistic distributions are statistically derived.By incorporating parameter uncertainties,the surface displacement of slopes and the failure probabilities of individual slip surfaces and the entire system are calculated.Case studies indicate that multi-mode dispersion curves achieve higher inversion accuracy for both deep and shallow weak layers compared to fundamental-mode dispersion curves,and Love waves are less affected by undulations at rock layer interfaces than Rayleigh waves.Slope faults exhibit characteristic wave fluctuations within specific ranges in first-arrival travel time records.Inversion based on these features enables the localization of local faults.In the case of multi-slip surface slopes,deep slip surfaces are identified as the primary controlling factor,and the system failure probability is more significantly affected by the coefficient of variation of the internal friction angle than by cohesion.This method effectively detects geological structures,locates weak layers and faults,and quantifies uncertainties in strength parameters,providing a scientific basis for slope stability analysis and mitigation measures.

Abstract:Riverside highway zones are prone to high risks of geohazards such as landslides due to proximity to water bodies,steep terrain,and frequent anthropogenic activities.However,current single-source domain transfer learning methods face limitations in geohazard susceptibility prediction when significant discrepancies exist between source and target domains in hydrogeological conditions(e.g.,river density,rainfall intensity)and engineering disturbances(e.g.,highway construction),often leading to negative transfer issues and reduced model generalizability.This study proposes a multi-source domain transfer learning framework based on a multiple feature spaces adaptation network(MFSAN).Focusing on three riverside highway zones in Fujian Province,China,nine environmental factors(including highway density and river density as core hydrogeological features)were extracted to construct a landslide spatial database.The susceptibility models from Anxi County(source domain 1)and Dehua County(source domain 2)were transferred to Youxi County(target domain)with unlabeled samples for cross-regional landslide susceptibility evaluation.Comparative analyses were conducted against non-transferable learning models(NTL)and single-source domain adaptive models(domain adaptive neural network,DANN).The results demonstrate:(1)The MFSAN model achieved a cross-regional prediction accuracy of 0.851,outperforming single-source transfer models with improvements of 3.61%in accuracy,1.91%in AUC,and 9.64%in overall assessment metric(OA).(2)Historical landslide validation revealed that 79.2%of landslides occurred within high-to-extreme susceptibility zones predicted by MFSAN,the highest among all models.(3)MFSAN exhibited superior capability in capturing hydrogeological coupling effects unique to riverside environments.For instance,the concentration of hazard-prone sites within 3 km of highways(70%-83%)was accurately reflected in predictions.The MFSAN framework effectively integrates spatial features and disaster development patterns from multiple source domains,comprehensively capturing regional heterogeneity and providing an optimized solution for cross-regional geohazard susceptibility prediction.This approach demonstrates enhanced generalization capability and practical value for mitigating landslide risks in complex engineering environments.

Abstract:The composite structure of anti-slide pile and anchor cable can give full play to the rigid constraint of anti-slide pile and the active tension of anchor cable to control slope deformation,showing good seismic performance,and has been widely used in landslide prevention in strong earthquake areas.However,at present,there is little research on the seismic dynamic response of slope strengthened by pile-anchor composite structure,and its cooperative seismic mechanism is not clear.Based on Newmark model,this paper presents a dynamic response analysis method of slope strengthened by pile-anchor composite structure considering earthquake time-history characteristics.The method is applied to the high slope of Shandong expressway,and the permanent displacement,safety factor and internal force of supporting structure of the slope with different reinforcement methods are analyzed.The results show that the pile-anchor composite structure effectively reduces the permanent displacement of the slope and ensures the stability of the slope.Compared with only anchor support and only pile support,the maximum anchorage tension at the anchorage end,the maximum shear force and the maximum bending moment of the pile body are reduced.With the increase of cohesion and internal friction angle,the yield acceleration of slope increases in direct proportion,while the permanent displacement transitions from sharp decrease to slow decrease,in which the influence of cohesion is more significant.By forming an active stress system,the pile-anchor composite structure increases the yield acceleration of the slope,realizes the coordinated stress of the pile and the anchor cable,and prevents excessive stress concentration near the sliding surface,which is an efficient reinforcement method.