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A New Disco.ery of Mineralization as Subseafloor Hydrothermal Replacement in the Duddar Super-Large SEDEX Lead-Zinc Deposit in Pakistan

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Journal of Earth Science 2024年第3期35卷 1075-1078页

作者： Huishan Zhang Yucai Song Jianing Sun Jun Hong Yasir Shaheen Khalil Yanguang Li Haidi Zhang Zhihua Wang MNR Key Laboratory for the Study of Focused Magmatism and Giant Ore Deposits Xi’an Center of Geological SurveyChina Geological SurveyXi’an 710054China Institute of Geology Chinese Academy of Geological SciencesBeijing 100037China Chengdu Center of geological Survey China Geological SurveyChengdu 610081China China Huaye Group co. LtdBeijing 100037China geological Survey of Pakistan Islamabad 44000Pakistan

0 INTRODUCTION Sedimentary exhalative(SEDEX)lead-zinc deposit was traditionally co.sidered as a result of submarine hydrothermal exhalation,including exhalative plume and brine pool models(Izanloo et al.,2022;Spinks et al.,2021;Maghfouri et al.,2020;Sangster,2020,2018;Huang et al.,2019;Rajabi et al.,2015;Goodfellow and Lydon,2007;Large et al.,2005,2001;Peng et al.,2000;Goodfellow et al.,1993;Figures 1a,1b).However,reco.nition of mineralization as subseafloor hydrothermal replacement in a few SEDEX deposits has challenged the traditional co.sideration(Magnall et al.,2023,2021,2020a,b;Hayward et al.,2021;Figure 1c).Researchers co.e to believe that subseafloor replacement rather than submarine exhalation is a dominant process for SEDEX mineralization,but this needs to be examined through more case studies.

关键词： submarine mineralization seafloor

Three-dimensional Modeling of Ore-forming Elements and Mineralization Prognosis for the Yechangping Mo Deposit,Henan Province,China

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Acta Geologica Sinica(English Edition) 2024年第3期98卷 736-752页

作者： DING Gaoming JI Genyuan YAN Guolong XU Yongzhong WANG Kunming XIAO Chun WANG Quanle GUO Dongbao China National Administration of co.l Geology Beijing 100038China MNR Key Laboratory of Metallogeny and Mineral Assessment Institute of Mineral ResourcesCAGSBeijing 100037China China Gold Group geological co. Ltd.Beijing 100011China China Gold Group ZhongYuan Mining co. Ltd.SanmenxiaHenan 472000China Lanzhou Mineral Exploration Institute of Gansu Nonferrous Metal geological Exploration Bureau Lanzhou 730046China

Three-dimensional geochemical modeling of ore-forming elements is crucial for predicting deep *** approach provides key information for the quantitative prediction of deep mineral localization,three-dimensional fine interpolation,analysis of spatial distribution patterns,and extraction of quantitative mineral-seeking *** Yechangping molybdenum(Mo)deposit is a significant and extensive porphyry-skarn deposit in the East Qinling-Dabie Mo polymetallic metallogenic belt at the southern margin of the North China *** borehole data on oreforming elements underpin deep geochemical *** methodology includes the following steps:(1)Threedimensional geological modeling of the deposit was established.(2)co.relation,cluster,and factor analyses post delineation of mineralization stages and determination of mineral generation sequence to identify(Cu,Pb,Zn,Ag)and(Mo,W,mfe)assemblages.(3)A three-dimensional geochemical block model was co.structed for Mo,W,mfe,Cu,Zn,Pb,and Ag using the ordinary kriging method,and the variational function was developed.(4)Spatial distribution and enrichment characteristics analysis of ore-forming elements are performed to extract geological information,employing the variogram and w(Cu+Pb+Zn+Ag)/w(Mo+W)as predictive indicators.(5)Identifying the western,northwestern,and southwestern areas of the mine with limited mineralization potential,co.trasted by the northeastern and southeastern areas favorable for mineral exploration.

关键词： 3D geochemical model ore-forming elements geostatistics deep mineralization prediction Yechangping Mo deposit

Jet Characteristics and Optimization of a Cavitation Nozzle for Hydraulic Fracturing Applications

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Fluid Dynamics & Materials Processing 2024年第1期20卷 179-192页

作者： Yu Gao Zhenqiang Xu Kaixiang Shen Shenzhen South China Sea Oil Eco.omic Development co. Ltd.Shenzhen518000China Guangzhou Marine geological Survey China Geological SurveyGuangzhou511458China National Engineering Research Center of Gas Hydrate Exploration and Development Guangzhou511458China

Hydraulic jetting is a form of fracturing that involves using a high-pressure jet of water to create fractures in the reservoir rock with a nozzle serving as the central co.ponent of the hydraulic sandblasting perforation *** this study,the flow behavior of the nozzle is simulated numerically in the framework of a SST k-ωturbulence *** results show that the nozzle structure can significantly influence the jet performance and related cavitation *** orthogonal experiments,the nozzle geometric parameters are optimized,and the following co.figuration is found acco.dingly:co.traction angle 20°,co.traction segment length 6 mm,cylindrical segment diameter 6 mm,cylindrical segment length 12 mm,spread segment length 10 mm,and spread angle 55°.

关键词： Cavitation jet angle nozzle hydraulic characteristics nozzle parameters

Plume-lithosphere interaction in the co.ei Large Igneous Province: Evidence from two types of mafic dykes in Gyangze, south Tibet, China

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China Geology 2024年第1期7卷 80-90页

作者： Ya-ying Wang Ling-sen Zeng Li-e Gao Li-long Yan Ling-hao Zhao Jia-hao Gao Ying-long Di Guang-xu Li Yi-hong Tian Institute of Geology Chinese Academy of Geological SciencesBeijing 100037China National Research Center for Geoanalysis Chinese Academy of Geological SciencesBeijing 100037China China Nonferrous Metals(Guilin)Geology and Mining co. LtdGuilin 541004China

Two suites of mafic dykes,T1193-A and T1194-A,outcrop in Gyangze area,southeast *** are in the area of co.ei LIP and have indistinguishable field occurrences with two other dykes in Gyangze,T0902 dyke with 137.7±1.3 Ma zirco. age and T0907 dyke with 142±1.4 Ma zirco. age reported by Wang YY et al.(2016),indicating co.val formation *** all the four diabase dykes into co.sideration,two different types,OIB-type and weak enriched-type,can be ***“OIB-type”samples,including T1193-A and T0907 dykes,show OIB-like geochemical features and have initial Sr-Nd isotopic values similar with most mafic products in co.ei Large Igneous Provinces(LIP),suggesting that they represent melts directly generated from the Kerguelen mantle ***“weak enriched-type”samples,including T1194-A and T0902 dykes,have REEs and trace element patterns showing withinplate affinity but have obvious Nb-Ta-Ti negative *** show uniform lowerεNd(t)values(−6‒−2)and higher 87Sr/86Sr(t)values(0.706‒0.709)independent of their MgO variation,indicating one enriched mantle *** their closely spatial and temporal relationship with the widespread co.ei LIP magmatic products in Tethyan Himalaya,these“weak enriched-type”samples are co.sistent with mixing of melts from mantle plume and the above ancient Tethyan Himalaya subco.tinental lithospheric mantle(SCLM)in different *** weak enriched mafic rocks in co.ei LIP form one special rock group and most likely suggest large scale hot mantle plume-co.tinental lithosphere *** process may lead to strong modification of the Tethyan Himalaya lithosphere in the Early Cretaceous.

关键词： OIB type diabase co.ei Large Igneous Province Weakly enriched diabase Plume-lithosphere interaction Nb-Ta-Ti negative anomaly Kerguelen plume geological survey engineering Tibet Plateau

co.parative study of different machine learning models in landslide susceptibility assessment: A case study of co.ghua District, Guangzhou, China

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China Geology 2024年第1期7卷 104-115页

作者： Ao Zhang Xin-wen Zhao Xing-yuezi Zhao Xiao-zhan Zheng Min Zeng Xuan Huang Pan Wu Tuo Jiang Shi-chang Wang Jun He Yi-yong Li Wuhan Center China Geological SurveyMinistry of Natural Resources(Geosciences Innovation Center of Central South China)Wuhan 430205China Guangzhou Institute of geological Survey Guangzhou 510080China Hubei Transportation Planning Design Institute co. LtdWuhan 430050China

Machine learning is currently one of the research hotspots in the field of landslide *** clarify and evaluate the differences in characteristics and prediction effects of different machine learning models,co.ghua District,which is the most prone to landslide disasters in Guangzhou,was selected for landslide susceptibility *** evaluation factors were selected by using co.relation analysis and variance expansion factor *** four machine learning methods namely Logistic Regression(LR),Random Forest(RF),Support Vector Machines(SVM),and Extreme Gradient Boosting(XGB),landslide models were *** analysis and evaluation of the model were co.ducted through statistical indices and receiver operating characteristic(ROC)*** results showed that LR,RF,SVM,and XGB models have good predictive performance for landslide susceptibility,with the area under curve(AUC)values of 0.752,0.965,0.996,and 0.998,*** model had the highest predictive ability,followed by RF model,SVM model,and LR *** frequency ratio(FR)accuracy of LR,RF,SVM,and XGB models was 0.775,0.842,0.759,and 0.822,*** and XGB models were superior to LR and SVM models,indicating that the integrated algorithm has better predictive ability than a single classification algorithm in regional landslide classification problems.

关键词： Landslides susceptibility assessment Machine learning Logistic Regression Random Forest Support Vector Machines XGBoost Assessment model geological disaster investigation and prevention engineering

Texture and Geochemistry of Multi-stage Hydrothermal Scheelite in the Mamupu Cu-Au-Mo(-W)Deposit,Eastern Tibet:Implications for Tungsten Mineralization in the Yulong Belt

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Acta Geologica Sinica(English Edition) 2024年第3期98卷 701-716页

作者： ZHANG Xiaoxu TANG Juxing LIN Bin WANG Qin HE Liang YAN Gang SHAO Rui WU Qiang DU Qiu ZHAXI Pingcuo Chengdu Center China Geological Survey(Geosciences Innovation Center of Southwest China)Chengdu 610081China MNR Key Laboratory of Metallogeny and Mineral Assessment Institute of Mineral ResourcesChinese Academy of Geological SciencesBeijing 100037China SinoProbe Laboratory Chinese Academy of Geological SciencesBeijing 100094China Earth Sciences co.lege Chengdu University of TechnologyChengdu 610059China No.6 geological Party Tibetan Bureau of Geology and Mineral Exploration and DevelopmentLhasa 851400China Tibet Shengyuan Mining Group co. Ltd.Lhasa 851400China

Multistage tungsten mineralization was recently disco.ered in the Mamupu co.per-polymetallic deposit in the southern Yulong porphyry co.per belt(YPCB),*** study reports the results of cathodoluminescence,trace element and Sr isotope analyses of Mamupu scheelite samples,undertaken in order to better co.strain the mechanism of W mineralization and the sources of the ore-forming *** different types of scheelite are identified in the Mamupu deposit:scheelite A(Sch A)mainly occurs in breccias during the prograde stage,scheelite B(Sch B)forms in the chlorite-epidote alteration zone in the retrograde stage,while scheelite C(Sch C)occurs in distal quartz sulfide *** extremely high Mo co.tent and negative Eu anomaly in Sch A represent high oxygen fugacity in the prograde *** with ore-related porphyries,Sch A has a similar REE pattern,but with higher ΣREE,more depleted HREE and slightly lower(^(87)Sr/^(86)Sr)i *** features suggest that Sch A is genetically related to ore-related porphyries,but extensive interaction with carbonate surrounding rocks affects the final REE and Sr isotopic *** B shows dark(Sch B-I)and light(Sch B-II)domains under CL *** Sch B-I to Sch B-II,LREEs are gradually depleted,with MREEs being gradually *** C has the highest LREE/HREE ratio,which indicates that it inherited the geochemical characteristics of fluids after the precipitation of HREE-rich minerals,such as diopside and garnet,in the early prograde *** Mo co.tent in Sch B and Sch C gradually decreased,indicating that the oxygen fugacity of the fluids changed from oxidative in the early stages to reductive in the later,the turbulent Eu anomaly in Sch B and Sch C indicating that the Eu anomaly in the Mamupu scheelite is not solely co.trolled by oxygen *** extensive interaction of magmatic-hydrothermal fluids and carbonate provides the necessary Ca^(2+)for the precipitation of scheelite in the Mamupu deposit.

关键词： scheelite geochemistry Mamupu Cu deposit Yulong porphyry co.per belt eastern Tibet

Delineating homogeneous domains of fractured rocks using topological manifolds and deep learning

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Journal of Rock Mechanics and Geotechnical Engineering 2024年第8期16卷 2996-3013页

作者： Yongqiang Liu Jianping Chen Fujun Zhou Jiewei Zhan Wanglai Xu Jianhua Yan co.lege of co.struction Engineering Jilin UniversityChangchun130026China China Railway First Survey and Design Institute Group co. Ltd.Xi’an710043China co.lege of geological Engineering and Geomatics Chang’an UniversityXi’an710054China

Determining homogeneous domains statistically is helpful for engineering geological modeling and rock mass stability *** this text,a technique that can integrate lithology,geotechnical and structural information is proposed to delineate homogeneous *** technique is then applied to a high and steep slope along a ***,geological and geotechnical domains were described based on lithology,faults,and shear ***,topological manifolds were used to eliminate the inco.patibility between orientations and other parameters(*** length and roughness)so that the data co.cerning various properties of each disco.tinuity can be matched and characterized in the same Euclidean ***,the influence of implicit co.bined effect in between parameter sequences on the homogeneous domains co.ld be *** learning technique was employed to quantify abstract features of the characterization images of disco.tinuity properties,and to assess the similarity of rock mass *** results show that the technique can effectively distinguish structural variations and outperform co.ventional *** can handle multisource engineering geological information and multiple disco.tinuity *** technique can also minimize the interference of human factors and delineate homogeneous domains based on orientations or multi-parameter with arbitrary distributions to satisfy different engineering requirements.

关键词： Homogeneous domain geological domain Geotechnical domain Structural domain Topological manifold Deep learning

Disco.tinuity development patterns and the challenges for 3D discrete fracture network modeling on co.plicated exposed rock surfaces

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Journal of Rock Mechanics and Geotechnical Engineering 2024年第6期16卷 2154-2171页

作者： Wen Zhang Ming Wei Ying Zhang Tengyue Li Qing Wang Chen Cao Chun Zhu Zhengwei Li Zhenbang Nie Shuonan Wang Han Yin co.lege of co.struction Engineering Jilin UniversityChangchun130026China Liaoning Nonferrous geological Exploration and Research Institute co. Shenyang110013China School of Earth Sciences and Engineering Hohai UniversityNanjing210098China Northeastern University Shenyang110819China

Natural slopes usually display co.plicated exposed rock surfaces that are characterized by co.plex and substantial terrain undulation and ubiquitous undesirable phenomena such as vegetation co.er and *** study presents a systematic outcrop research of fracture pattern variations in a co.plicated rock slope,and the qualitative and quantitative study of the co.plex phenomena impact on threedimensional(3D)discrete fracture network(DFN)*** the studies of the outcrop fracture pattern have been so far focused on local variations,thus,we put forward a statistical analysis of global *** entire outcrop is partitioned into several subzones,and the subzone-scale variability of fracture geometric properties is analyzed(including the orientation,the density,and the trace length).The results reveal significant variations in fracture characteristics(such as the co.centrative degree,the average orientation,the density,and the trace length)among different ***,the density of fracture sets,which is approximately parallel to the slope surface,exhibits a notably higher value co.pared to other fracture sets across all *** improve the accuracy of the DFN modeling,the effects of three co.mon phenomena resulting from vegetation and rockfalls are qualitatively analyzed and the co.responding quantitative data processing solutions are ***,the 3D fracture geometric parameters are determined for different areas of the high-steep rock slope in terms of the subzone *** results show significant variations in the same set of 3D fracture parameters across different regions with density differing by up to tenfold and mean trace length exhibiting differences of 3e4 *** study results present precise geological structural information,improve modeling accuracy,and provide practical solutions for addressing co.plex outcrop issues.

关键词： co.plicated exposed rock surfaces Disco.tinuity characteristic variation Three-dimensional discrete fracture network modeling Outcrop study Vegetation co.er and rockfalls

Quantitative characterization of the brittleness of deep shales by integrating mineral co.tent,elastic parameters,in situ stress co.ditions and logging analysis

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International Journal of co.l Science & Technology 2024年第1期11卷 167-179页

作者： Tongtong Luo Jianguo Wang Li Chen Chaoya Sun Qian Liu Fenggang Wang CCDC geological Exploration&Development Research Institute Chengdu610056SichuanChina China University of Petroleum(Beijing) ChangpingBeijing102249China Exploration and Development Department of Chongqing Shale Gas Exploration and Development co. Ltd.Chongqing834000China

Deep shale reservoirs(3500–4500 m)exhibit significantly different stress states than moderately deep shale reservoirs(2000–3500 m).As a result,the brittleness response mechanisms of deep shales are also *** is urgent to investigate methods to evaluate the brittleness of deep shales to meet the increasingly urgent needs of deep shale gas *** this paper,the quotient of Young’s modulus divided by Poisson’s ratio based on triaxial co.pression tests under in situ stress co.ditions is taken as SSBV(Static Standard Brittleness Value).A new and pragmatic technique is developed to determine the static brittleness index that co.siders elastic parameters,the mineral co.tent,and the in situ stress co.ditions(BIEMS).The co.fficient of determination between BIEMS and SSBV reaches 0.555 for experimental data and 0.805 for field *** co.fficient is higher than that of other brittleness indices when co.pared to *** can offer detailed insights into shale brittleness under various co.ditions,including different mineral co.positions,depths,and stress *** technique can provide a solid data-based foundation for the selection of‘sweet spots’for single-well engineering and the co.parison of the brittleness of shale gas production layers in different areas.

关键词： Deep shale reservoirs Brittleness Pressure effect Evaluation method Longmaxi formation Sichuan Basin