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International Journal of Geosciences 2024年第5期15卷 416-432页

作者： Mahendra Acharya Khomendra Bhandari Sandesh Dhakal Aasish Giri Prabin Kafle Central department of geology Tribhuvan University Kathmandu Nepal department of geology Tri-Chandra Multiple Campus Tribhuvan University Kathmandu Nepal Sri Revana Siddeshwara Institute of Technology Visvesvaraya Technological University Bengaluru India

The stability study of the ongoing and recurring Amalpata landslide in Baglung in nepal’s Gandaki Province is presented in this research. The impacted slope is around 200 meters high, with two terraces that have different slope inclinations. The lower bench, located above the basement, consistently fails and sets others up for failure. The fluctuating water level of the slope, which travels down the slope masses, exacerbates the slide problem. The majority of these rocks are Amalpata landslide area experiences several structural disruptions. The area’s stability must be evaluated in order to prevent and control more harm from occurring to the nearby agricultural land and people living along the slope. The slopes’ failures increase the damages of house existing in nearby area and the erosion of the slope. Two modeling techniques the finite element approach and the limit equilibrium method were used to simulate the slope. The findings show that, in every case, the terrace above the basement is where the majority of the stress is concentrated, with a safety factor of near unity. Using probabilistic slope stability analysis, the failure probability was predicted to be between 98.90% and 100%.

关键词： Finite Element Approach Limit Equilibrium Method Slope Factor of Safety

Provenance and paleogeographic evolution of the Upper Paleozoic–Lower Mesozoic strata in northern Laos

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Journal of Earth Science 2024年

作者： Jingjie Jin Xin Qian Vongpaseuth Senebouttalath Yuzhi Zhang Yuejun Wang Guangdong Provincial Key Lab of Geodynamics and Geohazards， School of Earth Sciences and Engineering， Sun Yat-sen University， and Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai) Ministry of Energy and mines， department of geology and Minerals

The Late Paleozoic–Early Mesozoic sedimentary system of the Luang Prabang Paleotethyan back-arc basin in northern Laos is important for investigating sedimentary provenance， paleogeographic patterns， and the tectonic evolution of the Eastern Paleotethyan Ocean. This study presents systematic stratigraphy， petrology， geochemistry， and detrital zircon U–Pb–Hf isotopic analyses for the Late Carboniferous–Jurassic sedimentary strata on both sides of the Luang Prabang basin. Based on distinct stratigraphic ages and provenance characteristics， the clastic rock samples can be divided into four groups. The Group 1 Late Carboniferous–Early Permian samples from the western part of the basin yield detrital zircon age-peaks of ～348 and ～1425 Ma， with corresponding εHf(t) values ranging from -2.0 to +15.5 and +1.5 to +14， respectively. The age spectrum of Group 2 Late Carboniferous–Early Permian samples from the eastern part of the basin shows major age-peaks of ～287 and ～1860 Ma， with εHf(t) values of -5.9–-0.9 and -3.6–+4.2， respectively. Group 3 Late Permian–Triassic samples exhibit age-peaks of ～242 and ～1853 Ma， along with εHf(t) values of -0.7–+14.4 and -5.4–-1.8， respectively. Group 4 Middle–Late Jurassic samples yield age-peaks of ～237，～431，～813，～1833， and ～2460 Ma， lacking Late Devonian (413–345 Ma) detrital zircons. All these data collectively suggest that the Group 1 sample primarily originated from the Sukhothai Arc in western Indochina， Group 2 was from the Kontum and Truong Son in eastern Indochina， and Group 3 has a combined provenance of the Sukhothai， Kontum， and Truong Son. Regional comparisons suggest that the Jurassic provenance was mainly derived from South China， which was imported through the northern river system. Our data， combined with the regional angular unconformities between Jurassic continental strata and pre-Jurassic marine strata， suggest that the Luang Prabang basin transformed into a superimposed collisional retroforeland basin during the Ju

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Rare-Element Pegmatites Rocks Rich and Li of the Aïr Massif of the Tchirozerine: Mineralogy and Chemical Composition Agadez Region-Northem Niger

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Open Journal of Applied Sciences 2024年第1期14卷 171-181页

作者： Ntoumbé Mama Hamza Bassara Amaya Adama Awona Paul Zéphyrin Nomenjanahary Limbisoa department of mines geology School of Geology and Mining Engineering University of Ngaoundere Meiganga Cameroon department of geology Faculty of Sciences and Technic University of Abdou Moumouni Niger department of Geomatic and geology Mapping School of Geology and Mining Engineering University of Ngaoundere Meiganga Cameroon National Advance School of Engineering of Yaounde Yaounde Cameroon School of Thematic Doctoral Faculty of Sciences University of Antsiranana Antsiranana Madagascar

The lithium potential in the Aïr massif is represented by mineral index of spodumene pegmatites and, lepidolite pegmatites. The mineral deposits of lithium occur in cluster or veins that cut the host rock or are located near the contact between the greenstone belt and granitic massif. The evidence of lithium is in the form of clusters or disseminated and stockwerk. Mineralogical characteristics show similarities between the Air Massif pegmatites and indicate the same homogenous source during the magma-generation process. The pegmatite rocks attracted the attention due to their wide exposure and composition, well appearance, and economically hosting of significant rare earth metals such as Sn and W. The mineralogical and petrographical investigations on the eight pegmatites rocks samples observed have a relative similarity, while a little difference in the shapes attributed to the ratio in the pegmatite rocks of the minerals. The occurrence of the kink band indicates the influence of the tectonic processes which affected the Aïr massif after the emplacement of late magmatic or post-magmatic pegmatites by injection into fractured rocks in the upper part of the crust. The Air Massif pegmatite has higher concentrations Li and of all trace elements except Hf and occasionally Zr, Ti, Sn and Mg of for the economic exploration.

关键词： Pegmatite Lithium Rare Elements Hydrothermal Processes Aïr Massif

Evolution of tectonic landscapes and deformation in the southeast Kumaun and western nepal Himalaya

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Journal of Mountain Science 2024年第8期21卷 2592-2617页

作者： Khayingshing LUIREI Girish Ch.KOTHYARI Param K GAUTAM Ambar SOLANKI Atul Kumar PATIDAR Sentisenla JAMIR Anirudh DATTA Tanupriya CHOUDHURY Wadia Institute of Himalayan geology Dehradun 248001India department of Petroleum Engineering and Earth Sciences University of Petroleum and Energy StudiesDehradun248007India department of geology Nagaland UniversityKohima 797004India Academy of Scientific and Innovative Research Ghaziabad 201002India CSE department Graphic Era deemed to be UniversityDehradun 248002India CSE department Symbiosis Institute of TechnologySymbiosis International(Deemed University)Pune 412114India

The area of the present investigation’s expanse constitutes the southernmost extent of the southeast Kumaun Himalaya and western nepal *** approaches have been employed to understand the landforms associated with tectonic deformation,through detailed field investigation supplemented by the geodetic,chronological,and morphometric *** morphogenic expressions of the Main Boundary Thrust(MBT)are reflected in the form of~25 km long E-W trending north dipping fault *** deformation along the strike length of the Himalayan Frontal Thrust(HFT)is noticed in the form of uplifted and incised fill terraces,and strath *** deformation within the fluvial sequences in the study area can be visualized in the form of sheared boulders and pebbles,tilted and faulted terrace ***,the chronological data of fluvial landforms in the study area suggests two major phases of tectonic deformations that have occurred around 58.7±10.8 ka and 3.88±0.4 *** chronology of late-Quaternary landforms advocates that the initial stage of aggradations in the Himalayan foothills commenced around 75.1±0.58 *** aggradational landforms resulted from the diverse depositional regime as evident from the nature of the sediment sequences from clasts dominated to thick mud *** rate of deformation in the southeastern Kumaun and western nepal Himalaya is±7 mm/yr,as per the data obtained from the Persistent Scatterer Interferometric Synthetic Aperture Radar(PSInSAR).The landform deformation pattern,phase of incision and aggradation,frequent occurrence of landslides,and recent past earthquake activity within the wide zone of the HFT,the MBT,and Ramgarh Thrust suggests that the southernmost front of the Kumaun Himalaya is active and has potential for future *** foothill zone of Himalayan towns are actively growing in terms of population and infrastructural ***,such intradisciplinary studies for tectonically active r

关键词： MBT HFT Fault trace Quaternary deposits sheared boulders

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Preliminary Palynostratigraphic Data on the Middle Albian-Lower Cenomanian of the Tarfaya Basin, Southwest Morocco

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Open Journal of geology 2024年第4期14卷 548-568页

作者： Khaoula Chafai Touria Hssaida Wafaa Maatouf Mohamed Z. Yousfi Sara Chakir Soukaina Jaydawi Hanane Khaffou department of geology Faculty of Sciences Ben M&#8217Sik University Hassan II Casablanca Morocco department of Petroleum Laboratory Office National des Hydrocarbures et des Mines Rabat Morocco department of geology Faculty of Sciences Dhar El Mahraz Sidi Mohamed Ben Abdellah University Fes Morocco department of geology Faculty of Sciences Mohammed V University Rabat Morocco

The Tarfaya-Laayoune-Boujdour basin is of great interest to oil exploration;on this aspect, there has been exploration by the Moroccan National Office of Hydrocarbons and Mining, which has shown indices of oil and/or gas recorded in most wells drilled in the Moroccan Atlantic margin. FD-1 well, object of this study, is one of these wells located in the offshore Tarfaya-Laayoune-Boujdour basin. A palynological examination of the processed samples revealed the existence of organic palynomorphs, well conserved and rich in dinoflagellate cysts. The latter are composed of worldwide marker taxa of high stratigraphic resolutions. Thus, the middle upper Albian (3408 - 3408.5 m) is determined by the presence of Cribroperidinium tensiftense, Tehamadinium coummia, Spiniferella cornuta, Chichaouadinium vestitum, Dinopterygium alatum and Litosphaeridium arundum. The upper Albian (3406.5 - 3408 m) is characterized by the FOs of marker taxa: Cyclonephelium chabaca, Cribroperidinium auctificum and Chichaouadinium vestitum. Lastly, the upper Albian-lower Cenomanian transition is defined between 3404 m and 3406.50 m, as suggested by the FOs of Chichaouadinium boydii, Dinopterygium tuberculatum, Sepispinula ancorifera, Litosphaeridium conispinum, Prolixosphaeridium conulum and Xenascus ceratioides.

关键词： Morocco Tarfaya-Laayoune-Boujdour Basin Albian-Cenomanian Transition Dinoflagellate Cysts Palynostratigraphy

Characteristics of Gold and Its Mineralization Style in the Boulon Djounga Eastern Perimeter of Liptako Mining Company (Central Southwestern Niger)

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Natural Resources 2024年第1期15卷 28-50页

作者： Gambo Ranaou Noura Kamayé Tourba Karimou Dia Hantchi Bouba Hassane Moussa Konaté department of geology Faculty of Science and Techniques Abdou Moumouni University Niamey Niger department of geology Faculty of Science and Techniques Dan Dicko Dankoulodo University Maradi Niger

The Boulon Djounga eastern perimeter is part of the Tiawa operating permit of the Société des mines du Liptako (SML), located in the central southwestern part of Liptako (Niger). In this study, we used field data, Reverse Circulation (RC) surveys and chemical analyzes of gold to determine the characteristics of gold and its mineralization style. The eastern perimeter of Boulon Djounga is represented by a succession of metabasalts and metasediments both intersected by intrusions of quartz and dolerite dykes, and covered by sandstone and clayey rocks. Gold is present in low contents (0.00 - 0.30 ppm) in the sedimentary cover and in medium (0.30 - 1.00 ppm) or high contents (1.00 - 4.534 ppm) in the metasediments, and in the gray quartz veins and locally in the volcanics. It exists in a disseminated state or in a concentrated state in the surrounding areas in the form of discrete grains associated with sulphurous minerals (pyrite: FeS2, chalcopyrite: CuFeS2 or arsenopyrite: FeAsS). The presence of gold in the quartz veins, and the NE-SW and NW-SE orientations of the ore bodies suggest that the eastern Boulon Djounga gold mineralization would be established during a late magmatic extensive phase.

关键词： Liptako Gold Mineralization Metasediments-Volcanics Quartz Veins Sulphurous Minerals Niger

Damage evolution of rock-encased-backfill structure under stepwise cyclic triaxial loading

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Journal of Rock Mechanics and Geotechnical Engineering 2024年第2期16卷 597-615页

作者： Xin Yu Yuye Tan Weidong Song John Kemeny Shengwen Qi Bowen Zheng Songfeng Guo Key Laboratory of Shale Gas and Geoengineering Institute of Geology and GeophysicsChinese Academy of SciencesBeijing100089China Innovation Academy for Earth Science Chinese Academy of SciencesBeijing100089China University of Chinese Academy of Sciences Beijing100049China School of Civil and Resources Engineering University of Science and Technology BeijingBeijing100083China Key Laboratory of High-Efficient Mining and Safety of Metal mines(Ministry of Education of China) University of Science and Technology BeijingBeijing100083China department of Mining and Geological Engineering University of ArizonaTucsonAZ86721USA

Rock-encased-backfill(RB)structures are common in underground mining,for example in the cut-andfill and stoping *** understand the effects of cyclic excavation and blasting activities on the damage of these RB structures,a series of triaxial stepwise-increasing-amplitude cyclic loading experiments was conducted with cylindrical RB specimens(rock on outside,backfill on inside)with different volume fractions of rock(VF=0.48,0.61,0.73,and 0.84),confining pressures(0,6,9,and 12 MPa),and cyclic loading rates(200,300,400,and 500 N/s).The damage evolution and meso-crack formation during the cyclic tests were analyzed with results from stress-strain hysteresis loops,acoustic emission events,and post-failure X-ray 3D fracture *** results showed significant differences between cyclic and monotonic loadings of RB specimens,particularly with regard to the generation of shear microcracks,the development of stress memory and strain hardening,and the contact forces and associated friction that develops along the rock-backfill *** important finding is that as a function of the number of cycles,the elastic strain increases linearly and the dissipated energy increases ***,compared with monotonic loading,the cyclic strain hardening characteristics are more sensitive to rising confining pressures during the initial compaction *** finding is that compared with monotonic loading,more shear microcracks are generated during every reloading stage,but these microcracks tend to be dispersed and lessen the likelihood of large shear fracture *** transition from elastic to plastic behavior varies depending on the parameters of each test(confinement,volume fraction,and cyclic rate),and an interesting finding was that the transformation to plastic behavior is significantly lower under the conditions of 0.73 rock volume fraction,400 N/s cyclic loading rate,and 9 MPa *** the findings have important practical implications on t

关键词： Rock and backfill Triaxial cyclic loading Volume fraction Damage evolution 3D visualization

珠穆朗玛峰北坡桤木属大气花粉传输路径与来源

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地球科学进展 2024年第4期39卷 419-428页

作者：程久菊吕新苗朱立平马庆峰 HUMAGAIN SIMA PAUDAYAL N KHUM 中国科学院青藏高原研究所青藏高原地球系统与资源环境全国重点实验室北京100101 中国科学院大学北京100049 Central department of geology Tribhuvan UniversityKathmandu 44600Nepal

认识区域大气花粉组成及其形成条件有利于明确不同类型花粉组合的气候与环境意义。利用布卡大气花粉采样器在珠穆朗玛峰北坡开展了连续2年(2012—2013年)的大气花粉观测研究。基于后向轨迹和潜在来源区域模型,探讨了秋季主要组分桤木属... 详细信息

认识区域大气花粉组成及其形成条件有利于明确不同类型花粉组合的气候与环境意义。利用布卡大气花粉采样器在珠穆朗玛峰北坡开展了连续2年(2012—2013年)的大气花粉观测研究。基于后向轨迹和潜在来源区域模型,探讨了秋季主要组分桤木属花粉的传输路径与潜在来源区域,分析了桤木属花粉与其植物分布和大气环流的关系及气候指示意义。结果显示:(1)桤木属花粉季气团传输路径主要来自于采样点西南方向;(2)桤木属花粉潜在来源区域与其气团传输路径基本一致,主要是喜马拉雅山脉中段,包括尼泊尔中部和东部以及西藏南部等地区;(3)桤木属花粉数量、传输路径和来源区域的年际变化与大气环流有关,受高空西风影响的西南气团对桤木属花粉影响更大。研究结果可以为认识珠穆朗玛峰北坡外来花粉的气候意义提供科学依据。

关键词：桤木属花粉传输路径来源区域后向轨迹模拟青藏高原

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Investigation of factors influencing roof stability at a Western *** coal mine

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International Journal of Mining Science and Technology 2019年第1期29卷 139-143页

作者： Meriel Young Gabriel Walton Elizabeth Holley department.geology&Geol.Engineering Colorado School of Mines department Mining Engineering Colorado School of Mines

The coal mine roof rating(CMRR) was developed to bridge the gap between geological variation in underground coal mines and engineering design. The CMRR accounts for the compressive strength of the immediate roof, the shear strength and intensity of any discontinuities present, and the moisture sensitivity of the immediate roof. The CMRR has been widely used and validated in Eastern US coal mines, but it has seen limited application in the Western US. This study focuses on roof behavior at a Western coal mine(Mine A). Mine A shows significant lateral geological variation, along with localized faulting and a laterally extensive sandstone channel network. The CMRR is not used to predict roof instability at the mine. It is, therefore, hypothesized that there are other factors that are correlated with roof instability in underground coal mines that could potentially also be considered in conjunction with the *** hypothesis was tested by collecting 30 CMRR measurements at Mine A. At each measurement location, a binary record of the roof condition(stable or unstable) was made, and other parameters such as depth of cover, presence of faulting, and sandstone channels were also recorded. ANOVA tests showed that the CMRR values and the roof conditions were not strongly correlated, indicating that the CMRR input criteria are not fully predictive of roof stability at this mine. The CMRR values showed statistically significant correlations(p less than 0.05) with faulting as well as with location at an intersection. For areas that had previously experienced roof fall but were currently stable, faulting was correlated with roof condition(p less than 0.05) only when the condition was classified as unstable.

关键词： Coal mine roof stability CMRR Western U.S.coal Case study

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Rock Mass Quality Rating Based on the Multi-Criteria Grey Metric Space

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Computer Modeling in Engineering & Sciences 2024年第9期140卷 2635-2664页

作者： Miloš Gligoric Zoran Gligoric Saša Jovanovic Suzana Lutovac Dragan Pamucar Ivan Jankovic Faculty of Mining and geology University of BelgradeBelgrade11000Serbia Faculty of Technical Sciences University of PrištinaKosovska Mitrovica38220Serbia department of Operations Research and Statistics Faculty of Organizational SciencesUniversity of BelgradeBelgrade11000Serbia College of Engineering Yuan Ze UniversityTaoyuan City320315TaiwanChina

Assessment of rock mass quality significantly impacts the design and construction of underground and open-pit mines from the point of stability and *** study develops the novel Gromov-Hausdorff distance for rock quality(GHDQR)methodology for rock mass quality rating based on multi-criteria grey metric *** usually presents the quality of surrounding rock by classes(metric spaces)with specified properties and adequate interval-grey *** the distance between surrounding rock sample characteristics and existing classes represents the core of this *** Gromov-Hausdorff distance is an especially useful discriminant function,i.e.,a classifier to calculate these distances,and assess the quality of the surrounding *** efficiency of the developed methodology is analyzed using the Mean Absolute Percentage Error(MAPE)*** existing methods,such as the Gaussian cloud method,Discriminant method,Mutation series method,Artificial neural network(ANN),Support vector machine(SVM),Grey wolf optimizer and Support vector classification method(GWO-SVC)and Rock mass rating method(RMR)are used for comparison with the proposed GHDQR *** share of the highly accurate category of 85.71%clearly indicates compliance with actual values obtained by the compared *** results of comparisons showed that the model enables objective,efficient,and reliable assessment of rock mass quality.

关键词： Rock mass rating multi-criteria class metric space interval-grey numbers