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Evaluating The Influence Of Recent Tectonic Activity On The River Evolution Using The Identification Of Knickpoints In The South Of Central Alborz Belt, Masoomeh Alaei, Alireza Nadimi, Homayon Safaei, Maryam Dehbozorgi Jul 2023

Evaluating The Influence Of Recent Tectonic Activity On The River Evolution Using The Identification Of Knickpoints In The South Of Central Alborz Belt, Masoomeh Alaei, Alireza Nadimi, Homayon Safaei, Maryam Dehbozorgi

Turkish Journal of Earth Sciences

Change in the steepness of river profiles caused by tectonic forces (uplift and material weakening in fault zones) causes the formation of the tectonically formed knickpoints (TFKs), which is an important geomorphic feature in bedrock river morphology. In this research, knickpoints in a wide area of the south of Central Alborz using the stream gradient (Gd) and the normalized steepness index (k$_{sn}$) were identified. According to the location of the knickpoints in relation to the faults in the area, the TFKs were identified. Analysis of the extracted TFKs with the longitudinal profile, logarithm slope-area plots, and natural logarithm gradient-distance plots …

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A Controlled Source Tomography In Sarımeşe, İzmit, At The Western Section Of North Anatolian Fault Zone, Tuğçe Ergün Jul 2023

A Controlled Source Tomography In Sarımeşe, İzmit, At The Western Section Of North Anatolian Fault Zone, Tuğçe Ergün

Turkish Journal of Earth Sciences

A high-resolution two-dimensional tomographic velocity image in the eastern Marmara region along a 1.2 km long N-S trending seismic profile, which crosses the surface rupture of the İzmit earthquake on the North Anatolian Fault (NAF) is presented. A vibroseis source at more than 180 points with 50 receivers was used along the long profile. A regularized inversion technique was applied to the first arrival travel times. More than 6500 first arrivals from 129 shot gathers were analyzed to construct velocity images and were qualitatively evaluated for the fault zone-related effects. The velocity model was constrained to a maximum depth of …

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Characteristic Features And Paleoseismological Behaviours Of The Anamas Block Boundary Faults, Southwestern Anatolia, Turkey, Seli̇m Özalp, Hasan Elmaci, Ayhan Yavuzoğlu, Meryem Kara Jul 2023

Characteristic Features And Paleoseismological Behaviours Of The Anamas Block Boundary Faults, Southwestern Anatolia, Turkey, Seli̇m Özalp, Hasan Elmaci, Ayhan Yavuzoğlu, Meryem Kara

Turkish Journal of Earth Sciences

The Anamas Block is located at the apex of the Isparta Angle which is one of the most important tectonic structures of Anatolia. The Isparta Angle, which has a complex tectonic structure, was formed as a result of compressional and extensional tectonic events that initiated from the Late Cretaceous continuing to the present. The GPS and kinematic data indicate the Anamas Block currently rotates clockwise due to the impact of the normal faults (Beyşehir Gölü and Sarıidris) with a minor right lateral strike-slip component on the east and west boundaries, while it is moved to the southeast by the effect …

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The Emergence Of Convergence, Shana M. Sundstrom, David G. Angeler, Jessica G. Ernakovich, Jorge H. Garcia, Joseph A. Hamm, Orville Huntington, Craig R. Allen Jul 2023

The Emergence Of Convergence, Shana M. Sundstrom, David G. Angeler, Jessica G. Ernakovich, Jorge H. Garcia, Joseph A. Hamm, Orville Huntington, Craig R. Allen

Faculty Publications

Science is increasingly a collaborative pursuit. Although the modern scientific enterprise owes much to individuals working at the core of their field, humanity is increasingly confronted by highly complex problems that require the integration of a variety of disciplinary and methodological expertise. In 2016, the U.S. National Science Foundation launched an initiative prioritizing support for convergence research as a means of “solving vexing research problems, in particular, complex problems focusing on societal needs.” We discuss our understanding of the objectives of convergence research and describe in detail the conditions and processes likely to generate successful convergence research. We use our …

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Exploring The Relationships Between Mammalian Functional Trait Distributions And Regional Biomes, With Application To Miocene Paleoecology, Devra Hock-Reid Jul 2023

Exploring The Relationships Between Mammalian Functional Trait Distributions And Regional Biomes, With Application To Miocene Paleoecology, Devra Hock-Reid

Department of Earth and Atmospheric Sciences: Dissertations, Theses, and Student Research

Paleoecology relies on understanding relationships between modern animals and their environment. Animals are adapted to niches in their environments, and those physical adaptations, or functional traits, are utilized as proxies to interpret aspects of paleo-ecosystems. Much is known about individual functional traits in extant mammals and their relationship to the environment. Less is known about how multiple functional traits across a community can be utilized for paleoecological interpretations. I develop models utilizing traits in mammalian communities at the biome level. For Chapter 1, I build a model for North American regional biomes using mammalian trait frequencies. I quantify changes in …

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Rift-Induced Disruption Of Cratonic Keels Drives Kimberlite Volcanism, Thomas M. Gernon, Stephen M. Jones, Sascha Brune, Thea K. Hincks, Martin Palmer, John C. Schumacher, Rebecca M. Primiceri, Matthew Field, William L. Griffin, Suzanne Y. O'Reilly, Derek Keir, Christopher J. Spencer, Andrew S. Merdith, Anne Glerum Jul 2023

Rift-Induced Disruption Of Cratonic Keels Drives Kimberlite Volcanism, Thomas M. Gernon, Stephen M. Jones, Sascha Brune, Thea K. Hincks, Martin Palmer, John C. Schumacher, Rebecca M. Primiceri, Matthew Field, William L. Griffin, Suzanne Y. O'Reilly, Derek Keir, Christopher J. Spencer, Andrew S. Merdith, Anne Glerum

Geology Faculty Publications and Presentations

Kimberlites are volatile-rich, occasionally diamond-bearing magmas that have erupted explosively at Earth’s surface in the geologic past1,2,3. These enigmatic magmas, originating from depths exceeding 150 km in Earth’s mantle1, occur in stable cratons and in pulses broadly synchronous with supercontinent cyclicity4. Whether their mobilization is driven by mantle plumes5 or by mechanical weakening of cratonic lithosphere4,6 remains unclear. Here we show that most kimberlites spanning the past billion years erupted about 30 million years (Myr) after continental breakup, suggesting an association with rifting processes. Our dynamical …

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Predictive Modeling Of Cave Entrance Locations: Relationships Between Surface And Subsurface Morphology, William Blitch, Adia R. Sovie, Benjamin W. Tobin Jul 2023

Predictive Modeling Of Cave Entrance Locations: Relationships Between Surface And Subsurface Morphology, William Blitch, Adia R. Sovie, Benjamin W. Tobin

International Journal of Speleology

Cave entrances directly connect the surface and subsurface geomorphology in karst landscapes. Understanding the spatial distribution of these features can help identify areas on the landscape that are critical to flow in the karst groundwater system. Sinkholes and springs are major locations of inflow and outflow from the groundwater system, respectively, however not all sinkholes and springs are equally connected to the main conduit system. Predicting where on the landscape zones of high connectivity exist is a challenge because cave entrances are difficult to detect and imperfectly documented. Wildlife research has a similar issue of understanding the complexities of where …

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Material Point Method-Based Simulation And Dynamic Characteristic Analysis Of Instability-Induced Landslide Movement: A Case Study Of The Yanguan Landslide In The Three Gorges Reservoir Area, Song Kun, Ruan Di, Lyu Honglin, Han Luyang, Huang Haifeng Jul 2023

Material Point Method-Based Simulation And Dynamic Characteristic Analysis Of Instability-Induced Landslide Movement: A Case Study Of The Yanguan Landslide In The Three Gorges Reservoir Area, Song Kun, Ruan Di, Lyu Honglin, Han Luyang, Huang Haifeng

Coal Geology & Exploration

The dynamic process and influence range of instability-induced landslide movement have important effects on the risk area division and prevention of landslide hazards. To accurately and systematically analyze the changes in the dynamic characteristics of landsides during their instability-induced movement, this study thoroughly investigated and analyzed the instability-induced movement process of the Yanguan landslide in the Three Gorges Reservoir area, Zigui County, Hubei Province. Through laboratory ring shear tests, this study determined the changing pattern of residual strength and the motion parameters of sliding zone soil under different shear rates. Accordingly, using the material point method (MPM), which is suitable …

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Uav Aerial Triangulation: Point Error Distributions And The Influencing Mechanisms Of Ground Control Points On Its Accuracy, Zha Jianfeng, Zhu Pengcheng, Wu Dejun, Ma Chenyang, Zhong Chongwu, Yin Hongwu, Wang Dong Jul 2023

Uav Aerial Triangulation: Point Error Distributions And The Influencing Mechanisms Of Ground Control Points On Its Accuracy, Zha Jianfeng, Zhu Pengcheng, Wu Dejun, Ma Chenyang, Zhong Chongwu, Yin Hongwu, Wang Dong

Coal Geology & Exploration

Unmanned aerial vehicles (UAVs) have been an important means of monitoring the surface deformation in mining areas since they are flexible, are insensitive to weather, and can swiftly acquire images of target areas. However, there is an urgent need to improve UAV-based measurement accuracy. Based on a systematic analysis of factors affecting the accuracy of surface measurement points, this study focuses on the influence of the quality of ground control points on the point error distribution and accuracy of aerial triangulation. Firstly, through a large number of repeated observations and experiments, this study investigated the error distributions of the planar …

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Ucg Pilot Tests In Eu Countries: A Review Of History And Progress, Jin Lili, Yang Lei, Wu Yarong, Wang Xiaofang, Yi Tongsheng, Qin Yong Jul 2023

Ucg Pilot Tests In Eu Countries: A Review Of History And Progress, Jin Lili, Yang Lei, Wu Yarong, Wang Xiaofang, Yi Tongsheng, Qin Yong

Coal Geology & Exploration

Underground coal gasification (UCG) is an important way of transforming China’s coal energy structure. European Union (EU) countries explored UCG for over 80 years, and their rich experience can be used as a reference for promoting UCG industrialization in China. The UK prepared for UCG pilot tests for the first time in the world. From 1944 to 2014, based on the experience of the former Soviet Union and the United States, EU countries successively implemented at least 12 UCG pilot test projects in three stages, making important contributions to the progress in UCG technologies. They invented the blind-hole method and …

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Ucg Engineering Demonstrations In Australia: History And Its Implications, Zhou Ze, Wang Lingxia, Qin Yong, Jin Jun, Yang Lei, Yi Tongsheng Jul 2023

Ucg Engineering Demonstrations In Australia: History And Its Implications, Zhou Ze, Wang Lingxia, Qin Yong, Jin Jun, Yang Lei, Yi Tongsheng

Coal Geology & Exploration

Underground coal gasification (UCG), which is a revolutionary coal mining technology, is an important direction for achieving a low-carbon and efficient coal energy structure in China and is also a potential explorable way to ensure the smooth realization of the peak carbon dioxide emissions and carbon neutrality in China. Based on a literature survey, this study sorts out the exploration process of UCG technologies in Australia and analyzes the gains and losses using field test cases. The experience in UCG technologies in Australia can provide a reference for the development of the technologies in China. The results show that the …

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Construction And Restoration Technology Of Terrain Remodeling Layer In The Restoration Of Ecological Geological Layer In Open-Pit Mining Areas, Zhao Xin, Wang Tong, Li Congcong, Lin Zhongyue, Li Fei, Wang Weichao, Feng Kangning, Yin Yalei, Jiang Zhe Jul 2023

Construction And Restoration Technology Of Terrain Remodeling Layer In The Restoration Of Ecological Geological Layer In Open-Pit Mining Areas, Zhao Xin, Wang Tong, Li Congcong, Lin Zhongyue, Li Fei, Wang Weichao, Feng Kangning, Yin Yalei, Jiang Zhe

Coal Geology & Exploration

Mining can easily result in a series of change in the geomorphic form, such as irregular mining pits, high and steep slopes, slag hills, primitive soil failure and accumulated water in mining pits in the plateau and alpine mining area, which is in disharmony with the surrounding environment. Such changes of geomorphic form will not only adversely affect the surface ecological environment, but also bring different degrees of influence and damage to the shallow groundwater seepage field and the permafrost. In particular, the geological hazards and disasters such as landslides and collapses may even be resulted in. In response to …

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Detection Of Near-Surface Cavities Using The 2d Multi-Parameter Full-Waveform Inversion Of Rayleigh Waves, Li Yu, Wang Jingqi, Guan Jianbo, Yan Yingwei Jul 2023

Detection Of Near-Surface Cavities Using The 2d Multi-Parameter Full-Waveform Inversion Of Rayleigh Waves, Li Yu, Wang Jingqi, Guan Jianbo, Yan Yingwei

Coal Geology & Exploration

The accurate detection of near-surface low-velocity anomalies (such as cavities), which has always been a valuable and challenging research topic in the field of geophysics, holds great significance for the fine-scale near-surface modeling in urban disaster assessment and the seismic exploration of coalfields under complex conditions. The full-waveform inversion (FWI) of surface waves is suitable for high-precision near-surface modeling. However, there still exist many urgent problems with the modeling in practical applications. To solve the key issues of the FWI of surface waves, such as multi-parameter crosstalk, actual data preprocessing, and source wavelet estimation, this study developed a complete method …

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Table Of Contents, The Editors Jul 2023

Table Of Contents, The Editors

Coal Geology & Exploration

No abstract provided.

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Research And Application Of Fracture Mechanics Model Of Stope Roof Under The Coupling Of Direct Roof And Basic Roof, Li Jinhua, Zheng Chengxian, Gu Shuancheng, Wu Baolin, Wang Xiong, Song Yongjun Jul 2023

Research And Application Of Fracture Mechanics Model Of Stope Roof Under The Coupling Of Direct Roof And Basic Roof, Li Jinhua, Zheng Chengxian, Gu Shuancheng, Wu Baolin, Wang Xiong, Song Yongjun

Coal Geology & Exploration

Periodic weighting is a typical characteristic of mine pressure. Accurate prediction of stope periodic weighting step is an important way to effectively reduce the occurrence of stope accidents. Aiming at the influence of the coupling between the basic roof defects and the direct roof on the periodic weighting step, the stope roof was regarded as a finite plate model with cracks. According to the coordinate deformation mechanism of the overburden rock, the fracture mechanics model of the stope roof was established based on the fracture mechanics theory. On this basis, the periodic weighting step function under the coupling between the …

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Research Advances On The Techno-Economic Evaluation Of Ucg Projects, Yi Tongsheng, Qin Yong, Zhou Yongfeng, Wang Lingxia, Jin Jun, Zhou Ze Jul 2023

Research Advances On The Techno-Economic Evaluation Of Ucg Projects, Yi Tongsheng, Qin Yong, Zhou Yongfeng, Wang Lingxia, Jin Jun, Zhou Ze

Coal Geology & Exploration

Underground coal gasification (UCG) is driven by China's development strategy for a clean and efficient coal energy structure. Its industrialization prospect depends on the economic and social benefits of UCG projects. Against this background, this study reviews the research advances on the economic evaluation of UCG projects at home and abroad and summarizes the current insights into the economic competitiveness of UCG projects. Through case analysis, it presents a basic model for the economic evaluation of the UCG-combined-cycle gas turbine (CCGT) - carbon capture and storage (UCG-CCGT-CCS) system and the main understanding of the model. Furthermore, this study discusses the …

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Underground Coal Gasification Field Tests In China: History And Prospects, Qin Yong, Yi Tongsheng, Yang Lei, Zhou Yongfeng, Wang Jun, Wang Lingxia Jul 2023

Underground Coal Gasification Field Tests In China: History And Prospects, Qin Yong, Yi Tongsheng, Yang Lei, Zhou Yongfeng, Wang Jun, Wang Lingxia

Coal Geology & Exploration

To achieve peak carbon dioxide emissions and carbon neutrality in China, a low-carbon and efficient coal energy structure is essential for the sustainable energy development of China. Underground coal gasification (UCG) is an important strategy for transforming the coal energy structure in China. Based on the review of previous literature, this study analyzes the exploration history of the UCG field tests in China and delivers the prospects of UCG industrialization in China. The analytical results show that the development and field tests of UCG technologies in China have experienced five stages, namely the initial attempt, silence/recovery, extensive explorations, making technological …

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Ucg Pilot Tests In The United States And Their Contributions To Modern Ucg Technologies, Huang Wan, Wang Jun, Wang Lingxia, Yi Tongsheng, Chen Kexin, Qin Yong Jul 2023

Ucg Pilot Tests In The United States And Their Contributions To Modern Ucg Technologies, Huang Wan, Wang Jun, Wang Lingxia, Yi Tongsheng, Chen Kexin, Qin Yong

Coal Geology & Exploration

The industrialization of underground coal gasification (UCG), which is conducive to the transformation and development of the coal energy structure and the improvement in the low-carbon utilization level of coal resources, is an environmentally friendly energy development technology in line with the sustainable development strategy. The international energy crisis from the 1980s to the 1990s prompted the United States to vigorously develop UCG technologies. Accordingly, this country has successively carried out six series of UCG pilot tests, which contribute greatly to the progress in UCG technologies and provided the critical foundation for the formation of modern UCG technologies worldwide. This …

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Construction And Engineering Applications Of Block Model For Coal Seam Value Considering The Variations In Coal Seam Thickness And Quality, Liu Feiyue, Yang Ke, Yang Tianhong, Kan Lei, Fu Kai Jul 2023

Construction And Engineering Applications Of Block Model For Coal Seam Value Considering The Variations In Coal Seam Thickness And Quality, Liu Feiyue, Yang Ke, Yang Tianhong, Kan Lei, Fu Kai

Coal Geology & Exploration

The variations in coal seam thickness and coal quality parameters (i.e., calorific value, volatile matter, ash content, and sulfur content) determine the spatial distribution of coal prices. The accurate characterization of coal seams’ economic value plays an important role in the rational mining and utilization of coal resources. This study first determined that the geological attributes of coal seams including their thickness and coal quality are regional variables. Based on this, this study discretized geological bodies in the study area using a block model. Then, using a geostatistical method, this study obtained the experimental semivariograms of coal seam thickness and …

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A New Type Of Ordovician Limestone Karst Water Inrush From The Floor Of Old Goaf: Formation Mechanism And The Prevention And Control Technology, Zhou Shuai, Li Shuqian, Yin Shangxian, Liang Manyu, Meng Haopeng, Qi Rongrong, Li Yuanyuan Jul 2023

A New Type Of Ordovician Limestone Karst Water Inrush From The Floor Of Old Goaf: Formation Mechanism And The Prevention And Control Technology, Zhou Shuai, Li Shuqian, Yin Shangxian, Liang Manyu, Meng Haopeng, Qi Rongrong, Li Yuanyuan

Coal Geology & Exploration

The Ordovician limestone water inrush accident occurred in the small coal-pit area in Xin’an Mine of Hebei Fengfeng mining area on October 25th, which resulted in the production level being flooded, with the coal mine shut-down. Specifically, the accident cause was analyzed, and the concept of Ordovician limestone karst water inrush from the floor of old goaf was proposed, with its difference from the connotation and denotation of water inrush from the old goaf or floor water inrush accidents induced by mining summarized. Then, the water inrush mechanism based on the dynamic evolution of stored energy release from …

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Ucg Industrialization In The Soviet Union: History And Comments, Kong Weimin, Zhou Yongfeng, Yi Tongsheng, Li Ping, Qin Yong, Zhou Ze Jul 2023

Ucg Industrialization In The Soviet Union: History And Comments, Kong Weimin, Zhou Yongfeng, Yi Tongsheng, Li Ping, Qin Yong, Zhou Ze

Coal Geology & Exploration

China's energy resources are originally poor in oil and gas but rich in coal. The industrialization of underground coal gasification (UCG) technologies, which is an important way of achieving a low-carbon and efficient coal energy structure in China, contributes to the smooth achievement of the peak carbon dioxide emissions and carbon neutrality in China. This study reviews the history of the field tests and industrialization of UCG technologies in the Soviet Union by systematically referencing and sorting literature, aiming to provide a reference for the present development and industrialization of UCG technologies in China. The results show that the development …

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Propagation Of Hydraulic Fractures In Thin Interbedded Tight Sandstones, Yang Fan, Mei Wenbo, Li Liang, Sun Zening, An Qi, Yang Qi, Lu Meiquan, Yang Ruiyue Jul 2023

Propagation Of Hydraulic Fractures In Thin Interbedded Tight Sandstones, Yang Fan, Mei Wenbo, Li Liang, Sun Zening, An Qi, Yang Qi, Lu Meiquan, Yang Ruiyue

Coal Geology & Exploration

Thin interbedded tight sandstone reservoirs are characterized by strong vertical heterogeneity due to the superimposed pattern of the deposited sandstones and mudstones. As a result, hydraulic fractures are difficult to propagate vertically to effectively connect the reservoirs. Given this, ascertaining the vertical propagation patterns of hydraulic fractures in thin interbeds is of great significance for the development of thin interbedded tight sandstones. With the thin interbedded tight sandstone reservoirs of the lower Shihezi Formation in the Linxing block, Ordos Basin as a case study, this study built the fracture propagation model of these sandstones. Accordingly, it analyzed the effects of …

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Applicability Evaluation Technology Of Perforating Parameters In Different Reservoirs, Bi Gang, Wu Jiemin, Yang Shangyu, Li Mengmeng, Han Fei, Wang Xin, Cui Ying Jul 2023

Applicability Evaluation Technology Of Perforating Parameters In Different Reservoirs, Bi Gang, Wu Jiemin, Yang Shangyu, Li Mengmeng, Han Fei, Wang Xin, Cui Ying

Coal Geology & Exploration

Perforating parameters have an important impact on the productivity of oil and gas wells. Currently, the optimization of perforating parameters is mostly based on single factor analysis, with no multi-factor comprehensive evaluation analysis performed. In this paper, the finite element simulation method was used to analyze and study the influence law of perforating parameters on wellhead flow under different reservoir conditions. Firstly, a geometric model of pressure drop in reservoir with perforation completion was established to simulate the fluid flow after perforation. In this way, the influence laws of perforating parameters, anisotropy parameters and natural fracture parameters on the pressure …

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Iron Occurrence In Coal Measures And Its Release Mechanism During Water-Rock Interactions: Taking A Mine In The Eastern Grassland As An Example, Wang Tiantian Jul 2023

Iron Occurrence In Coal Measures And Its Release Mechanism During Water-Rock Interactions: Taking A Mine In The Eastern Grassland As An Example, Wang Tiantian

Coal Geology & Exploration

The mine water with iron out of limit corrodes the water distribution pipeline and the industrial equipment, thereby damaging the liver of human body, and further threatening the human health. The enrichment or dilution of iron in mine water is determined by the iron content and its occurrence in coal measures, as well as its release mechanism during water-coal and water-rock interactions. Herein, 18 groups of coal and rock samples were collected from a mine in the eastern grassland, and had the iron content, occurrence and carrier in the coal measure analyzed with an inductively coupled plasma mass spectrometry (ICP-MS), …

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Change Detection Of Open-Pit Mines Based On Fm-Unet++ And Gf-2 Satellite Images, Du Shouhang, Li Wei, Xing Jianghe, Zhang Chengye, She Changchao, Wang Shaoyu, Li Jun Jul 2023

Change Detection Of Open-Pit Mines Based On Fm-Unet++ And Gf-2 Satellite Images, Du Shouhang, Li Wei, Xing Jianghe, Zhang Chengye, She Changchao, Wang Shaoyu, Li Jun

Coal Geology & Exploration

Automatic extraction of land use change information in open-pit mines using the remote sensing and deep learning technology is of great significance for the mining monitoring and ecological environmental protection. A novel deep learning model FM-UNet++ was constructed for the change of land use types in complex and heterogeneous mining scenarios, and the automatic change detection of open-pit mines was achieved using the Gaofen-2 (GF-2) satellite images. Firstly, the change detection dataset of open-pit mine was produced through data surveys and visual interpretation, which was augmented by data enhancement. Secondly, the FM-UNet++ for open-pit mine change detection was constructed by …

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A Method For Suppressing Casing Coupling Noise In Vsp Data Based On Morphological Component Analysis Of Characteristic Waves, Pan Long, Mao Haibo, Jiang Li, Hu Keyang, Dang Zhimin, Chen Wenchao Jul 2023

A Method For Suppressing Casing Coupling Noise In Vsp Data Based On Morphological Component Analysis Of Characteristic Waves, Pan Long, Mao Haibo, Jiang Li, Hu Keyang, Dang Zhimin, Chen Wenchao

Coal Geology & Exploration

During the acquisition of vertical seismic profile (VSP) data, coupling noise between casing strings frequently emerges due to poor well cementing or the presence of cement annulus between multiple casing layers. This type of noise features high energy, a wide spatial influence range, and slow attenuation. Furthermore, it overlaps effective signals in multiple domains, such as the time and frequency domains. Therefore, casing coupling noise severely affects the signal-to-noise ratio of VSP data. This study first introduces the basic theory of Morphological Component Analysis (MCA). Then, it conducts a comparative analysis of the distribution of effective signals and casing coupling …

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Influence Of High In-Situ Stress Areas In The Coal Seam Roofs On Microseism-Based Tomographic Inversion, Liu Kaihang, Feng Lei, Yun Meihou, Cao Yunxing, Tian Lin Jul 2023

Influence Of High In-Situ Stress Areas In The Coal Seam Roofs On Microseism-Based Tomographic Inversion, Liu Kaihang, Feng Lei, Yun Meihou, Cao Yunxing, Tian Lin

Coal Geology & Exploration

High in-situ stress areas in the coal seam roofs are prone to induce mine dynamic hazard such as rock bursts. To meet the demand for safe coal mining, this study achieved real-time monitoring and swift early warning of high in situ stress areas. Specifically, based on data transmitted from microseismic stations in real time, this study conducted the inversion of the wave velocities in coal seams and rocks using a fast three-dimensional (3D) tomographic inversion algorithm. The accuracy of tomographic inversion results directly determines the judgment on the locations of high in situ stress areas. Therefore, by building a 3D …

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Cambrian Explosion Condensed: High-Precision Geochronology Of The Lower Wood Canyon Formation, Nevada, Lyle L. Nelson, James L. Crowley, Emily F. Smith, Darin M. Schwartz, Eben B. Hodgin, Mark D. Schmitz Jul 2023

Cambrian Explosion Condensed: High-Precision Geochronology Of The Lower Wood Canyon Formation, Nevada, Lyle L. Nelson, James L. Crowley, Emily F. Smith, Darin M. Schwartz, Eben B. Hodgin, Mark D. Schmitz

Geosciences Faculty Publications and Presentations

The geologically rapid appearance of fossils of modern animal phyla within Cambrian strata is a defining characteristic of the history of life on Earth. However, temporal calibration of the base of the Cambrian Period remains uncertain within millions of years, which has resulted in mounting challenges to the concept of a discrete Cambrian explosion. We present precise zircon U–Pb dates for the lower Wood Canyon Formation, Nevada. These data demonstrate the base of the Cambrian Period, as defined by both ichnofossil biostratigraphy and carbon isotope chemostratigraphy, was younger than 533 Mya, at least 6 My later than currently recognized. This …

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Spatial Variations In Ancient Meteoric Water: An Investigation Of The Rattlesnake Tuff, Julian Michael Cohen Jul 2023

Spatial Variations In Ancient Meteoric Water: An Investigation Of The Rattlesnake Tuff, Julian Michael Cohen

Dissertations and Theses

Volcanic glass has been used extensively as a paleoclimate proxy. Deuterium (2H) concentrations in glass have been found to be stable over geologic timescales, making δD a reliable proxy for ancient water chemistry. However, continued work revolves around better understanding how different factors affect preserved water in ash. Here, I analyze δD in the Rattlesnake Tuff (RST), a widespread ca. 7 Ma ashflow tuff, and create an isoscape to assess variations in δD across Oregon during that time. Additionally, I examine compositional data from glass shards to explore the relationship between δD and shard composition. The RST exhibits well defined …

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Comparing Drone2map Versus Pix4dmapper When Creating Orthophoto Mosaics Over Homogeneous Land Features, Victoria Williams, Daniel R. Unger, David Kulhavy, I-Kuai Hung, Yanli Zhang Jul 2023

Comparing Drone2map Versus Pix4dmapper When Creating Orthophoto Mosaics Over Homogeneous Land Features, Victoria Williams, Daniel R. Unger, David Kulhavy, I-Kuai Hung, Yanli Zhang

International Journal of Geospatial and Environmental Research

This study evaluated two popular software packages currently used within the natural resources profession to create orthophoto mosaics: Drone2Map and Pix4Dmapper. Of particular concern was how effective these two software packages would perform in creating orthophoto mosaics over a city park in East Texas consisting of forest, open grass, and urban concrete surrounding a lake. Two drone flights over the city park were conducted. One flight was at 76 meters (250 feet) above ground with a single pass configuration. The other flight was at 122 meters (400 feet) above ground with a double pass configuration. Upon the completion of each …

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