Pub Date : 2024-12-01DOI: 10.1016/j.rines.2024.100045
Iman Nezamzadeh , Ali Faghih , Behnam Oveisi , Timothy Kusky , Narges Khajavi , Masoumeh Soleimani , Jiannan Meng
Investigating fault deformation in Late-Quaternary sediments provide valuable data to seismic hazard analysis especially relevant for the urban areas. Integration of displacement of geomorphic markers and ages of Quaternary sediment is needed to measure deformation rates accurately. In order to produce data on intermediate-term deformation rates along the Sabzpoushan Fault Zone (SFZ) situated in the Zagros Mountains of south-west Iran, the optically stimulated luminescence (OSL) dating technique was applied to the tectonically influenced terraces of the Mianrod River passing through the fault zone. Field evidence and satellite imagery revealed that geomorphic markers include strike-slip displacement of terraces, different levels of the fluvial markers, shifting in Bakhtiary Formation, fast change in trend of the river and expansion of erosional gully, deformed horizontally along the Fault Zone. These geomorphic indices suggest that Mianrod River deflected along the SFZ as a consequence of faulting during multiple faulting cycles. The OSL dates obtained from the study area indicate that strike-slip deformation rate along the Sabzpoushan Fault Zone is 1–2.8 ± 0.2 mm y−1 (for ∼100 ka). It is suggestive from the research that a significant part of this estimated rate of deformation results from aseismic crustal deformation, but the areas with the highest likelihood of the Sabzpoushan near-surface deformation, as well as the west parts of the city of Shiraz, should be considered as high seismic hazard areas.
研究晚第四纪沉积物中的断层变形为城市地区的地震危险性分析提供了宝贵的资料。为了准确地测量变形速率，需要将地貌标记物的位移与第四纪沉积物的年龄相结合。为了获得位于伊朗西南部扎格罗斯山脉的Sabzpoushan断裂带（SFZ）的中期变形速率数据，将光学激发发光（OSL）测年技术应用于流经该断裂带的Mianrod河受构造影响的阶地。现场证据和卫星影像显示，该地区的地貌标志包括阶地的走滑位移、河流标志的不同层次、巴赫蒂亚组的移动、河流走向的快速变化和侵蚀沟的扩张，并沿断裂带水平变形。这些地貌指标表明，在多个断裂旋回中，勉罗德河沿着SFZ发生了断裂。研究区OSL数据表明，Sabzpoushan断裂带的走滑变形速率为1 - 2.8±0.2 mm y−1（约100 ka）。研究表明，这一估计变形率的很大一部分是由地壳的地震变形引起的，但Sabzpoushan近地表变形可能性最大的地区以及设拉子市西部地区应被视为地震高危险区。
{"title":"On the use of displaced river terraces to characterize active tectonics of the Zagros orogenic belt, SW Iran","authors":"Iman Nezamzadeh , Ali Faghih , Behnam Oveisi , Timothy Kusky , Narges Khajavi , Masoumeh Soleimani , Jiannan Meng","doi":"10.1016/j.rines.2024.100045","DOIUrl":"10.1016/j.rines.2024.100045","url":null,"abstract":"<div><div>Investigating fault deformation in Late-Quaternary sediments provide valuable data to seismic hazard analysis especially relevant for the urban areas. Integration of displacement of geomorphic markers and ages of Quaternary sediment is needed to measure deformation rates accurately. In order to produce data on intermediate-term deformation rates along the Sabzpoushan Fault Zone (SFZ) situated in the Zagros Mountains of south-west Iran, the optically stimulated luminescence (OSL) dating technique was applied to the tectonically influenced terraces of the Mianrod River passing through the fault zone. Field evidence and satellite imagery revealed that geomorphic markers include strike-slip displacement of terraces, different levels of the fluvial markers, shifting in Bakhtiary Formation, fast change in trend of the river and expansion of erosional gully, deformed horizontally along the Fault Zone. These geomorphic indices suggest that Mianrod River deflected along the SFZ as a consequence of faulting during multiple faulting cycles. The OSL dates obtained from the study area indicate that strike-slip deformation rate along the Sabzpoushan Fault Zone is 1–2.8 ± 0.2 mm y<sup>−1</sup> (for ∼100 ka). It is suggestive from the research that a significant part of this estimated rate of deformation results from aseismic crustal deformation, but the areas with the highest likelihood of the Sabzpoushan near-surface deformation, as well as the west parts of the city of Shiraz, should be considered as high seismic hazard areas.</div></div>","PeriodicalId":101084,"journal":{"name":"Results in Earth Sciences","volume":"2 ","pages":"Article 100045"},"PeriodicalIF":0.0,"publicationDate":"2024-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142748230","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The current investigation has been carried out to determine the potentially dangerous glacial lakes (PDGLs) and glacier recession and in the Bhut and Warwen sub-basins of Chenab basin using the Landsat series of data. In order to assess the glacier dynamics from 2000 to 2020 the consecutive set of 5-year intervals data were used and it is found that, glaciers are shrinked in area as 1049.94 km2 in 2000, to 988.07 km2 in 2020, indicating a notable decrease in glacier extent over the twenty-year period. Further, an empirical approach was used to identify the PDGLs in the study area. The results of PDGLs shows that there are a total of 55 glacial lakes have the potential to be hazardous. Out of them, 11 are classified as high hazard, 18 as moderate hazard; and the remaining 26 are designated as low hazard. The PDGLs in the region have seen a surge in their numbers in the last few decades due to topographical as well as climate variables. The receding of glaciers and the risk of landslides in the region greatly influences PDGLs. The dangers among these lakes in the region have accumulated so much sediments and the glacial melt and their bearing capacity has come up to certain threshold causing the GLOFs and landslide lake outburst floods (LLOFs) in the region.
{"title":"Multi-criteria assessment of PDGLs for GLOFs hazards in the Bhut and Warwan sub-basins of the Chenab basin, Northwestern Himalaya","authors":"Ajay Kumar Taloor , Gurnam Parsad , Savati Sharma , Shiwalika Sambyal , Gulshan Kumar , Ravi Sharma , Girish Ch Kothyari , Meenakshi Sharma","doi":"10.1016/j.rines.2024.100046","DOIUrl":"10.1016/j.rines.2024.100046","url":null,"abstract":"<div><div>The current investigation has been carried out to determine the potentially dangerous glacial lakes (PDGLs) and glacier recession and in the Bhut and Warwen sub-basins of Chenab basin using the Landsat series of data. In order to assess the glacier dynamics from 2000 to 2020 the consecutive set of 5-year intervals data were used and it is found that, glaciers are shrinked in area as 1049.94 km<sup>2</sup> in 2000, to 988.07 km<sup>2</sup> in 2020, indicating a notable decrease in glacier extent over the twenty-year period. Further, an empirical approach was used to identify the PDGLs in the study area. The results of PDGLs shows that there are a total of 55 glacial lakes have the potential to be hazardous. Out of them, 11 are classified as high hazard, 18 as moderate hazard; and the remaining 26 are designated as low hazard. The PDGLs in the region have seen a surge in their numbers in the last few decades due to topographical as well as climate variables. The receding of glaciers and the risk of landslides in the region greatly influences PDGLs. The dangers among these lakes in the region have accumulated so much sediments and the glacial melt and their bearing capacity has come up to certain threshold causing the GLOFs and landslide lake outburst floods (LLOFs) in the region.</div></div>","PeriodicalId":101084,"journal":{"name":"Results in Earth Sciences","volume":"2 ","pages":"Article 100046"},"PeriodicalIF":0.0,"publicationDate":"2024-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142757456","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-12-01DOI: 10.1016/j.rines.2024.100048
C.J. Rakesh , Govindaraju , S. Sudha , S. Lokanath , D.R. Thippeswamy
The groundwater resources have been under significant constraints due to excessive exploitation and climate change. It is imperative to comprehend these dwindling resources' characteristics, given their distribution and occurrence variability across the space and time. A semi-arid climate characterizes the study area and agriculture is the primary occupation, their reliance on groundwater is indispensable due to the lack of surface water sources and erratic rainfall patterns. Consequently, the study employed the Schlumberger array of 200 m-spaced half-current electrodes Vertical Electrical Sounding (VES) survey was conducted at 100 VES locations to identify groundwater potential zones. Further, curve-matching and correlation of lithologies have been carried out from various VES-soundings, and also generated pseudo-cross sections of the subsurface geometry. The results revealed the existence of five geoelectrical resistivity layers as follows layer 1–6 to 422 Ωm, layer 2–8 to 7708 Ωm, layer 3–4 to 37117 Ωm, layer 4–37 to 95059 Ωm, and layer 5–205 to 83142 Ωm. The iso-apparent resistivity maps of the study area reveal values ranging for the first layer 11Ωm - 333 Ωm, the second layer 23Ωm - 5347Ωm, the third layer 11Ωm - 26734Ωm and 10Ωm - 67250Ωm for the fourth layer. The present research determined that the third and fourth layer constitute the principal aquifers due to their fractured structures. As a result, these layers produce a significant quantity of groundwater in the north-eastern (NE) and southern (S) regions of the study region. As a consequence of these findings, further exploration and management of groundwater resources in the study areas can be carried out with valuable insight.
{"title":"Geo-electrical investigation for groundwater reserves in the Boranakanive Reservoir Catchment in Tumkur district, Karnataka, India","authors":"C.J. Rakesh , Govindaraju , S. Sudha , S. Lokanath , D.R. Thippeswamy","doi":"10.1016/j.rines.2024.100048","DOIUrl":"10.1016/j.rines.2024.100048","url":null,"abstract":"<div><div>The groundwater resources have been under significant constraints due to excessive exploitation and climate change. It is imperative to comprehend these dwindling resources' characteristics, given their distribution and occurrence variability across the space and time. A semi-arid climate characterizes the study area and agriculture is the primary occupation, their reliance on groundwater is indispensable due to the lack of surface water sources and erratic rainfall patterns. Consequently, the study employed the Schlumberger array of 200 m-spaced half-current electrodes Vertical Electrical Sounding (VES) survey was conducted at 100 VES locations to identify groundwater potential zones. Further, curve-matching and correlation of lithologies have been carried out from various VES-soundings, and also generated pseudo-cross sections of the subsurface geometry. The results revealed the existence of five geoelectrical resistivity layers as follows layer 1–6 to 422 Ωm, layer 2–8 to 7708 Ωm, layer 3–4 to 37117 Ωm, layer 4–37 to 95059 Ωm, and layer 5–205 to 83142 Ωm. The iso-apparent resistivity maps of the study area reveal values ranging for the first layer 11Ωm - 333 Ωm, the second layer 23Ωm - 5347Ωm, the third layer 11Ωm - 26734Ωm and 10Ωm - 67250Ωm for the fourth layer. The present research determined that the third and fourth layer constitute the principal aquifers due to their fractured structures. As a result, these layers produce a significant quantity of groundwater in the north-eastern (NE) and southern (S) regions of the study region. As a consequence of these findings, further exploration and management of groundwater resources in the study areas can be carried out with valuable insight.</div></div>","PeriodicalId":101084,"journal":{"name":"Results in Earth Sciences","volume":"2 ","pages":"Article 100048"},"PeriodicalIF":0.0,"publicationDate":"2024-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142757457","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-10-24DOI: 10.1016/j.rines.2024.100044
Naeem Abbas , Kegang Li , Yewuhalashet Fissha , Jitendra Khatti , Merhawi Berhe Geberegergis , N.Rao Cheepurupalli , Blessing Olamide Taiwo , Zemicael Gebrehiwot , Yemane Kide , N. Sri Chandrahas
In this study, the dynamics of jointed rock masses in the challenging geological setting of the Himalayas, with a focus on tunneling activities and recommendations of support for jointing rock mass, were investigated. The jointing in Himalayan rocks mass poses significant implications for tunnel stability, demanding a detailed analysis of joint characteristics, such as joint connectivity and spacing. The parameter of joint connectivity rate along the Himalayas becomes a key focus, impacting rock mass strength for tunneling. The study utilized quadratic polynomial and reciprocal expressions of power functions, to characterize the nonlinear variation of jointed rock mass strength concerning joint connectivity rate. Integration of these results leads to unified equations that consider rock type dependence, having a realistic representation of jointed rock behavior. Numerical analysis reveals that jointing in rock affects instability through complex stress regimes, identifying critical stress concentration points. The effectiveness of support measures like rock bolts and shotcrete are validated, demonstrating their role in reducing displacements in tunnels.
{"title":"Reliability analysis of support strategies in tunnel construction: Insights from geomechanical analysis of jointed rock masses","authors":"Naeem Abbas , Kegang Li , Yewuhalashet Fissha , Jitendra Khatti , Merhawi Berhe Geberegergis , N.Rao Cheepurupalli , Blessing Olamide Taiwo , Zemicael Gebrehiwot , Yemane Kide , N. Sri Chandrahas","doi":"10.1016/j.rines.2024.100044","DOIUrl":"10.1016/j.rines.2024.100044","url":null,"abstract":"<div><div>In this study, the dynamics of jointed rock masses in the challenging geological setting of the Himalayas, with a focus on tunneling activities and recommendations of support for jointing rock mass, were investigated. The jointing in Himalayan rocks mass poses significant implications for tunnel stability, demanding a detailed analysis of joint characteristics, such as joint connectivity and spacing. The parameter of joint connectivity rate along the Himalayas becomes a key focus, impacting rock mass strength for tunneling. The study utilized quadratic polynomial and reciprocal expressions of power functions, to characterize the nonlinear variation of jointed rock mass strength concerning joint connectivity rate. Integration of these results leads to unified equations that consider rock type dependence, having a realistic representation of jointed rock behavior. Numerical analysis reveals that jointing in rock affects instability through complex stress regimes, identifying critical stress concentration points. The effectiveness of support measures like rock bolts and shotcrete are validated, demonstrating their role in reducing displacements in tunnels.</div></div>","PeriodicalId":101084,"journal":{"name":"Results in Earth Sciences","volume":"2 ","pages":"Article 100044"},"PeriodicalIF":0.0,"publicationDate":"2024-10-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142553920","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-10-18DOI: 10.1016/j.rines.2024.100043
Jesús Rodrigo-Comino , Manuel Seeger
The global scientific community, particularly soil erosion researchers, is increasingly recognizing the urgent need to address plastic pollution and the accumulation of microplastics in soil. Human activities such as urban expansion, food packaging, and the use of agricultural materials have driven a significant rise in microplastic contamination. The problem is compounded by the difficulty, expense, and time-intensive nature of analyzing soil erosion samples to accurately identify microplastic types, sources, and their effects. Soil erosion, while naturally shaping landscapes like hillslopes, deltas or river valleys, has evolved into a critical issue due to human-induced changes, threatening fertile agricultural zones and areas prone to landslides, with serious economic and human consequences. While validated methods exist to quantify soil erosion, runoff, and pollutant concentrations, these techniques inadvertently introduce microplastics into the environment by plastic materials during sampling, transport, and lab analysis. This not only skews historical and current data on microplastic levels in soils but also alters natural soil conditions around research plots. To address these challenges, this paper advocates for the refinement of measurement techniques to minimize contamination, a reassessment of current methodologies, and a concerted effort to reduce human impact on soil health, thereby safeguarding a critical natural resource.
{"title":"Exploring the unintended contribution of soil erosion research to microplastic contamination","authors":"Jesús Rodrigo-Comino , Manuel Seeger","doi":"10.1016/j.rines.2024.100043","DOIUrl":"10.1016/j.rines.2024.100043","url":null,"abstract":"<div><div>The global scientific community, particularly soil erosion researchers, is increasingly recognizing the urgent need to address plastic pollution and the accumulation of microplastics in soil. Human activities such as urban expansion, food packaging, and the use of agricultural materials have driven a significant rise in microplastic contamination. The problem is compounded by the difficulty, expense, and time-intensive nature of analyzing soil erosion samples to accurately identify microplastic types, sources, and their effects. Soil erosion, while naturally shaping landscapes like hillslopes, deltas or river valleys, has evolved into a critical issue due to human-induced changes, threatening fertile agricultural zones and areas prone to landslides, with serious economic and human consequences. While validated methods exist to quantify soil erosion, runoff, and pollutant concentrations, these techniques inadvertently introduce microplastics into the environment by plastic materials during sampling, transport, and lab analysis. This not only skews historical and current data on microplastic levels in soils but also alters natural soil conditions around research plots. To address these challenges, this paper advocates for the refinement of measurement techniques to minimize contamination, a reassessment of current methodologies, and a concerted effort to reduce human impact on soil health, thereby safeguarding a critical natural resource.</div></div>","PeriodicalId":101084,"journal":{"name":"Results in Earth Sciences","volume":"2 ","pages":"Article 100043"},"PeriodicalIF":0.0,"publicationDate":"2024-10-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142526105","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-10-11DOI: 10.1016/j.rines.2024.100042
Sheharyar Ahmad, Muhammad Shareef Shazil, Ahmad Furqan Hassan, Bashra Afzal
Morphometric analysis is essential for understanding drainage networks and landform evolution, particularly in complex mountainous regions like the Swat Valley. Accurate characterization of these features aids in water resource management and mitigating climate-induced challenges. The study employed GIS and remote sensing technologies, utilizing SRTM-30m DEM data to perform a comprehensive morphometric and hypsometric analysis. Key morphometric parameters such as basin size, stream order, bifurcation ratio, drainage density, circularity ratio, and elongation ratio were calculated by using Whitebox tool. Additionally, three-dimensional parameters including basin relief, roughness number, ruggedness index, and slope were analyzed. Hypsometric analysis was conducted to examine area-elevation relationships, using empirical formulas and contour data. The basin was found to be irregularly shaped, with an elongation ratio of 6.97 and a circulatory ratio of 0.3091, indicating an elongated form. Flow accumulation data highlighted areas of rapid and moderate water flow. Hypsometric analysis showed that 14 sub-basins were in an erosional stage, 8 were mature, and the remainder were older and more resistant to erosion. The overall hypsometric integral (HI) of 0.406 reflects moderate elevation variation across the basin. The study provides critical insights into the geomorphometric controls of the Swat Valley's drainage system, contributing to improved water resource management strategies. Understanding morphometric and hypsometric characteristics is vital for adapting to climate-induced risks and safeguarding water resources in mountainous landscapes.
{"title":"Geo-spatial assessment of geomorphic characteristics of Swat Valley, Pakistan","authors":"Sheharyar Ahmad, Muhammad Shareef Shazil, Ahmad Furqan Hassan, Bashra Afzal","doi":"10.1016/j.rines.2024.100042","DOIUrl":"10.1016/j.rines.2024.100042","url":null,"abstract":"<div><div>Morphometric analysis is essential for understanding drainage networks and landform evolution, particularly in complex mountainous regions like the Swat Valley. Accurate characterization of these features aids in water resource management and mitigating climate-induced challenges. The study employed GIS and remote sensing technologies, utilizing SRTM-30m DEM data to perform a comprehensive morphometric and hypsometric analysis. Key morphometric parameters such as basin size, stream order, bifurcation ratio, drainage density, circularity ratio, and elongation ratio were calculated by using Whitebox tool. Additionally, three-dimensional parameters including basin relief, roughness number, ruggedness index, and slope were analyzed. Hypsometric analysis was conducted to examine area-elevation relationships, using empirical formulas and contour data. The basin was found to be irregularly shaped, with an elongation ratio of 6.97 and a circulatory ratio of 0.3091, indicating an elongated form. Flow accumulation data highlighted areas of rapid and moderate water flow. Hypsometric analysis showed that 14 sub-basins were in an erosional stage, 8 were mature, and the remainder were older and more resistant to erosion. The overall hypsometric integral (HI) of 0.406 reflects moderate elevation variation across the basin. The study provides critical insights into the geomorphometric controls of the Swat Valley's drainage system, contributing to improved water resource management strategies. Understanding morphometric and hypsometric characteristics is vital for adapting to climate-induced risks and safeguarding water resources in mountainous landscapes.</div></div>","PeriodicalId":101084,"journal":{"name":"Results in Earth Sciences","volume":"2 ","pages":"Article 100042"},"PeriodicalIF":0.0,"publicationDate":"2024-10-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142445051","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-09-27DOI: 10.1016/j.rines.2024.100039
Ayokunle Adewale Akinlalu, Oluwapelumi Idowu Obideyi, Daniel Oluwafunmilade Afolabi , Kola Abdul-Nafiu Adiat, Oluwamayowa Joseph Adeola
This study employed a knowledge–driven model (stepwise weight assessment ratio analysis (SWARA)) for the prospectivity mapping of gold in parts of Ilesa Schist belt, Southwestern Nigeria. Aeromagnetic, aero-radiometric and remote sensing (Atmospheric Spaceborne Thermal Emission and reflection Radiometer (ASTER) data) datasets were utilized for this study. Data enhancement techniques were performed on the aeromagnetic data to produce the lineament map of the study area. Also, analyses of the aeroradiometric and ASTER datasets were used in delineating hydrothermally altered zones in the study area. Lithology, lineament density, hydrothermal alteration and slope were the factors considered to produce the gold potential map of the study area using the SWARA model for weight assignment. The study showed that NE–SW trending structures aid the transportation of hydrothermal and mineralizing fluids in the study area. Furthermore, gold mineralisation is observed to occur majorly on the granitoids. From the SWARA model, weight assignment results showed that the factors influencing gold mineralisation in descending order of importance are hydrothermal alteration, lithology, lineament density and slope. The produced gold mineralisation map based on the weight assignment classified the study area into five classes: background, low, moderate, high and very high with the southern, western and northwestern axis of the study area having moderate to very high potential of gold mineralisation. Qualitative validation using mining pits showed 73 % success rate while quantitative validation utilizing linear regression model showed a success rate of 74 % substantiating the reliability of the model.
本研究采用了一个知识驱动模型（逐步权重评估比率分析（SWARA）），用于绘制尼日利亚西南部伊莱萨片岩带部分地区的金矿远景图。本研究使用了航磁、航空辐射测量和遥感（大气空间热发射和反射辐射计（ASTER）数据）数据集。对航磁数据进行了数据增强技术处理，以绘制研究区域的线状图。此外，还利用对空气辐射计和 ASTER 数据集的分析来划定研究区域的热液蚀变区。考虑了岩性、线状密度、热液蚀变和坡度等因素，利用 SWARA 模型进行权重分配，绘制了研究区域的金矿潜力图。研究表明，东北-西南走向的构造有助于热液和成矿流体在研究区域的输送。此外，还观察到金矿化主要发生在花岗岩上。SWARA 模型的权重分配结果表明，影响金矿化的因素依次为热液蚀变、岩性、线状密度和坡度。根据权重分配绘制的金矿化地图将研究区域划分为五个等级：背景、低、中、高和极高，研究区域的南部、西部和西北部轴线具有中到极高的金矿化潜力。利用矿坑进行定性验证的成功率为 73%，而利用线性回归模型进行定量验证的成功率为 74%，这证明了模型的可靠性。
{"title":"Gold prospectivity mapping using “SWARA” model on geophysical datasets in parts of Ilesa Schist belt, Southwestern Nigeria","authors":"Ayokunle Adewale Akinlalu, Oluwapelumi Idowu Obideyi, Daniel Oluwafunmilade Afolabi , Kola Abdul-Nafiu Adiat, Oluwamayowa Joseph Adeola","doi":"10.1016/j.rines.2024.100039","DOIUrl":"10.1016/j.rines.2024.100039","url":null,"abstract":"<div><div>This study employed a knowledge–driven model (stepwise weight assessment ratio analysis (SWARA)) for the prospectivity mapping of gold in parts of Ilesa Schist belt, Southwestern Nigeria. Aeromagnetic, aero-radiometric and remote sensing (Atmospheric Spaceborne Thermal Emission and reflection Radiometer (ASTER) data) datasets were utilized for this study. Data enhancement techniques were performed on the aeromagnetic data to produce the lineament map of the study area. Also, analyses of the aeroradiometric and ASTER datasets were used in delineating hydrothermally altered zones in the study area. Lithology, lineament density, hydrothermal alteration and slope were the factors considered to produce the gold potential map of the study area using the SWARA model for weight assignment. The study showed that NE–SW trending structures aid the transportation of hydrothermal and mineralizing fluids in the study area. Furthermore, gold mineralisation is observed to occur majorly on the granitoids. From the SWARA model, weight assignment results showed that the factors influencing gold mineralisation in descending order of importance are hydrothermal alteration, lithology, lineament density and slope. The produced gold mineralisation map based on the weight assignment classified the study area into five classes: background, low, moderate, high and very high with the southern, western and northwestern axis of the study area having moderate to very high potential of gold mineralisation. Qualitative validation using mining pits showed 73 % success rate while quantitative validation utilizing linear regression model showed a success rate of 74 % substantiating the reliability of the model.</div></div>","PeriodicalId":101084,"journal":{"name":"Results in Earth Sciences","volume":"2 ","pages":"Article 100039"},"PeriodicalIF":0.0,"publicationDate":"2024-09-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142356735","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-09-26DOI: 10.1016/j.rines.2024.100040
Omid Memarian Sorkhabi
Extreme weather patterns can affect ground and satellite sensors before and after their occur. This study focused on tornadoes that occurred on December 10 and 11, 2021 in the state of Kentucky. The main goal of this research was to develop a deep learning algorithm based on history to predict this phenomenon. Four scenarios were created based on temperature, air pressure, wind speed and their combination. The temperature-based scenario shows high accuracy and shows the time series of temperature rise several degrees before the tornado. In the second step, the normalized difference vegetation index (NDVI) anomaly was calculated and classified for Mayfield city. Severe NDVI anomalies showed high consistency with enhanced Fujita scale and ultra-high-resolution satellite imagery, with a correlation greater than 0.9.
{"title":"An LSTM deep learning framework for history-based tornado prediction using meteorological data and damage assessment using NDVI anomalies","authors":"Omid Memarian Sorkhabi","doi":"10.1016/j.rines.2024.100040","DOIUrl":"10.1016/j.rines.2024.100040","url":null,"abstract":"<div><div>Extreme weather patterns can affect ground and satellite sensors before and after their occur. This study focused on tornadoes that occurred on December 10 and 11, 2021 in the state of Kentucky. The main goal of this research was to develop a deep learning algorithm based on history to predict this phenomenon. Four scenarios were created based on temperature, air pressure, wind speed and their combination. The temperature-based scenario shows high accuracy and shows the time series of temperature rise several degrees before the tornado. In the second step, the normalized difference vegetation index (NDVI) anomaly was calculated and classified for Mayfield city. Severe NDVI anomalies showed high consistency with enhanced Fujita scale and ultra-high-resolution satellite imagery, with a correlation greater than 0.9.</div></div>","PeriodicalId":101084,"journal":{"name":"Results in Earth Sciences","volume":"2 ","pages":"Article 100040"},"PeriodicalIF":0.0,"publicationDate":"2024-09-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142416299","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-09-18DOI: 10.1016/j.rines.2024.100038
Opiriyabo Ibim Horsfall , Mfonobong Joseph Akpan , Nyakno Jimmy George
This study investigates the GABO field in the onshore Niger Delta Basin using well logs and core samples, with a focus on rock type distribution, reservoir continuity, and petrophysical properties to enhance hydrocarbon exploration accuracy. The research involved detailed analysis of core descriptions and images from GABO-20, along with petrophysical data from wells GABO-4, GABO-12, GABO-13, GABO-20, and GABO-51, aiming to identify rock types, evaluate reservoir quality, and determine the spatial distribution of petrophysical properties. The methodology included rigorous well log quality checks, data correlation between wells, petrophysical property evaluation, and lithofacies description. The analysis revealed thirty-five hydrocarbon-bearing zones, with GABO-20 showing average shale fraction values between 0.111 and 0.335, total porosity ranging from 0.242 to 0.329, and hydrocarbon saturation from 0.667 to 0.923, indicating substantial porosity and hydrocarbon saturation conducive to extraction. Well correlations demonstrated excellent sand-shale continuity within the reservoir intervals. Lithofacies analysis of the GABO-20 core identified eight distinct facies, including shale poles, liquid-rich shales, and sandstone poles, revealing a complex distribution of reservoir qualities with significant variations in potential. Cores 1 and 2 exhibited favourable conditions for hydrocarbon production, while Core 3 showed lower reservoir quality due to increased clay content. The depositional settings of the GABO field, particularly in the lower delta plain and delta front zones, showed well-developed reservoir bodies with moderate potential in the tidal zone and little potential in the shaly prodelta environment. This distribution highlights the complexity of the deltaic system and its implications for reservoir modeling and utilization. Reservoir zones associated with High-Quality Reservoir Facies exhibited strong petrophysical properties, suggesting excellent hydrocarbon production potential. The study underscores the importance of detailed reservoir characterization to optimize recovery strategies, offering valuable insights into the distribution and quality of reservoir sands, reducing subsurface uncertainty, and emphasizing the integration of facies and petrophysical approaches for a better understanding of reservoir characteristics in the GABO field.
{"title":"Reservoir characterization of GABO field in the niger delta basin using facies and petrophysical analyses","authors":"Opiriyabo Ibim Horsfall , Mfonobong Joseph Akpan , Nyakno Jimmy George","doi":"10.1016/j.rines.2024.100038","DOIUrl":"10.1016/j.rines.2024.100038","url":null,"abstract":"<div><p>This study investigates the GABO field in the onshore Niger Delta Basin using well logs and core samples, with a focus on rock type distribution, reservoir continuity, and petrophysical properties to enhance hydrocarbon exploration accuracy. The research involved detailed analysis of core descriptions and images from GABO-20, along with petrophysical data from wells GABO-4, GABO-12, GABO-13, GABO-20, and GABO-51, aiming to identify rock types, evaluate reservoir quality, and determine the spatial distribution of petrophysical properties. The methodology included rigorous well log quality checks, data correlation between wells, petrophysical property evaluation, and lithofacies description. The analysis revealed thirty-five hydrocarbon-bearing zones, with GABO-20 showing average shale fraction values between 0.111 and 0.335, total porosity ranging from 0.242 to 0.329, and hydrocarbon saturation from 0.667 to 0.923, indicating substantial porosity and hydrocarbon saturation conducive to extraction. Well correlations demonstrated excellent sand-shale continuity within the reservoir intervals. Lithofacies analysis of the GABO-20 core identified eight distinct facies, including shale poles, liquid-rich shales, and sandstone poles, revealing a complex distribution of reservoir qualities with significant variations in potential. Cores 1 and 2 exhibited favourable conditions for hydrocarbon production, while Core 3 showed lower reservoir quality due to increased clay content. The depositional settings of the GABO field, particularly in the lower delta plain and delta front zones, showed well-developed reservoir bodies with moderate potential in the tidal zone and little potential in the shaly prodelta environment. This distribution highlights the complexity of the deltaic system and its implications for reservoir modeling and utilization. Reservoir zones associated with High-Quality Reservoir Facies exhibited strong petrophysical properties, suggesting excellent hydrocarbon production potential. The study underscores the importance of detailed reservoir characterization to optimize recovery strategies, offering valuable insights into the distribution and quality of reservoir sands, reducing subsurface uncertainty, and emphasizing the integration of facies and petrophysical approaches for a better understanding of reservoir characteristics in the GABO field.</p></div>","PeriodicalId":101084,"journal":{"name":"Results in Earth Sciences","volume":"2 ","pages":"Article 100038"},"PeriodicalIF":0.0,"publicationDate":"2024-09-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2211714824000256/pdfft?md5=774792e7761d840fe9d27748cb893569&pid=1-s2.0-S2211714824000256-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142270514","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-08-24DOI: 10.1016/j.rines.2024.100037
Vahid Tavakoli , Hosein Barfizadeh
This article reviews and assesses the reservoir characteristics of several geologic Formations in the northeast of the Arabian plate, from the Permian–Triassic to Oligo-Miocene, and evaluates the complex interrelations between tectonic activities, paleoclimatic conditions and diagenetic alterations. All of these Formations have been deposited in a ramp depositional setting. Both dolomitization and dissolution diagenetic processes have significantly enhanced the reservoir quality by altering the porosity and permeability of the Permian–Triassic Kangan and the Dalan Formations. The diagenetic processes of dissolution, fracturing, and localized dolomitization have enhanced the reservoir properties of the Fahliyan Formation's carbonate sequence. The Cretaceous Dariyan exhibits a gradual facies transition where dissolution enhances reservoir quality, while cementation and compaction diminish reservoir properties. For the mid-Cretaceous Sarvak Formation, the investigation addressed the diagenetic history triggering the creation of secondary porosity, related to meteoric processes and karstification. Finally, the Oligo-Miocene Asmari Formation is presented as a major hydrocarbon reservoir with extensive carbonate facies. Tectonic-driven fracturing and faulting increased reservoir quality by altering primary porosity and permeability and inducing significant diagenetic changes within a complex biodiverse reef ecosystem. This paper aims to comprehensively review and analyze the interaction between facies, diagenesis, tectonic activities, and paleoclimate across several geological Formations in the study area. By synthesizing existing literature and conducting a comparative analysis, the study seeks to elucidate how these factors collectively influence reservoir properties and dynamics. This approach not only identifies current knowledge gaps but also provides insights into potential avenues for future research and scientific exploration.
{"title":"The role of plate movements on reservoir development of the Iranian carbonate formations: A review of the interplay between tectonics, paleoclimate, and diagenesis","authors":"Vahid Tavakoli , Hosein Barfizadeh","doi":"10.1016/j.rines.2024.100037","DOIUrl":"10.1016/j.rines.2024.100037","url":null,"abstract":"<div><p>This article reviews and assesses the reservoir characteristics of several geologic Formations in the northeast of the Arabian plate, from the Permian–Triassic to Oligo-Miocene, and evaluates the complex interrelations between tectonic activities, paleoclimatic conditions and diagenetic alterations. All of these Formations have been deposited in a ramp depositional setting. Both dolomitization and dissolution diagenetic processes have significantly enhanced the reservoir quality by altering the porosity and permeability of the Permian–Triassic Kangan and the Dalan Formations. The diagenetic processes of dissolution, fracturing, and localized dolomitization have enhanced the reservoir properties of the Fahliyan Formation's carbonate sequence. The Cretaceous Dariyan exhibits a gradual facies transition where dissolution enhances reservoir quality, while cementation and compaction diminish reservoir properties. For the mid-Cretaceous Sarvak Formation, the investigation addressed the diagenetic history triggering the creation of secondary porosity, related to meteoric processes and karstification. Finally, the Oligo-Miocene Asmari Formation is presented as a major hydrocarbon reservoir with extensive carbonate facies. Tectonic-driven fracturing and faulting increased reservoir quality by altering primary porosity and permeability and inducing significant diagenetic changes within a complex biodiverse reef ecosystem. This paper aims to comprehensively review and analyze the interaction between facies, diagenesis, tectonic activities, and paleoclimate across several geological Formations in the study area. By synthesizing existing literature and conducting a comparative analysis, the study seeks to elucidate how these factors collectively influence reservoir properties and dynamics. This approach not only identifies current knowledge gaps but also provides insights into potential avenues for future research and scientific exploration.</p></div>","PeriodicalId":101084,"journal":{"name":"Results in Earth Sciences","volume":"2 ","pages":"Article 100037"},"PeriodicalIF":0.0,"publicationDate":"2024-08-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2211714824000244/pdfft?md5=cfd1b18a79d3f850eff1d8a3ab88c9b1&pid=1-s2.0-S2211714824000244-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142087280","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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