Geosystems and Geoenvironment最新文献

{"title":"Multiple drivers of the recent South Lhonak glacial lake outburst flood in Sikkim Himalaya and its aftermath on Teesta River Valley","authors":"Soumik Saha ,&nbsp;Biswajit Bera ,&nbsp;Debashish Sengupta ,&nbsp;Uttam Mukhopadhyay ,&nbsp;Debasis Ghosh ,&nbsp;Lakpa Tamang ,&nbsp;Sumana Bhattacharjee ,&nbsp;Nairita Sengupta","doi":"10.1016/j.geogeo.2025.100375","DOIUrl":"10.1016/j.geogeo.2025.100375","url":null,"abstract":"<div><div>Glacial lake outburst floods (GLOFs) are the most severe cryospheric hazard in the ‘Third Pole’ region, encompassing the Tibetan Plateau and surrounding areas including the Himalayas, Hindu Kush, Kunlun, and Tianshan mountains. Understanding the proper response of glaciers to the current situation of global warming is vital because of their role as a water source in the Asian region. Numerous glacial lakes are formed in the higher Himalayan areas due to the contemporary increase in global temperature. The upper part of the Teesta Basin, Sikkim hosts several glacial lakes including one of the largest and fastest growing South Lhonak Lake (5200 m from the mean sea level). Recently, a devastating GLOF event occurred in South Lhonak Lake after the breaching of moraine dams on midnight of October 3, 2023. This disastrous GLOF event collapsed the Chungthang Dam, located approximately 65 km downstream of the lake and accelerated extensive casualties along with infrastructural damages. It is identified that; the impact of cloudburst may be a significant triggering factor behind this event. The satellite imagery and digital elevation models also revealed that a sudden collapse of lateral moraine eventually produced an impulse wave which accelerated the breaching process. Additionally, this study also combined with advanced remote sensing applications. Satellite imageries indicate a huge reduction of the lake area after the GLOF event (1.66 km² before the GLOF event and 0.63 km² after the GLOF). The overtopping volume of the water has been estimated as approximately 106,400 <span><math><msup><mrow><mi>m</mi></mrow><mn>3</mn></msup></math></span>, with a duration of 12.78 s. The peak discharge during overtopping touched approximately 16,651.02 cumecs, indicating the maximum flow rate during the phase. The results have been validated by the high-resolution satellite data across various sites.</div></div>","PeriodicalId":100582,"journal":{"name":"Geosystems and Geoenvironment","volume":"4 2","pages":"Article 100375"},"PeriodicalIF":0.0,"publicationDate":"2025-03-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143643142","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}

{"title":"Tonian shoshonitic to ultrapotassic granitoids from Chhotanagpur Gneissic Complex, Eastern Indian Shield: Age, origin and tectonic implications","authors":"Ankita Basak ,&nbsp;Bapi Goswami ,&nbsp;Yoann Gréau ,&nbsp;Susmita Das ,&nbsp;Chittaranjan Bhattacharyya","doi":"10.1016/j.geogeo.2025.100373","DOIUrl":"10.1016/j.geogeo.2025.100373","url":null,"abstract":"<div><div>This work reports petrogenesis of an ultrapotassic granitoid pluton emplaced in the Tonian (949.4 ± 2.3 Ma; new LA-ICPMS zircon U–Pb dating) along a regional shear zone during the post-collisional stage of the Grenvillian Satpura orogeny in Eastern India. The hypidiomorphic granitoids comprise dominantly perthite, microcline (BaO up to 5.85 wt.%), quartz, albite and subordinate amphibole ± diopside ± epidote, allanite, titanite, magnetite ± ilmenite ± biotite ± calcite. Preservation of magmatic epidotes and resorbed boundaries indicates rapid ascent of the granitoid magma. Mylonitic deformation overprinted the southern part of the E-W trending pluton. Magmatic epidote with resorbed boundaries suggests rapid magma ascent. The metaluminous granitoids display affinities with shoshonitic rocks, i.e., enrichment of K₂O (5.79–11.41 wt.%), large ion lithophile elements (Ba 461.5–7004.8 ppm; Sr 151.3–3548.3 ppm), light rare earth elements (LREE 111.2–1317.7 ppm) and high K₂O/Na₂O (1.77–11.35) and La_CN/Yb_CN (11.7–82.48) ratios with both negative and positive Eu-anomalies (Eu/Eu* = 0.58–1.43; average 0.89). Trace element characteristics of zircons demonstrate their magmatic origin. Pseudosection modeling displays high temperature (∼800°C), high <em>f</em>O₂ (ΔNNO +0.8 to +2.6), and CO₂ activity (0.9) of the magma that intruded at shallow crustal depth (∼300 MPa). Biotite remains unstable at this physicochemical condition of the shoshonitic magma. Metaluminous nature, high (La/Yb)_CN (11.7–82.48) and Sr/Y (6.46–277.21) ratios, and Nb/U (avg. 7.4), Ce/Pb (avg. 6.8), Nb/Ta (avg. 11.9), Zr/Hf (avg. 31.61), and low Rb/Sr (0.09–1.39) ratios of these rocks indicate the derivation of the magma from partial melting of the mafic lower crust. Batch melting modeling shows the granitoid magma originated from 5 to 30 % batch melting of K–Ba–Sr-rich shoshonitic mafic (hornblende granulite) source. The study proposes new (Ba + Sr)–Ti–P and Ba–Sr–Ti triangular diagrams for distinguishing mantle vs. crustal sources of post-collisional granitoids.</div></div>","PeriodicalId":100582,"journal":{"name":"Geosystems and Geoenvironment","volume":"4 2","pages":"Article 100373"},"PeriodicalIF":0.0,"publicationDate":"2025-02-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143593753","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}

{"title":"Nappe tectonics in the Matomb-Hegba area, South-Central Cameroon: Implications on the tectonic evolution of the Yaoundé Group in the Central African Orogenic Belt","authors":"Victor Metang,&nbsp;Henri Appolinaire Kenzo,&nbsp;Rose Noel Ngo Belnoun,&nbsp;Dior-Christelle Mboutchouang,&nbsp;Steve Franck Bamou-Wandji,&nbsp;Brigitte Domkam,&nbsp;Boris Toyi Tchouta","doi":"10.1016/j.geogeo.2025.100372","DOIUrl":"10.1016/j.geogeo.2025.100372","url":null,"abstract":"<div><div>This paper documents the thrust tectonics in the Yaoundé Group using detailed field mapping and satellite imagery data. The litho-stratigraphic of the Matomb-Hegba area located W of the Pan-African Yaoundé series comprised two main metasedimentary units: (1) garnet-kyanite migmatites at the top, dated at 622 ± 43 Ma, and (2) garnet-rutile micaschists at the bottom, with ages ranging between 546 and 604 Ma. The contact between the two lithological units is materialized by a ductile shear zone evidenced by structural and remote sensing data: inversion of the foliation at the contact of the shear zone, P₂ folds with southern vergence, E-W to NE-SW sinistral shear planes, uniform dip (towards the SE) and several criteria indicating a sinistral and dextral kinematics respectively in light grey mylonites and in dark grey mylonites along the ductile shear zone. During D₂ deformation stage, subhorizontal S₂ foliation associated to NE-SW Lm₂ mineral lineations were developed in garnet-kyanite migmatites. The thrusting contact zone is characterized by mylonitized micaschists (light grey mylonites) and migmatites (dark grey mylonites) separated by talcschist and amphibolite boudins which would have served as a ‘‘soap layer’’ leading to the slipping of garnet-kyanite migmatites over garnet-rutile micaschists. The disposition of garnet-kyanite migmatites (sometimes outcrop in the form of klippes) over garnet-rutile micaschists, the presence of a ductile shear zone at the contact of the two lithological units, and the NE-SW mineral lineation suggest the existence of at least two tectonic nappes (garnet-kyanite migmatites and garnet-rutile micaschists) with NE-SW-trends in the Yaoundé Group. This nappe disposition induced by ductile shear corroborates well with the compressive shear tectonics as described in the NE of Brazil and in the northern and eastern part of the Saharan Block.</div></div>","PeriodicalId":100582,"journal":{"name":"Geosystems and Geoenvironment","volume":"4 2","pages":"Article 100372"},"PeriodicalIF":0.0,"publicationDate":"2025-02-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143636883","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}

{"title":"Integration of geospatial techniques and machine learning in land parcel prediction","authors":"Nekkanti Haripavan ,&nbsp;Subhashish Dey ,&nbsp;Chimakurthi Harika Mani Chandana","doi":"10.1016/j.geogeo.2025.100371","DOIUrl":"10.1016/j.geogeo.2025.100371","url":null,"abstract":"<div><div>The integration of geospatial techniques and machine learning algorithms has revolutionized our ability to analyze and predict changes in land parcels. In this research work leverage the power of Google Earth Engine to observe and interpret historical data spanning the last 2014–2023 years, in order to make informed predictions about future land parcel transformations. Our research will highlight the key components of this plan including data acquisition, preprocessing, feature engineering, and the application of machine learning models. We will explore how Google Earth Engine provides a robust platform for accessing vast geospatial datasets and performing complex analyses. By harnessing the temporal and spectral information captured by Earth observation satellites, we aim to identify patterns and trends in land parcel changes. These insights are used to train and fine-tune our machine learning models, which will subsequently forecast future land parcel developments. The project underscores the practical significance of our research work, as it can be applied to more domains such as urban planning, agriculture, forestry, and environmental monitoring. Furthermore, it showcases the potential of technology to enhance our understanding of the dynamic nature of our environment, and the role that predictive analytics plays in informed decision-making. One significant benefit is the feature selection that may be customized thanks to machine learning and geospatial approaches. Researchers and practitioners can customize their models by choosing the most pertinent variables for each land parcel forecasts from a wide range of spatial features. This flexibility guarantees that models can concentrate on the spatial features that have the biggest influence on the desired outcomes, improving the forecasts' overall performance and interpretability.</div></div>","PeriodicalId":100582,"journal":{"name":"Geosystems and Geoenvironment","volume":"4 2","pages":"Article 100371"},"PeriodicalIF":0.0,"publicationDate":"2025-02-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143593754","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}

{"title":"Artificial intelligence and machine learning to enhance critical mineral deposit discovery","authors":"Rhys S. Davies ,&nbsp;McLean Trott ,&nbsp;Jaakko Georgi ,&nbsp;Alexander Farrar","doi":"10.1016/j.geogeo.2025.100361","DOIUrl":"10.1016/j.geogeo.2025.100361","url":null,"abstract":"<div><div>The application of machine learning (ML) in mineral exploration has garnered significant attention and investment, yet greenfield mineral deposit discovery rates remain unchanged. This limited success stems from challenges such as low data quality outside existing mines, inconsistent sampling, limited interdisciplinary collaboration, and the unique complexity of geoscientific problems. Unlike traditional ML applications, mineral exploration demands a focus on subtle variations within finite search spaces, requiring an exploratory rather than accuracy-driven approach. Effective implementation necessitates collaboration between data scientists and geoscientists, leveraging ML as a tool to test hypotheses and analyse diverse datasets. However, reliance solely on ML overlooks the critical role of human creativity in generating and evaluating novel search strategies. Broader adoption of statistical methods, integrated spatial models, and innovative data preparation techniques can address the inconsistencies in exploration datasets. Furthermore, subjective modelling approaches, such as Delphi methods, can complement ML by incorporating expert judgment to overcome predictive limitations. By combining technological advancements with human expertise, the mineral exploration industry can enhance discovery success and achieve long-term sustainability. There is an important short-term requirement to secure the supply of critical metal resources, as their supply from existing mines and brownfield exploration is finite and commercial recycling of critical metals is still in its infancy.</div></div>","PeriodicalId":100582,"journal":{"name":"Geosystems and Geoenvironment","volume":"4 2","pages":"Article 100361"},"PeriodicalIF":0.0,"publicationDate":"2025-02-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143526796","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}

{"title":"Exploration of iron ore deposits in parts of Kogi State, northcentral Nigeria: Analyses from airborne magnetic and ASTER datasets","authors":"Ayokunle Adewale Akinlalu","doi":"10.1016/j.geogeo.2025.100359","DOIUrl":"10.1016/j.geogeo.2025.100359","url":null,"abstract":"<div><div>Kogi State is known for its iron ore deposits, and Kakanda township is one of those places that possess iron ore deposits. However, little information about the extent and locations of possible iron ore mineralized zones is available due to limited research in that area. Hence, this study utilized aeromagnetic and Advanced Spaceborne Thermal Emission Reflection Radiometer (ASTER) datasets for the delineation of ironstone and banded iron deposits comprising magnetite and hematite in Kakanda and its environs in Kogi State, northcentral Nigeria. Enhancement techniques such as residual magnetic amplitude and analytic signal amplitude carried out on the aeromagnetic data revealed the concentration of iron ore deposits, especially in the southern, eastern and western parts of the study area. This finding is consistent with signatures derived from other data enhancement techniques involving the total horizontal derivative, tilt derivative and 3D Euler deconvolution techniques, which are principally used to map structures guiding mineralization in the study area. Furthermore, analyses of the ASTER dataset using true and false color composites and combinations of band ratios indicate the occurrence of iron oxide and clay alterations related to iron ore mineralization in the study area. The signatures related to iron ore mineralization in the aeromagnetic data and ASTER dataset are consistent with each other. The overlap of these signatures was used to produce the iron ore prospectivity map of the study area. The study showed that areas of delineated lineament coincide with areas of iron ore mineralization. In the same vein, areas of dense lineaments coincide with areas of iron ore mineralization, especially in the southern and eastern parts of the study area. Therefore, the mineralization in the study area is structurally controlled. The iron ore prospectivity map produced will serve as reference for mineral explorationists in the area to engage in targeted exploration, rather than random exploration and exploitation especially in developing countries which impacts the environment negatively. Hence, further exploration activities involving electrical resistivity and gravity surveys and geochemical studies should focus on areas where there is an evident overlap of lineament and signatures reflecting iron ore mineralization in the study area.</div></div>","PeriodicalId":100582,"journal":{"name":"Geosystems and Geoenvironment","volume":"4 2","pages":"Article 100359"},"PeriodicalIF":0.0,"publicationDate":"2025-02-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143643101","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}

{"title":"High-K, I-type Tonian post-collisional magmatism in the South Delhi Terrane, NW India: Petrogenetic and tectonic implications","authors":"Manisha,&nbsp;Parampreet Kaur,&nbsp;Naveen Chaudhri","doi":"10.1016/j.geogeo.2025.100360","DOIUrl":"10.1016/j.geogeo.2025.100360","url":null,"abstract":"<div><div>The limited whole-rock geochemical data of the granitoids exposed in the southern domain of the South Delhi Terrane, Aravalli orogen, northwestern India characterised these rocks as subduction-related continental arc I-type granites. The new comprehensive mineralogical and geochemical data of these Tonian (975–965 Ma) granitoids, particularly those exposed around the Bekariya region, reveal that they are not continental arc I-type granites. These granitoids are rather high-K, I-type, weakly peraluminous to metaluminous, magnesian to ferroan, calc-alkalic to calcic and emplaced in a post-collisional extension regime. They comprise predominantly high-temperature (764–845°C) granitoids, along with a subordinate volume of low-temperature (669–776°C) granitoids. The nearly flat to variably inclined [(Gd/Yb)_N = 1.0–4.8)] and depleted [(Gd/Yb)_N = 2.8–3.0)] HREE patterns of the granitoids with notable negative (Eu/Eu* = 0.21–0.71) and insignificant (Eu/Eu* = 0.83–0.85) Eu anomalies, respectively and variable Sr/Y ratios (0.6–93.9), imply variation in the depth of their magma generation. Taken together, these data suggest that the high-temperature I-type Bekariya granitoids most likely originated from dehydration partial melting of metabasaltic-metandesitic crust that required a significant influx of heat in a post-collisional or post-orogenic setting. In contrast, the minor low-temperature I-type granitoids probably resulted from partial melting of a similar source by the infiltration of a water-rich fluid phase in a subduction-related setting. Furthermore, the study signifies that I-type granitoids are more voluminous than A-type granitoids in the South Delhi Terrane and were emplaced coevally in a post-collisional extension regime during the Tonian period.</div></div>","PeriodicalId":100582,"journal":{"name":"Geosystems and Geoenvironment","volume":"4 2","pages":"Article 100360"},"PeriodicalIF":0.0,"publicationDate":"2025-02-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143479179","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}

{"title":"Innovative airborne geophysical strategies to assist the exploration of critical metal systems","authors":"Karl Kwan ,&nbsp;Stephen Reford","doi":"10.1016/j.geogeo.2024.100344","DOIUrl":"10.1016/j.geogeo.2024.100344","url":null,"abstract":"<div><div>Critical metals are essential in sustaining the high technology and the green energy transition of modern societies. The future discovery of new critical metal deposits will likely be made at increasing depths and under thick cover sequences. The key roles of the four airborne geophysical exploration methods, gravity, magnetometry, electromagnetism and gamma-ray spectrometry, are reviewed in this article. The measured data from airborne magnetic, gravity and electromagnetic surveys can be inverted to reveal the distribution of underlying mineral prospects in terms of magnetic susceptibility, density and electrical resistivity/conductivity beneath the surface.</div><div>The interpretation of geophysical data is important in relating geophysical responses to the lithology and geophysical anomalies to potential exploration targets that are concealed under cover. Gamma-ray spectrometry can identify near-surface hydrothermal alteration zones and uranium systems. Structural complexity maps can provide additional key parameters for the exploration targeting of structurally controlled critical metal systems. We briefly discuss the application of airborne geophysical methods to efficiently guide the exploration of concealed critical metal deposits. A robust understanding of the geological setting of the respective mineral prospect is the most relevant factor in choosing the most efficient geophysical exploration strategy. Geophysical tools will likely play an increasingly important role in guiding the future discovery of concealed critical mineral systems.</div></div>","PeriodicalId":100582,"journal":{"name":"Geosystems and Geoenvironment","volume":"4 1","pages":"Article 100344"},"PeriodicalIF":0.0,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143131372","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}

{"title":"Critical metals exploration and energy transition – A perspective","authors":"Allan Trench,&nbsp;John Sykes","doi":"10.1016/j.geogeo.2025.100353","DOIUrl":"10.1016/j.geogeo.2025.100353","url":null,"abstract":"<div><div>The critical metals theme is well established, with long-run demand-side growth driven by cleaner energy and new technology applications. Delivering the energy transition comes with a parallel requirement to discover and then develop new sources of critical metals supply. Constraints on new supply start with the exploration process, where land access, and satisfying administrative, legislative and stakeholder requirements have become more challenging, uncertain, slower, and costly in recent years. The consequences of higher exploration access costs, and extended timelines, favour major mining companies over junior explorers, where the majors have sustainable cash flows. Greater uncertainties in land access globally favours established mining jurisdictions with a track record of resolving competing land use issues, over and above more frontier jurisdictions that lack both a track record and streamlined processes to facilitate multiple new resource developments.</div><div>Technical constraints to discover and develop adequate new sources of supply also vary between critical metals. Whilst accurate forecasts of the timing of new supply is difficult, including the identification of discovery and development constraints, and the relative resource depletion between markets, paradoxically, it is the newer, niche, critical metals markets that may prove less difficult to expand supply versus the larger critical metals markets. The reasons are twofold: Firstly, that absolute tonnage requirements for new critical metals supply are lower in the emerging markets (e.g., lithium, vanadium, niobium) than for larger markets (e.g., copper). As such, fewer new discoveries and mine developments are required to fulfill anticipated market growth requirements in the smaller critical metals markets. Secondly, that the exploration search-space within established mining jurisdictions for the emerging critical metals markets is immature, allowing for new Tier-1 discoveries to emerge early. In contrast, within the major critical metals markets such as copper, the exploration search-space in established mining jurisdictions is mature, resulting in lower exploration efficiency and fewer, deeper, new Tier-1 discoveries. The consequence is that discovery-led bottlenecks to future metals supply for the energy transition may be fewer in the niche critical metals markets than for mainstream metals markets, that also have new energy applications vital to the clean energy transition.</div><div>Given that the mining history and production of many critical metals is recent, the recycling of critical metals does not present a solution to satisfying new demand: exploration and discovery are pivotal. By discovering the critical metals for low-carbon and “renewable” energy technologies, mineral exploration has a key role to play in facilitating the green energy transition.</div></div>","PeriodicalId":100582,"journal":{"name":"Geosystems and Geoenvironment","volume":"4 1","pages":"Article 100353"},"PeriodicalIF":0.0,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143511056","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}

{"title":"Litho-tectonostratigraphy of the Dhanjori Basin, India: A fold-thrust sequence and its tectonic relation with the Singhbhum Shear Zone","authors":"Saptarshi Mallick ,&nbsp;Arup Ratan Manna ,&nbsp;Arun Kumar Kujur ,&nbsp;J.P. Mohakul","doi":"10.1016/j.geogeo.2025.100351","DOIUrl":"10.1016/j.geogeo.2025.100351","url":null,"abstract":"<div><div>Based on direct field evidence, litho-tectonostratigraphy of the Neoarchaean-Palaeoproterozoic Dhanjori Basin, situated at the northeastern fringe of the Singhbhum Craton (SC), is being appraised for the first time. Entire sequence of the Dhanjori Basin is presently interpreted as a single-stack of volcano-sedimentary assemblage of terrestrial clastic metasedimentary rocks of conglomerate-quartzite-phyllite in the lower part followed by meta-volcanic-volcaniclastic sequence. Singhbhum Shear Zone (SSZ) marks the eastern boundary of the Dhanjori Basin with Singhbhum Group representing North Singhbhum Mobile Belt (NSMB). In the western and southern margin, the Dhanjori sequence exhibits angular unconformity with the Palaeoarchean Iron Ore Group (IOG) represented by the Badampahar-Gorumahisani Belt and nonconformity with the Singhbhum Granite Complex and Mayurbhanj Granite-Gabbro which also indicates its post Iron Ore Orogenic development along SC margin. The rocks of the Dhanjori Basin and NSMB have undergone the same progressive deformational event of the North Singhbhum Orogeny but the Dhanjori Basin escaped the initial phase of it. SSZ, developed during later phase of this progressive deformational event, affected both of these packages. Prior to this, the Dhanjori Basin was undeformed. Four splays of SSZ transects the Dhanjori Basin longitudinally. These splays are characterized by development of two sets of mylonitic fabrics with moderate to low east-northeasterly dip and downdip mineral stretching lineation. They have resulted in thrust related repetition of the Dhanjori sequence within interior part of the basin. The third set of planes having same trend as mylonitic fabric but dipping steeply in opposite direction, is present in the form of spaced cleavage, kinks and fractures. These planes are formed out of stress release after the episodes of shearing-mylonitisation-thrusting. Older quartzites are thrusted over younger metavolcanics in all along the eastern margin and central part. Isolated overthrusted units of NSMB also overlie the Dhanjori package as thrust klippe. Mafic-Ultramafic rocks with plutonic fabric, present in the southeastern and northern part of Dhanjori Basin, exhibits intrusive relation with the Dhanjori package.</div></div>","PeriodicalId":100582,"journal":{"name":"Geosystems and Geoenvironment","volume":"4 1","pages":"Article 100351"},"PeriodicalIF":0.0,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143131357","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}