Geological Journal最新文献

{"title":"Discovery and Significance of the Neoproterozoic Gabbro Intrusion in the Bayan Obo Group Along the Northern Margin of the North China Craton","authors":"Hao Hu,&nbsp;Yuan Li,&nbsp;Zhiguang Zhou,&nbsp;Guosheng Wang,&nbsp;Shen Gao,&nbsp;Jianfeng Chen,&nbsp;Chenfei Feng","doi":"10.1002/gj.5132","DOIUrl":"https://doi.org/10.1002/gj.5132","url":null,"abstract":"<div>\u0000 \u0000 <p>The tectonic position of the North China Craton within the Rodinia supercontinent remain unclear due to the scarcity of early Neoproterozoic magmatic rocks in the region, resulting in limited paleomagnetic data. In this study, we report the discovery of a Neoproterozoic metamorphic gabbro intrusion within the Bayan Obo Group, located in the northwestern Bayan Obo rift zone at the northern margin of the North China Craton. This finding offers crucial geological insights into addressing this key scientific question. We utilised petrography, whole-rock geochemistry, zircon U–Pb geochronology, and Sr-Nd isotopic analysis to investigate the genesis and source of the gabbroic rock and its tectonic setting. The metamorphosed gabbro has a zircon ²⁰⁶Pb/²³⁸U weighted mean age of 925.9 ± 7.2 Ma, with low SiO₂ (46.46%–48.28%), high Na₂O (2.95%–3.56%), and low K₂O (0.761%–1.41%), and has the signature of sub-alkaline tholeiitic basalt. It is enriched in large-ion lithophile elements (Rb, Ba, Th, U, K, Pb) and depleted in high-field-strength elements (Nb, Ta). The rock is also enriched in light rare earth elements, shows a negative Eu anomaly, and has a positive <i>ε</i>Nd(<i>t</i>) value (+0.1 ~ +0.8). The metamorphosed gabbro shares geochemical characteristics and Nd isotopic compositions with contemporaneous mafic intrusions, including the 945–890 Ma mafic sills in southeastern North China Craton, the ~925 Ma Dashigou mafic dike swarm in central North China Craton, the ~925 Ma gabbro in Guyang, northern North China Craton, and the 827–819 Ma gabbro in Langshan, western North China Craton. This age suggests that the gabbro may represent a response to a large-scale mafic magmatic event in central-eastern North China Craton during the early Neoproterozoic, potentially linked to the initial breakup of the Rodinia supercontinent.</p>\u0000 </div>","PeriodicalId":12784,"journal":{"name":"Geological Journal","volume":"60 6","pages":"1409-1430"},"PeriodicalIF":1.4,"publicationDate":"2025-01-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144207002","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Petrogenesis and Tectonic Setting of the Xishan Pluton in Nanling Range: Lithogeochemistry, Zircon U–Pb Chronology and Hf Isotope Evidence","authors":"Jianfeng Li,&nbsp;Wei Yang,&nbsp;Jianming Fu,&nbsp;Youyue Lu,&nbsp;Shunbo Cheng,&nbsp;Zhengwei Qin","doi":"10.1002/gj.5096","DOIUrl":"https://doi.org/10.1002/gj.5096","url":null,"abstract":"<p>In this article, a systematic LA-ICP-MS zircon U–Pb geochronology study was carried out on the Xishan pluton in Nanling Range. The results show that the formation ages of granitic porphyroclastic lava, medium-fine-grained porphyritic granite, and dacite are 154.0 ± 1.2–156.1 ± 2.0, 153.2 ± 0.9–157.3 ± 3.2, and 151.2 ± 3.1 Ma, which are determined to be the early Yanshanian. Geochemical data show that the Xishan pluton was characterised by rich silicone-alkali and poor calcium–magnesium with K₂O/Na₂O ratios of 1.65–2.22, Al₂O₃ of 1.00–1.14, and FeO*/MgO ratios of 8.33–19.0 (with an average of 12.94). The rare earth content of granites ranges from 322.92 to 441.54 ppm, which is significantly higher than the world average. The rare earth element distribution curve is right-leaning light rare earth enrichment type, with obvious negative europium anomaly, and the δEu values range from 0.06 to 0.24; These rocks are enriched in high-field-strength elements (HFSEs, e.g., Ga, Y, Nb, Zr, and Hf) and depleted elements such as Ba, Nd, Sr, P, Ti, etc, with Ga/Al ratios of 2.95 × 10⁻⁴ to 4.59 × 10⁻⁴ (with an average of 3.50 × 10⁻⁴); Zr + Nb + Ce + Y of 367.1–652.5 ppm (with an average of 441.95 ppm) and zircon saturation temperatures Tzr is 755.04°C–892.50°C (with an average of 810.04°C), similar to geochemical features of A-type granites. The Hf isotope study shows that the <i>ε</i>\u0000 _Hf(<i>t</i>) of the Xishan pluton ranges from 2.11 to −8.77, and the petrographic, geochemical and available data confirm that it originates from the mixing of crustal and mantle-derived magma, and the contribution of the latter is &lt; 10%. The hafnium II model age of the Xishan pluton is 1251–1766 Ma, which confirms that its source rocks were detached from the mantle reservoir at the time of the Middle Proterozoic. Combined with the evolutionary history of the Nanling Range area, it is assumed that the Jiangnan Orogenic Zone was partially reactivated by the continuous lateral subduction of the ancient Pacific Plate in the Late Mesozoic, which triggered partial melting of the crust to form the A₂-type granite type, which is the origin of the Xishan pluton.</p>","PeriodicalId":12784,"journal":{"name":"Geological Journal","volume":"60 3","pages":"674-699"},"PeriodicalIF":1.4,"publicationDate":"2025-01-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143530787","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Geochemistry and Source Characteristics of Dykes Straddling the Panvel Flexure, India and Their Relationship to the Deccan-Aged Seychelles Intrusives","authors":"Raghuram,&nbsp;Raymond A. Duraiswami,&nbsp;S. V. Chinchu,&nbsp;Chandan Saha","doi":"10.1002/gj.5123","DOIUrl":"https://doi.org/10.1002/gj.5123","url":null,"abstract":"<div>\u0000 \u0000 <p>Several dykes straddle the Panvel flexure (PF) and intrude the compound pāhoehoe flows in the West Coast of India. Three geochemically distinct groups of dykes, that is, olivine normative tholeiites, quartz normative tholeiites with geochemical affinity to the Bushe, Poladpur and Ambenali formations and a nepheline normative alkali basalt are emplaced straddling the PF, striking parallel to the West Coast Fault (WCF) and the PF (NNW–SSE). The quartz normative tholeiites from the present study are restricted to the east of the PF axis and olivine normative tholeiites dominate west of the PF axis. The presence of olivine-bearing dykes west of the PF axis may represent the upper parts of a plumbing system that has tapped either a large basic magma chamber variably, that accumulated fairly large quantities of primary magma at the crust–mantle boundary or a distinct but linked magma reservoir that underwent different AFC processes to produce the olivine tholeiites straddling the flexure. Quartz tholeiite east of the PF axis represents differentiated products of these reservoirs. WCF and PF are imprints of the separation of Seychelles from India associated with the rifting subsidence of the crust and upliftment of the Western Ghats. Deccan age (69.1–73.5 Ma) dykes occurring in Praslin, Félicité and Mahé islands of Seychelles are quartz normative, olivine normative and nepheline normative, respectively, forming three distinct geochemical groups and are chemically akin to the Bushe and Khandala formations when plotted in bivariate ratio plots. Trace and REE-based models of intrusions straddling the PF and their counterparts in the Seychelles; indicate partial melting of dominantly garnet lherzolite source. Partial melting curves show olivine normative and quartz normative tholeiite dykes from Seychelles to dominantly have spinel lherzolite source with different degrees of partial melting. In contrast, the nepheline normative dyke has a spinel + garnet lherzolite source.</p>\u0000 </div>","PeriodicalId":12784,"journal":{"name":"Geological Journal","volume":"60 6","pages":"1271-1303"},"PeriodicalIF":1.4,"publicationDate":"2025-01-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144206799","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Deformation Mechanism of Large-Scale Ancient Reservoir Landslides Driven by the Monitoring Data and Numerical Simulation","authors":"Huiwen Deng,&nbsp;Wengang Zhang,&nbsp;Luqi Wang,&nbsp;Yanfei Kang,&nbsp;Yucheng Wang,&nbsp;Lin Wang,&nbsp;Yulin Zou","doi":"10.1002/gj.5130","DOIUrl":"https://doi.org/10.1002/gj.5130","url":null,"abstract":"<div>\u0000 \u0000 <p>Globally, the reactivation of ancient landslides in reservoir areas poses severe threats to the safety of human society and the natural environment, attracting widespread attention in the fields of science and engineering. The periodic reservoir water level fluctuations and precipitation are the main reasons for the reactivation of ancient landslides, and the complexity of landslide disaster prevention and control is expected to increase due to the combined effects of both factors. In this study, a comprehensive method of on-site investigation, displacement monitoring, and numerical simulation has been proposed to analyse the seepage field, stability, and deformation field of the landslide by considering the ancient Qingshi landslide in the Three Gorges Reservoir Area (TGRA) as an example. The numerical simulation method is used to simulate the dynamic evolution process of the Qingshi landslide, and the measured data validates the accuracy of the method. The results indicate that the fluctuations in the reservoir water level and rainfall significantly affect the stability of the Qingshi landslide. The increase in landslide activity is dominated by reservoir water level fluctuations, rather than rainfall. In addition, this study also identifies the potential sliding surface of the landslide and predicts the possible mode of instability. This research can provide technical support and decision-making reference for the early warning and control of landslide disasters in reservoir areas.</p>\u0000 </div>","PeriodicalId":12784,"journal":{"name":"Geological Journal","volume":"60 5","pages":"1170-1183"},"PeriodicalIF":1.4,"publicationDate":"2025-01-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143914280","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Sedimentology of Lower Triassic (Induan Stage) Mixed Carbonate-Siliciclastic Succession of an Epeiric Carbonate Ramp at the Northeastern Passive Margin of the Arabian Plate, Northern Iraq-Kurdistan Region","authors":"Sardar M. Balaky,&nbsp;Irfan Sh. Asaad,&nbsp;Mazin Y. Tamar-Agha,&nbsp;Ahmed E. Radwan","doi":"10.1002/gj.5124","DOIUrl":"https://doi.org/10.1002/gj.5124","url":null,"abstract":"<div>\u0000 \u0000 <p>The Mirga Mir Formation (Lower Triassic) was studied for its sedimentology and lithostratigraphy from two outcrops (Nazdur and Beduhe areas) c. 20 km apart, in the Northern Iraq-Kurdistan Region. The collected samples were investigated by standard polarised microscope, X-ray diffraction and scanning electron microscopy to infer their mineralogical characteristics, provenance and paleodepositional environments. The Mirga Mir Formation is a mixed carbonate-siliciclastic succession consisting of thin-, medium-, occasionally thick-bedded, and yellowish-grey limestones, sandy dolomitic and argillaceous limestones, alternating with thin- to thick-bedded grey shale/marl. Thin-laminated siltstones and fine- to coarse-grained sandstones are seen in the lower and middle parts of the formation. The petrographic study of carbonates and clastics (sandstones) showed that most limestones are carbonate mud (micrite). The skeletal grains consist principally of thin-shelled pelagic bivalves (<i>Posidonia</i>), serpulid worm tubes (<i>Spirorbis</i>), microgastropods, ammonoids, calcispheres, brachiopods, dasyclad green algae, miliolid foraminifers and ostracods. Non-skeletal grains include ooids, peloids, intraclasts and extraclasts. Depending on field observations, five different lithologic units were recognised. These are in ascending order: oolitic limestone unit, sandy limestone-shale unit, shale-limestone unit, argillaceous limestone-shale unit and brecciated-slumped limestone unit. Sandstones occur as thin beds within the lower and middle parts of the studied formation. In addition, thick coarse-grained sandstone beds occur in the middle part of the Nazdur section only. Petrographically, thin sandstone beds consist of fine-grained quartz. The thick sandstone bed is an immature, litharenite and consists of rock fragments (mostly sedimentary), quartz and feldspars. The X-ray diffraction analysis and scanning electron microscope micrographs of shales revealed that the abundant clay minerals in the Mirga Mir Formation are illite, followed by kaolinite and chlorite. In addition to illite-chlorite mixed layers, non-clay minerals include calcite and quartz, with low feldspars. Based on detailed microfacies analysis of the limestones, 12 microfacies types from the carbonates and mixed detrital carbonates are distinguished. These facies were subdivided, according to their environmental interpretation, into five facies associations: Offshoal/basinal, Foreshoal/slope, Shoal, Back Shoal/Lagoon. The study introduces a good example of a gently sloping epeiric carbonate ramp that shows a gradual shallowing of the basin from the offshoal/basinal sediments to the foreshoal/slope and backshoal/lagoonal environments.</p>\u0000 </div>","PeriodicalId":12784,"journal":{"name":"Geological Journal","volume":"60 6","pages":"1304-1328"},"PeriodicalIF":1.4,"publicationDate":"2025-01-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144206950","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Green Improvisation and Knowledge Absorption: Catalysts for Geo-Sustainable Environmental Management Initiatives","authors":"Shao Jianbing,&nbsp;Hassan Ahmad,&nbsp;Asad Hassan Butt,&nbsp;Jihen Bousrih","doi":"10.1002/gj.5114","DOIUrl":"https://doi.org/10.1002/gj.5114","url":null,"abstract":"<div>\u0000 \u0000 <p>This research examines the dynamic relationships between green improvisation, green absorptive capacity, environmental management initiatives (EMIs), corporate social responsibility (CSR) authenticity, and their combined impact on firms' green competitive advantage and environmental performance. The study empirically tested seven hypotheses, utilising structural equation modelling (SEM) via SmartPLS. Data was collected from the employees of firms situated in Pakistan through a survey in a time span of 6 months. Results indicate that green improvisation significantly enhances EMIs, highlighting the importance of innovative and adaptive approaches in environmental stewardship. Green absorptive capacity was found to effectively acquire and assimilate environmental knowledge, positively influencing EMIs. Additionally, EMIs were shown to strengthen CSR authenticity, thereby improving firms' green competitive advantage and environmental performance. The mediating role of CSR authenticity was confirmed, revealing its significance in translating effective environmental management into tangible outcomes. Moreover, green creativity was found to moderate the relationship between EMIs and CSR authenticity, with novel environmental solutions enhancing the effectiveness of CSR activities. These findings contribute to the literature on environmental management by elucidating the mechanisms through which environmental initiatives lead to competitive and ecological benefits. The study provides actionable insights for firms aiming to integrate environmental strategies into their core business practices, achieving a sustainable competitive edge in today's green economy.</p>\u0000 </div>","PeriodicalId":12784,"journal":{"name":"Geological Journal","volume":"60 4","pages":"958-976"},"PeriodicalIF":1.4,"publicationDate":"2025-01-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143749576","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Astronomical Forcing of Paleolake-Level Fluctuations in the Eastern Ordos Basin Between the Late Carboniferous and Early Permian","authors":"Yuge Cao,&nbsp;Jianqiang Wang,&nbsp;Wenjing Yang,&nbsp;Shuhang Yu","doi":"10.1002/gj.5128","DOIUrl":"https://doi.org/10.1002/gj.5128","url":null,"abstract":"<div>\u0000 \u0000 <p>A precisely constrained and high-resolution geochronology will enhance our understanding of sedimentary evolution, tectonic influences and climatic variations, all of which contribute to hydrocarbon exploration. According to sedimentary analysis, the North China Craton is believed to have undergone a transition in its sedimentary environment from a marine to a terrestrial lacustrine–fluvial system during the Late Palaeozoic. However, the geochronology and driving forces associated with transgression and regression remain understudied. In this study, we employed a cyclostratigraphic method to analyse the gamma-ray logging data from a Late Palaeozoic sequence in the Y69 well in the eastern Ordos Basin. We established an astronomical time-scale for this sequence, spanning approximately 10.83 million years, from ~299.94 ± 0.32 Ma to ~289.11 ± 0.32 Ma, in order to provide a geochronological framework for the evolution of the Ordos Basin. Subsequently, we reconstructed paleolake-level variations by applying sedimentary noise modelling to the tuned gamma-ray series and conducted periodicity analysis to identify astronomical signals. Our results indicate that water-level fluctuations in the eastern Ordos Basin were modulated by ~1.2-Myr obliquity and ~ 2.4-Myr eccentricity cycles, suggesting long-term astronomical forcing on hydrological circulation. The in-phase correlation between the reconstructed water level and global sea level at ~1.2-Myr intervals suggests that sedimentation was controlled by oceanic systems through transgression/regression events before ~294 Ma. Conversely, the anti-phase correlation between the reconstructed water level and global sea level at the same interval indicates that sedimentation was influenced by terrestrial systems through aquifer depletion and recharge after ~294 Ma. This shift in the correlation between water levels and global sea levels reflects the transition from an oceanic to a terrestrial sedimentary environment. These findings provide a high-resolution geochronological framework for further investigations and offer new insights into hydrological circulation, improving our understanding of the driving mechanisms behind sedimentary evolution in the North China Craton during the Late Palaeozoic Ice Age.</p>\u0000 </div>","PeriodicalId":12784,"journal":{"name":"Geological Journal","volume":"60 6","pages":"1370-1393"},"PeriodicalIF":1.4,"publicationDate":"2025-01-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144206615","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Paleoenvironment, Provenance and Chert Origin of the Lower Cretaceous Xiguayuan Formation (Luanping Basin, North China): Evidence From the Geochemistry of Lacustrine Sediments","authors":"Chao Han,&nbsp;Lu Liu,&nbsp;Pengfei Xiang,&nbsp;Haibo Jia,&nbsp;Xiao Gao,&nbsp;Qiang Li","doi":"10.1002/gj.5111","DOIUrl":"https://doi.org/10.1002/gj.5111","url":null,"abstract":"<div>\u0000 \u0000 <p>Industrial shale oil/gas flow have been discovered in the Luanping Basin, and the hydrocarbon potential of the Lower Cretaceous Xiguayuan Formation (Luanping Basin, North China) has attracted the attention of geologists in recent years. The paleoenvironmental conditions, provenance and chert origin of the Xiguayuan Formation were studied using the geochemistry of lacustrine sediments in the Caoying section. A pronounced positive correlation between the oxygen and carbon isotopes of autogenous carbonates indicates the Early Cretaceous Luanping paleolake was an alternating depositional environment of open and closed, with obvious evaporation. The V/(V + Ni) ratios, negative Ce and Eu anomalies suggest that the Xiguayuan Formation was deposited in anoxic conditions with fewer instances of euxinic conditions. Sr/Ba, <i>Z</i> and <i>S</i> values together demonstrate a brackish to saline waterbody under semi-arid and fluctuating semi-humid paleoclimatic conditions. Various indicators show that they are predominantly derived from felsic igneous rocks and minor probable basic source supply with minor sedimentary recycling. The cherts are developed in Unit 1 and Unit 2, compared with Unit 3, Unit 1 and Unit 2 show relatively open, less reductive, high salinity. A theoretical formation model of alternating rise and drop in lake levels in the basin was established to show syndepositional bedded chert-bearing sedimentary succession. The acid river dominate water and the evaporation in front fan delta environment maybe the main factor that lead silica precipitation.</p>\u0000 </div>","PeriodicalId":12784,"journal":{"name":"Geological Journal","volume":"60 4","pages":"904-922"},"PeriodicalIF":1.4,"publicationDate":"2025-01-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143749575","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Suitability Evaluation of CO2 Geological Storage in Deep Coal Seam: A Case Study in the Eastern Margin of Ordos Basin, China","authors":"Haojie Ma,&nbsp;Yanjun Meng,&nbsp;Xinyu Zhang,&nbsp;Xiaosong Cui,&nbsp;Jiaoxia Wang","doi":"10.1002/gj.5127","DOIUrl":"https://doi.org/10.1002/gj.5127","url":null,"abstract":"<div>\u0000 \u0000 <p>CO₂ coal seam storage is a significant component of carbon capture and storage technology, which serves as a pivotal technical instrument for the reduction of greenhouse gas emissions. The Ordos Basin develops a considerable number of unminable coal seams, which present an optimal place for CO₂ coal seam storage. This paper presents an investigation into the geological characteristics of the No.4 coal seam reservoir in the Shanxi Formation of Permian age and the No.8 coal seam reservoir in the Benxi Formation of Carboniferous age. To explore the adsorption capacity of coal rock and the sealing performance of caprock, relevant experiments were conducted. The results of the experiments demonstrate that the adsorption capacity of CO₂ on the coal samples is 1.11–3.73 times that of CH₄. The results of the breakthrough pressure test demonstrate that the mudstone sealing performance is the most effective, followed by dense limestone and sandy mudstone. Combined with the geological data of the study area, the analytic hierarchy process method was used to evaluate the CO₂ storage potential of coal seams. The areas suitable for geological storage of CO₂ in the study area are located in the central part and the south-central part.</p>\u0000 </div>","PeriodicalId":12784,"journal":{"name":"Geological Journal","volume":"60 6","pages":"1346-1369"},"PeriodicalIF":1.4,"publicationDate":"2025-01-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144206617","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Geochemistry of Core Sediments From the Southeast Coast of Bangladesh: Constraints on Chemical Weathering, Paleoenvironmental Conditions, Provenance, and Tectonic Setting","authors":"H. M. Zakir Hossain,&nbsp;Anas Al Hossain,&nbsp;Md. Aminul Islam,&nbsp;Zhifei Liu,&nbsp;Mingyang Yu","doi":"10.1002/gj.5122","DOIUrl":"https://doi.org/10.1002/gj.5122","url":null,"abstract":"<div>\u0000 \u0000 <p>Major, trace, and rare-earth elements (REEs) were examined on modern sediments of a 70-m long core collected from the southeast coast of Bangladesh to understand chemical weathering, paleo-redox sensitivity, sediment maturity, source rock composition, and tectonic setting during the deposition of sediments. The core samples contained high SiO₂ (62–91 wt.%) and low Al₂O₃ (~5–17 wt.%) that showed a marked negative correlation (<i>r</i> = −0.98) with linear trends, indicating that the quartz rather than aluminosilicates mainly controlled SiO₂. Substantial depletion of major labile elements (e.g., Na₂O, CaO*, K₂O, Ba, and Sr) compared with the upper continental crust (UCC) indicates the destruction of feldspar during chemical weathering in the source area. The index of compositional variability (ICV) and the SiO₂/Al₂O₃ ratio of the sediments varied from 0.79 to 1.83 and 3.47–22.69, respectively, indicating immature to moderate compositional and mineralogical maturity. The chemical index of alteration (CIA, ~67–81), chemical index of weathering (CIW, ~69–91), and plagioclase index of alteration (PIA, ~71–92) parameters suggest moderate to high chemical weathering intensity in the source area, which was favoured and accelerated by the warm and humid conditions. The elemental ratios of V/Cr, Ni/V, Ni/Co, U/Th, Cu/Zn, and V/V + Ni suggested oxic to sub-oxic paleoenvironmental conditions that prevailed during sediment deposition. Provenance discrimination diagrams and elemental ratios (e.g., Th/Sc, Zr/Sc, La/Sc, Cr/V, and Co/Th) suggest their derivation from felsic source rocks (e.g., granodiorite, rhyolite, and granite). The chondrite-normalised (REEs) distributions show light REE enrichment (La_N/Yb_N, 7.61–14.35), nearly flat heavy REE (Gd_N/Yb_N, 1.33–2.25), and marked Eu anomalies (Eu/Eu*, ~0.58–1.40), suggesting an influx of sediments from felsic provenance. The REE patterns and parameters are similar throughout the sequence, confirming that the overall source composition remained unchanged. The tectonic setting discrimination diagrams show that the core sediments were mainly derived from active and passive margin environments.</p>\u0000 </div>","PeriodicalId":12784,"journal":{"name":"Geological Journal","volume":"60 5","pages":"1252-1269"},"PeriodicalIF":1.4,"publicationDate":"2025-01-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143914477","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}