Geological Journal最新文献

{"title":"Geochronological and Geochemical Constraints on the Granitic Gneisses of South China Affinity Within the Sulu Ultrahigh-Pressure Belt, Eastern China: Early Response to the Breakup of Rodinia Supercontinent","authors":"Lixiang Zhao,&nbsp;Zhengjiang Ding,&nbsp;Junyang Lv,&nbsp;Bin Wang,&nbsp;Qibin Zhang,&nbsp;Jiawen Teng,&nbsp;Caijie Liu,&nbsp;Ye Qian","doi":"10.1002/gj.70090","DOIUrl":"https://doi.org/10.1002/gj.70090","url":null,"abstract":"<div>\u0000 \u0000 <p>The Rongcheng area is situated along the northeastern tectonic margin of the Sulu orogenic belt, where extensive exposures of Neoproterozoic granitic gneisses are present. These rocks are intimately associated with the breakup of the Rodinia supercontinent and serve as an optimal geological archive for investigating the mechanisms underlying the assembly of the Rodinia supercontinent. However, considerable controversy persists in research on rock genesis and tectonic setting. This study systematically investigates the petrography, whole-rock geochemistry, zircon U–Pb geochronology and Lu-Hf isotopic compositions of Neoproterozoic granitic gneisses from the Rongcheng area to constrain their diagenetic age, petrogenesis, tectonic setting and geological implications. The obtained ²⁰⁶Pb/²³⁸U weighted mean ages ranging from 750 to 798 Ma demonstrate that the protoliths of these granitic gneisses were emplaced during the Neoproterozoic period. Geochemically, the granitic gneisses constitute an I-A type peraluminous granite-granodiorite suite within the high-K calc-alkaline series, characterised by high SiO₂ contents (66.09–76.91 wt%), alkali enrichment (Na₂O + K₂O = 6.56–9.15 wt%) and CaO depletion (0.35–3.60 wt%). These rocks exhibit significant enrichment in light rare earth elements (LREEs) and large-ion lithophile elements (LILEs; e.g., Ba, K and U), accompanied by marked depletion in heavy rare earth elements (HREEs) and high-field-strength elements (HFSEs; e.g., Nb, Ta, Y and Ti). Lu-Hf isotopic analyses reveal ε_Hf (t) values ranging from −21.0 to −1.37 and two-stage Hf model ages (T_DM2Hf) spanning 1.77 to 2.88 Ga, indicative of Paleoproterozoic to Archean crustal residence. Petrogenetic constraints indicate the Rongcheng granitic gneisses primarily originated from the partial melting of crustal materials with minor contributions from mantle sources, as evidenced by their negative εHf(t) values (−21.0 to −1.37). These rocks formed within a Neoproterozoic post-collisional extensional environment, representing the initial response to the breakup of the Rodinia supercontinent in the northeastern Sulu orogenic belt.</p>\u0000 </div>","PeriodicalId":12784,"journal":{"name":"Geological Journal","volume":"61 8","pages":"2293-2309"},"PeriodicalIF":2.6,"publicationDate":"2026-08-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148696464","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":"Hydrocarbon Generation Potential and Hydrocarbon Expulsion Process of Shahezi Formation Mudstone in Xujiaweizi Fault Depression in Songliao Basin","authors":"Jianchen Wu,&nbsp;Zhenxue Jiang,&nbsp;Zhongyan Jiang,&nbsp;Weihao Sun,&nbsp;Jiamin Lu,&nbsp;Lidong Sun","doi":"10.1002/gj.70089","DOIUrl":"https://doi.org/10.1002/gj.70089","url":null,"abstract":"<div>\u0000 \u0000 <p>The Shahezi Formation is another major set of source rocks in the Songliao Basin following the Qingshankou Formation. However, due to its deeper burial, its hydrocarbon generation and expulsion potential, as well as the processes involved, remain unclear. This study focuses on the Shahezi Formation source rocks in the Songliao Basin. Using the hydrocarbon generation potential method, and based on Rock-Eval pyrolysis, TOC testing, <i>R</i>\u0000 _o testing, and basin modelling, it systematically evaluates the hydrocarbon generation and expulsion processes and potential of the Shahezi Formation source rocks in the Xujiaweizi fault depression. The results indicate that the hydrocarbon expulsion threshold of the Shahezi Formation source rocks is <i>R</i>\u0000 _o = 0.807%, with a maximum hydrocarbon generation potential of 498.71 mgHC/gTOC and a peak expulsion efficiency of 64.4%. The hydrocarbon generation centre is located in the central depression of the Xujiaweizi Fault Depression. The maximum hydrocarbon generation intensity and expulsion intensity reach 1000 × 10⁴ and 500 × 10⁴ t/km², respectively. Based on these parameters, the total hydrocarbon generation and expulsion volumes of the Shahezi Formation source rocks are calculated to be 81.54 × 10⁸ and 46.72 × 10⁸ t. These findings suggest that the deep formations of the Xujiaweizi Fault Depression hold significant exploration potential for natural gas resources. The geological resource volume of petroleum in the Shahezi Formation is estimated at 0.13 × 10¹² m³, with the total volume of hydrocarbons retained within the source rocks estimated at 0.484 × 10¹² m³. The western Xujiaweizi and Anda–Songzhan areas exhibit considerable exploration potential.</p>\u0000 </div>","PeriodicalId":12784,"journal":{"name":"Geological Journal","volume":"61 8","pages":"2279-2292"},"PeriodicalIF":2.6,"publicationDate":"2026-08-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148696611","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":"Experimental Study on Permeability Behavior of Helium Within Its Source Rocks in the Sichuan Basin, Southwest China","authors":"Jianglin He,&nbsp;Shuangjian Li,&nbsp;Ankun Zhao,&nbsp;Xiaolin Zhou,&nbsp;Zhenghe Wang,&nbsp;Jian Gao,&nbsp;Ping Yang,&nbsp;Dong Wang","doi":"10.1002/gj.70091","DOIUrl":"https://doi.org/10.1002/gj.70091","url":null,"abstract":"<div>\u0000 \u0000 <p>Understanding helium migration in source rocks is critical to resolving constraints imposed by helium's weak sourcing on modern enrichment models. This work investigates the permeability behaviour of helium in granite and shale across the Sichuan Basin to elucidate their contrasting controls on helium accumulation. Basing on the permeability behaviour of helium and nitrogen in shale and granite in the southwest of Sichuan Basin, it is found: (1) Helium permeability decreases by 81.06%–98.03% under confining pressure escalation (2–60 MPa), exhibiting negative correlations with rock strength/water saturation and a positive correlation with porosity. (2) Single-phase helium systems maintain higher permeability than two-phase gas-water pore systems, where dissolution/exsolution cycling governs flow. At &gt; 60% water saturation, gas properties no longer exert a dominant control over the sample's permeability. When water saturation &gt; 60%, gas-phase dominance ceases—granites show solubility-driven permeability evolution, while shales remain compaction-controlled. (3) Granite permeability plunges about 95.7% when heated from 25°C to 85°C, attributed to thermal grain expansion reducing pore-throat volumes. (4) Subsurface helium transport progresses through three stages. In shallow burial stages, it is dominated by groundwater-driven dissolved helium migration. In the middle/deep burial stages, flow decelerates due to the Jamin effect and aqueous phase trapping, with permeability increasingly controlled by dissolution/exsolution cycling in both lithologies. (5) In the Weiyuan gas field, helium accumulation derives from water-dissolved migration during granite burial. Shales indirectly control enrichment through (i) post-maturation migration retardation via the Jamin effect/aqueous phase trapping and (ii) compartmentalisation of underlying helium-saturated aquifers. Bedding orientation governs shale permeability anisotropy, contrasting with granite's isotropic pore geometry.</p>\u0000 </div>","PeriodicalId":12784,"journal":{"name":"Geological Journal","volume":"61 8","pages":"2310-2334"},"PeriodicalIF":2.6,"publicationDate":"2026-08-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148696331","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":"Soil Erosion Susceptibility in the Gopad River Basin: An Interactive Geospatial and Statistical Approach for Effective Sub-Watershed Prioritisation","authors":"Anjanay Kumar,&nbsp;Kuldeep Prakash,&nbsp;Prinsi Singh,&nbsp;Suraj Kumar,&nbsp;Sunil Kumar Patel","doi":"10.1002/gj.70101","DOIUrl":"https://doi.org/10.1002/gj.70101","url":null,"abstract":"<div>\u0000 \u0000 <p>Rivers are dynamic hydro-geomorphological systems that shape landscapes, transfer energy, and sustain ecosystems. Although the Gopad River Basin (GRB) is a significant tributary of the Son River in central India, it remains largely underexplored, even as it faces growing pressures from soil erosion, land degradation, and climate variability. Addressing this gap, the present study aims to assess and prioritise erosion-prone sub-watersheds to support sustainable watershed management. An integrated methodology combining morphometric analysis, hypsometric assessment, and principal component analysis-weighted sum approach (PCA-WSA) was employed. Essential morphometric parameters, including drainage density, form factor, bifurcation ratio, and rho coefficient have been recognised as significant indicators of erosion risk. Findings reveal that sub-watersheds 1, 4, 6, 7, 8, 9, 10, 12, 13, and 16 are critically susceptible to erosion, necessitating urgent soil and water conservation measures. Other sub-watersheds exhibit moderate to low risk, reflecting spatial heterogeneity in erosion vulnerability. The study offers a novel, data-driven, and spatially explicit framework that integrates geomorphometric parameters with statistical optimisation, moving beyond conventional single-method approaches. This contributes significantly to regional watershed planning by enabling targeted resource allocation, evidence-based prioritisation, and improved erosion mitigation strategies, while also providing a transferable framework for comparable basins.</p>\u0000 </div>","PeriodicalId":12784,"journal":{"name":"Geological Journal","volume":"61 8","pages":"2520-2537"},"PeriodicalIF":2.6,"publicationDate":"2026-08-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148696361","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 U–Pb Zircon Ages of the Bandal Granitoids Complex of the Himachal Region, Northwestern Himalaya (India): Constraints on Crustal Evolution and Columbia Supercontinent Assemblage","authors":"P. C. Sethy,&nbsp;Ajay Kumar Maurya,&nbsp;Paramjeet Singh,&nbsp;Saurabh Singhal,&nbsp;Amit Chahar,&nbsp;A. Krishnakanta Singh,&nbsp;M. R. Singh","doi":"10.1002/gj.70096","DOIUrl":"https://doi.org/10.1002/gj.70096","url":null,"abstract":"<div>\u0000 \u0000 <p>To investigate the Paleoproterozoic magmatism and tectonic setting along the northern margin of the Indian block, and their potential link with the Archean–Paleoproterozoic Aravalli-Delhi-Bundelkhand (ADB) Craton of northwestern India, we integrate field observations, whole-rock geochemical analyses, and U–Pb zircon geochronological data of the Bandal Granitoids Complex (BGC) in the Lesser Himalayan region of the Himachal Pradesh. The whole-rock geochemistry of granitic gneiss samples suggests that the peraluminous S-type granite, characterised by Nb, Sr, P, and Ti depletion, reflects subduction-related accretion along the northern margin of the Indian block. The U–Pb zircon age of the BGC granitoids ranges from ~1.92 to 1.88 Ga and ~1.86 to 1.85 Ga with a few inherited older ages of ~2.45–2.33 Ga. Based on the geochemical and U–Pb zircon age results, it is inferred that Paleoproterozoic magmatism along the north margin of the Indian block is associated with the subduction–accretion process at ~1.97–1.92 Ga, followed by slab rollback and break-off that subsequently triggered back-arc basin development at ~1.86–1.85 Ga. Moreover, comparison of available U–Pb zircon ages from the LHS zone and the ADB Craton suggests continuous subduction accretion and back-arc magmatism between ~2.10 and 1.85 Ga, associated with the assembly of the Columbia supercontinent.</p>\u0000 </div>","PeriodicalId":12784,"journal":{"name":"Geological Journal","volume":"61 8","pages":"2433-2455"},"PeriodicalIF":2.6,"publicationDate":"2026-08-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148696442","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":"Mesozoic–Cenozoic Thermochronology of the Tarim–Southern Tianshan System, NW China","authors":"Shuangfeng Zhao,&nbsp;Wen Chen,&nbsp;Jingbo Sun,&nbsp;Ze Shen,&nbsp;Jie Zhang","doi":"10.1002/gj.70088","DOIUrl":"https://doi.org/10.1002/gj.70088","url":null,"abstract":"<p>The Tarim Basin, an oil-bearing basin in northwest China, is tectonically and sedimentologically linked to the Southern Tianshan Orogenic Belt. This study investigates the coupling mechanism between the Tarim Basin and the Southern Tianshan using low-temperature thermochronology, with a focus on its influence on the basin's tectonothermal evolution and hydrocarbon processes. The thermochronological results provide several key insights: (1) The central AFT ages of the core samples range from 156.9 Ma to 46.0 Ma. Single-grain AHe ages vary between 15.66 Ma and 0.10 Ma, while single-grain ZHe ages range from 276.9 Ma to 129.6 Ma. For the surface outcrop samples, single-grain AHe ages range from 22.96 Ma to 3.10 Ma. The majority of the single-grain AHe ages show some degree of dispersion, and the ZHe ages of most samples exceed their corresponding stratigraphic ages. (2) A thermal history model for the Kuqa Depression was established based on AHe (apatite (U–Th)/He) and AFT (apatite fission track) age data from core samples. The model reveals that the AHe closure temperature is 80°C ± 5°C, while the AFT closure temperature is 140°C ± 5°C, indicating non-zero ages for the AHe and AFT systems at temperatures 5°C–30°C above the nominal closure temperatures. (3) Reverse thermal modelling indicates that the Tarim–Southern Tianshan system experienced multi-stage exhumation (or burial) during the Mesozoic–Cenozoic, influenced by distant tectonic events such as the collision of the Qiangtang and Lhasa plates with the southern margin of Eurasia. The Southern Tianshan underwent three primary exhumation stages: the Middle Triassic–Early Jurassic, Early Cretaceous, and Paleogene–present. The northern margin of the Tarim Basin experienced two major exhumation phases, during the Late Cretaceous and the late Miocene to present. Tectonic uplift in the Tarim Basin occurred much later than in the Southern Tianshan, reflecting a shift in deformation from the orogenic belt to the basin. (4) The coupling between the basin and mountain range has had a profound impact on the thermal history and petroleum system of the Tarim Basin. This coupling controls the present-day terrestrial heat flow within the basin, influencing the maturity of source rocks and the distribution of oil and gas. During the late Himalayan period, basin–mountain coupling led to the formation of numerous new faults, unconformities, and associated traps in the depression, which facilitated the generation and accumulation of large-scale hydrocarbon resources. However, this coupling also modified and disrupted some pre-existing oil reservoirs.</p>","PeriodicalId":12784,"journal":{"name":"Geological Journal","volume":"61 8","pages":"2258-2278"},"PeriodicalIF":2.6,"publicationDate":"2026-08-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/gj.70088","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148696460","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Provenance and Tectonic Setting of the Neogene Clastic Sedimentary Rocks in the Offshore Bay of Bengal, Bangladesh","authors":"M. Julleh Jalalur Rahman,&nbsp;Tanusree Datta,&nbsp;Ming Ma,&nbsp;Abu Sadat Md. Sayem,&nbsp;Songjian Ao,&nbsp;Rashed Abdullah,&nbsp;Md. Sakawat Hossain","doi":"10.1002/gj.70087","DOIUrl":"https://doi.org/10.1002/gj.70087","url":null,"abstract":"<div>\u0000 \u0000 <p>The offshore Bengal Basin experienced sedimentation due to the interaction between the Indo-Asian collision and the amalgamation of Indo-Burma. To infer the provenance, paleoweathering and tectonic evolution of the Neogene sedimentary rocks from the Sangu Gas Field in the Bay of Bengal, Bangladesh, this study presents a new set of whole-rock geochemical and detrital zircon U–Pb data. Major and trace element geochemistry indicates that these Neogene sediments originated from an active continental margin (ACM) tectonic environment associated with the recycled orogen, aligning well with the sandstones' quartz-feldspar-lithic composition. The geochemical characteristics and elemental ratios of the Neogene sedimentary rocks [e.g., Eu/Eu* (0.55–0.58), (La/Lu)_N (9.2–10.0), La/Sc (2.30–3.98) and (La/Yb)_N (8.46–10.03)], indicate a primary origin from felsic source rocks. The source rocks are dominantly granites that had undergone mild to moderate chemical weathering. The U–Pb ages of the Pliocene Tipam Group and the Miocene Surma Group range from 22.49 to 2794.45 and 28.04 to 3168.21 Ma, respectively. The sandstones of the Tipam and Surma groups exhibit a notable zircon age peak at around 440–620 Ma, which bears similarities to the Tethyan Himalaya (TH), Upper Lesser Himalaya (ULH) and Indo-Burman Ranges (IBR). The secondary peaks at ~1500–2000 Ma correspond to the Lesser Himalaya (LH) ages. The additional subordinate peaks at ~700–1200 Ma reflect the age of the Higher Himalaya (HH). The notable increase in the younger detrital zircon (&lt; 200 Ma) populations was observed in the Tipam Group samples (~22%). These additional young zircons were possibly derived from the recycled Paleogene arc of the Indo-Burma Ranges that might have originated from the Burma magmatic arc.</p>\u0000 </div>","PeriodicalId":12784,"journal":{"name":"Geological Journal","volume":"61 8","pages":"2236-2257"},"PeriodicalIF":2.6,"publicationDate":"2026-08-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148696560","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":"The Petrophysical Characteristics and Controlling Factors of the Wufeng Formation–Longmaxi Formation Shale Reservoirs in the Fuyan Syncline, Northern Guizhou","authors":"Ye Tao,&nbsp;Zhidong Bao,&nbsp;Jiliang Yu,&nbsp;Yitian Li","doi":"10.1002/gj.70092","DOIUrl":"https://doi.org/10.1002/gj.70092","url":null,"abstract":"<div>\u0000 \u0000 <p>The physical properties of shale reservoirs are critical to the enrichment mechanisms of shale oil and gas. To clarify the differences in reservoir physical properties and their primary controlling factors of the Wufeng-Longmaxi Formation shales in northern Guizhou, this study systematically employed multi-scale characterisation techniques, including mineral composition analysis, scanning electron microscopy (SEM) observation, organic geochemical testing, low-temperature nitrogen adsorption, and high-pressure mercury intrusion (HPMI). By combining HPMI and nitrogen adsorption experiments to achieve cross-scale characterisation of pore structures, we investigated reservoir heterogeneity among different lithofacies and identified key controlling factors. Results indicate that the shales in the study area can be classified into four typical lithofacies: organic-rich layered siliceous shale (F1), organic-bearing laminated clayey shale (F2), organic-poor laminated clayey shale (F3), and organic-poor laminated mixed shale (F4). Among them, F1 exhibits the highest pore volume (PV) and specific surface area (SSA), characterised by well-developed organic pores and microfractures; F2 has moderate PV and SSA, with microfractures as the dominant pore type; F3 and F4 show lower PV and SSA, dominated by dissolution pores. The fractal dimensions of the shales range from 2.6114 to 2.6528 (<i>D</i>\u0000 _{\u0000 <i>1</i>\u0000}) and 2.8040 to 2.9024 (<i>D</i>\u0000 _{\u0000 <i>2</i>\u0000}), showing weak negative correlations with total organic carbon (TOC) content, BJH pore volume, and BET specific surface area, while weakly positively correlated with clay mineral content. Further analysis reveals that TOC content and microfracture density are significantly positively correlated with PV and SSA across all four lithofacies, serving as the dominant factors regulating reservoir physical property differences. In contrast, mineral composition shows weaker correlations with PV and SSA, acting as secondary controlling factors. Notably, significant differences in preservation conditions exist between the Wufeng-Longmaxi Formation shales in northern Guizhou and the Sichuan Basin, leading to regional variations in the primary controlling factors of reservoir physical properties.</p>\u0000 </div>","PeriodicalId":12784,"journal":{"name":"Geological Journal","volume":"61 8","pages":"2335-2356"},"PeriodicalIF":2.6,"publicationDate":"2026-08-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148696508","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":"Comprehensive Evaluation of Fractures in Ultra-Deep Basement Gas Reservoirs: A Case Study From the Northern Qaidam Basin","authors":"Xianhua Huang,&nbsp;Houjiang Fan,&nbsp;Jianru Tang,&nbsp;Jing Yang,&nbsp;Chuanjian He,&nbsp;Shuai Yin","doi":"10.1002/gj.70068","DOIUrl":"https://doi.org/10.1002/gj.70068","url":null,"abstract":"<div>\u0000 \u0000 <p>Fractures are key factors influencing the formation of ultra-deep basement gas reservoirs and the productivity of gas wells. Therefore, establishing a comprehensive fracture evaluation method suitable for ultra-deep basement gas reservoirs is of great significance for guiding their exploration and development. This study takes the Devonian basement reservoir in the K2 well block of the northern Qaidam Basin as an example, systematically investigates the fracture characteristics of ultra-deep basement gas reservoirs by integrating core data, FMI (Formation MicroImager) logging and seismic data, and proposes a multi-scale fracture modelling approach. The results show that the fracture linear density in the basement reservoirs of the study area typically ranges from 0.5 to 6 strips/m, with a certain negative correlation between single-layer thickness and fracture density. When the thickness of a single lithological layer exceeds 10 m, the fracture density is generally less than 1 fracture/m. Based on sensitivity analysis of basement fractures, a comprehensive fracture index (<i>F</i>\u0000 _{\u0000 <i>D</i>\u0000}) was constructed for fracture identification in basement reservoirs. Under the constraints of single-well fracture development and orientation statistics, large-scale fractures in the basement formations of the study area were extracted using seismic fracture anti-tracking attributes. A discrete fracture network (DFN) modelling method with multi-parameter constraints was employed to systematically integrate geological information such as anti-tracking attributes, distance to faults and structural curvature. Then, combined with fracture statistics from single-well FMI logging, a multi-constrained modelling approach was used to establish a small-to-large-scale DFN model consistent with geological laws. Finally, a multi-scale fusion DFN modelling technique was applied to achieve 3D coupling of large- and small-scale fracture systems within a unified grid framework. The consistency rate between well-log-interpreted and simulated fracture linear densities in the basement formations exceeds 93%, demonstrating the reliability of the fracture prediction results.</p>\u0000 </div>","PeriodicalId":12784,"journal":{"name":"Geological Journal","volume":"61 7","pages":"1926-1942"},"PeriodicalIF":2.6,"publicationDate":"2026-07-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148532865","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":"Analysing the Drivers of Cropland Footprint in Leading Agricultural Nations: Evidence From MMQR Approach","authors":"Ibrahim Cutcu,&nbsp;Magdalena Radulescu","doi":"10.1002/gj.70072","DOIUrl":"https://doi.org/10.1002/gj.70072","url":null,"abstract":"<p>Climate change represents the biggest current challenge for us and for future generations. Its impact on agriculture is undeniable, considering the food security goal. Thus, the cropland footprint has been distinguished as a comprehensive index for assessing the impact of environmental changes in agricultural areas determined by the increased living standards of people and consumption habits. This paper investigates the determinants of the cropland footprint in the top 10 agricultural countries from 1991 to 2021. Among the determinants considered are GDP per capita, urbanisation rate, employment in agriculture, arable land, fertiliser consumption and annual mean temperature. The second-generation panel data analysis technique MMQR was used in the study, after checking for Durbin–Hausman co-integration and the Pesaran CSD test. The results reveal that arable land significantly increases the cropland footprint in higher quantiles (e.g., coefficient = 0.0053 at the 0.90 quantile), while fertiliser consumption shows a significant negative effect across most quantiles (e.g., coefficient = −0.0543 at the 0.30 quantile). Additionally, GDP per capita positively influences the cropland footprint across all quantiles (e.g., coefficient = 0.2138 at the 0.50 quantile). The results from the MMQR analysis suggest that arable land has a significant and positive impact on the cropland footprint in medium and high quantiles. Additionally, fertiliser consumption and GDP per capita demonstrate significant negative and positive impacts, respectively, on the cropland footprint across almost all quantiles. Conversely, urbanisation, annual average temperature and agriculture employment do not significantly impact the cropland footprint. Based on the results, we can state that using fertilisers can help diminish the cropland footprint by increasing the fertility and productivity of the cultivated areas. At the same time, increased GDP per capita and enlarged arable land will increase the cropland footprint. In the context of robust economic growth, fertilisers are important factors to decrease the cropland footprint as a result of using large arable lands for crop purposes.</p>","PeriodicalId":12784,"journal":{"name":"Geological Journal","volume":"61 7","pages":"2002-2019"},"PeriodicalIF":2.6,"publicationDate":"2026-07-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/gj.70072","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148532992","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}