Geological Journal最新文献

{"title":"Impact of Multi-Scale Laminae Characteristics on Lacustrine Shale Reservoir Quality: A Case Study From the Second Member of the Kongdian Formation in the Cangdong Sag, Bohai Bay Basin, China","authors":"Zheng Fang,&nbsp;Xiugang Pu,&nbsp;Shiyue Chen,&nbsp;Jihua Yan,&nbsp;Huiyu Yang,&nbsp;Binyu Ma,&nbsp;Qingmin Dong","doi":"10.1002/gj.70067","DOIUrl":"https://doi.org/10.1002/gj.70067","url":null,"abstract":"<div>\u0000 \u0000 <p>Lamina is the fundamental unit for pore development and hydrocarbon accumulation in lacustrine shale. Taking the shale from the Second Member of the Kongdian Formation in the Cangdong Sag, Bohai Bay Basin, China, as an example, this study integrates technical approaches (X-ray diffraction, nuclear magnetic resonance, field emission scanning electron microscopy, advanced mineral identification and characterisation system and modular automated processing system) to investigate the relationship between the fabric characteristics at both lamina and lithofacies scale and reservoir quality. The results show that five lamina types are identified in the Ek₂ shale based on inorganic–organic compositions as felsic laminae, mixed laminae, clay laminae, dolomite laminae and organic matter laminae. The storage capacity of shale reservoirs, encompassing pore quantity, size and distribution, is determined by the arrangement patterns of inorganic–organic components within the individual lamina. The rigid framework formed by felsic minerals promotes the development and preservation of interparticle pores and shrinkage organic matter pores, while multiphase crystallisation of dolomite reduces primary intercrystalline pores. Lamina-scale pore characteristics superimpose on the lithofacies scale through lamination structures, dictating reservoir quality heterogeneity among different lithofacies. The connectivity and seepage condition of shale reservoirs are determined by the differentiation degree and contact pattern of adjacent laminae within the lamination structure. The laminated felsic shale develops a cross-lamina connected pore–fracture network, with macropores and microfractures being more extensively developed, which is the most promising lithofacies for shale oil exploration and development.</p>\u0000 </div>","PeriodicalId":12784,"journal":{"name":"Geological Journal","volume":"61 7","pages":"1904-1925"},"PeriodicalIF":2.6,"publicationDate":"2026-07-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148532770","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":"Late Cretaceous Tectonic–Thermal Events Recorded in Qiangtang Terrane, Central Tibet","authors":"Yi-long Zheng,&nbsp;Gen-hou Wang,&nbsp;Zhong-bao Zhao,&nbsp;Xiao Liang,&nbsp;Hui-le Feng,&nbsp;Zhi-wen Guo,&nbsp;Jixin Hu","doi":"10.1002/gj.70075","DOIUrl":"https://doi.org/10.1002/gj.70075","url":null,"abstract":"<div>\u0000 \u0000 <p>Integrated with new field and analytical data, this study investigates the tectonic evolution of the central Qiangtang Terrane through multi-chronological analysis of the Ejiumai Complex, a key outcrop in the northern Central Qiangtang Metamorphic Belt (CQMB). The complex, situated in the high-altitude (&gt; 4800 m) interior of the Tibetan Plateau, comprises granitic gneisses, paragneisses, and marbles intruded by tourmaline-bearing leucogranite veins, preserving critical records of pre-Cenozoic orogenic processes. Data from previous studies and our investigation reveal that the protoliths of the Ejiumai Complex originated during the Early Palaeozoic and experienced peak metamorphism in the Late Triassic. Hydrothermal zircons extracted from leucogranite veins display distinctive spongy textures with abundant inclusions and weak cathodoluminescence response. LA-ICP-MS U–Pb dating of these zircons yields Cretaceous ages ranging from 89 to 69 Ma, characterised by significant Th-U content variations (Th = 8–1274 ppm, U = 96–2997 ppm). Complementary ⁴⁰Ar/³⁹Ar thermochronology of biotite (69.7 ± 0.5 Ma) and muscovite (70.4 ± 0.5 Ma and 70.7 ± 0.4 Ma) from host rocks indicates rapid Late Cretaceous cooling following thermal resetting. Synthesis of these results with regional geology suggests a two-phase Cretaceous tectonic evolution: (1) 89–69 Ma crustal shortening manifested through thrusting and folding accompanied by intense hydrothermal activity, and (2) subsequent rapid exhumation and cooling prior to Cenozoic India-Asia collision. This revised chronology demonstrates that major crustal thickening in central Qiangtang initiated during the Late Cretaceous as part of the broader Mesozoic Tethyan orogenic system related to Lhasha-Qiangtang collision.</p>\u0000 </div>","PeriodicalId":12784,"journal":{"name":"Geological Journal","volume":"61 7","pages":"2056-2071"},"PeriodicalIF":2.6,"publicationDate":"2026-07-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148534240","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":"Remnants of Older Crustal Component in Mafic Magmas: Compelling Evidence From the Whole-Rock Geochemistry and Heterochronous Zircons of Mafic Dyke From Karimnagar Granulite Belt, Eastern Dharwar Craton, Southern India","authors":"N. Sridhar,&nbsp;R. Mallikarjuna Reddy,&nbsp;M. Santosh,&nbsp;K. S. V. Subramanyam,&nbsp;Rohit Pandey,&nbsp;Cheng-Xue Yang,&nbsp;Sourav Naskar","doi":"10.1002/gj.70081","DOIUrl":"https://doi.org/10.1002/gj.70081","url":null,"abstract":"<div>\u0000 \u0000 <p>The rarity of zircon occurrence in ultramafic-mafic systems offers valuable insights into the geological processes related to its formation, mixing of heterogeneous magmas, assimilation of surrounding wall rock, or the combination of various source materials apart from the conventional geochronology. This study reports an undocumented mafic dyke of picritic affinity from the Karimnagar Granulite Belt (KGB) of southern India, characterised by olivine, two pyroxenes, chrome spinel, plagioclase, and high MgO (16 wt.%), Cr (2624 ppm), and Ni (815 ppm). Prominent negative Nb, Ta, and Ti, positive Zr, and Hf anomalies, along with enriched LILE and LREE, indicate that the dyke has undergone crustal contamination. However, the Th/Yb and Nb/Yb ratios suggest that mantle metasomatism preceded crustal contamination, significantly contributing to the mildly alkaline character of the studied rocks. Most recovered zircons show clear signs of a magmatic origin, reflected in their REE profiles and Th/U ratios (&gt; 0.5), although some exhibit evidence of post-crystallisation processes. The dating results show an age range from the Neoarchean to the Paleoproterozoic (2.7–1.9 Ga), making it unlikely to represent the intrusion age of the dyke. This age range indicates that ancient crustal material has significantly influenced the mafic magma, emphasising the zircon's xenocrystic nature and suggesting a source from continental granitoids with arc affinity. The age coherence between the studied zircon and the zircons of KGB charnockites indicates that 2.5 Ga was the major crustal growth episode. This study reveals that heterochronous zircons, paired with traditional geochemical proxies, are crucial for understanding ancient crustal components within mafic magmas, highlighting the complex dynamics of the cryptic mixing process.</p>\u0000 </div>","PeriodicalId":12784,"journal":{"name":"Geological Journal","volume":"61 7","pages":"2145-2165"},"PeriodicalIF":2.6,"publicationDate":"2026-07-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148534105","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":"Rotational Deformation of the Chuan Dian Fragment Since the Cenozoic: Constraints From Palaeomagnetic Data From Eocene Igneous Rocks in the Jianchuan Basin, China","authors":"Pengsheng Ji,&nbsp;Saisai Li,&nbsp;Hongrui Zhang,&nbsp;Zengqian Hou,&nbsp;Xin Li","doi":"10.1002/gj.70048","DOIUrl":"https://doi.org/10.1002/gj.70048","url":null,"abstract":"<div>\u0000 \u0000 <p>The Chuan Dian Fragment (CDF) is the leading edge of the outward expansion of the Tibetan Plateau. Understanding the rotational deformation of the CDF over time is critical to understanding plateau growth and collisional orogenies. We carried out detailed rock magnetism and palaeomagnetism studies on intrusive rocks with zircon U–Pb ages of 37–33 Ma in the interior of the Jianchuan Basin, China in the western part of the CDF. We isolated the high-temperature magnetic components of the intrusive rocks. The site mean direction of the high-temperature remanent magnetic components yielded <i>Dg</i> = 17.3 ± 7.5° and <i>Ig</i> = 51.5 ± 4.6°, with <i>k</i> = 169.5 and <i>α</i>\u0000 ₉₅ = 4.6°. Our results show that the Jianchuan Basin has rotated 15.0° ± 6.8° clockwise relative to East Asia since the Eocene. After collating Cretaceous and Cenozoic palaeomagnetic data related to the CDF, we propose that the rotational extrusion of the CDF was achieved through the differential rotation of numerous sub-blocks separated by faults. The rotational deformation of the sub-blocks and the activity of the faults shows a gradual increase from northwest to southeast. The rotational deformation of the CDF can be divided into three stages at 35–15, 15–5 and 5–0 Ma. The results show that the precise timing of fault activity, fault characteristics and palaeomagnetic data with accurate chronological constraints are effective in revealing the detailed rotational deformation of blocks in oblique collision belts. This study highlights that the Cenozoic rotational extrusion in the southeastern Tibetan Plateau may involve differential rotation and extrusion of numerous small blocks, segmented by faults of varying scales.</p>\u0000 </div>","PeriodicalId":12784,"journal":{"name":"Geological Journal","volume":"61 6","pages":"1538-1555"},"PeriodicalIF":2.2,"publicationDate":"2026-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148167008","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":"Foraminiferal Assemblages, Biostratigraphy and Lithostratigraphy of the Permian Deposits in NW Iran: A Constraint for Paleogeographic Reconstruction","authors":"Nakisa Rezazadeh,&nbsp;Mohammad Reza Vaziri,&nbsp;Ahmad Lotfabad Arab","doi":"10.1002/gj.70047","DOIUrl":"https://doi.org/10.1002/gj.70047","url":null,"abstract":"<div>\u0000 \u0000 <p>This study investigates foraminiferal assemblages, biostratigraphy and lithostratigraphy of the Permian deposits in northwestern Iran, specifically focusing on the Sariqaiyeh and Alibalta sections. Our findings reveal that the Permian carbonate successions can be subdivided into 13–14 lithostratigraphic members based on distinct facies characteristics and grain composition. Detailed analysis of foraminiferal assemblages allowed us to establish several biozones, including: <i>Schubertella-Mesoschubertella</i> (Yakhtashian-Kubergandian), <i>Eotuberitina</i>, <i>Deckerella-Paradunbarula-Globivalvulina-Tetrataxis</i> (Early Murghabian), <i>Protonodosaria-Pseudolangella</i> (Middle-Late Murghabian), <i>Paraglobivalvulina</i> (Midian), <i>Ichthyolaria-Dagmarita</i> (Dzhulfian) and <i>Paraglobivalvulinoides-Reichelina</i> (Dzhulfian-Dorashamian). The similarities in foraminiferal assemblages and lithological characteristics between the studied sections and the Alborz structural zone suggest that both regions experienced comparable sedimentary and paleogeographic conditions influenced by the collapse of the Cimmerian terrane. This connection likely facilitated a shared faunal and sedimentological environment between the Palaeotethys and Neotethys oceans. Consequently, our study contributes to a better understanding of the paleogeographic reconstruction of the region during the Permian period and emphasises the significance of lithology and foraminifers in lithostratigraphic–biostratigraphic correlations in northwestern Iran.</p>\u0000 </div>","PeriodicalId":12784,"journal":{"name":"Geological Journal","volume":"61 6","pages":"1513-1537"},"PeriodicalIF":2.2,"publicationDate":"2026-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148167041","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":"A Middle Jurassic Liostrea birmanica Shell Bed From the South Qiangtang Basin, North Tibet, China","authors":"Jiahao Li,&nbsp;Michael Hautmann,&nbsp;Igor Kosenko,&nbsp;Jungang Peng,&nbsp;Qianqi Zhang,&nbsp;Jingeng Sha,&nbsp;Haichun Zhang","doi":"10.1002/gj.70060","DOIUrl":"https://doi.org/10.1002/gj.70060","url":null,"abstract":"<div>\u0000 \u0000 <p>The Qiangtang Basin, Tibetan Plateau, is a Mesozoic marine basin characterised by well-developed Jurassic marine sedimentary systems. The South Qiangtang Basin, being closer to the Bangong-Nujiang suture zone, exhibits more localised and complex Jurassic strata compared to the North Qiangtang Basin. This study focuses on the Middle Jurassic 114 Daoban Formation in the South Qiangtang Basin, which consists of marine siliciclastic and carbonate rocks with abundant bivalve fossils, particularly <i>Liostrea birmanica</i>. We analyse the taxonomy, shell microstructure, and palaeoecology of <i>L. birmanica</i>. Based on its shell morphology and sedimentary context, we suggest that <i>L. birmanica</i> adopted a reclining lifestyle on soft substrates, representing an adaptation to soft substratum environments. The microstructure of the shells, composed mainly of irregularly foliated layers, distinguishes <i>Liostrea</i> from morphologically similar genera. The occurrence of monospecific shell beds of <i>L</i>. <i>birmanica</i> across a broad area suggests their potential as regional marker beds for refining the Jurassic stratigraphic framework in the South Qiangtang Basin. This research contributes to a better understanding of the palaeoecology and biostratigraphy of Jurassic marine systems in the Tibetan Plateau.</p>\u0000 </div>","PeriodicalId":12784,"journal":{"name":"Geological Journal","volume":"61 6","pages":"1759-1770"},"PeriodicalIF":2.2,"publicationDate":"2026-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148174379","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":"Geochemical Characteristics and Zircon U–Pb Geochronology of the Granitoid From West of Yazd, Central Iran","authors":"Mahnaz Khodami,&nbsp;John M. Cottle,&nbsp;Maryam Bendokht,&nbsp;Ali Reza Davoudian,&nbsp;Nahid Shabanian","doi":"10.1002/gj.70057","DOIUrl":"https://doi.org/10.1002/gj.70057","url":null,"abstract":"<div>\u0000 \u0000 <p>The origin and tectonic significance of Eocene granitoids in Central Iran remain poorly constrained, particularly concerning their source and geodynamic context within the broader framework of Neo-Tethyan subduction. This study aims to address this knowledge gap by focusing on the granitoids located near Khezrabad, west of Yazd. Khezrabad Granitoid was investigated to elucidate their source, tectonic setting, and magmatic evolution. Whole-rock geochemistry, zircon U–Pb geochronology, and zircon geochemistry were employed. U–Pb dating of zircon yielded a crystallisation age of 39.8 ± 0.2 Ma, corresponding to the Middle Eocene (Bartonian). Ti-in-zircon thermometry indicates crystallisation temperatures between 630°C and 730°C, while Th/U ratios of 0.17–0.87 in zircon are suggestive of a magmatic origin. The granitic rocks exhibit metaluminous, high-K calc-alkaline, I-type characteristics, with enrichment in light rare earth elements and depletion in Nb, Ta, Ti and Sr relative to primitive mantle. These features are indicative of magmatism within an active continental margin and were generated by the partial melting of meta-igneous rocks in the middle continental crust as a result of subduction of the Neo-Tethys beneath the Sanandaj-Sirjan Zone in Central Iran.</p>\u0000 </div>","PeriodicalId":12784,"journal":{"name":"Geological Journal","volume":"61 6","pages":"1696-1715"},"PeriodicalIF":2.2,"publicationDate":"2026-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148174504","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":"Uplift and Erosion in the Western Himalaya: Insight From U–Pb Ages of Detrital Zircon Recovered From the Miocene Foreland Basin Deposits, Pakistan","authors":"Muhammad Nouman Ali Naseem,&nbsp;Upendra Baral,&nbsp;Muhammad Qasim,&nbsp;Javed Iqbal Tanoli,&nbsp;Qasim Ur Rehman,&nbsp;Lin Ding,&nbsp;Andreas Scharf","doi":"10.1002/gj.70063","DOIUrl":"https://doi.org/10.1002/gj.70063","url":null,"abstract":"<div>\u0000 \u0000 <p>Sandstone petrography and detrital zircon U–Pb geochronology of the Miocene Murree Formation, exposed in Muzaffarabad and Murree areas, provide insights into sediment provenance and Himalayan foreland basin evolution following the India–Eurasia collision. Detrital zircon ages cluster at ~1300–400 Ma, ~1900–1400 Ma, and ~2600–2300 Ma, indicating erosion from the Tethyan and Higher Himalaya, with minor contributions from the Lesser Himalaya (LH). Younger ages (&gt; 100 Ma) suggest the recycling of foreland sediments from Eurasian sources during fold–thrust belt propagation. Notably, ~1600–1700 Ma and ~550–450 Ma (Cambro-Ordovician granites) detritus indicate erosion from inner LH rocks exposed in the hanging wall of the Panjal Thrust (PT). These provenance signatures suggest PT was active during deposition of the Murree Formation, driving inner LH erosion and sediment influx into the foreland basin.</p>\u0000 </div>","PeriodicalId":12784,"journal":{"name":"Geological Journal","volume":"61 6","pages":"1832-1847"},"PeriodicalIF":2.2,"publicationDate":"2026-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148174818","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":"Full-Scale Pore Structure of Deep Coals and Its Relationship on Coal Facies: A Typical Case and Experimental Study","authors":"Bin Zhang,&nbsp;Shu Tao,&nbsp;Yi Cui,&nbsp;Fan Yang,&nbsp;Qinghe Jing,&nbsp;Jie Guo,&nbsp;Bin Yu,&nbsp;Xinyang Men,&nbsp;Yijie Wen","doi":"10.1002/gj.70058","DOIUrl":"10.1002/gj.70058","url":null,"abstract":"<div>\u0000 \u0000 <p>The pore structure of coals significantly affects storage and migration of coalbed methane (CBM). In this study, high-pressure mercury intrusion (HPMI), low-temperature N₂ adsorption (LT-N₂A), low-temperature CO₂ adsorption (LT-CO₂A), nuclear magnetic resonance (NMR), and scanning electron microscopy (SEM) tests were employed to characterise the full-scale pore structures of the Jurassic Xishanyao Formation (J₂x) and Badaowan Formation (J₁b) coals. Additionally, the influence of coal facies on pore structure was confirmed using maceral and proximate analysis. The results indicate that pore structures and coal facies of J₂x and J₁b coals exhibit distinct differences with regularities. The J₂x coals are associated with arid forest swamps and upper delta plains, while J₁b coals correspond to humid forest swamps and lower delta plains. Vitrinite content, ash yield, volatile yield, micropore proportion, vitrinite/inertinite ratio (V/I), and gelation index (GI) increase from J₂x to J₁b coals. In contrast, inertinite content, fixed carbon, mesopores and macropores proportions, texture preservation index (TPI), and vegetation index (VI) decrease. These changes suggest variations in plant types, water cover, and redox conditions in the paleoenvironment. From J₂x to J₁b coals, the increase in water cover, the reduction of woody plants, and the enhancement of reducing conditions lead to corresponding changes in pore structure.</p>\u0000 </div>","PeriodicalId":12784,"journal":{"name":"Geological Journal","volume":"61 6","pages":"1716-1731"},"PeriodicalIF":2.2,"publicationDate":"2026-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147884132","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":"Thermal Evolution History Reconstruction of the Dengying Formation to Longmaxi Formation in the Micangshan Uplift Area, Based on Multiple Paleothermometers and Basin Modelling Techniques","authors":"Tianzi Wang,&nbsp;Qiang Yu,&nbsp;Tao Tian,&nbsp;Wei Chang,&nbsp;Lijuan He,&nbsp;Qike Yang,&nbsp;Ruize Yuan","doi":"10.1002/gj.70059","DOIUrl":"https://doi.org/10.1002/gj.70059","url":null,"abstract":"<div>\u0000 \u0000 <p>Evaluation of shale maturity in strata lacking vitrinite is a significant challenge in unconventional oil and gas geology research. Maturity and thermal evolution history of the Lower Silurian and underlying formations of the Micangshan Uplift are poorly understood. This study focuses on the Dengying–Longmaxi formations in the Micangshan Uplift, conducting analyses of clay mineral composition, illite crystallinity, bitumen reflectance, bitumen laser Raman spectroscopy, thermal conductivity and heat production rate measurements. These are integrated with apatite fission track data to reconstruct the burial–thermal evolution history. The results indicate: (1) the source rocks have illite crystallinity ranging from 0.49 to 0.88, <i>R</i>\u0000 _b from 1.23% to 3.5%, <i>R</i>\u0000 _o from 1.16% to 2.68%, indicating a high to over-mature stage. (2) Bitumen laser Raman spectroscopy reveals _Rmc\u0000 <i>R</i>\u0000 _o values of 1.57% to 3.54% and B<i>R</i>\u0000 _o values of 1.53% to 3.66%, suggesting high organic matter maturity. (3) the maximum paleogeotemperature experienced since the Lower Palaeozoic ranges from 180°C to 222°C, with a geothermal gradient of 3.1°C/100m to 3.9°C/100 m. (4) the study area has undergone four tectonic uplifts since 550 Ma, with maturity evolving from low to over-mature. Regional uplift and denudation since 150 Ma halted further heating. The complex tectonic–thermal evolution of Dengying–Longmaxi shale since the Late Palaeozoic, coupled with favourable paleogeotemperature, maturity, porosity and adsorption capacity evolution, suggests significant shale gas exploration potential, warranting further resource exploration and evaluation.</p>\u0000 </div>","PeriodicalId":12784,"journal":{"name":"Geological Journal","volume":"61 6","pages":"1732-1758"},"PeriodicalIF":2.2,"publicationDate":"2026-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148174786","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}