Geological Journal最新文献

{"title":"Do Investments in Artificial Intelligence, Economic Policy Uncertainty and Economic Growth Hurt or Help Biodiversity in the United States?","authors":"Babatunde Sunday Eweade","doi":"10.1002/gj.70056","DOIUrl":"https://doi.org/10.1002/gj.70056","url":null,"abstract":"<div>\u0000 \u0000 <p>Biodiversity loss remains a critical environmental concern, particularly in developed economies like the United States where rapid technological advancement and economic growth pose sustainability challenges. This study investigates the effects of investment in Artificial Intelligence (AI), Economic Policy Uncertainty (EPU), Renewable Energy Consumption (REC) and Economic Growth (GDP) on Biodiversity (BIO) in the United States from 2013Q1 to 2024Q4. Employing a wavelet-based quantile framework, specifically Wavelet Quantile Correlation (WQC) and Wavelet Quantile-on-Quantile Granger Causality (WQQGC), the analysis captures dynamic, nonlinear and scale-dependent interactions. The results reveal that AI and GDP exhibit predominantly negative long-term effects on biodiversity, while REC demonstrates conditional positive impacts. EPU shows mixed influences depending on quantile levels and time horizons. These findings highlight the complex and asymmetric nature of the relationship between economic and technological drivers and biodiversity. Policy implications call for AI innovations aligned with ecological goals, stable energy policies and sustainable growth strategies that integrate biodiversity considerations. The study contributes to the literature by applying a novel time-frequency-quantile approach to uncover hidden dependencies, offering a robust basis for biodiversity-conscious policymaking in the face of economic and technological transformation.</p>\u0000 </div>","PeriodicalId":12784,"journal":{"name":"Geological Journal","volume":"61 6","pages":"1683-1695"},"PeriodicalIF":2.2,"publicationDate":"2026-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148174380","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":"Thermochronological Constraints on the Synchronisation of Reservoir Densification and Hydrocarbon Emplacement in the Upper Triassic Chang 8 Tight Sandstone, Ordos Basin","authors":"Youwei Duan,&nbsp;Xianyang Liu,&nbsp;Xiujuan Wang,&nbsp;Jihong Li,&nbsp;Shutong Li,&nbsp;Ruiliang Guo,&nbsp;Junlin Chen,&nbsp;Xiaofeng Ma,&nbsp;Xiaoyan Li,&nbsp;Shan Zhang,&nbsp;Wei Wang,&nbsp;Shuning Kang","doi":"10.1002/gj.70061","DOIUrl":"https://doi.org/10.1002/gj.70061","url":null,"abstract":"<div>\u0000 \u0000 <p>The Chang 8 sandstone in the Ordos Basin is a typical tight reservoir, with reservoir quality and heterogeneity controlled by sedimentation and diagenesis. This study focuses on petrology, diagenetic processes, and cement origins, exploring their effects on reservoir quality and heterogeneity. It highlights the cementation sequence constrained by formation temperatures and how this influences porosity evolution and hydrocarbon emplacement. High carbonate cement content, especially near the sand-mud interface within 1 m of the margin, significantly reduces reservoir quality, with carbonate cementation likely supplied by adjacent mudstones. Authigenic chlorite growth is characterised by an inner rim and an outer layer, continuously expanding from the grain surface into the surrounding pore space. Dissolution plays a limited role in improving reservoir quality, and pore redistribution during precipitation in an enclosed diagenetic system may even decrease permeability. Cements play a key role in tightening the reservoir, preserving information on diagenetic temperatures and hydrocarbon charging. By using oxygen isotopes, fluid inclusions, chemical compositions, and Raman spectroscopy, the formation temperatures of cements are determined, enabling the reconstruction of cement paragenesis. This allows dynamic coupling of cementation and reservoir densification with hydrocarbon filling. The study finds that during the main hydrocarbon charging period (80°C–120°C), significant porosity reduction leads to tightness, suggesting that hydrocarbon accumulation occurs before the reservoir becomes significantly tight. This work provides new insights into the coupling of diagenesis and hydrocarbon emplacement, offering a theoretical basis for predicting sweet spots in tight reservoirs with similar geological conditions globally.</p>\u0000 </div>","PeriodicalId":12784,"journal":{"name":"Geological Journal","volume":"61 6","pages":"1771-1806"},"PeriodicalIF":2.2,"publicationDate":"2026-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148174822","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":"","authors":"","doi":"","DOIUrl":"","url":null,"abstract":"","PeriodicalId":12784,"journal":{"name":"Geological Journal","volume":"61 5","pages":""},"PeriodicalIF":2.2,"publicationDate":"2026-05-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148064668","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":"Insights to Pyrochlore and Apatite Evolutionary Trends: Constraints From Mineral and Bulk Chemistry of Saidiwasan Sövites, Gujarat, India","authors":"Sunit Mohanty,&nbsp;Himansu Sekhar Sahoo,&nbsp;Shrinivas Viladkar,&nbsp;Chiranjeeb Chatterjee,&nbsp;K. L. Mundra,&nbsp;Arundhuti Ghatak","doi":"10.1002/gj.70025","DOIUrl":"https://doi.org/10.1002/gj.70025","url":null,"abstract":"<div>\u0000 \u0000 <p>The Saidiwasan (also known as Siriwasan) carbonatite-sill is located approximately 10 km to the north of the well-known Ambadungar carbonatite–alkaline complex within the Chhota Udaipur carbonatite-alkaline province. This complex comprises prominent sövite plugs within carbonatitic breccias, each exhibiting diverse and variable mineralogical assemblages that include pyroxene, amphibole, apatite, pyrochlore, perovskite and titanite. The enrichment of rare earth elements (REEs) in the Saidiwasan sövites is closely associated with the presence of pyrochlore, perovskite, apatite and monazite. This study employs detailed mineral chemistry to elucidate the secondary processes affecting pyrochlore and apatite grains. Primary magmatic pyrochlore in Saidiwasan sövites are characterised by elevated concentrations of calcium, niobium, fluorine and sodium, which are subsequently replaced by secondary cation-deficient grains due to supergene weathering. These alterations primarily occur at the A site and occasionally at the B site, involving the substitution of fluorine by hydroxide (OH–) groups. During alteration, calcium and sodium are leached from the pyrochlore structure, with charge balance maintained by the substitution of REE, Th, U, Ba or Sr. In the later supergene stages, marginal and fractured zones of pyrochlore grains experience metamictization, resulting in Pb-rich and cation-deficient hydrated varieties. Fluoro-apatites within the sövites display significant REE concentrations and are relatively unaltered. LREE constitute the dominant proportion of the total REE content in Saidiwasan apatite. Based on mineral chemistry and bulk rock analyses, this study aims to provide a comprehensive understanding of the Saidiwasan sövites. Despite its promising characteristics, the Saidiwasan carbonatite complex remains underexplored and largely overlooked within the Chhota Udaipur Province, although it possesses significant potential for hosting economically viable mineral deposits, thus warranting further investigation and exploration.</p>\u0000 </div>","PeriodicalId":12784,"journal":{"name":"Geological Journal","volume":"61 4","pages":"1081-1104"},"PeriodicalIF":2.2,"publicationDate":"2026-04-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147708234","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":"Chemostratigraphy of the Permian Fengcheng Formation Shale From Well HS-1 in the Hala'alat Mountain Area, Northwestern Junggar Basin: Implications for Hydrocarbon Generation Potential, Palaeoenvironmental Conditions and Organic Matter Accumulation","authors":"Jian Zhou,&nbsp;Kuihua Zhang,&nbsp;Guanlong Zhang,&nbsp;Qianjun Wang,&nbsp;Zengbao Zhang,&nbsp;Hongzhou Yu,&nbsp;Wei Xiong,&nbsp;Meiyuan Song,&nbsp;Changling Cheng,&nbsp;Hai Li,&nbsp;Shaohua Zhang","doi":"10.1002/gj.70020","DOIUrl":"https://doi.org/10.1002/gj.70020","url":null,"abstract":"<div>\u0000 \u0000 <p>The Permian Fengcheng Formation in the Junggar Basin, particularly within the Mahu Sag, has become a focal point for shale oil exploration. However, the hydrocarbon generation potential, palaeoenvironmental conditions and organic matter accumulation in the relatively underexplored Hala'alat Mountain area, located northwest of the Mahu Sag, remain insufficiently understood. This study systematically investigates the hydrocarbon generation potential, palaeoenvironmental conditions, and organic matter accumulation of the Fengcheng Formation shales from Well HS-1 in the Hala'alat Mountain area through comprehensive chemostratigraphic analyses, including total organic carbon (TOC) content, Rock-Eval pyrolysis and handheld X-ray fluorescence (XRF). TOC values range from 0.08 wt.% to 2.83 wt.%, with significant enrichment below 2020 m, indicating enhanced preservation of organic matter at greater depths. Hydrogen index (HI) values suggest a predominance of oil-prone Type II kerogen, while Tmax values (418°C–442°C) confirm the thermal maturity of the organic matter, placing it within the primary oil generation window. Chemostratigraphic trends reveal a significant palaeoenvironmental shift at 2020 m of Well HS-1, transitioning from an anoxic, saline, and arid environment in the lower section to a more oxygenated, fresher and humid environment in the upper intervals. Redox-sensitive proxies, combined with palaeosalinity and palaeoclimate indicators, suggest that optimal conditions for organic matter preservation occurred below 2020 m, where sustained anoxia, moderate salinity and limited terrestrial input facilitated the accumulation of organic-rich sediments. These findings provide essential insights into the hydrocarbon potential and depositional history of the Fengcheng Formation and offer a valuable framework for future exploration in this underexplored region.</p>\u0000 </div>","PeriodicalId":12784,"journal":{"name":"Geological Journal","volume":"61 4","pages":"1014-1028"},"PeriodicalIF":2.2,"publicationDate":"2026-04-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147708325","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":"Correlation of Paleo-Mesozoic Sandstones Based on Heavy Mineral Chemistry and Th–U–Total Pb Monazite Dating: Implications on Paleogeographic Reconstruction in Eastern Gondwanaland","authors":"Sankar Kumar Nahak,&nbsp;Sanghita Dasgupta,&nbsp;N. Prabhakar,&nbsp;Santanu Banerjee","doi":"10.1002/gj.70023","DOIUrl":"https://doi.org/10.1002/gj.70023","url":null,"abstract":"<div>\u0000 \u0000 <p>The correlation between continental sandstones in adjacent sedimentary basins, lacking biostratigraphic control, is often problematic. Based on petrography, paleocurrent data, heavy mineral analysis, and monazite dating, this study correlates Paleo-Mesozoic sandstones in the Wardha Basin with those in the adjacent Pranhita-Godavari (P-G) Basin, and presents a paleogeographic reconstruction of eastern Gondwanaland. Predominantly quartzose to feldspathic-quartzose arenites of the Wardha Basin, showing N-NW paleocurrent, contain heavy minerals such as ilmenite, garnet, zircon, rutile, monazite, tourmaline, and staurolite. Burial dissolution has caused preferential leaching of staurolite and rutile in relatively older sediments. The abundance of almandine garnet indicates the predominant granulite and subordinate amphibolite sources. The tourmaline chemistry, indicating the dominance of dravite and schorl, relates them primarily to amphibolites and granitoids, whilst rutile chemistry tracks them to metapelitic sources. The prevalence of leucoxene in younger formations reflects ilmenite alteration, indicating progressive tectonic stability and humidity from the Upper Carboniferous to Lower Triassic period. The Th–U–total Pb dating of detrital monazite in sandstones yields three major groups at (1) 2496–2395 Ma, (2) 927–722 Ma, and (3) 552–438 Ma. Heavy mineral chemistry, paleocurrent data, and monazite dating track sediment sources to the Eastern Ghats Mobile Belt, Karimnagar Granulite Belt, and Antarctica through the axial drainage system. Whilst local sediment sources include amphibolites and granitoids in Bastar Craton, hosting Bhopalpatnam Granulite Belt, Mul and Dongargarh granite, and Bengpal Group. Good matching of heavy mineral chemistry and monazite dating confirms the genetic relationship between Wardha Basin and Pranhita-Godavari Basin.</p>\u0000 </div>","PeriodicalId":12784,"journal":{"name":"Geological Journal","volume":"61 4","pages":"1041-1065"},"PeriodicalIF":2.2,"publicationDate":"2026-04-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147708384","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":"Zircon Trace Elements as Indicators of Physicochemical Conditions and Mineralisation Potential in the Nannihu Porphyry Mo–W Deposit, East Qinling, China","authors":"Cheng Wang,&nbsp;Fan Yang,&nbsp;Leon Bagas,&nbsp;Zhenyu Qin,&nbsp;Feifan Xu,&nbsp;Jinhu Ma,&nbsp;Weidong Ren","doi":"10.1002/gj.70024","DOIUrl":"https://doi.org/10.1002/gj.70024","url":null,"abstract":"<div>\u0000 \u0000 <p>Physical and chemical (physicochemical) conditions are crucial for the genesis of a mineralised porphyry. For instance, a hydrothermal system with high oxygen fugacity facilitates Mo migration and precipitation. Zircon, the most common mineral enriched in rare earth elements (REEs), is widely used to determine the oxygen fugacity, magma evolution and mineralisation potential of a porphyry body. The Nannihu is a giant Mo–W porphyry deposit in the Qinling Orogen of central China and consists of porphyritic monzogranite. Previous studies have primarily focused on the age and petrogenesis of the deposit, but the physicochemical conditions remain poorly understood. Additionally, the mineralisation potential of the porphyry has not been evaluated, hampering the discovery of concealed Mo–W ores. In this study, we present in situ trace element analysis of zircon from the Nannihu porphyry to decipher the physicochemical conditions, magma evolution and evaluate the mineralisation potential of the area. The REE contents of the zircons range from 357 to 4768 ppm, characterised by depleted light REEs (LREEs) and enriched heavy REEs (HREEs). Using the zircon–Ti-thermometer and Ce/Ce* ratio, the crystallisation temperature of the Nannihu porphyry is estimated to be ~651°C–769°C, with an oxygen fugacity ranging from −30 to −1.7. By contrast, the crystallisation temperatures of the Nannihu porphyry are similar to those of nearby Shibaogou, Huangbeiling and Shangfanggou plutons in the Luanchuan region; its oxygen fugacity is moderate compared to these plutons. The porphyry formed in an intraplate setting and is derived from the crust. The crust in the Nannihu region underwent double thickening during ~148–138 Ma, reaching a depth of ~60 km. The zircons in the porphyry represent early products of a magma rich in H₂O with a high oxygen fugacity, potentially influenced by F-rich hydrothermal input, which indicates a high prospectivity for Mo–W mineralisation in the vicinity of the deposit.</p>\u0000 </div>","PeriodicalId":12784,"journal":{"name":"Geological Journal","volume":"61 4","pages":"1066-1080"},"PeriodicalIF":2.2,"publicationDate":"2026-04-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147708385","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":"Sensitivity Analysis of Factors Affecting Stability of High and Steep Rocky Slopes in Seasonal Frozen Region: A Case Study of Huinan County","authors":"Lingjie Pan,&nbsp;Chenglong Yu,&nbsp;Libo Liu,&nbsp;Huanan Liu,&nbsp;Jiquan Zhang,&nbsp;Yichen Zhang,&nbsp;Haoxin Chen","doi":"10.1002/gj.70014","DOIUrl":"https://doi.org/10.1002/gj.70014","url":null,"abstract":"<div>\u0000 \u0000 <p>Geological disasters caused by the instability of high and steep rocky slopes in seasonal frozen regions are often harmful, and the reasons for their instability vary. Therefore, it is particularly important to study the influencing factors of the stability of highly steep rocky slopes in seasonal frozen regions, and to explore the primary and secondary order of each influencing factor. Geological disasters are frequent in Huinan County, Tonghua City, Jilin Province, especially small- to medium-scale high- steep rocky slopes landslides and avalanches, which seriously threaten the surrounding infrastructure construction and ecological environment. In this study, on the basis of field investigation and collected primary data, five typical high-steep rock masses in Huinan County were selected as the research objects. Through literature research and mechanism analysis of rock slope, three first-order influencing factors are identified, and then subdivided into 8 second-order influencing factors. Numerical simulation through ABAQUS and sensitivity analysis using grey correlation analysis revealed that cohesion is the most sensitive factor, followed by internal friction angle, while freeze–thaw cycles are less sensitive, which suggests that priority should be given to increasing rock cohesion in the management of this type of slope. At the same time, it also provides the effective scientific basis for high and steep rocky slopes in the quaternary freezing zone for the protection and reinforcement projects.</p>\u0000 </div>","PeriodicalId":12784,"journal":{"name":"Geological Journal","volume":"61 4","pages":"893-911"},"PeriodicalIF":2.2,"publicationDate":"2026-04-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147708207","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":"Permian Carbonaceous Shales From Raniganj Sub-Basin—A Potential Source of Hydrocarbons? Inferences Drawn From Kerogen Characteristics and Kinetics","authors":"Monalisa Mallick,&nbsp;Barnita Banerjee,&nbsp;Nihar Ranjan Kar,&nbsp;Runcie Paul Mathews,&nbsp;Vikram P. Singh,&nbsp;Manish Tiwari,&nbsp;E. V. S. S. K. Babu,&nbsp;Tanveer Hassan,&nbsp;Satendra Kumar Gupta","doi":"10.1002/gj.70028","DOIUrl":"https://doi.org/10.1002/gj.70028","url":null,"abstract":"<div>\u0000 \u0000 <p>The present study reports a geochemical evaluation of Permian aged Raniganj, Barren Measure and Barakar shales from R1 and R4 boreholes from the NE part of the Raniganj sub-basin. We have investigated organic matter characteristics, stable isotopic composition, hydrocarbon potential and kerogen kinetics to decipher shale gas potential as well as artificial hydrocarbon generation prospect. The shales contain high total organic carbon (TOC) content ~2.5–26.5 wt%, mainly Type III kerogen with minor Type II/III kerogen. The provenance of organic matters has been determined using δ¹³C_org and δ¹⁵N_bulk composition and Total Nitrogen content to be predominantly terrestrial deposited primarily in an oxic to suboxic environment. Kinetic parameters for kerogen degradation reactions namely, activation energies (Ea) distribution, frequency factors are in the range of typical Type III kerogen. A narrow range of peak Ea distribution indicates relative homogeneity of organic matter which is also evident from FTIR spectra showing relative abundance of aromatic compounds. Maceral assemblage reveals substantial presence of Type I/Type II liptinite macerals namely, alginite, sporinite, cutinite along with Type III vitrinite macerals which likely elevated the kerogen type and hydrogen index (HI), and resulted in a narrow Ea distribution. The kerogen transformation ratio and the hydrocarbon generation rate indicate considerably earlier onset of kerogen transformation and quicker completion of hydrocarbon generation for R4 shales suggesting better potential for R4 shales relative to R1 shales. Furthermore, Rock-Eval parameters S2, TOC, Hydrogen Index, <i>T</i>_max summarise that the shales derived predominantly from terrestrial sources contain mainly Type III with some mixed Type II–III kerogen with potential for wet/dry gas generation. In the absence of any post-depositional igneous activity in the NE part of the Raniganj sub-basin, the shales are in an early matured state unlike shales from the NW part.</p>\u0000 </div>","PeriodicalId":12784,"journal":{"name":"Geological Journal","volume":"61 4","pages":"1143-1166"},"PeriodicalIF":2.2,"publicationDate":"2026-04-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147708245","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":"Petrographic, Geochemical and Sr–Nd Isotopic Studies of the Shales From the Lower Cuddapah Basin: Implications for Palaeoweathering, Provenance and Proterozoic Crustal Evolution","authors":"Tavheed Khan,&nbsp;D. Srinivasa Sarma","doi":"10.1002/gj.70013","DOIUrl":"https://doi.org/10.1002/gj.70013","url":null,"abstract":"<div>\u0000 \u0000 <p>The Proterozoic to Neoproterozoic Cuddapah Basin (CB) contains a thick pile (i.e., 6–12 km) of arenaceous, argillaceous and carbonate rocks with substantial igneous rocks. The evolution of the CB is mainly defined based on igneous rocks with a limited study on siliciclastic rocks. Here we report geochemical and isotopic data from shale samples of the Lower Cuddapah formations for the first time to comprehend their provenance, palaeoweathering, and tectonic setting. The shale samples were collected from Gulcheru, Vempalle and Tadpatri formations of the Lower CB. The geochemical and isotopic data divide Gulcheru Formation shales into two groups: Gulcheru shale I (GS I) and Gulcheru shale II (GS II). The CIA (chemical index of alteration), CIW (chemical index of weathering) and Al₂O₃–CaO + Na₂O–K₂O (ACNK) diagram of the shales decipher a low chemical weathering for the GS I. In contrast, GS II, Vempalle shale (VS) and Tadpatri shale (TS) exhibit a medium to high degree of chemical weathering. The major and trace element ratios, provenance diagrams, and higher sub-chondritic εNd(t) values of GS I (−8.18 to −7.62) compared to GS II (−5.34 to −3.63), VS (−6.25 to −4.41) and TS (−5.2 to −3.78) along with f_Sm/Nd versus ɛNd(t) diagram suggest the decrease of sediment input from older crustal provenance, that is, Eastern Dharwar Craton (EDC) with increase of ‘more juvenile’ source. The tectonic discrimination diagrams, as well as the primitive mantle (PM) normalised multi-element diagram, characterise a back-arc origin of the CB. The more evolved εNd(t) values and younger detrital zircon grains in the Pulivendla Formation indicate that the basin was opened by westerly subduction along the east coast of India at ~2 Ga. The continuous collision of the Dharwar Craton with Antarctica at ~1.6 Ga suggests the last phase of the Columbia Supercontinent formation.</p>\u0000 </div>","PeriodicalId":12784,"journal":{"name":"Geological Journal","volume":"61 4","pages":"861-892"},"PeriodicalIF":2.2,"publicationDate":"2026-04-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147708274","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}