Journal of Asian Earth Sciences最新文献

{"title":"The redox transformation in the Yangtze Sea across the Ordovician-Silurian transition: Evidence from zinc isotopes in organic-rich shales","authors":"Jixin Jia ,&nbsp;Xuebin Du ,&nbsp;Ke Zhao ,&nbsp;Yongchao Lu ,&nbsp;Zhanhong Liu","doi":"10.1016/j.jseaes.2025.106579","DOIUrl":"10.1016/j.jseaes.2025.106579","url":null,"abstract":"<div><div>Across the Ordovician-Silurian transition, the Yangtze Sea exhibited a complex redox pattern influenced by various environmental factors. Consequently, investigating this phenomenon is crucial for understanding the paleoenvironmental changes and their implications. Numerous and continuously evolving geochemical proxies provide insights into the redox conditions of paleo-oceans, among which the zinc isotope composition (δ⁶⁶Zn) in organic rich shales has been recently discovered as a potential alternative proxy for local marine redox conditions. In this study, the core JY143, drilled in the middle Yangtze shelf, was selected as the research subject. The variation in δ⁶⁶Zn values can be categorized into three distinct stages. The substantial influx of isotopically light Zn from igneous materials and its interaction with seawater may contribute to an overall lighter Zn isotope composition in seawater (δ⁶⁶Zn_sw). Under conditions characterized by high paleoproductivity and elevated organic burial rates, biological absorption of light Zn is primarily responsible for the low δ⁶⁶Zn values observed in organic-rich shales, indicating that organic-rich shales serve as an isotopically light Zn sink in the Yangtze Sea across the transition. Notably, the δ⁶⁶Zn_sw values observed during stage 1 are significantly lower than those recorded in stages 2 and 3, as well as below lithogenic source, possibly because during the early diagenetic stage, an excess of isotopically light Zn relative to ZnS in pore water was remobilized and subsequently released into deep seawater under oxidizing conditions. In summary, the transformation from an oxic environment to an anoxic (and even euxinic) environment resulted in a marked increase in δ⁶⁶Zn_sw values. This study presents new evidence from Zn isotopes regarding the oxic-anoxic (and even euxinic) transformation in the Yangtze Sea during the transition, while further underscoring the potential utility of δ⁶⁶Zn in organic-rich shales as a redox proxy for local paleo-ocean environments.</div></div>","PeriodicalId":50253,"journal":{"name":"Journal of Asian Earth Sciences","volume":"286 ","pages":"Article 106579"},"PeriodicalIF":2.7,"publicationDate":"2025-03-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143680929","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Fluoride enrichment in geothermal waters based on H, O, Sr, and Li isotopes of the Taiyuan Basin, North China","authors":"Chang Lu ,&nbsp;Ying Li ,&nbsp;Xiaocheng Zhou ,&nbsp;Yuwen Wang ,&nbsp;Weiye Shao ,&nbsp;Zhaojun Zeng ,&nbsp;Zhaofei Liu ,&nbsp;Dawei Liao ,&nbsp;Hui Zhang ,&nbsp;Huimin Mu","doi":"10.1016/j.jseaes.2025.106574","DOIUrl":"10.1016/j.jseaes.2025.106574","url":null,"abstract":"<div><div>Hydrochemical characteristics and fluid evolution are crucial for understanding geothermal water origins, assessing water quality, and evaluating regional seismic activity. This study investigates the hydrogeochemical processes responsible for elevated fluoride concentrations in the geothermal waters of the Taiyuan Basin. The investigation employed a combined approach, utilising water chemistry and isotopic data (δD, δ¹⁸O, ⁸⁷Sr/⁸⁶Sr, and δ⁷Li) from three distinct water sample types. These analyses elucidate the sources and mechanisms controlling fluoride enrichment in geothermal systems. The fluoride concentrations in these waters, ranging from 6.19 mg/L to 21.08 mg/L, were primarily influenced by water–rock interactions, mixing processes, and cation exchange. The isotopic data (δ¹⁸O and δD) indicate a meteoric origin for the geothermal waters and substantial interaction with carbonate and silicate minerals at reservoir temperatures between 110 °C and 140 °C. Elevated ⁸⁷Sr/⁸⁶Sr ratios (up to 0.716827) and δ⁷Li values (ranging from 8.2 ‰ to 20.4 ‰) further highlight extensive water–rock interactions, particularly with carbonate, evaporite, and clastic rocks. These processes facilitate the release of fluorides and other ions, thereby contributing to the increased salinity of geothermal fluids. Cation exchange, particularly between Na⁺ and Ca²⁺, further promoted fluoride retention in the solution, while evaporite dissolution contributed to the observed high salinity. The mixing between deep geothermal waters and shallower groundwater also influences geochemical variability. However, fluoride enrichment primarily occurs within the deeper geothermal reservoirs. This study highlights the complex interactions between hydrogeological, geochemical, and isotopic characteristics in controlling the fluoride concentrations within the Taiyuan Basin.</div></div>","PeriodicalId":50253,"journal":{"name":"Journal of Asian Earth Sciences","volume":"287 ","pages":"Article 106574"},"PeriodicalIF":2.7,"publicationDate":"2025-03-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143696069","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Anisotropy of magnetic susceptibility reveals the magma flow direction and emplacement history of Malani rhyolites, northwest India","authors":"Animireddi Venkata Satyakumar ,&nbsp;Mamilla Venkateshwarlu ,&nbsp;Pradyut Phukon","doi":"10.1016/j.jseaes.2025.106573","DOIUrl":"10.1016/j.jseaes.2025.106573","url":null,"abstract":"<div><div>Magma flow directions and emplacement may offer crucial details on the geodynamic and tectonic settings of magmatism. Malani Igneous Suite (MIS) in northwest India is a large silicic igneous province of the Neoproterozoic age. The eruption of MIS has been divided into three phases, with felsic (rhyolitic) lava flows and granitic plutons dominating the first phase and mafic lavas and felsic and mafic dykes acting as secondary components. The magma flow direction and emplacement history of Malani rhyolites are poorly understood. We study the magnetic mineralogy, microscopic observations, and anisotropy of magnetic susceptibility (AMS) of the Malani rhyolites to determine the magma flow directions and the emplacement mechanism. Ti-magnetite and Ti-hematite pseudo-single domains are the primary carrier minerals in the rhyolites. Prolate, oblate, and triaxial magnetic ellipsoid are observed and describe normal, intermediate, and inverse fabrics related to magma flow during emplacement. The principal susceptibility axes are well-clustered and independent of their shape factor (T) with a triaxial distribution, indicating well-developed magnetic lineation and foliation. In all three magnetic susceptibility axes, the magnetic lineation (K₁) aligns finest with the microscopic flow indicators. AMS investigation shows that the magnetic fabric is consistent with an ∼ E-W trending flow. The azimuthal orientation of magnetic lineation is consistent in all the sites representing an undisputed ∼ E-W trending flow sense; the plunge of the lineation is mutually opposite, hindering an unambiguous flow direction. AMS fabrics also show downward and upward flow that could be related to flank and summit eruptions.</div></div>","PeriodicalId":50253,"journal":{"name":"Journal of Asian Earth Sciences","volume":"286 ","pages":"Article 106573"},"PeriodicalIF":2.7,"publicationDate":"2025-03-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143680930","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Thermo-rheological structure of the lithosphere in Hainan Island, Southeast China and its geothermal significance","authors":"Kefu Li ,&nbsp;Chuanqing Zhu ,&nbsp;Mengfei Zhang ,&nbsp;Shudi Xing ,&nbsp;Yanyu Jia ,&nbsp;Chenxing Li","doi":"10.1016/j.jseaes.2025.106565","DOIUrl":"10.1016/j.jseaes.2025.106565","url":null,"abstract":"<div><div>Based on heat flow, seismic wave velocity, and rheological parameter data, this study constructs a thermo-rheological model of the lithosphere beneath Hainan Island, China. Using this model, we have determined the thermal structure, thermal lithosphere thickness, and rheological structure of the lithosphere beneath Hainan Island. The results indicate a “cold crust, hot mantle” thermal structure, with mantle heat flow ranging from 49 to 58 mW/m², contributing over 65 % of the total heat flow. Hainan Island exhibits a relatively thin thermal lithosphere that gradually thickens from north to south, and characterized by a high surface heat flow with corresponding changing trends. The rheological structure of Hainan Island follows a “brittle-ductile–brittle-ductile” pattern, characteristic of a “strong crust and weak mantle” configuration. Our analysis suggests that the high thermal state/condition and unique thermo-rheological structure of Hainan Island are closely related to the geodynamic background of Pacific plate subduction and the upwelling of the Hainan mantle plume. This upwelling has led to the formation of a high-temperature anomaly zone in the upper mantle beneath the island. Additionally, the thermal structure of the lithosphere significantly controls its rheological strength, with terrestrial heat flow influencing the regional strength of the lithosphere.</div></div>","PeriodicalId":50253,"journal":{"name":"Journal of Asian Earth Sciences","volume":"284 ","pages":"Article 106565"},"PeriodicalIF":2.7,"publicationDate":"2025-03-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143687366","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Structural Heterogeneity and Seismogenesis of the National Capital Region NCR-Delhi, India","authors":"Sasi Kiran Gera ,&nbsp;Ajay Pratap Singh ,&nbsp;Ambikapathy Ammani ,&nbsp;Sandeep ,&nbsp;Om Prakash Mishra","doi":"10.1016/j.jseaes.2025.106576","DOIUrl":"10.1016/j.jseaes.2025.106576","url":null,"abstract":"<div><div>The local earthquake tomography technique has been applied to determine seismic velocities (Vp and Vs) and Poission’s ratio (ϭ) to unravel the connection between the variability of structural heterogeneities and seismogenesis with reference to seismotectonic of the National Capital Region (NCR) of India. This investigation analyzed about 6000 direct phase arrival data for crustal earthquakes recorded by 26 seismic stations ascribed to the National Seismological Network of India. We observed that the seismogenic structures are closely aligned with the sub-surface geological and tectonic patterns. Structural heterogeneities in high seismic velocities (Vp, Vs) and low Poisson’s ratio (ϭ) are associated with in-situ geological structures at depths &lt; 30 km, where seismicity is concentrated conspicuously. This suggests that the competed rocks at shallow depths may be capable of seismogenesis in the area where most earthquakes occur. Specifically, ridges of the NCR inferred low Vp, Vs, and a high ϭ at deeper depths &gt; 30 km, suggesting underneath geological formations associated with potentially fluid-filled rock matrix. In contrast, areas with several fault dispositions exhibited high Vp, Vs, and low ϭ, suggesting the competency for brittle failure. The seismic events are prevalent across various velocity zones but are much pronounced in areas with high ϭ, from which we infer that seismogenesis of the NCR-Delhi is dictated by weaker structural heterogeneities associated with fluid-filled rock matrix having interlinkages with past river microchannels containing fluids at depths where a majority of earthquakes occurred.</div></div>","PeriodicalId":50253,"journal":{"name":"Journal of Asian Earth Sciences","volume":"286 ","pages":"Article 106576"},"PeriodicalIF":2.7,"publicationDate":"2025-03-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143759961","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Differential geological responses and geodynamic mechanisms of major Cenozoic tectonic Movements in the East China Sea Shelf basin","authors":"Yiming Jiang ,&nbsp;Xianjun Tang ,&nbsp;Xiaowei Fu ,&nbsp;Rongquan Zhong ,&nbsp;Weilin Zhu","doi":"10.1016/j.jseaes.2025.106569","DOIUrl":"10.1016/j.jseaes.2025.106569","url":null,"abstract":"<div><div>The East China Sea Shelf Basin (ECSSB) underwent complex tectonic evolution during the Cenozoic, shaped by interactions with surrounding geotectonic processes. This study examines six key tectonic interfaces (T80, T50, T40, T20, T12, T10) using 2D seismic data to assess their characteristics, distribution, and genesis. The T80 interface marks the transition of the Changjiang Depression into a post-rift stage, driven by the initial subduction of the Pacific-Izanagi ridge. Subsequent ridge subduction formed the T50 interface, characterized by magmatic activity, compression, uplift, and the deposition of large alluvial fans in northern ECSSB. The T40 interface, formed during the breakup of the South China Sea, is associated with widespread erosion and a significant hiatus in the southern ECSSB. The T20 interface reflects the initial subduction of the Philippine Sea Plate, triggering magmatic belt migration and uplift in the Diaoyu Island Fold Zone. The T12 interface highlights lateral compression linked to the early rifting of the Okinawa Trough, forming a central anticline in the Xihu Sag. Finally, the T10 interface, caused by arc-continent collision, contributed to deltaic deposition in the southeastern basin. These interfaces exhibit significant spatiotemporal variations, revealing the interplay between subduction, rifting, compression, and uplift. This study refines the understanding of tectonic phases in the ECSSB. The findings provide new perspectives on the basin’s geological complexity, contributing to broader knowledge of West Pacific geodynamics and basin evolution.</div></div>","PeriodicalId":50253,"journal":{"name":"Journal of Asian Earth Sciences","volume":"284 ","pages":"Article 106569"},"PeriodicalIF":2.7,"publicationDate":"2025-03-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143704453","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Genesis of dykes and mantle-crust interaction in the Keregetas swarm, Eastern Kazakhstan","authors":"Alexey S. Volosov ,&nbsp;Sergey V. Khromykh ,&nbsp;Andrey E. Izokh ,&nbsp;Pavel D. Kotler ,&nbsp;Dina V. Semenova ,&nbsp;Anna V. Kulikova ,&nbsp;Anna V. Naryzhnova","doi":"10.1016/j.jseaes.2025.106563","DOIUrl":"10.1016/j.jseaes.2025.106563","url":null,"abstract":"<div><div>Post-orogenic dyke swarms have occurred in many orogens within the CAOB. The dyke swarms that contains various rocks can provide information about the process of mantle magmas differentiation during uplift and interaction with crustal material at different levels. The Keregetas dyke swarm (Eastern Kazakhstan) contain more than 200 dykes of different compositions, intrusions of biotite granites and amphibole leucogranites in a comparatively small area. We present geochronology, petrography, mineralogy, major and trace element chemistry and Nd isotopic data. U-Pb (zircon) and Ar-Ar (amphibole) geochronological data indicate that all rocks were emplaced synchronously in the Early Permian (292–282 Ma). Detailed study of the mineralogical and geochemical data suggests that the two processes determined the magmatic rock diversity within Keregetas swarm: differentiation of the parental mafic magma and melting of crustal sources at different levels. All rocks show positive ℇNd(T) values which confirms the role of upper mantle in their formation. A two-stage model for the formation of the Keregetas dyke swarm was proposed: (1) differentiation and assimilation of mafic magma and the formation of leucogranitic magma during partial melting in the lower crust, and (2) the formation of granodiorite and granite magmas as a result of partial melting in the middle crust. The geodynamic setting responsible for the formation of the Keregetas dyke swarm was the process of post-collisional lithosphere extension in the Early Permian, occurring against the backdrop of a thermal anomaly in the upper mantle caused by the activity of the Tarim mantle plume.</div></div>","PeriodicalId":50253,"journal":{"name":"Journal of Asian Earth Sciences","volume":"284 ","pages":"Article 106563"},"PeriodicalIF":2.7,"publicationDate":"2025-03-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143645038","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Sedimentary evolution for the Wuling secondary rift of the western Nanhua Rift and exhalative-sedimentary mineralization cycles of “Datangpo-type” manganese ore deposits in South China","authors":"Chonglong Wu ,&nbsp;Sui Zhang ,&nbsp;Kai Xu ,&nbsp;Liangjun Yuan ,&nbsp;Chunfang Kong ,&nbsp;Zhiting Zhang ,&nbsp;Hongqian Shen","doi":"10.1016/j.jseaes.2025.106566","DOIUrl":"10.1016/j.jseaes.2025.106566","url":null,"abstract":"<div><div>The “Datangpo-type” manganese ore deposits, hosted within the Neoproterozoic Nanhua system (<em>Pt₃³n</em>) in the Tongren area of northeastern Guizhou Province (China), represents a newly identified deep-seated manganese-bearing fluid exhalative-sedimentary deposit. Using basic theories and methods of basin analysis and sedimentology, the main ore-bearing structural unit of the Songtao–Guzhang graben (level III) in the Nanhua Rift was analyzed to determine the metallogenic mechanism and distribution law governing Datangpo-type manganese ore deposits, with systematic focus on the sedimentary facies and depositional environments of the Nanhua system. Analysis revealed that the sedimentary characteristics of terrigenous clastic rocks and the vertical evolution of sedimentary facies in the Nanhua system reflect a complete rift-filling sequence, i.e., sections of initial, accelerated, rapid, decelerated, and ceased subsidence filling. The spatial distributions and vertical changes in rhodochrosite ore beds in terms of structure, thickness, and grade were obviously controlled by the rift stage and changes in the exhalative strength of the manganese-containing fluid, in addition to the sedimentary environment and sedimentary process. The strata hosting rhodochrosite ore beds are located mainly in the basal part of the first member of the Datangpo Formation, i.e., at the bottom of the section of rapid subsidence filling, which is a product of deep manganese-containing fluid exhalative-sedimentary processes from the early stage of maximum rifting. The exhalative-sedimentary processes of ore-forming materials exhibit five major macrocycles, and reveal spatiotemporal patterns in the mineralization of rhodochrosite ores across the study area.</div></div>","PeriodicalId":50253,"journal":{"name":"Journal of Asian Earth Sciences","volume":"287 ","pages":"Article 106566"},"PeriodicalIF":2.7,"publicationDate":"2025-03-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143777439","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Tracing metal sources in orogenic gold deposits of the Timburu Goldfield, Meratus, Indonesia: A geochemical and statistical approach","authors":"Andy Yahya Al Hakim ,&nbsp;Arjan H. Dijkstra ,&nbsp;Frank Melcher ,&nbsp;Viktor Bertrandsson Erlandsson ,&nbsp;Monika Feichter","doi":"10.1016/j.jseaes.2025.106561","DOIUrl":"10.1016/j.jseaes.2025.106561","url":null,"abstract":"<div><div>Orogenic gold deposits at the Timburu Goldfield, Indonesia, are primarily hosted by metamorphosed ultramafic and volcanic rocks, as well as quartz lodes formed along shear zones. Gold mineralisation developed along the lithological contacts between serpentinites, porphyritic intrusions, and granitoids. The mineralization is represented by electrum and hessite, with trace amounts of chalcopyrite, galena, tetrahedrite, and Co-Ni-As-S phases. The alteration mineralogy of mafic rocks in Timburu includes magnesite, dolomite, sericite, albite, calcite, and chlorite. This study integrates a multi-statistical evaluation of in-situ trace-element data, geological relationships, and detailed mineralogical characterisation to better understand the evolution of geochemical reservoirs responsible for metal accumulation during orogenic events. Principal component analysis (PCA) produced three significant components that explained 80% of the cumulative variance. We divide the pyrite data into three groups based on trace element correlations, which are likely linked to pyrite texture and paragetic sequences. The results show that the Ni-Co and other metals were leached from metamorphosed ultramafic rocks and mobilised during alteration. Metals, including Au have been released during greenschist- to amphibolite-facies metamorphism in the context of a continent–continent collision. The rare earth element (REE) patterns of metavolcanic and serpentinised ultramafic rocks may be similar to other accretionary complexes formed during continent–continent collision. The transformation of serpentinite to listvenite is controlled by the addition of carbon dioxide and the mobilisation of SiO₂, MgO, and CaO. Chemical changes during alteration are primarily dominated by the incorporation of trace elements into pyrite.</div></div>","PeriodicalId":50253,"journal":{"name":"Journal of Asian Earth Sciences","volume":"285 ","pages":"Article 106561"},"PeriodicalIF":2.7,"publicationDate":"2025-03-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143684794","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Origin, maturity and geochemistry of natural gas in the Yancheng Sag, Subei Basin, China: Insights from pyrolysis experiments and basin modeling","authors":"Yuantao Tang ,&nbsp;Kai Xue ,&nbsp;Xianzhi Gao ,&nbsp;Yan Song ,&nbsp;Heyong Li ,&nbsp;Yonghui Wang","doi":"10.1016/j.jseaes.2025.106558","DOIUrl":"10.1016/j.jseaes.2025.106558","url":null,"abstract":"<div><div>Natural gas-sources correlation is crucial for determining the target of natural gas accumulation. The Zhujiadun gas field discovered in the Cretaceous Taizhou-Paleogene Funing (K₂<em>t</em>-E₁<em>f</em>) formations is one of the most important gas fields in the Subei Basin. However, the origin of natural gas in the Zhujiadun gas field is controversial, seriously restricting future exploration. In this study, organic geochemistry, gold-tube hydrous pyrolysis experiments, and basin modeling were performed to comprehensively investigate the origin, maturity and geochemistry of natural gas in the Zhujiadun gas field. The results show that: (1) the natural gas in this gas field is sapropelic-sourced thermogenic gas, which is predominately from the secondary cracking of crude oil. (2) New empirical equations for calculating the maturity of natural gas in the Yancheng sag are established based on the relationship between the carbon isotopic composition of methane and the thermal maturity of kerogen. The calculated average Ro value of natural gas is 2.2 %. (3) The Yancheng Sag has evolved through three subsidence cycles. Potential Paleozoic source rocks are currently in the post-maturity period, while the Paleogene source rocks are still in the oil generation window. (4) The natural gas in the Zhujiadun gas field predominantly originates from the source rocks of the Ordovician Wufeng-Silurian Gaojianbian formations. These results provide insights into the source of natural gas in the Zhujiadun gas field and a basis for natural gas exploration in the future.</div></div>","PeriodicalId":50253,"journal":{"name":"Journal of Asian Earth Sciences","volume":"285 ","pages":"Article 106558"},"PeriodicalIF":2.7,"publicationDate":"2025-03-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143698077","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}