Journal of Asian Earth Sciences最新文献

{"title":"Origin of Pb–Zn deposits in the Hengyang Basin in the central part of the Qin-Hang metallogenic belt (South China): An example from the Yantianqiao deposit","authors":"Hongjie Shen ,&nbsp;Yu Zhang ,&nbsp;Yuzhou Feng ,&nbsp;Yongjun Shao ,&nbsp;Huajie Tan ,&nbsp;Yuming Liang ,&nbsp;Fubing Jiang ,&nbsp;Zebin Tang ,&nbsp;Shan Liu ,&nbsp;Bing Zhu ,&nbsp;Junhong Liao","doi":"10.1016/j.jseaes.2025.106824","DOIUrl":"10.1016/j.jseaes.2025.106824","url":null,"abstract":"<div><div>The metallogenesis of hydrothermal vein-type Pb–Zn deposits in the Hengyang Basin, part of the central Qin-Hang Metallogenic Belt (QHMB, South China), remains debate, with magmatic-hydrothermal and MVT models proposed. Yantianqiao (33903 t @ 3.25 % Pb and 1542 t @ 2.62 % Zn) is a representative deposit, features four distinct mineralization stages: (I) quartz-pyrite, (II) quartz-pyrite-chalcopyrite, (III) main-ore quartz-galena-sphalerite, and (IV) quartz-calcite. The limited pyrite δ³⁴S range (−5.8 to −1.7 ‰), similar ²⁰⁷Pb/²⁰⁶Pb ratios between galena (0.8483–0.8488) and the Zhaobingshan granodiorite (corrected average 0.86), and sphalerite geochemistry (Fe-In-enriched, Ga-Ge-depleted), reveal a genetic link between mineralization and the granodiorite. The low Co/Ni ratios (average 2.01) and δ³⁴S_V-CDT values (−4.0 ‰) of Stage I pyrite, commonly trapping silicate inclusions, indicate the marked fluid-rock interaction. The high Se/Te ratios (14.3) and As concentrations (median: 249 ppm), but depleted Co-Ni, of Stage II pyrite (Py-II) suggest minor meteoric fluid influx during this stage, also evidenced by the reported quartz H–O isotopes. Furthermore, low-<em>f</em>S₂ condition (−10.5 to −12.4) and Mn-depletion (0.869 ppm) of Stage III sphalerite (Sp-III) reflect the waning magmatism and increased meteoric fluid influx during Stage III, consistent with its low formation temperature revealed by Ni-Se-Bi-Mo depletion and SPRFT geothermometer result (119 ± 29 °C) of Sp-III. Therefore, Yantianqiao is inferred to be a magmatic-hydrothermal deposit genetically related to the Zhaobingshan granodiorite, with Pb–Zn mineralization driven by a progressively increasing meteoric fluid influx. This study advances the understanding of Pb–Zn ore genesis in the Hengyang Basin and provides insights applicable to similar sedimentary basins worldwide.</div></div>","PeriodicalId":50253,"journal":{"name":"Journal of Asian Earth Sciences","volume":"294 ","pages":"Article 106824"},"PeriodicalIF":2.4,"publicationDate":"2025-10-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145266669","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":"Influence of late Quaternary climate change and Neo-tectonic on fluvial aggradation and incision in the Markanda valley, NW Himalaya","authors":"Mohammad Atif Raza ,&nbsp;Radhakrishna Vishnu Chunchekar ,&nbsp;Neha Singh ,&nbsp;Sharat Dutta ,&nbsp;Ramanathan Bhavani ,&nbsp;Nigar Jahan ,&nbsp;Abhinandan Srivastava ,&nbsp;Kankanaa Mondal ,&nbsp;Satavisha Ganguly ,&nbsp;Mohd. Sadiq","doi":"10.1016/j.jseaes.2025.106822","DOIUrl":"10.1016/j.jseaes.2025.106822","url":null,"abstract":"<div><div>Tectonics and surface processes shape the Earth, and the Himalayas are a key region for studying the relationship between fluvial dynamics and active tectonics. Our study focuses on the monsoon-dominated Markanda River Valley, in NW Himalaya, aiming to reveal the river geomorphology and sedimentation history and elucidate the interactions between monsoonal variability and tectonic activity. Through detailed field mapping, sedimentological measurements and Optically Stimulated Luminescence (OSL) dating, we identified at least five major aggradation phases (&gt;45 to 38 ka, &gt;27–23 ka, ∼17–12 ka, 10–5.8 ka and 3.4–3 ka) with intermittent incision phases. These phases are the reflection of the changes in the strength of the Indian Summer Monsoon (ISM), aligning with global climatic events during the Pleistocene-Holocene transition. Geomorphological, sedimentological, and geochronological analyses reveal fan inter-fingering with fluvial facies from &gt; 45 ka to 38 ka, indicating a high-energy environment and strong monsoons. Incision during the Last Glacial Maximum (∼25 ka) reflects weakened ISM, reducing sediment flux, while rapid aggradation (∼17–12 ka, 10–5.8 ka), corresponds to strengthened ISM. We estimate an average uplift rate of 4.4 ± 0.4 mm/year along the HFT over 7 ka and the regional comparisons confirm the climatic coherence. The evidence of HFT reactivation aligns with documented tectonic events, however, ISM fractionations significantly influenced aggradation and incision in the Markanda Valley.</div></div>","PeriodicalId":50253,"journal":{"name":"Journal of Asian Earth Sciences","volume":"294 ","pages":"Article 106822"},"PeriodicalIF":2.4,"publicationDate":"2025-10-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145266668","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":"Seismically induced soft-sediment deformation in alluvial fans: mechanisms and implications for geological evolution of the Ordos Basin (China)","authors":"Ahmer Bilal ,&nbsp;Renchao Yang ,&nbsp;Shaojie Chen ,&nbsp;Nils Lenhardt ,&nbsp;Muhammad Saleem Mughal ,&nbsp;George Kontakiotis","doi":"10.1016/j.jseaes.2025.106821","DOIUrl":"10.1016/j.jseaes.2025.106821","url":null,"abstract":"<div><div>Well-exposed soft-sediment deformation structures (SSDS) outcrops are rare and often mistaken for tectonic folds, leading to limited research and underutilisation in sedimentary geology. The Taitongshan section of the Middle-Permian Shihezi Formation in the Ordos Basin, China, provides insights into SSDS, whose spatial distribution and sedimentation reveal information about paleoenvironments, tectonic movements, and seismic events crucial for understanding basin development. This study uses fieldwork and sedimentology to investigate SSDS formation and triggers. Fieldwork identified six siliciclastic facies with SSDS and associated syndepositional structures. Sedimentological interpretations highlighted the connection between seismic activity and the genesis of SSDS, reinforcing their value as proxies for tectonic events in basin evolution studies. SSDS formation is triggered by seismic shaking, initiating liquefaction, erosion, slurry-clump formation, hydroplastic deformation, mass consolidation, and lithification. Rayleigh waves-induced liquefaction in partially-lithified subsurface sediments forms water escape structures. Provenance analysis reveals seismically active, orogenic source areas southwest and southeast of the NCC, with significant uplift and erosion during the Middle-Permian. Key findings indicate that the Middle-Permian braided river facies of the Taitongshan section originated from the Qilian Orogenic Belt, followed by a subsequent provenance shift towards the eastern-North Qinling Orogeny (NQLO), highlighting the dynamic tectonic forces driving rapid provenance shifts, further shaping sediment deposition and advancing basin evolution. Furthermore, the southeastern NCC experienced a more rapid uplift than the southwestern part during that time. These facies were deposited on the distal fan region of a prograding alluvial fan, where seismites likely formed due to active seismicity in the NQLO. The study identifies inter-facies shifts during seismite formation, introducing an innovative concept beyond traditional in-situ genesis models and broadening the understanding of sedimentary dynamics. This critical role of SSDS in sedimentation architecture enhances the understanding of basin evolution in sedimentary geology and provides a framework for interpreting similar structures globally.</div></div>","PeriodicalId":50253,"journal":{"name":"Journal of Asian Earth Sciences","volume":"294 ","pages":"Article 106821"},"PeriodicalIF":2.4,"publicationDate":"2025-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145266671","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":"Towards resolving the paleoposition of the North China Block at the Carboniferous-Permian boundary: preliminary paleomagnetic results of limestones from the ∼300 Ma Taiyuan Formation, North China.","authors":"Wenhao Liu ,&nbsp;Donghai Zhang ,&nbsp;Nan Jiang ,&nbsp;Qian Zhao ,&nbsp;Yigui Han ,&nbsp;Jinlong Yao ,&nbsp;Qian Liu ,&nbsp;Baochun Huang ,&nbsp;Guochun Zhao","doi":"10.1016/j.jseaes.2025.106818","DOIUrl":"10.1016/j.jseaes.2025.106818","url":null,"abstract":"<div><div>The North China Block (NCB), sandwiched between the Paleo-Tethys and Paleo-Asian Ocean realms, is crucial to the paleogeographic reconstruction of the East Asian blocks in the assembly of the Pangea supercontinent. However, paleoposition of the NCB remains poorly constrained during ∼330–290 Ma, due to difficulties in obtaining reliable paleomagnetic results from the pervasive coal-bearing strata. To solve this puzzle, we find the exclusive targets, several layers of limestones from the Taiyuan Formation in the Xiangning and Lingchuan areas, southern Shanxi Province, and conducted a combined petrographic, rock magnetic, and paleomagnetic study. The dominant magnetic carriers of the Xiangning limestones are magnetite and subordinate pigmentary hematite. The hematite is of secondary origin, while the unoxidized magnetite retains the ability to carry primary remanences. Magnetic carriers of the Lingchuan limestones are magnetite, subordinate hematite, and pyrite. Characteristic remanent magnetizations are isolated from 61 of 99 samples. The newly obtained Lingchuan pole is close to the 120 Ma pole of the NCB, possibly indicating a secondary remagnetization obtained in the Yanshanian Orogeny. The Xiangning pole is located at P_lat = 39.9°N, P_long = 340.7°E (A₉₅ = 5.0°<em>,</em> n = 6 samples). Although limited specimens are insufficient to reliably constrain the paleoposition of the NCB, we note the invaluable preliminary pole does not overlap with any younger poles, shedding light on finally resolving the paleoposition of the NCB at the Carboniferous-Permian boundary. Thus, we suggest the Xiangning limestones likely record primary remanences, indicating an equatorial paleolatitude of the NCB.</div></div>","PeriodicalId":50253,"journal":{"name":"Journal of Asian Earth Sciences","volume":"293 ","pages":"Article 106818"},"PeriodicalIF":2.4,"publicationDate":"2025-09-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145219799","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":"Revisiting the seismic hazard of surrounding faults following the 2021 Maduo (China) MW 7.3 earthquake based on the updated co-seismic slip model","authors":"Lei Liu ,&nbsp;Yujiang Li ,&nbsp;Lingyun Ji ,&nbsp;Qi Liu ,&nbsp;Yanhui Liu","doi":"10.1016/j.jseaes.2025.106815","DOIUrl":"10.1016/j.jseaes.2025.106815","url":null,"abstract":"<div><div>The 2021 <em>M</em>_W7.3 Maduo (Qinghai, China) earthquake occurred on the Kunlun Pass–Jiangcuo fault within the Bayan Har block. Due to limited observational data, discrepancies exist among published co-seismic slip models, which directly impact the seismic hazard analysis for surrounding faults. In this study, we jointly inverted the co-seismic slip model of the Maduo earthquake using co-seismic observations from campaign GNSS stations, regional continuous GNSS stations, and InSAR data. Our results reveal that the geometry of the rupture fault exhibits significant variation along its strike and comprises five distinct fault segments. The earthquake exhibits a peak slip of 4.0 m, with a seismic moment of 1.69 × 10²⁰ N m, corresponding to an <em>M</em>_W7.42. Constrained by this co-seismic slip model, we further investigated the co- and post-seismic Coulomb stress change of surrounding faults, employing a three–dimensional viscoelastic finite element model of the eastern Bayan Har block. Our findings indicate that the Maduo earthquake induced significant stress loading (&gt;1.0 × 10⁴ Pa) on the Maqin–Maqu and Tuosuo Lake segments of the Eastern Kunlun fault, the southeastern segment of the Xizangdagou fault, etc. These findings, integrated with the elapsed time of historic earthquakes on both the Maqin–Maqu and Tuosuo Lake segments, which have approached or exceeded their recurrence intervals, underscore the need for increased attention to these fault segments.</div></div>","PeriodicalId":50253,"journal":{"name":"Journal of Asian Earth Sciences","volume":"294 ","pages":"Article 106815"},"PeriodicalIF":2.4,"publicationDate":"2025-09-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145219782","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":"Interplay of abiotic, biotic, and environmental controls on travertine formation: Insights from Baishuitai (White Water Terraces), Southwest China","authors":"Zhijun Wang ,&nbsp;Jian-Jun Yin","doi":"10.1016/j.jseaes.2025.106820","DOIUrl":"10.1016/j.jseaes.2025.106820","url":null,"abstract":"<div><div>Travertines, striking carbonate formations created by mineral-rich spring waters, develop through an interplay of abiotic and biotic processes. Yet, the roles and interactions of these processes across travertine systems remain unclear. In this study, we investigated the Baishuitai, a large, active travertine in Southwest China, using geochemical and petrographic methods to explore how abiotic and biotic processes interact and drive travertine deposition and decipher the environmental factors controlling them. The results show that the travertines are precipitated by waters issuing from springs that have relatively low temperatures (∼10.8 °C) and are highly enriched in Ca²⁺ and HCO₃⁻ (∼200 mg/L and 770 mg/L, respectively) and CO₂ (∼10^−0.9 atm). Geochemical data (e.g., δ¹³C_DIC: −0.1 ‰) confirm that these waters originate from a mix of meteoric recharge and deep-seated CO₂ transported via neotectonic faults. Owing to the enrichment of CO₂ in spring water, significant calcite precipitation occurs primarily through abiotic processes that are driven by rapid CO₂ degassing along the flow path. Additionally, microbial biofilms greatly modulate the deposition by creating localized zones for mineralization, providing crystal nucleation sites, and trapping particles with their mucilage. The interplay of abiotic and microbially influenced processes varies in different depositional environments and is mainly governed by water chemistry dynamics, topography-driven flow conditions, biological growth pattern, and seasonal climate changes. The study illuminates the primacy of abiotic processes, the subtle yet crucial role of microbes, and the environmental controls sculpting travertine in low-temperature, CO₂-rich systems, which has significance to the full understanding of the development of travertine formations.</div></div>","PeriodicalId":50253,"journal":{"name":"Journal of Asian Earth Sciences","volume":"294 ","pages":"Article 106820"},"PeriodicalIF":2.4,"publicationDate":"2025-09-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145219781","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 the Katbasu gold deposit in the western Tianshan, NW China: Constraints from fluid inclusions and H-O, S, and Pb isotopes","authors":"Jianye Zhang ,&nbsp;Yongjun Li ,&nbsp;Panlong Wang ,&nbsp;Wei Li ,&nbsp;Qian Wang ,&nbsp;Nanhe Peng ,&nbsp;Hao Fu ,&nbsp;Gaoxue Yang","doi":"10.1016/j.jseaes.2025.106819","DOIUrl":"10.1016/j.jseaes.2025.106819","url":null,"abstract":"<div><div>The Katbasu gold deposit, located in the western Tianshan tectonic belt of Xinjiang, China. The genesis of this deposit remains controversial. This study conducted field geological investigations, fluid inclusion (FIs) studies, and stable isotopes (H-O, S, and Pb) analyses. The results indicate that the host rocks exhibit pyritization, the ore minerals are dominated by pyrite with minor chalcopyrite, sphalerite, galena, and native gold. The hydrothermal mineralization period can be divided into three stages: quartz-pyrite veins (early stage), native gold-polymetallic sulfide-quartz veins (middle stage), and quartz-carbonate veins (late stage). The homogenization temperatures of FIs for the early, middle, and late stages are 296.6–344.4℃, 206.4–297.7℃, and 146.7–199.2℃, respectively. The corresponding salinities range from 9.74–12.55 wt%, 5.26–11.61 wt%, and 3.71–5.56 wt%, with densities of 0.76–0.85 g/cm³, 0.77–0.90 g/cm³, and 0.90–0.95 g/cm³. The δ¹⁸O_fluid values range from 3.2 to 3.6 ‰, while the δD values range from −93.4 to −98.1 ‰. The H-O isotopic indicates that the ore-forming fluids were primarily derived from metamorphic water, with involvement of meteoric water. The δ³⁴S_H2S values range from 7.08 ‰ to 9.78 ‰, with ²⁰⁶Pb/²⁰⁴Pb ratios of 18.26 to 19.38, ²⁰⁷Pb/²⁰⁴Pb ratios of 15.60 to 15.65, and ²⁰⁸Pb/²⁰⁴Pb ratios of 38.17 to 38.49. The S and Pb isotopic suggest that the metamorphic stratigraphy played a significant role. Based on previous studies, FIs data, and isotopic compositions of H-O, S, and Pb, the Katbasu gold deposit is classified as an early skarn-type magmatic-hydrothermal deposit and was subsequently overprinted by an orogenic-type gold deposit.</div></div>","PeriodicalId":50253,"journal":{"name":"Journal of Asian Earth Sciences","volume":"294 ","pages":"Article 106819"},"PeriodicalIF":2.4,"publicationDate":"2025-09-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145219871","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":"Effects of secondary pores within K-feldspar and laumontite on the reservoir quality of tight sandstone from the Upper Triassic succession, Ordos Basin, China","authors":"Lei Xu ,&nbsp;Baobao Cao","doi":"10.1016/j.jseaes.2025.106817","DOIUrl":"10.1016/j.jseaes.2025.106817","url":null,"abstract":"<div><div>The Chang-6 member of the Upper Triassic Yanchang Formation in the Ordos Basin is a productive tight sandstone reservoir. In addition to residual primary intergranular pores, secondary pores within K-feldspar and laumontite are key components of the pore system in these reservoirs. However, the specific roles of these secondary pores in reservoir quality remain unquantified. This study integrated back-scattered scanning electron microscopy with energy dispersive spectrum (BSEM-EDS) analysis, image processing, and fractal analysis to characterize the secondary pore structures within K-feldspar and laumontite. To address challenges in quantifying their contributions to reservoir quality, a novel method combining the results of BSEM-EDS, mercury intrusion capillary pressure (MICP), and nuclear magnetic resonance (NMR) was developed. The results indicate that the secondary pores within K-feldspar and laumontite primarily serve as reservoir throats, controlling reservoir permeability. K-feldspar dissolution exhibits a negative correlation with its Na⁺ content, especially when primary intergranular pores are incompletely filled by interstitial materials. Laumontite dissolution is inhibited by high Ca²⁺ concentration in the formation water and a closed diagenetic environment. Mineral brittleness and cleavages significantly influence the pore structure complexity of K-feldspar and laumontite. Compared with laumontite secondary pores, K-feldspar secondary pores contribute more substantially to reservoir quality, providing critical insights for “sweet spot” identification in tight sandstone reservoirs.</div></div>","PeriodicalId":50253,"journal":{"name":"Journal of Asian Earth Sciences","volume":"294 ","pages":"Article 106817"},"PeriodicalIF":2.4,"publicationDate":"2025-09-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145219783","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":"The formation and evolutionary process of earth fissure group in Dacheng County, Northern Hebei Plain, China","authors":"Fujiang Wang ,&nbsp;Feiyong Wang ,&nbsp;Jianbing Peng ,&nbsp;Jishan Xu","doi":"10.1016/j.jseaes.2025.106816","DOIUrl":"10.1016/j.jseaes.2025.106816","url":null,"abstract":"<div><div>Nearly a thousand earth fissures have developed in the Hebei Plain, with a total length exceeding 100 km, making it one of the most severely affected areas by earth fissure disasters in China. Approximately 70 % of the earth fissures in the Hebei Plain are tectonic in nature, among which the earth fissure groups in Dacheng County are a typical example, causing significant economic losses locally. To reveal the genetic mechanisms of the earth fissure groups in Dacheng County, methods including historical data collection, geological surveys, measurements, trenching, drilling, geophysical exploration, and InSAR were employed to investigate their development process and analyze the evolution of controlling factors across different periods. The results show that the current earth fissure group in Dacheng County consist of eight earth fissures, predominantly striking NE and parallel to Dacheng faults, with a total length of 5 km. Most earth fissures are located on the hanging wall of faults, with damage manifested as field ruptures and sinkholes, primarily causing tensile damage to buildings. On shallow profiles, there is no significant vertical displacement of strata, but faults are present at greater depths and correspond to the locations of the main earth fissures. The development of the earth fissure groups in Dacheng County is considered to have occurred in three distinct stages. Initially, the first exposure of the earth fissure groups was triggered by seismic forces that activated the underlying faults, resulting in numerous vertical fractures within the overlying soil. Some of these vertical fractures extended to the surface, forming earth fissures, while others remained concealed, laying the structural foundation for the continued development of the earth fissure groups. Secondly, the overpumping of groundwater led to differential settlement of the soil layers, accelerating the exposure and expansion of the earth fissures. Finally, significant surface water from heavy rainfall and irrigation infiltrated through the fractures, with intense water erosion causing the earth fissures to repeatedly expose at the surface. This study has significant guiding importance and practical value for the research and prevention of earth fissures in the Hebei Plain.</div></div>","PeriodicalId":50253,"journal":{"name":"Journal of Asian Earth Sciences","volume":"293 ","pages":"Article 106816"},"PeriodicalIF":2.4,"publicationDate":"2025-09-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145219796","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":"Ore genesis of the Baimashan Fe-S crypto-explosive breccia deposit in Fanchang volcanic basin, eastern China: insights into the ultra-shallow intrusive metallogenesis","authors":"Songsong Zhang ,&nbsp;Shu Zhang ,&nbsp;Xiaoyong Yang ,&nbsp;Yu Wang ,&nbsp;Wei Li ,&nbsp;Yunlou Yang ,&nbsp;Guohui Wei","doi":"10.1016/j.jseaes.2025.106812","DOIUrl":"10.1016/j.jseaes.2025.106812","url":null,"abstract":"&lt;div&gt;&lt;div&gt;The Baimashan iron-sulfur polymetallic deposit exemplifies an ultra-shallow cryptoexplosive breccia-type deposit situated in the Fanchang region of the Middle-Lower Yangtze Metallogenic Belt (MLYMB) in eastern China, with its formation occurring at a depth of approximately 400 m. Analyzing its metallogenic characteristics and processes offers significant insights into the late Mesozoic ultra-shallow mineralization within the MLYMB. A thorough petrographic analysis reveals that magnetite (Mag, 0.5–1 mm) is associated with a specific metallogenic stage, while pyrite can be categorized into Py Ⅰ (early stage, 0.5–1 mm) and Py II (late stage, &lt;0.1 mm). Laser ablation-inductively coupled plasma-mass spectrometry (LA-ICP-MS) techniques, including element point and mapping analyses, in addition to in-situ sulfur isotope analysis of pyrite, are employed to determine the genesis of the deposit and the evolution of the ore-forming hydrothermal fluid. The temporal signal diagram derived from LA-ICP-MS point analysis, element binary diagrams, and LA-ICP-MS mapping outcomes collectively demonstrate that the majority of trace elements present in both magnetite and pyrite exist as solid solution within the mineral structure. However, magnetite contains partial incorporation of Co, Ni, As, Sb, Ti, Sn, and W, while pyrite incorporates Ag, Bi, Tl, and Sb into its sulfide inclusions. Additionally, LA-ICP-MS analysis reveals that Py Ⅰ exhibits relatively higher concentrations of Co, Ni, and As, whereas Py II shows enrichment of Cu, Pb, Zn, Ag, Sb, and Tl. Notably, the Co/Ni ratios in both Py Ⅰ and Py II exhibit similar trends and temperature ranges, suggesting a shared variation in temperature during their formation. Moreover, the Co/Ni mapping image’s cross section provides a detailed depiction of the temperature fluctuations during the process of pyrite formation. The discriminant diagram provides evidence supporting the hydrothermal origin of magnetite, and all suggests that pyrite was formed in a hydrothermal environment with lower temperatures with two hydrothermal pulses. Analysis of in-situ sulfur isotopes reveals that the δ&lt;sup&gt;34&lt;/sup&gt;S values of Py Ⅰ range from +3.41 ‰ to +5.54 ‰, with an average of 4.63 ‰, while Py II has δ&lt;sup&gt;34&lt;/sup&gt;S values ranging from +2.47 ‰ to +4.50 ‰, with an average of 3.62 ‰. Through a comparative analysis and discussion of regional skarn-type and porphyrite-type iron ores, it is inferred that the ore-forming fluid exhibits characteristics indicative of a mixture between magmatic hydrothermal fluid and meteroic water, with minimal involvement of brine from gypsum layers. Building upon this research, this paper develops a metallogenic model for the Baimashan ultra-shallow intrusive deposit. By examining the mineralization processes of porphyrite-type iron deposits, it is suggested that too early occurrence of cryptoexplosion, resulting from ultra-shallow emplacement, is detrimental to the enrichment and mineralizati","PeriodicalId":50253,"journal":{"name":"Journal of Asian Earth Sciences","volume":"294 ","pages":"Article 106812"},"PeriodicalIF":2.4,"publicationDate":"2025-09-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145219784","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}