Geoscience frontiers最新文献

{"title":"Characteristics and distribution of late Carboniferous to early Permian wildfires and their controlling factors","authors":"Yanan Li ,&nbsp;Jingqi Xue ,&nbsp;Shuai Wang ,&nbsp;Zhaorui Ye ,&nbsp;Jiao Fang ,&nbsp;Xiongxiong Li","doi":"10.1016/j.gsf.2025.102100","DOIUrl":"10.1016/j.gsf.2025.102100","url":null,"abstract":"<div><div>The late Carboniferous to early Permian period is renowned for extensive coal formation and frequent paleowildfires. Nonetheless, the nature and distribution of these wildfires varied significantly over time. In an effort to elucidate the patterns of paleowildfires during the late Paleozoic Ice Age and to probe into the controlling mechanisms of paleowildfires under icehouse conditions, a comprehensive analysis was performed on coal samples from the Taiyuan and Shanxi formations within the Dacheng coalfield of Hebei Province, North China. The dataset was augmented with global inertinite data from the late Carboniferous to early Permian periods and was compared to paleowildfire patterns from the Pliocene to Holocene epochs. The results show that paleowildfires in the Dacheng coalfield of North China transitioned from moderate-scale, low-intensity surface fires to large-scale, relatively high-intensity ground fires. Globally, the distribution of paleowildfires shifted from Euramerica to Gondwana, Cathaysia, and Angara from 300 Ma to 290 Ma, accompanied by a corresponding increase in inertinite content. This spatial and temporal variation in wildfire activity appears to have been strongly influenced by paleoclimate and atmospheric conditions. At 300 Ma, cooler and wetter paleoclimate, coupled with relatively low atmospheric <em>p</em>O₂ levels, likely contributed to a reduced incidence of paleowildfires. In contrast, at 290 Ma, warmer paleoclimate, higher atmospheric <em>p</em>O₂ levels, and the flourishing mires in Gondwana, Cathaysia, and Angara were conducive to more intense paleowildfires. This pattern is further supported by the comparison to more recent icehouse periods. Similar to the late Carboniferous–early Permian period, wildfire activity increased from the Pliocene to the Holocene, highlighting the critical role of climatic conditions in driving wildfire proliferation under icehouse conditions. However, the Pleistocene to Holocene wildfires were less intense than those of the late Carboniferous–early Permian, suggesting that atmospheric oxygen concentrations played a key role in modulating the evolution of the fire systems over geological timescales. These findings underscore the complex interplay between climate, atmospheric composition, and vegetation in shaping wildfire dynamics across Earth’s history.</div></div>","PeriodicalId":12711,"journal":{"name":"Geoscience frontiers","volume":"16 5","pages":"Article 102100"},"PeriodicalIF":8.5,"publicationDate":"2025-06-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144490310","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"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 snapshot of subduction initiation within a back-arc basin: Insights from Shiquanhe ophiolite, western Tibet","authors":"Wei-Liang Liu ,&nbsp;Hui Liang ,&nbsp;Harald Furnes ,&nbsp;Xu Zhang ,&nbsp;Qing-Gao Zeng ,&nbsp;Yao-Liang Ma ,&nbsp;Chi Yan ,&nbsp;Ru-Xin Ding ,&nbsp;Yun Zhong ,&nbsp;Run-Xi Gu","doi":"10.1016/j.gsf.2025.102088","DOIUrl":"10.1016/j.gsf.2025.102088","url":null,"abstract":"<div><div>Back-arc basins are key sites for oceanic lithosphere formation and consumption at convergent plate boundaries, and their formation and subduction processes can be highly variable. The tectonic setting and evolution of the Meso-Tethys Shiquanhe-Jiali ophiolite sub-belt (SJO sub-belt) within Bangong-Nujiang Suture Zone (BNSZ), central Tibet, are disputed for the complex rock composition and ages. In this paper, we present geochronology, geochemistry and field observations on the Shiquanhe ophiolite, providing a representative ophiolite example in the western end of SJO. Based on investigation of the petrogenesis and tectonic setting of different rock types, combined with the U-Pb dating, we propose a two-stage subduction model for explaining the tectonic evolution of SJO as well as the wither away of a back-arc basin. Geochemical and geochronological data indicate that the ca. 183 Ma LAN (north of Lameila) gabbros formed in the forearc setting and represent the early-stage subduction of the Bangong Meso-Tethys. This subduction induced the back-arc spreading recorded in the ca. 170 Ma gabbros and lower pillow basalts of PL-SDN (Pagelizanong-Shiquanhe Dam Nan) ophiolitic fragments in the Shiquanhe ophiolite. The basaltic lavas overlying the lower basalts, represented by the ca. 168–164 Ma diabasic and boninite dikes have forearc characteristics, and they represent the back-arc basin subduction initiation at a late stage. This work thus recovered the multiple tectonic evolution of SJO sub-belt and emphasise the importance of the back-arc basin subduction in the evolution of ancient oceans.</div></div>","PeriodicalId":12711,"journal":{"name":"Geoscience frontiers","volume":"16 5","pages":"Article 102088"},"PeriodicalIF":8.5,"publicationDate":"2025-06-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144365867","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Efficient rock joint detection from large-scale 3D point clouds using vectorization and parallel computing approaches","authors":"Yunfeng Ge ,&nbsp;Zihao Li ,&nbsp;Huiming Tang ,&nbsp;Qian Chen ,&nbsp;Zhongxu Wen","doi":"10.1016/j.gsf.2025.102085","DOIUrl":"10.1016/j.gsf.2025.102085","url":null,"abstract":"<div><div>The application of three-dimensional (3D) point cloud parametric analyses on exposed rock surfaces, enabled by Light Detection and Ranging (LiDAR) technology, has gained significant popularity due to its efficiency and the high quality of data it provides. However, as research extends to address more regional and complex geological challenges, the demand for algorithms that are both robust and highly efficient in processing large datasets continues to grow. This study proposes an advanced rock joint identification algorithm leveraging artificial neural networks (ANNs), incorporating parallel computing and vectorization of high-performance computing. The algorithm utilizes point cloud attributes—specifically point normal and point curvatures—as input parameters for ANNs, which classify data into rock joints and non-rock joints. Subsequently, individual rock joints are extracted using the density-based spatial clustering of applications with noise (DBSCAN) technique. Principal component analysis (PCA) is subsequently employed to calculate their orientations. By fully utilizing the computational power of parallel computing and vectorization, the algorithm increases the running speed by 3–4 times, enabling the processing of large-scale datasets within seconds. This breakthrough maximizes computational efficiency while maintaining high accuracy (compared with manual measurement, the deviation of the automatic measurement is within 2°), making it an effective solution for large-scale rock joint detection challenges.</div></div>","PeriodicalId":12711,"journal":{"name":"Geoscience frontiers","volume":"16 5","pages":"Article 102085"},"PeriodicalIF":8.5,"publicationDate":"2025-06-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144270561","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Global projections of future landslide susceptibility under climate change","authors":"Yu Duan ,&nbsp;Mingtao Ding ,&nbsp;Yufeng He ,&nbsp;Hao Zheng ,&nbsp;Ricardo Delgado-Téllez ,&nbsp;Sergey Sokratov ,&nbsp;Francisco Dourado ,&nbsp;Sven Fuchs","doi":"10.1016/j.gsf.2025.102074","DOIUrl":"10.1016/j.gsf.2025.102074","url":null,"abstract":"<div><div>Landslides pose a significant threat to both human society and environmental sustainability, yet, their spatiotemporal evolution and impacts on global scales in the context of a warming climate remain poorly understood. In this study, we projected global landslide susceptibility under four shared socioeconomic pathways (SSPs) from 2021 to 2100, utilizing multiple machine learning models based on precipitation data from the Coupled Model Intercomparison Project Phase 6 (CMIP6) Global Climate Models (GCMs) and static metrics. Our results indicate an overall upward trend in global landslide susceptibility under the SSPs compared to the baseline period (2001–2020), with the most significant increase of about 1% in the very far future (2081–2100) under the high emissions scenario (SSP5-8.5). Currently, approximately 13% of the world’s land area is at very high risk of landslide, mainly in the Cordillera of the Americas and the Andes in South America, the Alps in Europe, the Ethiopian Highlands in Africa, the Himalayas in Asia, and the countries of East and South-East Asia. Notably, India is the country most adversely affected by climate change, particularly during 2081–2100 under SSP3-7.0, with approximately 590 million people—23 times the global average—living in areas categorized as having very high susceptibility.</div></div>","PeriodicalId":12711,"journal":{"name":"Geoscience frontiers","volume":"16 4","pages":"Article 102074"},"PeriodicalIF":8.5,"publicationDate":"2025-05-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144239781","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Geodynamic record of Rodinia breakup to Gondwana formation: Insights from bulk geochemistry, whole-rock Sr-Nd isotopes, and zircon U-Pb-Hf data of Katherina Ring Complex, Sinai Peninsula, Egypt","authors":"Mohamed Faisal ,&nbsp;Huan Li ,&nbsp;Chao Sun ,&nbsp;Muhammad A. Gul ,&nbsp;Abdulgafar K. Amuda ,&nbsp;Wenbo Sun ,&nbsp;Jar Ullah ,&nbsp;Ibrahim H. Khalifa ,&nbsp;Sara Mustafa","doi":"10.1016/j.gsf.2025.102082","DOIUrl":"10.1016/j.gsf.2025.102082","url":null,"abstract":"<div><div>The Arabian-Nubian Shield (ANS) serves as a key geological archive, preserving the tectono-thermal evolution associated with the Rodinia breakup (∼900–800 Ma) and Gondwana formation (∼800–620 Ma). The Katherina Ring Complex (KRC), located in the Sinai Peninsula, Egypt (northern ANS), exemplifies continental growth through multistage magmatism and orogenesis, spanning the Tonian to Ediacaran periods (∼900–530 Ma). Despite its importance, debates persist regarding the nature, age, crustal characteristics, and magma source evolution of its constituent units. Situated in the northwestern part of the KRC, the Wadi Rofaiyed Cu deposit offers an exceptional natural laboratory for investigating continental crust formation during this interval, owing to its superb exposure and preservation. This study integrates detailed fieldwork, petrographic analyses, whole-rock geochemistry, Sr-Nd isotopes, and in situ zircon U-Pb-Lu-Hf isotopic data. It aims to (i) establish a robust chronological framework for the unmetamorphosed plutonic rocks of the KRC, (ii) advance the understanding of associated geodynamic processes, and (iii) elucidate the episodic magmatism events. The findings show that Wadi Rofaiyed juvenile crust developed in four main phases: (i) a subduction-accretionary phase (∼755 Ma) characterized by intense calc-alkaline magmatism, originating from the partial melting of mafic lower crust; (ii) a syn-collisional phase (∼630 Ma) occurred during the collision between the Saharan metacraton and the younger ANS crust, producing I-type granitoids formed through magma mixing and crustal anatexis; (iii) a post-collisional phase characterized by intermediate I-type (∼595 Ma) to felsic A-type alkaline magma (∼594 Ma), originated from the partial melting of the overthickened lower crust corresponding to lithospheric delamination; and (iv) an anorogenic phase (∼530 Ma) related to the final amalgamation of Greater Gondwana. Isotopic analyses across all four magmatic phases reveal low initial ⁸⁷Sr/⁸⁶Sr (0.702648–0.703311) and positive <em>ε</em>_Hf(<em>t</em>) (+2.84 to +7.78) and <em>ε</em>_Nd(<em>t</em>) (+2.61 to +5.21) values, consistent with lower crustal sources with depleted mantle-like signatures. The model ages (<em>T</em>_DM2) for these magmatic rocks derived from zircon Hf (1.2–1.5 Ga) and whole-rock Nd isotopes (0.96–1.17 Ga) support a predominantly juvenile crustal origin. These findings underscore the multistage tectono-magmatic evolution of the northern ANS, advancing our understanding of obduction-accretion dynamics and crustal development during the Neoproterozoic.</div></div>","PeriodicalId":12711,"journal":{"name":"Geoscience frontiers","volume":"16 4","pages":"Article 102082"},"PeriodicalIF":8.5,"publicationDate":"2025-05-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144222522","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Extreme gradient boosting with Shapley Additive Explanations for landslide susceptibility at slope unit and hydrological response unit scales","authors":"Ananta Man Singh Pradhan ,&nbsp;Pramit Ghimire ,&nbsp;Suchita Shrestha ,&nbsp;Ji-Sung Lee ,&nbsp;Jung-Hyun Lee ,&nbsp;Hyuck-Jin Park","doi":"10.1016/j.gsf.2025.102081","DOIUrl":"10.1016/j.gsf.2025.102081","url":null,"abstract":"<div><div>This study provides an in-depth comparative evaluation of landslide susceptibility using two distinct spatial units: and slope units (SUs) and hydrological response units (HRUs), within Goesan County, South Korea. Leveraging the capabilities of the extreme gradient boosting (XGB) algorithm combined with Shapley Additive Explanations (SHAP), this work assesses the precision and clarity with which each unit predicts areas vulnerable to landslides. SUs focus on the geomorphological features like ridges and valleys, focusing on slope stability and landslide triggers. Conversely, HRUs are established based on a variety of hydrological factors, including land cover, soil type and slope gradients, to encapsulate the dynamic water processes of the region. The methodological framework includes the systematic gathering, preparation and analysis of data, ranging from historical landslide occurrences to topographical and environmental variables like elevation, slope angle and land curvature etc. The XGB algorithm used to construct the Landslide Susceptibility Model (LSM) was combined with SHAP for model interpretation and the results were evaluated using Random Cross-validation (RCV) to ensure accuracy and reliability. To ensure optimal model performance, the XGB algorithm’s hyperparameters were tuned using Differential Evolution, considering multicollinearity-free variables. The results show that SU and HRU are effective for LSM, but their effectiveness varies depending on landscape characteristics. The XGB algorithm demonstrates strong predictive power and SHAP enhances model transparency of the influential variables involved. This work underscores the importance of selecting appropriate assessment units tailored to specific landscape characteristics for accurate LSM. The integration of advanced machine learning techniques with interpretative tools offers a robust framework for landslide susceptibility assessment, improving both predictive capabilities and model interpretability. Future research should integrate broader data sets and explore hybrid analytical models to strengthen the generalizability of these findings across varied geographical settings.</div></div>","PeriodicalId":12711,"journal":{"name":"Geoscience frontiers","volume":"16 4","pages":"Article 102081"},"PeriodicalIF":8.5,"publicationDate":"2025-05-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144239776","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Detrital zircon geochronology of lower Palaeozoic sedimentary rocks from the COSC-2 borehole, Scandinavian Caledonides","authors":"Grzegorz Ziemniak ,&nbsp;Iwona Klonowska ,&nbsp;William C. McClelland ,&nbsp;Oliver Lehnert ,&nbsp;Simon Cuthbert ,&nbsp;Isabel Carter ,&nbsp;Riccardo Callegari ,&nbsp;Katarzyna Walczak","doi":"10.1016/j.gsf.2025.102077","DOIUrl":"10.1016/j.gsf.2025.102077","url":null,"abstract":"<div><div>Detrital zircon geochronology is reported from the c. 1200 m thick Cambro-Ordovician sedimentary succession recovered in core from the COSC-2 continental drilling project in the Scandinavian Caledonides. Above a regolith marking the sub-Cambrian peneplain, a lower to middle Cambrian(?) succession comprises conglomerate, sandstone and shale overlain by gravity flows fining upwards into the Alum Shale Formation. First results of detrital zircon geochronology from the Cambrian(?) succession show that the basal section of the autochthonous cover is characterized by mainly late Paleoproterozoic – early Mesoproterozoic detrital grains. The middle part of the succession is dominated by late Paleoproterozoic detritus with minor Mesoproterozoic and Archean input. The upper part of lower Cambrian(?) succession is characterized by Archean to Cambrian detritus. The maximum depositional age is calculated to 530.5 ± 4 Ma for the upper part of the lower Cambrian succession. Two samples from the Lower Ordovician(?) succession above the Alum Shale Formation show predominantly Mesoproterozoic to early Neoproterozoic (1.5–0.9 Ga) ages.</div><div>The autochthonous lower Cambrian(?) passive margin succession in the lower section is dominated by local detritus, sourced exclusively from the Eastern Segment of the Sveconorwegian Orogen, which includes the basement studied in COSC-2. Up-section, the provenance shifts towards the Transscandinavian Igneous Belt and Svecofennian Orogen sources, with the youngest part of the succession showing a notable input of Neoproterozoic –Cambrian active margin detritus. The Ordovician(?) succession is characterized by populations, likely derived from the Sveconorwegian Orogen, and a minor cratonic contribution.</div><div>Statistical analysis of detrital zircon datasets across Baltica suggests that the Southern Baltica/Sandomirian Arc, rather than the Timanian Orogen, was a significant source of detrital material across the paleocontinent. The influence of Timanian Orogen grains is limited to northernmost Scandinavia, whereas Sandomirian detritus reached central Scandinavia in the lower to middle Cambrian and remained prevalent in southern Scandinavia into the Lower Ordovician.</div></div>","PeriodicalId":12711,"journal":{"name":"Geoscience frontiers","volume":"16 4","pages":"Article 102077"},"PeriodicalIF":8.5,"publicationDate":"2025-05-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144222769","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"In situ Rb–Sr insights in the cooling history of the Petermann Orogeny, Central Australia","authors":"Alejandra Bedoya ,&nbsp;Stijn Glorie ,&nbsp;Martin Hand ,&nbsp;Christopher L. Kirkland ,&nbsp;Alexander T. De Vries Van Leeuwen","doi":"10.1016/j.gsf.2025.102080","DOIUrl":"10.1016/j.gsf.2025.102080","url":null,"abstract":"<div><div>The Ediacaran–Cambrian Petermann Orogen is a dextral transpressional orogen exposed in central Australia, which facilitated the exhumation of a high-pressure core and the deformation of the Neoproterozoic–Palaeozoic Amadeus Basin. Several studies have investigated the metamorphic and deformational evolution of the Petermann Orogen; however, the spatiotemporal variation of the deformation and cooling history is yet to be fully understood. In situ muscovite and biotite Rb–Sr geochronology, in combination with Ti-in-quartz thermometry is applied to map the spatiotemporal deformation and cooling patterns of the northern part of the Petermann Orogen. Interpreted muscovite Rb–Sr growth ages obtained from samples in the Petermann Nappe Complex (PNC), range between c. 598 Ma and 565 Ma, which correlate with the timing of deformation during the 600–520 Ma Petermann Orogeny. Interpreted muscovite and biotite cooling ages are younger in the east of the PNC (c. 556–541 Ma) and broadly correlate with the regional pattern of crustal heat production, suggesting that the geothermal gradient had a significant control on the timing and duration of cooling. Biotite Rb–Sr cooling ages between c. 555 Ma and 497 Ma for the orogenic core show no correlation with high heat production areas, however, differences in exhumed crustal levels across the Petermann Orogen are observed: high-P granulite facies rocks in the orogenic core vs middle-upper crustal rocks in the PNC, indicating that at least part of the spatiotemporal variation of cooling ages can be attributed to differential exhumation during the Petermann Orogeny. Hence, crustal heat production and differential exhumation were likely the main controlling factors on the duration and variation of cooling rates in the Petermann Orogen.</div></div>","PeriodicalId":12711,"journal":{"name":"Geoscience frontiers","volume":"16 4","pages":"Article 102080"},"PeriodicalIF":8.5,"publicationDate":"2025-05-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144138434","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Provenance evolution from subduction to arc-continent collision: An example from Zagros–Makran Transition Zone","authors":"Parisa GholamiZadeh ,&nbsp;Bo Wan ,&nbsp;Guido Meinhold ,&nbsp;Rasoul Esmaeili ,&nbsp;Mohammad Ebrahimi","doi":"10.1016/j.gsf.2025.102079","DOIUrl":"10.1016/j.gsf.2025.102079","url":null,"abstract":"<div><div>Arc-continent collision zones are critical areas where uplift, accretion, and erosion processes significantly influence the growth, elimination, or recycling of the continental crust. The Zagros–Makran Transition Zone, located along the Minab-Zendan Fault, represents a convergence boundary between the Zagros continental domain and the Makran accretionary prism in southern Iran from the Cretaceous onwards. Several tectonic slices, including Neotethys ophiolitic remnants and the Ganj and Bajgan-Durkan complexes, have accreted along the southern margin of the Eurasian Plate during subduction in the western Makran wedge. To clarify the growth steps of the Makran Prism and the internal deformation associated with arc-continent collision, we used a provenance study of sandstones from the western Makran accretionary prism involving petrography of the main detrital components and U–Pb dating, Hf isotopic values, and trace elements of detrital zircon grains. Our findings reveal a progressive scenario in which oceanic arc-related rocks of the ∼ 99 Ma Ganj Complex with Hf values ranging from +10 to +16 were uplifted during the Early to Late Eocene. The Eocene fore-arc sediments were sourced from the ∼ 49–47 Ma Urumieh-Dokhtar Magmatic Arc with Hf values between −5 and +12, as well as from the Ganj Complex. The Jurassic–Cretaceous Bajgan-Durkan Complex was uplifted due to the Late Eocene to Oligocene collision of various terranes along the southern margin of the Eurasian Plate. This led to a major sediment influx into the Makran trench with a detrital signal in the range ∼ 175–160 Ma with Hf isotopic values from −3 to +4 and alongside the Urumieh-Dokhtar Magmatic Arc with detrital ages ranging ∼ 46–37 Ma and ca. 80 Ma. Notably, metamorphic lithic grains began to appear in the sediments in the Late Eocene. The initial arrival of sediments from the Arabian margin to the arc-continent suture zone along the Minab-Zendan Fault indicates the onset of initial collision. During the Late Oligocene–Early Miocene, detrital zircon ages in the range of ∼ 610–520 Ma, sourced from the Arabian basement, were deposited in the trench basin together with components from the Eocene Urumieh-Dokhtar Magmatic Arc and Cretaceous ophiolitic clasts of ∼ 93 Ma with Hf isotopic values of +12 to +16. Following the development and uplift of the orogen from the Middle Miocene onward, detrital zircon grains from the Cretaceous–Miocene Urumieh-Dokhtar Magmatic Arc, Jurassic–Cretaceous Bajgan-Durkan Complex, and Cretaceous ophiolites are present in both the Makran and Zagros sedimentary domains.</div></div>","PeriodicalId":12711,"journal":{"name":"Geoscience frontiers","volume":"16 4","pages":"Article 102079"},"PeriodicalIF":8.5,"publicationDate":"2025-05-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144147790","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Central Indian Ocean Basin micrometeorite collections: Type, flux, etching and its implication to ocean biogeochemistry","authors":"N.G. Rudraswami ,&nbsp;V.P. Singh ,&nbsp;K.T. Basil Saleem","doi":"10.1016/j.gsf.2025.102078","DOIUrl":"10.1016/j.gsf.2025.102078","url":null,"abstract":"<div><div>Extraterrestrial phenomena have influenced Earth’s processes throughout geological history. Evaluating the impact of extraterrestrial material on the environment is crucial for understanding the evolution of Earth and life. This study incorporates the investigation of micrometeorites (MMs), abundant cosmic materials on Earth, to understand their influence on the chemical composition and biogeochemistry of the ocean. Comprehensive etching and flux analyses reveal that ∼95% of cosmic spherules (CSs) entering seawater are etched or wholly dissolved, supplying nutrients to phytoplankton. Barred spherules show the highest degree of etching (∼19%), followed by porphyritic (∼17%), glass (∼15%), cryptocrystalline (∼12%), scoriaceous (∼10%), G-type (∼9%), and I-type (∼6%). Annually, ∼3080 tonnes (t) of olivine from MMs dissolve into seawater, contributing ∼495 t of Mg²⁺, ∼1110 t of Fe²⁺, and ∼1928 t of silicic acid. This signifies that over the Indian Ocean’s ∼40 Myr history, ∼23 Gt of olivine from CSs has dissolved, providing nutrients to seawater and sequestering ∼7 Gt of CO₂. The world ocean during this time has sequestered ∼35 Gt of CO₂, with fluctuations influenced by extraterrestrial activity. For instance, the Veritas event, lasting ∼1.5 Myr, sequestered ∼6 Gt of CO₂ from the atmosphere. A robust flux calculation based on ∼2 t of deep-sea sediments from 3610 MMs provides a more accurate estimate of the time-averaged flux of ∼229 t yr⁻¹. These comprehensive analyses reveal MM’s original characteristics, post-deposition processes, geological record and their overall impact on Earth’s marine environments, thereby contributing to our knowledge of the interconnection between terrestrial and extraterrestrial processes.</div></div>","PeriodicalId":12711,"journal":{"name":"Geoscience frontiers","volume":"16 4","pages":"Article 102078"},"PeriodicalIF":8.5,"publicationDate":"2025-05-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144123976","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}