Earth-Science Reviews最新文献

{"title":"Gravity maps of the African continental crustal and mantle structure","authors":"Franck Eitel Kemgang Ghomsi ,&nbsp;Robert Tenzer ,&nbsp;Wenjin Chen ,&nbsp;Alexey Baranov ,&nbsp;Ojima Isaac Apeh ,&nbsp;Tan Xiaolong ,&nbsp;Hong Guoqing ,&nbsp;Julienne Stroeve","doi":"10.1016/j.earscirev.2026.105412","DOIUrl":"10.1016/j.earscirev.2026.105412","url":null,"abstract":"<div><div>The African continent is characterized by a complex tectonic and geological history, with its current configuration shaped by the assemblage of Precambrian cratons and fragments delineated by Proterozoic and Paleozoic mobile belts. Knowledge of its lithospheric structure has primarily been derived from sparsely and irregularly distributed seismic surveys, limiting continent-wide analysis. To address this issue, we utilize satellite (e.g., GOCE, GRACE) and terrestrial gravity observations, integrated with lithospheric structure models, to compile a suite of gravity maps on a 5′ × 5′ geographical grid. The maps of the free-air, Bouguer, crust-stripped, mantle, lithosphere-stripped, and sub-lithospheric mantle gravity disturbances enable detailed interpretation of Africa's lithospheric architecture. Our methodology enhances traditional gravimetric studies by applying advanced corrections for topographic, bathymetric, sediment, crustal, and lithospheric mantle density heterogeneities, revealing deeper structural signatures. The free-air gravity map exhibits a signature of topographic and upper crustal density variations, with positive anomalies (+50 to +150 mGal) over elevated regions (e.g., Ethiopian Plateau) and negative anomalies (−50 to −150 mGal) over sedimentary basins (e.g., Congo Basin). The Bouguer gravity map highlights tectonic and volcanic features, reflecting crustal thickness variations, with isostatic equilibrium in cratons and disequilibrium along continental rifts like the East African Rift System (EARS). The crust-stripped gravity map mirrors Moho geometry, showing a stark contrast between thin oceanic and thick continental crust. The mantle gravity map exhibits a thermal signature, with gravity lows marking active divergent margins along the East and West Rift Systems and highs coinciding with cold, stable Archean cratons. Combined Bouguer and mantle gravity analyses confirm a non-collisional origin of mountain ranges along the EARS. Notably, the southern portion of the EARS lacks a clear thermal signature, suggesting distributed deformation at diffuse plate boundaries. These findings, alongside signatures of the African Superswell and the Congo Craton subsidence, provide new insights into Africa's geodynamic evolution, supporting future geophysical and resource exploration efforts.</div></div>","PeriodicalId":11483,"journal":{"name":"Earth-Science Reviews","volume":"275 ","pages":"Article 105412"},"PeriodicalIF":10.0,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146072659","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 review on geochemical carbon dioxide removal potential of mafic and ultramafic rocks in India","authors":"Shreya Katre,&nbsp;K. Ravi,&nbsp;Archana M. Nair","doi":"10.1016/j.earscirev.2026.105419","DOIUrl":"10.1016/j.earscirev.2026.105419","url":null,"abstract":"<div><div>Scalable geochemical Carbon Dioxide Removal (CDR) technologies are essential for limiting global warming to 1.5 °C. These technologies capture and permanently store atmospheric CO₂ as carbonates using alkaline substrates such as mafic and ultramafic rocks rich in calcium (Ca) and magnesium (Mg) minerals. This study is the first to comprehensively map and assess the significant geological resources of India for geochemical CDR. Ophiolitic sequences, mafic dyke swarms in cratons, and basaltic formations contain diverse Ca- and Mg-rich silicate minerals, providing substantial alkalinity sources for effective CO₂ sequestration through aqueous engineered carbon mineralisation and enhanced chemical weathering. Analysis of 500 data points across India revealed an average CDR potential of ∼424 gCO₂/kg through alkalinity production and ∼270 gCO₂/kg via carbonation. Ultramafic rocks, including dunite, harzburgite, and peridotite, demonstrated the highest average CDR potential (∼647 gCO₂/kg), while mafic rocks, such as gabbro and basalt, showed moderate potential (∼308 gCO₂/kg). A shrinking core model assessed how rock composition affects cumulative CDR potential over 0–70 years under ambient conditions. Dunite showed the highest sCDR potential (∼441 gCO₂/kg), followed by peridotite (∼298 gCO₂/kg), while plagioclase-rich rocks like gabbro exhibited much lower rates (&lt;30 gCO₂/kg). These results underline the high CDR efficiency of ultramafic rocks and highlight olivine-rich rocks as promising candidates for rapid CO₂ mineralisation, achieving substantial sequestration on human timescales. In summary, this study highlights the vast potential of India's geological resources for CDR through geochemical pathways.</div></div>","PeriodicalId":11483,"journal":{"name":"Earth-Science Reviews","volume":"275 ","pages":"Article 105419"},"PeriodicalIF":10.0,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146110674","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":"Estimating paleotemperature using stable isotopes of soil-formed phyllosilicates from paleosols: A review","authors":"Kate Andrzejewski ,&nbsp;Julia A. McIntosh ,&nbsp;Erik L. Gulbranson ,&nbsp;Daniel Ibarra","doi":"10.1016/j.earscirev.2026.105417","DOIUrl":"10.1016/j.earscirev.2026.105417","url":null,"abstract":"<div><div>Fossilized soils, or paleosols, contain soil-formed phyllosilicates whose stable isotopic compositions may be used to calculate paleotemperature and thus reconstruct ancient terrestrial environments. Though paleosols are common in the geologic record, the use of phyllosilicates as paleotemperature proxies is limited in the literature owing to difficulties with selecting optimal paleosols, isolation from non-clay minerals and organic materials, mixtures of phyllosilicates in natural samples, wide variations of chemical compositions for phyllosilicates, and limited to undefined equilibrium fractionation factors between phyllosilicates-water. Here, we address these challenges by examining and comparing methods used for sample selection, mineral isolation, pretreatments, mineral identification, conventional and developing methods for oxygen and hydrogen isotopic analyses, and determination of phyllosilicate-water equilibrium fractionation factors, concluding with recommendations for best approaches for paleotemperature estimation. Additionally, we discuss how to identify and avoid detrital phyllosilicates, the impacts of diagenesis, comparison of stable isotope and non-isotope paleosol paleotemperature proxies, and challenges and opportunities for broadly using paleosols as paleoclimate archives. With ongoing efforts to refine this multi-faceted paleotemperature approach, the stable isotope geochemistry of soil-formed phyllosilicates continues to be an invaluable proxy system, enhancing our understanding of terrestrial paleoenvironments and paleoclimate.</div></div>","PeriodicalId":11483,"journal":{"name":"Earth-Science Reviews","volume":"275 ","pages":"Article 105417"},"PeriodicalIF":10.0,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146110675","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":"Surging glaciers in Svalbard: Observing their distribution, characteristics and evolution","authors":"William D. Harcourt ,&nbsp;Danni M. Pearce ,&nbsp;Wojciech Gajek ,&nbsp;Harold Lovell ,&nbsp;Erik S. Mannerfelt ,&nbsp;Andreas Kääb ,&nbsp;Douglas I. Benn ,&nbsp;Adrian Luckman ,&nbsp;Richard Hann ,&nbsp;Jack Kohler ,&nbsp;Tazio Strozzi ,&nbsp;Rebecca McCerery ,&nbsp;Bethan J. Davies","doi":"10.1016/j.earscirev.2026.105410","DOIUrl":"10.1016/j.earscirev.2026.105410","url":null,"abstract":"<div><div>Glacier surges are episodes of significantly increased ice flow due to ice-dynamical feedbacks, and are often repeated in a quasi-periodical manner. Ice mass is redistributed during a surge, which leads to surface lowering at high elevation as ice is transferred down-glacier and thickening nearer the terminus. In this paper, we review different approaches for monitoring and detecting glacier surges in Svalbard, one of the most prominent global clusters of surge-type glaciers. Current surge detection is mainly based upon tracking the speed of glaciers over time, measuring elevation and frontal changes, and more recently automatically detecting surface changes such as increased crevassing. Thermal and hydrological changes near the glacier bed drive surge dynamics and can be measured using geophysical sensors such as ground-penetrating radar (GPR) and seismometers. When glaciers surge, they often produce diagnostic landforms in subglacial and proglacial environments, allowing historical surging to be identified even if surges have not been directly observed.</div><div>Through this review, we have compiled an updated database of surge-type glaciers in Svalbard and find that 36% of glaciers display surge-type behaviour, which accounts for 75% of the total glacier area on Svalbard. Only 10% of all glaciers have been directly observed to surge, yet account for 48% of the total glacier area on Svalbard. Svalbard surge-type glaciers have gentler slopes, are generally longer, and extend across a larger elevation range compared to non surge-type glaciers across the archipelago. We find that the behaviour of surge-type glaciers is variable and more closely resembles a continuum from glaciers that do not surge to those which redistribute mass in a single event of strongly enhanced ice flux. We can describe the variability in surge behaviour using the concept of enthalpy and a six-stage surge model that characterises the build-up of energy at the glacier bed driven initially by thermal change and then ice acceleration which is prompted by changes in subglacial hydrology. Observations of glacier surges have improved significantly with routine mapping from satellites such as Sentinel-1, Sentinel-2 and the Landsat satellite series. Furthermore, an increasing number of geophysical measurements is enabling an improved understanding of subglacial processes before, during and after a surge, which is crucial for improving models of surge behaviour. As our observations of surges continue to improve, we expect to uncover new elements and details of surge behaviour, reaffirming the need to rethink the binary classification of glaciers as either ‘surge-type’ or ‘not surge-type’ in Svalbard and across the world.</div></div>","PeriodicalId":11483,"journal":{"name":"Earth-Science Reviews","volume":"275 ","pages":"Article 105410"},"PeriodicalIF":10.0,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146048598","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":"Automated characterization of microfracture systems in organic-rich shales and their influence on porosity using convolutional neural networks on FIB-SEM images: A review","authors":"Bo Liu ,&nbsp;Qamar Yasin ,&nbsp;Eshimiakhe Daniel ,&nbsp;Ghulam Mohyuddin Sohail ,&nbsp;Mengdi Sun ,&nbsp;David A. Wood","doi":"10.1016/j.earscirev.2026.105415","DOIUrl":"10.1016/j.earscirev.2026.105415","url":null,"abstract":"<div><div>Characterization of microfracture systems and nanopore networks in organic-rich shales is critical for understanding fluid transport, hydrocarbon storage capacity, and the feasibility of carbon dioxide (CO₂) sequestration. However, the inherent heterogeneity, complex morphology, and nano-scale features of shale microstructures present significant challenges for conventional image segmentation techniques. This study reviews and evaluates the performance of state-of-the-art deep learning architectures for automated high-precision segmentation of microfractures and pore systems in FIB-SEM images of organic-rich shales. To enhance the generalizability of each model, a hybrid training dataset comprising 5,000 real and 5,000 synthetically generated GAN-based FIB-SEM images is evaluated. Quantitative analysis reveals that Kite-Net (KiU-Net) outperforms both Swin UNET Transformers (Swin-UNETR) and Attention U-Net, achieving an overall segmentation accuracy of 94%, precision of 94%, and recall of 93%. Notably, KiU-Net excels in accurately delineating microfractures and complex pore geometries within kerogen-rich matrices. Based on KiU-Net's superior validation performance compared to the two other deep learning models, we employed it to segment 3D FIB-SEM image stacks, enabling volumetric reconstruction and analysis of pore connectivity. Results revealed marked morphological distinctions between organic and inorganic pores, with over 94% of pores existing as isolated, non-percolating clusters, a finding consistent with prior geological investigations. Cross-validation considering various shales and coals further validates the model's effectiveness across a range of lithofacies. Our study presents a scalable deep learning framework for analyzing nanoscale shale microstructures from images.</div></div>","PeriodicalId":11483,"journal":{"name":"Earth-Science Reviews","volume":"275 ","pages":"Article 105415"},"PeriodicalIF":10.0,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146095930","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 Oman subduction-driven obduction and mountain building: Kinematic modeling from Mid-Cretaceous through balanced and restored cross-sections","authors":"Mahdi Najafi ,&nbsp;Jaume Vergés ,&nbsp;David Cruset ,&nbsp;Philippe Razin ,&nbsp;Marc Viaplana-Muzas ,&nbsp;Montserrat Torne ,&nbsp;Daniel García-Castellanos ,&nbsp;Ana M. Negredo ,&nbsp;Vincenzo Spina ,&nbsp;Manel Fernàndez ,&nbsp;Ivone Jiménez-Munt","doi":"10.1016/j.earscirev.2026.105391","DOIUrl":"10.1016/j.earscirev.2026.105391","url":null,"abstract":"<div><div>The Semail Ophiolite in Oman has been central to obduction research for over 50 years. Our new study builds on this legacy, introducing 254-km long balanced and restored NE-SW cross-sections that run from the Semail Ophiolite to the Fahud foreland. These sections through Central Oman, resolve geometric inconsistencies, providing a clearer, quantifiable crustal-scale kinematic model from Mid-Cretaceous to present-day. Our findings reveal a ∼ N030° compressional direction from 15 new localities, reconstruct a 235 km minimum length pre-obduction hyperextended Hawasina Basin, and identify the 16–22-km wide Sumeini slope as a crucial low-angle footwall ramp for allochthonous nappes. We have also pinpointed four main detachment levels shaping the Central Oman Mountains: the Semail Ophiolite and Hawasina basal detachments, the Jabal Akhdar flat-ramp-flat thick-skinned thrust, and the Ara Salt detachment. Through stepwise kinematic reconstructions, we defined three key subduction-driven obduction stages from Mid-Cretaceous: 1) Pre-obduction Stage (Albian-Cenomanian boundary to 95.2 Ma) characterized by NE-dipping intra-oceanic subduction and slab rollback; 2) Obduction Stage (∼95.2–80 Ma) depicting the Semail Ophiolite and Hawasina nappes obduction over the Oman margin; and 3) Post-obduction Mountain-building Stage since Campanian times. Finally, we have estimated a convergence rate of 22 mm/yr during the Late Cretaceous (95.2 to 85 Ma), accounting for near half of the total convergence between Arabia and Eurasia. This study provides a powerful new framework for understanding obduction and mountain building, serving as a valuable template for investigating regions where later continental collision has obscured evidence of these processes.</div></div>","PeriodicalId":11483,"journal":{"name":"Earth-Science Reviews","volume":"274 ","pages":"Article 105391"},"PeriodicalIF":10.0,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145957247","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":"Influence of plant terrestrialization on coal accumulation and deep time terrestrial carbon storage","authors":"Jing Lu ,&nbsp;Xue Peng ,&nbsp;Lusheng Yin ,&nbsp;Ziyu Ling ,&nbsp;Minfang Yang ,&nbsp;Peixin Zhang ,&nbsp;Kai Zhou ,&nbsp;Le Liu ,&nbsp;Shifeng Dai ,&nbsp;Longyi Shao ,&nbsp;Jason Hilton","doi":"10.1016/j.earscirev.2026.105390","DOIUrl":"10.1016/j.earscirev.2026.105390","url":null,"abstract":"&lt;div&gt;&lt;div&gt;Plant terrestrialization—the early evolution of terrestrial vegetation originating, establishing, and expanding during the Silurian-Carboniferous—was a critical event in the evolution of the terrestrial biosphere that shaped the way to a habitable Earth. Under favorable paleobotanical, paleoclimatic, paleogeographical, and paleotectonic conditions, large quantities of plant remains can accumulate as peat in wetlands, forming a key component of the global carbon cycle, a major terrestrial carbon sink, and eventually coal deposits. However, the direct influence of terrestrialization on coal accumulation and coal quality remains unclear. This review examines the synergistic interplay between the evolutionary characteristics of coal-forming vegetation across the Rhyniophytic, Eophytic and Paleophytic Terrestrialization Phases and global coal accumulation, focusing on coal composition and seam thickness. In the Silurian radiation prelude, plants were mostly aquatic algae and early vascular plants (e.g., &lt;em&gt;Cooksonia, Rhynia&lt;/em&gt;) inhabiting near-water environments, with poorly developed vascular tissues and low biomass. No terrestrial coal accumulated. In the Rhyniophytic to early Eophytic Floras, early vascular plants still dominated, but body sizes and biomass increased, and organs including roots and primitive small leaves evolved. Coal-bearing sediments were sporadically distributed along equatorial tropical coastlines and in shallow marine environments, composed predominantly of detrital organic matter derived. In the late Eophytic to early Paleophytic floras, evolution of secondary xylem (wood), arborescence, and concentrated root systems increased biomass, with peat accumulating from higher plants in equatorial tropical coastal plains and forming sporadically mineable humic coals with ∼50% liptinite. The early Paleophytic Flora witnessed the evolution of deep root systems and the seed habit, enabling plants to gradually occupy drier environments. Peat accumulation intensified with humic coals dominated by liptinite (∼70%) widespread in equatorial coastal plains. In the middle Paleophytic Flora, lycopods, sphenopsids, ferns and pteridosperms further developed, and arborescence became more prevalent, with industrially significant humic coals (vitrinite content &gt;40%) accumulating widely in low-latitude tropical and mid-latitude temperate zones. The late Paleophytic Flora witnessed proliferation of existing lineages with &lt;em&gt;Cordaites&lt;/em&gt; emerging as dominant coal-forming gymnosperms in lycophyte dominated wetlands. Extensive workable humic coal seams developed across low-latitude tropical and mid-latitude temperate zones. These patterns indicate that terrestrial vegetation not only contributed directly to peat formation but also influenced coal maceral composition and coal seam distribution. Vegetation further shaped surface environments favorable for peat accumulation in indirect and lasting ways, thereby establishing terrestrial e","PeriodicalId":11483,"journal":{"name":"Earth-Science Reviews","volume":"274 ","pages":"Article 105390"},"PeriodicalIF":10.0,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145974259","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":"Chemical and lithological heterogeneity of upwelling mantle plumes inducing Zn isotope variation in Ocean Island Basalts","authors":"Xiao-Yu Zhang ,&nbsp;Li-Hui Chen ,&nbsp;Gang Zeng ,&nbsp;Xiao-Jun Wang ,&nbsp;Albrecht W. Hofmann ,&nbsp;Takeshi Hanyu ,&nbsp;Wei-Qiang Li","doi":"10.1016/j.earscirev.2025.105378","DOIUrl":"10.1016/j.earscirev.2025.105378","url":null,"abstract":"<div><div>Ocean Island Basalts, generated by partial melting of mantle plumes, show large δ⁶⁶Zn variations (up to 0.22 ‰). Modelling indicates δ⁶⁶Zn variations in melts generated by melting of solely CO₂-free peridotite, within melting range of OIBs (2–8 %), are very limited (∼0.02 ‰), excluding melting processes as the major control. Instead, large δ⁶⁶Zn variations observed in OIBs are more likely attributed to source heterogeneity. Here we compile Zn isotopes and elemental ratios (CaO/Al₂O₃ and Zn/Fe) of globally distributed, nearly primitive OIBs, including new data from Pitcairn and Samoa lavas, to further clarify the relationship between Zn isotopic variations in OIBs and chemical heterogeneity of mantle plumes. Regarding their Zn isotopic variability, global OIBs can be divided into three groups: (1) Low-δ⁶⁶Zn group, including Iceland and Kilauea lavas, displays MORB-like δ⁶⁶Zn (0.27 ± 0.03 ‰), CaO/Al₂O₃ and Zn/Fe, suggesting a source of CO₂-free peridotite. (2) Samples from Crozet, Madeira, Louisville and Samoa have slightly higher δ⁶⁶Zn (0.32 ± 0.06 ‰) and Zn/Fe than those of MORBs, indicating the presence of MORB-like pyroxenite in their sources. (3) OIBs from Cook-Austral, St. Helena, Koloa and Pitcairn show significantly higher δ⁶⁶Zn values (0.38 ± 0.05 ‰) than MORBs and other OIBs. Besides of their heavy Zn isotopes, they have distinct CaO/Al₂O₃ from MORBs and other OIBs, suggesting different source lithologies. Cook-Austral and St. Helena lavas have high CaO/Al₂O₃ and MORB-like Zn/Fe, suggesting carbonated peridotite source. Koloa lavas' high CaO/Al₂O₃ plus super-MORB Zn/Fe suggest carbonated pyroxenite source, whereas Pitcairn lavas' low CaO/Al₂O₃ and super-MORB Zn/Fe indicate a decarbonated pyroxenite source. Therefore, Zn isotopic variations in OIBs are predominantly controlled by recycled carbonate-related heterogeneity within mantle plumes.</div></div>","PeriodicalId":11483,"journal":{"name":"Earth-Science Reviews","volume":"274 ","pages":"Article 105378"},"PeriodicalIF":10.0,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145882867","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":"The carbon isotope offset between leaf wax C29 and C31 n-alkanes as a proxy of precipitation seasonality","authors":"Liping Tian ,&nbsp;Yanming Ruan ,&nbsp;Jiantao Cao ,&nbsp;Li Li ,&nbsp;Guodong Jia","doi":"10.1016/j.earscirev.2025.105379","DOIUrl":"10.1016/j.earscirev.2025.105379","url":null,"abstract":"<div><div>The carbon isotope composition of leaf wax long-chain <em>n</em>-alkanes (δ¹³C_{<em>n</em>-alkanes}) is commonly used to reconstruct the past C₃/C₄ vegetation ratio and associated hydroclimate changes. However, the significance of isotopic differences among their homologues remains poorly understood. Our comprehensive analysis of global δ¹³C_{<em>n</em>-alkanes} data from modern samples (<em>n</em> = 725) reveals that the offset between δ¹³C₂₉ and δ¹³C₃₁ <em>n</em>-alkanes (∆δ¹³C_29–31) generally negatively correlates with seasonal precipitation parameters, most strongly with dry month length. This correlation likely stems from variations in the consumption of δ¹³C-depleted internal carbon during the recycling process between <em>n</em>C₂₉ and <em>n</em>C₃₁ alkane, which compensate for weathered waxes and differ between C₃ and C₄ plants. To validate the potential of ∆δ¹³C_29–31 as a precipitation seasonality proxy, we investigated δ¹³C_{<em>n</em>-alkanes} in a Sunda Shelf sediment core and re-examined published records from Southeast Asia (<em>n</em> = 5), Africa (<em>n</em> = 8), and South America (<em>n</em> = 3). These records show the ∆δ¹³C_29–31 index aligns well with changes in C₃/C₄ vegetation across different time scales (last glaciation, glacial-interglacial cycles, and Neogene period), with C₄ expansions corresponding to negative ∆δ¹³C_29–31 excursions. Since C₄ plants have a competitive advantage under increased precipitation seasonality, the concurrent negative ∆δ¹³C_29–31 excursions with C₄ expansions validate the ∆δ¹³C_29–31 index as an indicator of precipitation seasonality. Given the paucity of proxy indicators for precipitation seasonality, the ∆δ¹³C_29–31 index holds considerable significance. Further research is warranted to explore its quantitative relationship with seasonal precipitation and to unravel the underlying mechanisms on ecological scales, ranging from individual plants to entire ecosystems.</div></div>","PeriodicalId":11483,"journal":{"name":"Earth-Science Reviews","volume":"274 ","pages":"Article 105379"},"PeriodicalIF":10.0,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145861005","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":"Low-latitude glaciation in the Cretaceous greenhouse: reviewing the cryosphere reach during an archetypal hothouse Earth","authors":"Juan Pedro Rodríguez-López ,&nbsp;Pedro Ángel Fernández-Mendiola ,&nbsp;Ginés A. de Gea ,&nbsp;José A. Arz ,&nbsp;Ignacio Arenillas ,&nbsp;Vicente Gilabert ,&nbsp;Luis Arlegui ,&nbsp;Ana R. Soria ,&nbsp;Vincent Fernández ,&nbsp;William Amidon ,&nbsp;Andrew Kylander-Clark ,&nbsp;Jaime Frigola ,&nbsp;Marc Cerdà-Domènech ,&nbsp;Joshua Garber ,&nbsp;Jerónimo López-Martínez ,&nbsp;Julian B. Murton ,&nbsp;Carlos L. Liesa","doi":"10.1016/j.earscirev.2025.105351","DOIUrl":"10.1016/j.earscirev.2025.105351","url":null,"abstract":"<div><div>The traditional \"Hothouse–Icehouse\" dichotomy and the prevailing \"Cretaceous greenhouse\" narrative fail to accurately represent the geological record. Geological evidence reveals an unknown Late Cretaceous glaciation (82.8–80.96 Ma, the Campanian Barrika glaciation), with tidewater glaciers grounded at an unusually low palaeolatitude (35°N), at a time when Mesozoic temperatures have been modelled near their highest. The Barrika glaciation constitutes the last known low-latitude glaciation on Earth since the Last Paleozoic Ice Age (LPIA), which reached 30°N. The Barrika glaciation is characterized by a remarkably well-preserved glaciomarine record of subtropical tidewater glaciers associated with outlets of an extensive ice cap in Iberia. Our multiproxy analysis reveals five distinct glaciomarine units, indicative of glacial advances and retreats with a 360-kyr spacing. Calving fronts of tidewater glaciers delivered large icebergs to the palaeo-Atlantic Ocean. This glaciation correlates with a peak of ultra-depleted δD ice-sheet-related meltwater signals from Antarctica and other independent indicators of global change. This discovery of a low-latitude glaciation during a purported 'hothouse' period fundamentally challenges simplified Cretaceous climate models. It underscores the critical need for refined paleoclimate proxies and integrated Earth system modelling to fully comprehend such transient yet significant glacial episodes. The robust multiproxy workflow developed for the Barrika glaciation offers a powerful tool for identifying other unknown glaciations in deep-time greenhouse stages. Despite its generally warm reputation, the 77.06-million-year-long Cretaceous Period surprisingly records the lowest latitudinal glaciation since the Paleozoic. Remarkably, 55% of this time shows evidence of meltwaters linked to Antarctic ice sheets, with ice-rafted debris and glacial deposits present for 53% of the period. Glendonites, indicators of cold conditions, are found in 24% of Cretaceous time, and glacio-eustasy played a significant role in short-term sea-level changes for a striking 86% of the period. Collectively, this evidence of an active Cretaceous cryosphere is strengthened by evidence of permafrost in plateaus and high-altitude deserts, coupled by robust geochemical palaeoclimate proxies. Our findings suggest that the conventional 'hothouse–icehouse' scheme applied on deep-time climate requires reconsideration, pointing instead to a much more complex Earth climate evolution that will require a thorough re-evaluation of geochemical proxies used during the Mesozoic.</div></div>","PeriodicalId":11483,"journal":{"name":"Earth-Science Reviews","volume":"274 ","pages":"Article 105351"},"PeriodicalIF":10.0,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145613840","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}