Pub Date : 2026-02-12DOI: 10.1016/j.earscirev.2026.105424
C.D. Teixeira, T.J. Girelli, H. Serratt, F. Chemale
{"title":"Reply to Comment on “Revisiting the Dom Feliciano Belt and surrounding areas – An integrated geophysical and isotope geology approach”","authors":"C.D. Teixeira, T.J. Girelli, H. Serratt, F. Chemale","doi":"10.1016/j.earscirev.2026.105424","DOIUrl":"https://doi.org/10.1016/j.earscirev.2026.105424","url":null,"abstract":"","PeriodicalId":11483,"journal":{"name":"Earth-Science Reviews","volume":"71 1","pages":""},"PeriodicalIF":12.1,"publicationDate":"2026-02-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146160272","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}
Pub Date : 2026-02-11DOI: 10.1016/j.earscirev.2026.105425
Ellen Wohl, Nikolai Maximenko, Rebecca Helm
{"title":"Global wood cascades from terrestrial sources to terrestrial, freshwater, and marine sinks","authors":"Ellen Wohl, Nikolai Maximenko, Rebecca Helm","doi":"10.1016/j.earscirev.2026.105425","DOIUrl":"https://doi.org/10.1016/j.earscirev.2026.105425","url":null,"abstract":"","PeriodicalId":11483,"journal":{"name":"Earth-Science Reviews","volume":"317 1","pages":""},"PeriodicalIF":12.1,"publicationDate":"2026-02-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146153125","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}
Pub Date : 2026-02-10DOI: 10.1016/j.earscirev.2026.105423
Giuseppe Betino De Toni
Teixeira et al. (2025) integrated previously published regional geophysical and geochronological data with new gravimetric surveys of the Dom Feliciano Belt (DFB) and surrounding areas. However, the paper contains a few inaccuracies and overlooks some publications that should be considered in a review. This comment aims to deepen the discussion by recognizing some data not considered in their paper, foccusing in a critical evaluation of (1) "terrenology" as a working philosophy in the context of DFB, considering (2) the authochtonous nature of major tectonic domains, (3) the non-continuity between Dorsal de Canguçu and Major Gercino shear zones, and (4) the controversial origin of hinterland batholiths either as post-collisional or magmatic arc.
Teixeira等人(2025)将先前发表的区域地球物理和地质年代学数据与Dom Feliciano带(DFB)及周边地区的新重力测量数据相结合。然而,这篇论文包含了一些不准确的地方,并且忽略了一些应该在评论中考虑的出版物。这篇评论的目的是通过承认他们的论文中没有考虑到的一些数据来深化讨论,重点是对以下几个方面进行批判性评估:(1)“气源学”作为DFB背景下的工作哲学,考虑(2)主要构造域的权威性,(3)Dorsal de canguu和major Gercino剪切带之间的不连续性,以及(4)腹地岩基的有争议的起源,无论是碰撞后的还是岩浆弧。
{"title":"Comment on “Revisiting the Dom Feliciano Belt and surrounding areas – An integrated geophysical and isotope geology approach” by Teixeira et al","authors":"Giuseppe Betino De Toni","doi":"10.1016/j.earscirev.2026.105423","DOIUrl":"10.1016/j.earscirev.2026.105423","url":null,"abstract":"<div><div>Teixeira et al. (2025) integrated previously published regional geophysical and geochronological data with new gravimetric surveys of the Dom Feliciano Belt (DFB) and surrounding areas. However, the paper contains a few inaccuracies and overlooks some publications that should be considered in a review. This comment aims to deepen the discussion by recognizing some data not considered in their paper, foccusing in a critical evaluation of (1) \"terrenology\" as a working philosophy in the context of DFB, considering (2) the authochtonous nature of major tectonic domains, (3) the non-continuity between Dorsal de Canguçu and Major Gercino shear zones, and (4) the controversial origin of hinterland batholiths either as post-collisional or magmatic arc.</div></div>","PeriodicalId":11483,"journal":{"name":"Earth-Science Reviews","volume":"276 ","pages":"Article 105423"},"PeriodicalIF":10.0,"publicationDate":"2026-02-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146153130","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}
Pub Date : 2026-02-09DOI: 10.1016/j.earscirev.2026.105416
Lei Zhao, Qiang Wei, David French, James C. Hower, Ian T. Graham, Gregory C. Smith
{"title":"The influence of terrestrial plants on the enrichment of critical metals in coal","authors":"Lei Zhao, Qiang Wei, David French, James C. Hower, Ian T. Graham, Gregory C. Smith","doi":"10.1016/j.earscirev.2026.105416","DOIUrl":"https://doi.org/10.1016/j.earscirev.2026.105416","url":null,"abstract":"","PeriodicalId":11483,"journal":{"name":"Earth-Science Reviews","volume":"1 1","pages":""},"PeriodicalIF":12.1,"publicationDate":"2026-02-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146153131","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}
Organic-inorganic interactions are ubiquitous within organic-rich shale systems and exert a pivotal control on the formation and evolution of integrated shale source-reservoir systems. However, a comprehensive and in-depth understanding of the microscale physicochemical processes underpinning these interactions in shale source-reservoir systems remains lacking to date. This review provides a holistic elaboration of the evolutionary processes of shale source-reservoir systems and systematically synthesizes the diverse pathways of organic-inorganic interactions in organic-rich shales. At the macroscale, climatic conditions and provenance jointly constrain the mineral composition during sedimentation. At the microscale, minerals exhibit selective adsorption characteristics toward organic matter (OM) owing to differences in adsorption mechanisms, which directly modulates the abundance and type of OM in sediments. The physical protection afforded by mineral pores mitigates the oxidation of organic carbon and regulates the overall reactivity and burial efficiency of organic carbon. During the thermal evolution stage, minerals and transition metals significantly accelerate kerogen cracking by reducing reaction activation energy, providing proton donors, or facilitating free radical reactions. Notably, under high-temperature conditions, inorganic-derived hydrogen and oxygen drive extensive organic-inorganic interactions, which exert a profound impact on deep hydrocarbon generation potential, natural gas isotopic compositions, and the upper limit of secondary pore formation. The generation of organic acids fuels pore evolution in shale reservoirs; secondary pores formed via mineral dissolution alter the pore characteristics and heterogeneity of shales. Ions released during dissolution drive mineral transformation and authigenic mineral precipitation. Coupled with the involvement of exogenous hydrogen, the sustained acid generation from hydrocarbon pyrolysis in deep reservoirs perpetuates this pore-forming effect. During the mature to high-maturity stages, organic-inorganic interactions exert a prominent influence on pore formation and heterogeneity. Even at higher thermal maturity levels, these interactions persist due to the participation of inorganic hydrogen and oxygen, yet the depth threshold of organic-inorganic interactions remains undefined. The formation of integrated shale source-reservoir systems is a complex, dynamic evolutionary process involving the coupling of multiple components, stages, and mechanisms. Focusing on the regulatory mechanisms of organic-inorganic interactions in integrated shale source-reservoir systems, this review synthesizes key scientific issues including mineral - and transition metal compound-catalyzed hydrocarbon generation, hydrocarbon evolution involving multi-source hydrogen, and pore development under varying maturity conditions. It aims to provide theoretical support and scientific guidance for the exploration and
{"title":"Impact of organic-inorganic interactions on shale source-reservoir systems","authors":"Yue Huang, Zhenkai Huang, Xi Li, Guangyou Zhu, Zhiyuan Lu, Siyu Chen, Ruilin Wang, Wanyan Lan, Jiezhi Zhang","doi":"10.1016/j.earscirev.2026.105422","DOIUrl":"https://doi.org/10.1016/j.earscirev.2026.105422","url":null,"abstract":"Organic-inorganic interactions are ubiquitous within organic-rich shale systems and exert a pivotal control on the formation and evolution of integrated shale source-reservoir systems. However, a comprehensive and in-depth understanding of the microscale physicochemical processes underpinning these interactions in shale source-reservoir systems remains lacking to date. This review provides a holistic elaboration of the evolutionary processes of shale source-reservoir systems and systematically synthesizes the diverse pathways of organic-inorganic interactions in organic-rich shales. At the macroscale, climatic conditions and provenance jointly constrain the mineral composition during sedimentation. At the microscale, minerals exhibit selective adsorption characteristics toward organic matter (OM) owing to differences in adsorption mechanisms, which directly modulates the abundance and type of OM in sediments. The physical protection afforded by mineral pores mitigates the oxidation of organic carbon and regulates the overall reactivity and burial efficiency of organic carbon. During the thermal evolution stage, minerals and transition metals significantly accelerate kerogen cracking by reducing reaction activation energy, providing proton donors, or facilitating free radical reactions. Notably, under high-temperature conditions, inorganic-derived hydrogen and oxygen drive extensive organic-inorganic interactions, which exert a profound impact on deep hydrocarbon generation potential, natural gas isotopic compositions, and the upper limit of secondary pore formation. The generation of organic acids fuels pore evolution in shale reservoirs; secondary pores formed via mineral dissolution alter the pore characteristics and heterogeneity of shales. Ions released during dissolution drive mineral transformation and authigenic mineral precipitation. Coupled with the involvement of exogenous hydrogen, the sustained acid generation from hydrocarbon pyrolysis in deep reservoirs perpetuates this pore-forming effect. During the mature to high-maturity stages, organic-inorganic interactions exert a prominent influence on pore formation and heterogeneity. Even at higher thermal maturity levels, these interactions persist due to the participation of inorganic hydrogen and oxygen, yet the depth threshold of organic-inorganic interactions remains undefined. The formation of integrated shale source-reservoir systems is a complex, dynamic evolutionary process involving the coupling of multiple components, stages, and mechanisms. Focusing on the regulatory mechanisms of organic-inorganic interactions in integrated shale source-reservoir systems, this review synthesizes key scientific issues including mineral - and transition metal compound-catalyzed hydrocarbon generation, hydrocarbon evolution involving multi-source hydrogen, and pore development under varying maturity conditions. It aims to provide theoretical support and scientific guidance for the exploration and","PeriodicalId":11483,"journal":{"name":"Earth-Science Reviews","volume":"9 1","pages":""},"PeriodicalIF":12.1,"publicationDate":"2026-02-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146146322","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}
Pub Date : 2026-02-06DOI: 10.1016/j.earscirev.2026.105420
X. Rui , D.S. Stamps
Previous studies have constrained fault slip rates and crustal block geometries of the Southeastern Tibetan Plateau (SETP) with contradictory results due to complex geodynamics and deformation patterns as well as subjective choices of crustal block boundaries. In this work, we address the issue of uncertain crustal block geometries by employing an unsupervised machine learning Euler pole clustering algorithm that automatically resolves regions that behave as rigid blocks (clusters) rotating on a sphere using GNSS velocity vectors. Optimal clustering results, determined by F-test and Euler-vector (angular velocity vector) overlap analyses, indicate 4 elongated crustal blocks exist in the SETP that are approximately parallel and delineated by a set of arcuate sinistral-slip faults. Our clustering results redefine the first-order kinematics of the SETP region with new crustal block definitions that elucidate the dominance of sinistral-slip faults.
{"title":"Euler-pole clustering of GNSS velocities using unsupervised machine learning in the Southeastern Tibetan Plateau: Crustal block identification and the dominance of sinistral-slip faults","authors":"X. Rui , D.S. Stamps","doi":"10.1016/j.earscirev.2026.105420","DOIUrl":"10.1016/j.earscirev.2026.105420","url":null,"abstract":"<div><div>Previous studies have constrained fault slip rates and crustal block geometries of the Southeastern Tibetan Plateau (SETP) with contradictory results due to complex geodynamics and deformation patterns as well as subjective choices of crustal block boundaries. In this work, we address the issue of uncertain crustal block geometries by employing an unsupervised machine learning Euler pole clustering algorithm that automatically resolves regions that behave as rigid blocks (clusters) rotating on a sphere using GNSS velocity vectors. Optimal clustering results, determined by F-test and Euler-vector (angular velocity vector) overlap analyses, indicate 4 elongated crustal blocks exist in the SETP that are approximately parallel and delineated by a set of arcuate sinistral-slip faults. Our clustering results redefine the first-order kinematics of the SETP region with new crustal block definitions that elucidate the dominance of sinistral-slip faults.</div></div>","PeriodicalId":11483,"journal":{"name":"Earth-Science Reviews","volume":"276 ","pages":"Article 105420"},"PeriodicalIF":10.0,"publicationDate":"2026-02-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146135068","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}
Pub Date : 2026-02-05DOI: 10.1016/j.earscirev.2026.105418
Xiuling Ren , Fujun Niu , Degou Cai , Jing Luo , Qihao Yu , Minghao Liu , Guoan Yin , Zeyong Gao
Soil frost heave seriously threatens the stability of engineering structures and the normal operation of major infrastructures in cold regions. This paper aims to synthesize the development and state of the art in moisture migration, cryostructure, soil frost heave, as well as their underlying micro-mechanisms, impacting factors and simulation models. First, we provide a brief review on moisture migration, cryostructure and soil frost heave. Second, some microstructural experiments incorporate X-ray computed tomography (X-CT), scanning electron microscope (SEM), and nuclear magnetic resonance (NMR) were reviewed to elucidate the underlying micro-mechanisms. Third, impacting factors for soil frost heave covering soil intrinsic properties, testing and environmental conditions were summarized. Moreover, numerous frost heave models involving theoretical, numerical, and machine learning (ML) models were discussed. Then, we point out some limits and identify the direction of future efforts. Despite advances achieved through decades of researches, some issues remain in the research on the frost heave of the coarse-grained soils, and soils with admixtures. To solve these problems by performing one-dimensional (1D) freezing and microstructural experiments on these soils considering these factors, and establishing novel frost heave models. Overall, this review will provide significant references for further research on soil frost heave, and an important theoretical guidance for the prevention and control of the frost heave distresses of infrastructures.
{"title":"Moisture migration, ice lenses and frost heave characteristics of soils under one-dimensional freezing action: A critical literature review","authors":"Xiuling Ren , Fujun Niu , Degou Cai , Jing Luo , Qihao Yu , Minghao Liu , Guoan Yin , Zeyong Gao","doi":"10.1016/j.earscirev.2026.105418","DOIUrl":"10.1016/j.earscirev.2026.105418","url":null,"abstract":"<div><div>Soil frost heave seriously threatens the stability of engineering structures and the normal operation of major infrastructures in cold regions. This paper aims to synthesize the development and state of the art in moisture migration, cryostructure, soil frost heave, as well as their underlying micro-mechanisms, impacting factors and simulation models. First, we provide a brief review on moisture migration, cryostructure and soil frost heave. Second, some microstructural experiments incorporate X-ray computed tomography (X-CT), scanning electron microscope (SEM), and nuclear magnetic resonance (NMR) were reviewed to elucidate the underlying micro-mechanisms. Third, impacting factors for soil frost heave covering soil intrinsic properties, testing and environmental conditions were summarized. Moreover, numerous frost heave models involving theoretical, numerical, and machine learning (ML) models were discussed. Then, we point out some limits and identify the direction of future efforts. Despite advances achieved through decades of researches, some issues remain in the research on the frost heave of the coarse-grained soils, and soils with admixtures. To solve these problems by performing one-dimensional (1D) freezing and microstructural experiments on these soils considering these factors, and establishing novel frost heave models. Overall, this review will provide significant references for further research on soil frost heave, and an important theoretical guidance for the prevention and control of the frost heave distresses of infrastructures.</div></div>","PeriodicalId":11483,"journal":{"name":"Earth-Science Reviews","volume":"276 ","pages":"Article 105418"},"PeriodicalIF":10.0,"publicationDate":"2026-02-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146135070","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}
Pub Date : 2026-02-03DOI: 10.1016/j.earscirev.2026.105419
Shreya Katre, K. Ravi, Archana M. Nair
{"title":"A review on geochemical carbon dioxide removal potential of mafic and ultramafic rocks in India","authors":"Shreya Katre, K. Ravi, Archana M. Nair","doi":"10.1016/j.earscirev.2026.105419","DOIUrl":"https://doi.org/10.1016/j.earscirev.2026.105419","url":null,"abstract":"","PeriodicalId":11483,"journal":{"name":"Earth-Science Reviews","volume":"235 1","pages":""},"PeriodicalIF":12.1,"publicationDate":"2026-02-03","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}
Pub Date : 2026-02-03DOI: 10.1016/j.earscirev.2026.105417
Kate Andrzejewski, Julia A. McIntosh, Erik L. Gulbranson, Daniel Ibarra
{"title":"Estimating paleotemperature using stable isotopes of soil-formed phyllosilicates from paleosols: A review","authors":"Kate Andrzejewski, Julia A. McIntosh, Erik L. Gulbranson, Daniel Ibarra","doi":"10.1016/j.earscirev.2026.105417","DOIUrl":"https://doi.org/10.1016/j.earscirev.2026.105417","url":null,"abstract":"","PeriodicalId":11483,"journal":{"name":"Earth-Science Reviews","volume":"106 1","pages":""},"PeriodicalIF":12.1,"publicationDate":"2026-02-03","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}
Pub Date : 2026-02-01DOI: 10.1016/j.earscirev.2026.105413
Giuseppe Etiope, Geoffrey S. Ellis, Omid H. Ardakani, Christopher J. Boreham, Peter Klitzke, Antonio Martín-Monge, Humberto L.S. Reis, Alexis S. Templeton, Hyeong Soo Kim, Eric Gaucher, Olivier Sissmann
A comprehensive scientific research roadmap is essential to bridge knowledge gaps and deepen the understanding of key geological, geochemical, and geophysical aspects of natural hydrogen (H<ce:inf loc="post">2</ce:inf>) as a potential new energy resource. This paper reviews major scientific uncertainties on natural H<ce:inf loc="post">2</ce:inf>, suggesting research priorities, as a guide for defining exploration strategies, techniques, and data interpretation. The uncertainties concern all phases of the natural H<ce:inf loc="post">2</ce:inf> cycle, from generation (source rocks) through migration (advection and diffusion) and accumulation (reservoir and cap rocks) to the application and interpretation of subsurface and surface geochemical and geophysical exploration techniques. Understanding H<ce:inf loc="post">2</ce:inf> sources and generation rates (the amount of H<ce:inf loc="post">2</ce:inf> generated by a given volume of rock over time) is crucial for determining whether a geological H<ce:inf loc="post">2</ce:inf> system operates as a short-term dynamic system with rapid H<ce:inf loc="post">2</ce:inf> production and release, or as a conventional gas system with long-term accumulations, analogous to petroleum reservoirs. Preliminary estimates for serpentinisation, radiolysis, and organic matter degradation suggest that H<ce:inf loc="post">2</ce:inf> generation is not inherently fast, especially for non-hydrothermal continental systems (crystalline basement of shields, ophiolites, peridotite massifs, sedimentary basins), and long-term accumulations, like those of fossil natural gas systems, represent the most likely scenario. The mechanisms of H<ce:inf loc="post">2</ce:inf> migration through geological formations require application of fundamental principles of fluid-flow physics, distinguishing advection and diffusion, as well as their forms (from gas-phase, bubble flows to aqueous solutions). Additional studies of H<ce:inf loc="post">2</ce:inf> accumulation and retention in subsurface reservoirs could improve understanding of mechanisms of H<ce:inf loc="post">2</ce:inf> migration by focusing on the rock fluid-bearing properties and the factors affecting H<ce:inf loc="post">2</ce:inf> preservation, such as the presence of cap rocks impermeable to H<ce:inf loc="post">2</ce:inf>, pressure conditions, residence times, and microbial or abiotic consumption. Advanced techniques, including reservoir modelling, flow simulations, 3D imaging (micro-CT) of H<ce:inf loc="post">2</ce:inf>-bearing rocks, and extraction and analysis of gas occluded in rocks, can provide insights into the stability and potential recoverability of H<ce:inf loc="post">2</ce:inf> accumulations. The interpretation of surface exploration techniques, including gas geochemistry, geophysics, and remote sensing, long employed in mineral and energy resource exploration, is now being adapted for natural H<ce:inf loc="post">2</ce:inf> studies, but challenges remain in the data interpre
{"title":"Understanding the resource potential of natural hydrogen on Earth: Scientific gaps, uncertainties and recommendations","authors":"Giuseppe Etiope, Geoffrey S. Ellis, Omid H. Ardakani, Christopher J. Boreham, Peter Klitzke, Antonio Martín-Monge, Humberto L.S. Reis, Alexis S. Templeton, Hyeong Soo Kim, Eric Gaucher, Olivier Sissmann","doi":"10.1016/j.earscirev.2026.105413","DOIUrl":"https://doi.org/10.1016/j.earscirev.2026.105413","url":null,"abstract":"A comprehensive scientific research roadmap is essential to bridge knowledge gaps and deepen the understanding of key geological, geochemical, and geophysical aspects of natural hydrogen (H<ce:inf loc=\"post\">2</ce:inf>) as a potential new energy resource. This paper reviews major scientific uncertainties on natural H<ce:inf loc=\"post\">2</ce:inf>, suggesting research priorities, as a guide for defining exploration strategies, techniques, and data interpretation. The uncertainties concern all phases of the natural H<ce:inf loc=\"post\">2</ce:inf> cycle, from generation (source rocks) through migration (advection and diffusion) and accumulation (reservoir and cap rocks) to the application and interpretation of subsurface and surface geochemical and geophysical exploration techniques. Understanding H<ce:inf loc=\"post\">2</ce:inf> sources and generation rates (the amount of H<ce:inf loc=\"post\">2</ce:inf> generated by a given volume of rock over time) is crucial for determining whether a geological H<ce:inf loc=\"post\">2</ce:inf> system operates as a short-term dynamic system with rapid H<ce:inf loc=\"post\">2</ce:inf> production and release, or as a conventional gas system with long-term accumulations, analogous to petroleum reservoirs. Preliminary estimates for serpentinisation, radiolysis, and organic matter degradation suggest that H<ce:inf loc=\"post\">2</ce:inf> generation is not inherently fast, especially for non-hydrothermal continental systems (crystalline basement of shields, ophiolites, peridotite massifs, sedimentary basins), and long-term accumulations, like those of fossil natural gas systems, represent the most likely scenario. The mechanisms of H<ce:inf loc=\"post\">2</ce:inf> migration through geological formations require application of fundamental principles of fluid-flow physics, distinguishing advection and diffusion, as well as their forms (from gas-phase, bubble flows to aqueous solutions). Additional studies of H<ce:inf loc=\"post\">2</ce:inf> accumulation and retention in subsurface reservoirs could improve understanding of mechanisms of H<ce:inf loc=\"post\">2</ce:inf> migration by focusing on the rock fluid-bearing properties and the factors affecting H<ce:inf loc=\"post\">2</ce:inf> preservation, such as the presence of cap rocks impermeable to H<ce:inf loc=\"post\">2</ce:inf>, pressure conditions, residence times, and microbial or abiotic consumption. Advanced techniques, including reservoir modelling, flow simulations, 3D imaging (micro-CT) of H<ce:inf loc=\"post\">2</ce:inf>-bearing rocks, and extraction and analysis of gas occluded in rocks, can provide insights into the stability and potential recoverability of H<ce:inf loc=\"post\">2</ce:inf> accumulations. The interpretation of surface exploration techniques, including gas geochemistry, geophysics, and remote sensing, long employed in mineral and energy resource exploration, is now being adapted for natural H<ce:inf loc=\"post\">2</ce:inf> studies, but challenges remain in the data interpre","PeriodicalId":11483,"journal":{"name":"Earth-Science Reviews","volume":"37 1","pages":""},"PeriodicalIF":12.1,"publicationDate":"2026-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146098420","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}