Earth-Science Reviews最新文献

{"title":"Gaseous hydrocarbons cracking in shale: Mechanism, impact and resource significance","authors":"Bin Cheng ,&nbsp;Shida Li ,&nbsp;Jianbing Xu ,&nbsp;Zewen Liao","doi":"10.1016/j.earscirev.2025.105211","DOIUrl":"10.1016/j.earscirev.2025.105211","url":null,"abstract":"<div><div>Gaseous hydrocarbons (C₁ − C₅) are the primary components of shale gas. Their thermal degradation significantly impacts various aspects of shale gas reservoirs, including gaseous hydrocarbons composition and their carbon and hydrogen isotopes fractionation, H₂ generation, reservoir overpressure, mineral dissolution and brittle mineral formation, changes in reservoir properties and storage space, as well as the formation and identification of resource sweet spots. This study reviews the experimental simulations of gaseous hydrocarbon cracking and the geochemical research on major global shale gas reservoirs conducted over the past few decades. In shale gas reservoirs, C₅H₁₂, C₄H₁₀, C₃H₈, C₂H₆ and CH₄ initiate cracking at Ro values of approximately 1.0 %, 1.0 %, 1.3 %, 1.5 %, and 2.0 %, respectively, with main cracking stages occurring at Ro ranges of 1.7–2.4 %, 1.7–2.8 %, 1.8–3.2 %, 1.8–3.6 %, and 3.0–4.0 %. This cracking produces more gaseous molecules, significantly contributing to overpressure and H₂ in high-overmature reservoirs. Wet gas cracking contributes carbon isotope rollover but CH₄ cracking causes both carbon and hydrogen isotope reversals in shale gas. As CH₄ cracking onset marks peak gas generation of shale, carbon isotope reversal serves as a key sweet-spot indicator. Furthermore, hydrous pyrolysis of gaseous hydrocarbons generates formic and acetic acids that enhance porosity and permeability by dissolving carbonate and feldspar minerals. Concurrent silica precipitation during feldspar dissolution promotes quartz formation, improving reservoir fracturability. This study advances our understandings of the formation, evolution and associated geological and geochemical anomalies of shale gas reservoirs, which holds significant implications for the exploration and exploitation of shale gas resources.</div></div>","PeriodicalId":11483,"journal":{"name":"Earth-Science Reviews","volume":"270 ","pages":"Article 105211"},"PeriodicalIF":10.8,"publicationDate":"2025-07-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144579702","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":"Diagenesis of hydrocarbon-seep carbonates: Common patterns, divergent pathways and conceptual pitfalls","authors":"M. Jakubowicz ,&nbsp;S.A. Akam ,&nbsp;C. Argentino ,&nbsp;K. Hryniewicz ,&nbsp;G. Panieri ,&nbsp;S. Kiel ,&nbsp;Z. Belka","doi":"10.1016/j.earscirev.2025.105210","DOIUrl":"10.1016/j.earscirev.2025.105210","url":null,"abstract":"&lt;div&gt;&lt;div&gt;Authigenic carbonates formed at marine hydrocarbon seeps are an important component of carbon cycling at continental margins. Ancient hydrocarbon-seep deposits serve as archives of the evolution of chemosynthesis-based ecosystems, past pore-water chemistry, and the tectonic architecture and geological history of their host sedimentary basins. However, while modern and ancient seep deposits share many similarities, they also show notable differences in their petrological and geochemical characteristics. The insufficient understanding of the origin of these differences limits our ability to address fundamental questions about the palaeoecology of seep-specialised communities, the geological evolution of seep-hosting plate margins, and secular changes in the composition of the seeping fluids and/or seawater. Here, we critically evaluate the carbon, oxygen and strontium isotope signatures, as well as selected minor and trace element systematics of ancient seep carbonates. We identify distinctive, recurring patterns and discuss them in the context of current understanding of the controls on carbonate authigenesis and alteration in marine pore waters. The precipitation of seep carbonates mostly from sediment pore waters at the transition between the sulphate reduction and methanogenic zones favours the preservation of primary textural and geochemical characteristics. However, in this anoxic, spatially and temporarily complex setting, the concentrations of many minor and trace elements, including the refractory lithophile elements, are subject to increased mobility during fluid-rock interactions, mineral transformations and organic matter decomposition. This mobility complicates their traditional use as indicators of post-depositional alteration, laboratory artefacts, or original mineralogies. The high concentrations of strontium with non-marine &lt;sup&gt;87&lt;/sup&gt;Sr/&lt;sup&gt;86&lt;/sup&gt;Sr ratios that may be introduced with the seeping fluids offer insights into the fluid sources and basement characteristics, but also limit the utility of Sr isotope stratigraphy for dating seep deposits. A negative correlation between the δ&lt;sup&gt;13&lt;/sup&gt;C and δ&lt;sup&gt;18&lt;/sup&gt;O values, commonly observed in microcrystalline phases, most likely reflects the continuous cementation of seep carbonates during burial in the methanogenic zone. This process is driven by methanogenesis-associated aluminosilicate weathering, releasing &lt;sup&gt;13&lt;/sup&gt;C-enriched and &lt;sup&gt;18&lt;/sup&gt;O-depleted fluids. Another common pattern, the narrow clustering of strongly negative δ&lt;sup&gt;18&lt;/sup&gt;O signals, appears to record selective δ&lt;sup&gt;18&lt;/sup&gt;O resetting during fluid-dominated post-depositional alteration. The observed increased δ&lt;sup&gt;13&lt;/sup&gt;C values of seep carbonates during parts of the Paleozoic and Mesozoic may be associated with the secular changes in the dissolved inorganic carbon concentration of seawater, while the role of other controls remains unclear. Our work provides a timely synthesis of th","PeriodicalId":11483,"journal":{"name":"Earth-Science Reviews","volume":"270 ","pages":"Article 105210"},"PeriodicalIF":10.8,"publicationDate":"2025-07-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144605438","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":"Avalanche susceptibility factors, trends, techniques, and practices in Indian Himalaya: A review","authors":"Kirti Thakur ,&nbsp;Harish Kumar ,&nbsp;Snehmani","doi":"10.1016/j.earscirev.2025.105207","DOIUrl":"10.1016/j.earscirev.2025.105207","url":null,"abstract":"<div><div>Avalanche susceptibility mapping is the primary step for avalanche investigation, safer planning, and future development activities. Therefore, investigation of the terrain, snowpack and meteorological characteristics are crucial for the avalanche susceptibility assessment. In this paper, various parameters responsible for different types of avalanche occurrence and their significance are discussed for Indian Himalayas. This paper reviews 373 research papers published between 2013 and 2024 to gain insight into the current trends, techniques, and practices used in avalanche susceptibility mapping. After reviewing the related literature, it has been observed that no universally acceptable standard parameters or model exist that can describe all types of avalanche activities adequately. Secondly, based on expert knowledge about all snowpack and meteorological parameters, only twelve parameters are mainly used in the snow avalanche related prediction model. Hence, there is a need to explore the combination of other parameters and their impact to improve the model's accuracy. It highlights important aspects and provides a broader perspective on avalanche mapping that may be useful for practitioners worldwide, while also serving as a valuable database for researchers in this field, particularly those working in the Himalayan region. Finally, the vital issues arising in this research field that need to be addressed by the researchers are discussed. It is expected that the accuracy and applicability of models could be greatly improved, by incorporating big data geo-analytics techniques, utilizing deep learning methods, and spatiotemporal modelling.</div></div>","PeriodicalId":11483,"journal":{"name":"Earth-Science Reviews","volume":"269 ","pages":"Article 105207"},"PeriodicalIF":10.8,"publicationDate":"2025-06-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144522409","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":"Recent advances and future research directions in deep learning as applied to geochemical mapping","authors":"Ying Xu ,&nbsp;Renguang Zuo ,&nbsp;Zhiyi Chen ,&nbsp;Zixian Shi ,&nbsp;Oliver P. Kreuzer","doi":"10.1016/j.earscirev.2025.105209","DOIUrl":"10.1016/j.earscirev.2025.105209","url":null,"abstract":"<div><div>Geochemical survey data are a key tool for identifying geochemical patterns and anomalies relevant to mineral exploration. In the past decade, artificial intelligence (AI) has been widely applied in geochemical data mining to compensate for the shortcomings of traditional methods. Here, we first reviewed the applications of five popular deep learning algorithms (DLAs) adopted in the past six years (i.e., from 2019 to 2025), namely deep belief network, recurrent neural network, convolutional neural network, autoencoder, and generative adversarial network. We then examined recent state-of-the-art applications of DLAs in geochemical spatial pattern recognition, which served to highlight their advantages over the five popular DLAs previously discussed. Subsequently, we flagged three critical challenges in DLA-based geochemical mapping: (i) inadequate representation of complex spatial heterogeneity patterns of geochemical survey data, (ii) development of innovative models to overcome the limitations imposed by insufficient training samples, and (iii) systematic integration of geological constraints to enhance model accuracy and interpretability. To address these limitations, we proposed two promising, novel architectures: (i) graph self-supervised learning and (ii) graph reinforcement learning (GRL). Graph self-supervised learning represents geochemical data as graph structures, using self-supervised techniques to address training data limitations. Furthermore, the model uses Transformer for modeling global spatial relationships and embeds knowledge nodes for ensuring geological consistency during model training. Like the above, GRL employs graph representations of geochemical data, also combining graph convolutional networks within a reinforcement learning system. The key advancement of GRL involves the creation of reward functions that incorporate geological rules, thereby linking expert knowledge and DLAs through dynamic environment feedback. A case study is presented to demonstrate the effectiveness of these approaches and highlights the potential for integrating advanced methodologies to enhance the accuracy and reliability of geochemical anomaly identification in complex geological settings.</div></div>","PeriodicalId":11483,"journal":{"name":"Earth-Science Reviews","volume":"270 ","pages":"Article 105209"},"PeriodicalIF":10.8,"publicationDate":"2025-06-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144563618","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":"Meso–Cenozoic exhumation history of Northeast Asia and its connections with tectonic and climatic factors","authors":"Hongtao Wang ,&nbsp;Shichao Li ,&nbsp;Rong Yang ,&nbsp;Xiaopeng Yang ,&nbsp;Fangbin Liu ,&nbsp;Zheren Zhao","doi":"10.1016/j.earscirev.2025.105208","DOIUrl":"10.1016/j.earscirev.2025.105208","url":null,"abstract":"<div><div>Northeast Asia, a prominent basin-and-range system during the Mesozoic–Cenozoic, provides a unique context for studying how deep Earth processes influence surface landscape evolution. However, the comprehensive exhumation history and its connections to tectonic and climatic factors remain poorly understood. In this study, we analyze spatiotemporal variations in exhumation rates across Northeast Asia by compiling and inverting a dataset of apatite and zircon fission track and (U-Th)/He ages, alongside crustal deformation and paleoclimate data. Our results reveal differential rapid exhumation from the Late Jurassic to Early Cretaceous (150–110 Ma), primarily driven by the closure of the Mongol–Okhotsk Ocean and subduction of the paleo-Pacific plates, further enhanced by increased precipitation. From 110 to 90 Ma, exhumation rates progressively decreased from the continental margin to the interior (∼0.69 km/Myr to ∼0.20 km/Myr), influenced mainly by compressional deformation. During the late Cretaceous to Paleocene (90–60 Ma), the Northeast Asian mountains underwent widespread rapid exhumation, with a peak rate of 0.85 km/Myr. However, toward the end of this period, exhumation slowed due to the diminished tectonic forces from paleo-Pacific plates subduction and arid climatic conditions. Cenozoic localized exhumation was driven primarily by mid-ocean ridge and Pacific Plate subduction, with minimal climatic influence. The present-day basin-and-range landscape of Northeast Asia is the cumulative outcome of tectonic and climatic forcing since the Mesozoic.</div></div>","PeriodicalId":11483,"journal":{"name":"Earth-Science Reviews","volume":"269 ","pages":"Article 105208"},"PeriodicalIF":10.8,"publicationDate":"2025-06-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144535796","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 deep conductive layer in the icelandic crust","authors":"Knútur Árnason, Benoit Gibert, Claire Bouligand, Arnar MÁr VilhjÁlmsson","doi":"10.1016/j.earscirev.2025.105198","DOIUrl":"https://doi.org/10.1016/j.earscirev.2025.105198","url":null,"abstract":"Early MT resistivity soundings in Iceland revealed a Deep Conductive Layer (DCL), a layer with anomalously high conductivity, at the depth of 5-15 km (upper seismic layer 3) in the crust under most of the country. When first observed in the 1970s, the DCL was interpreted as partial melt below a thin and hot crust. Later seismic and gravity studies have showed that the crust is 20–40 thick, dense and relatively cold. The DCL is thus an intra-crustal layer below the brittle/ductile transition and does not correlate with any currently known seismic feature. In this paper we try to narrow down possible origin(s) and nature of the enigmatic DCL and how its presence can be understood in the framework of the thick and cold crustal model. We review existing electrical conductivity data from early MagnetoTelluric measurements done in the 1970s and 1980s and from recent surveys mostly done in the context of geothermal exploration. The DCL domes up beneath central volcanoes with high temperature geothermal areas. It is found to be electrically anisotropic, being more conductive in the spreading direction than is the tectonic/fracture direction. We review several possible conduction mechanisms that could explain the high conductivity in the light of recent experimental work on electrical conductivity of minerals and rocks and discuss the possible prevailing conduction mechanisms in the light of existing geophysical and petrological observations in Iceland. These investigations show that seismic and electrical surveys are both compatible with the presence of melt in the DCL in the volcanic plumbing system associated to volcanoes. Outside active volcanoes, seismic properties of the DCL, inferred from local tomography, are not compatible with the presence of melt or even aqueous fluid in the DCL but confirm thick, cold and fluid-free lower crust, leaving only solid-state conduction as a viable conduction mechanism. Review of laboratory measurements on various type of minerals lead to the conclusion that Fe<ce:glyph name=\"sbnd\"></ce:glyph>Ti oxides or hydrated minerals, such as amphibole, could explain the DCL. In Eyjafjörður, North Iceland, the only low-temperature area studied using MT to date, the DCL locally domes up to shallow depths under area the geothermal areas. This suggests possible correlation of low-temperature geothermal activity and a relatively shallow DCL. Detailed mapping of the DCL might therefore be an important tool in prospection of for low-temperature geothermal resources.","PeriodicalId":11483,"journal":{"name":"Earth-Science Reviews","volume":"148 1","pages":""},"PeriodicalIF":12.1,"publicationDate":"2025-06-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144503855","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":"Facies stacking patterns in modern carbonate peritidal settings and their sequence-stratigraphic implications","authors":"John M. Rivers,&nbsp;Robert W. Dalrymple","doi":"10.1016/j.earscirev.2025.105201","DOIUrl":"10.1016/j.earscirev.2025.105201","url":null,"abstract":"<div><div>The ‘shallowing-upward’ (parasequence) motif has long dominated the understanding of bed-scale carbonate cycles and, ultimately, sequence-stratigraphic models for platform-interior deposits of the rock record. To evaluate the viability of the shallowing-upward assumption, a review of mid- to late-Holocene coastal carbonate successions from many “classic” peritidal settings was undertaken. This assessment shows that the simple shallowing-upward assumption is largely unsupported by the aggregate of modern-systems observations. Tidal flats generally do not prograde directly into lagoons to create muddy shallowing-upward cycles, and lagoons are not observed to prograde over their own protective shoal barriers to create grainy shallowing-upward cycles. Instead, transgressive deposits comprise an important component of carbonate depositional successions, forming deepening-upward motifs, where cycle-base tidal-flat and lagoonal remnants are overlain by a ravinement surface, signifying the passing of a transgressing carbonate barrier, and then are overlain by open-platform deposits. Overlying this, regressive deposits, where present, are represented by lagoonal abandonment and grainy shoreface progradation capped by strandplains, with overlying accommodation only for thin, discontinuous, intertidal mud flats and their subtidal drainage channels in inter-ridge swales. These observations indicate that the construct of the parasequence is less useful than that of a high-order sequence containing transgressive and regressive components. The implications of these observations and interpretations are wide-ranging and have generated the need for updated sequence-stratigraphic models for coastal carbonates based on modern coastal systems, and with which the rock record can be compared. These models are meaningfully different from models currently in use with respect to predictions of large-scale subsurface connectivity.</div></div>","PeriodicalId":11483,"journal":{"name":"Earth-Science Reviews","volume":"269 ","pages":"Article 105201"},"PeriodicalIF":10.8,"publicationDate":"2025-06-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144503850","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":"Classic, modern, and physics-based rheological laws for geophysical granular flows in a landslide hazard chain","authors":"Mohsen Kamali Zarch ,&nbsp;Limin Zhang ,&nbsp;S. Mohsen Haeri ,&nbsp;Jian He","doi":"10.1016/j.earscirev.2025.105204","DOIUrl":"10.1016/j.earscirev.2025.105204","url":null,"abstract":"<div><div>Geophysical granular and particle-laden flows, in a typical landslide hazard chain, pose significant risks to human life and infrastructure. The governing rheological constitutive law of the flowing mixture plays a crucial role in assessing their mobility and consequences. Developing a generic constitutive law, capable of capturing the evolving nature of mixture properties across different flow regimes in a landslide hazard chain, requires the incorporation of several physical concepts and is an active research question. This technical review presents a comprehensive review of existing rheological laws by classifying them into classic, modern, and physics-based mixture laws. Firstly, a preliminary classification of particle-fluid mixtures is proposed, encompassing dilute, moderate, and high ranges of solid concentrations. Next, following the continuum mechanics, the various types of particle-fluid mixture representations, from single-phase to multi-phase conceptualizations are presented. With a focus on flow index classification, the classic laws that assume a fixed relation over a single flow regime are explored. By switching to different flow regimes, rather than flow indexes, the modern laws that aim to capture the rheological behavior of flowing mixtures across different flow regimes are reviewed. Finally, the physics-based mixture rheological laws which combine the existing classic and modern rheological laws for fluid and solid phases, and further include additional novel rheological laws for interphase interaction forces, are reviewed. This review enlightens the existing research trends on classic and modern rheological laws, describes their capabilities, and highlights missed concepts that are required for the development of a generic rheological law for landslide hazard chains. Enhanced understanding of the evolution of rheological behavior of flowing mixtures over various flow regimes in a landslide hazard chain improves further studies on hazard simulation and prediction, risk mitigation, and land use planning.</div></div>","PeriodicalId":11483,"journal":{"name":"Earth-Science Reviews","volume":"269 ","pages":"Article 105204"},"PeriodicalIF":10.8,"publicationDate":"2025-06-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144503851","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 South China Block: A reef-building focal point in Givetian (Middle Devonian) of eastern Palaeotethys","authors":"Jiayuan Huang ,&nbsp;Stephen Kershaw ,&nbsp;Kun Liang ,&nbsp;Wenkun Qie","doi":"10.1016/j.earscirev.2025.105202","DOIUrl":"10.1016/j.earscirev.2025.105202","url":null,"abstract":"<div><div>The Middle Devonian witnessed the expansion of global coral-stromatoporoid reefs, but knowledge of reefs derives mainly from Laurussia and adjacent regions. Although South China Block (SCB) is renowned for reef proliferation in the eastern Palaeotethys, reef growth and their global implications remain under-explored. Using data from 353 references and 6731 thin sections, this study provides a comprehensive summary regarding reef ecosystems of SCB, plus comparison and integration with global records. Two main findings are outlined: (1) <strong>Reef growth</strong>. Three well-differentiated ecological associations and six high-resolution developing stages are recognised, and the mid-Givetian marked the peak of reef-building. The transition from epicontinental seas to rifting platforms reflects reef expansion from extensive open marine biostromes to barrier reef–lagoon communities. Reef growth was driven primarily by climate, temperature, and sea-level changes/tectonic activities, facilitating carbonate precipitation and extensive shallow-water habitats. (2) <strong>Global implications</strong>. Compared with major reef regions, the significance of SCB is noted in three aspects, including abundant fossil materials, unusual palaeogeographic location (eastern Palaeotethys), and exceptional reef pattern (broad inland sea to platforms and intra-platform basins). Based on the newly refined reef database, the global spatial distribution of Givetian reefs indicates SCB as a reef-building hotspot in eastern Palaeotethys. Moreover, the new temporal trajectory implies the reef peak occurred earlier in the Middle Devonian, supporting Givetian as an acme of Phanerozoic reef-building. Overall, this study highlights the underestimated role of SCB in understanding global Givetian reef expansion, Phanerozoic reef evolution, and the intricate interplay of local/global factors controlling reef growth.</div></div>","PeriodicalId":11483,"journal":{"name":"Earth-Science Reviews","volume":"269 ","pages":"Article 105202"},"PeriodicalIF":10.8,"publicationDate":"2025-06-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144503856","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":"Marine-sedimentary manganese metallogenesis through geologic time and its coupling with major geoenvironmental events","authors":"Liping Liu ,&nbsp;Xiaohu Li ,&nbsp;Jun Liu ,&nbsp;Hongxian Chu ,&nbsp;Hongsong Wang ,&nbsp;Fengyou Chu","doi":"10.1016/j.earscirev.2025.105205","DOIUrl":"10.1016/j.earscirev.2025.105205","url":null,"abstract":"&lt;div&gt;&lt;div&gt;Marine-sedimentary manganese (Mn) deposits, which boast significant reserves compared with other Mn deposit types, are vital sources of Mn for steel manufacturing and the global chemical industry. Recent discoveries of new marine-sedimentary Mn deposits and the application of advanced analytical methods have led to fresh insights into marine-sedimentary Mn metallogenesis. Mn is a redox-sensitive element. However, Mn cycling, which encompasses transport, deposition, and mineralization, is not a straightforward redox chemical process. Over the past two decades, studies on the biogeochemical behaviors of Mn and geological case studies of sedimentary Mn deposits have highlighted the crucial role of microorganisms in Mn cycling, which exceeds that of inorganic reactions alone. Nevertheless, the specific geoenvironmental conditions that facilitate microbially mediated Mn metallogenesis and the interrelationships among these events remain unclear. In this study, we review significant marine-sedimentary Mn deposits throughout geological history and their metallogenic geoenvironmental contexts. Our findings suggest that, despite the extensive temporal gaps between sedimentary Mn deposits, they likely share a similar metallogenesis mechanism. Pre-accumulated Mn(II) is converted to Mn oxides through the activation of multicopper oxidase enzymes under obligatory oxic conditions. In deposition sites with sufficient organic matter, heterotrophic microbes subsequently reduce Mn oxides to Mn carbonates by coupling with organic matter decomposition under suboxic or anoxic conditions. We propose four essential geoenvironmental prerequisites for large-scale Mn metallogenesis: the Mn source, high availability of molecular oxygen in water, a redox-stratified restricted setting, and the exchange of anoxic with oxic water columns. These conditions fundamentally arise from the breakup and assembly of supercontinents throughout Earth's history. Rifting has created a series of restricted basins, where hydrothermal activity has provided a substantial source of Mn(II). Continental inputs from weathering-derived Mn, including lateritic crusts, may also play a crucial role in the genesis of large sedimentary Mn accumulations and should not be overlooked. The sustained increase in atmospheric and hydrospheric oxygen levels has primarily been driven by photosynthesis, mantle overturning, and the expansion of continental regions. The anoxic depths of redox-stratified restricted rift basins have served as effective reservoirs for pre-accumulated Mn(II) and have provided refuge for calm biomat formation by limiting debris input. The exchange of oxygenated surface water with anoxic, metal-rich water in deep basins, facilitated by currents or fluctuations in sea level, creates the oxic conditions required for the enzymatic processes that promote microbial Mn(II) oxidation. We also identify several scientific issues that warrant further research, including the effects of th","PeriodicalId":11483,"journal":{"name":"Earth-Science Reviews","volume":"269 ","pages":"Article 105205"},"PeriodicalIF":10.8,"publicationDate":"2025-06-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144519236","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}