Javiera González , Verónica Oliveros , Friedrich Lucassen , Christian Creixell , Felipe Coloma , Ricardo Velásquez , Laura Hernández , Paulina Vásquez , Simone A. Kasemann
{"title":"The Triassic magmatism in southwestern Gondwana: An example of arc batholith construction in a retreating margin","authors":"Javiera González , Verónica Oliveros , Friedrich Lucassen , Christian Creixell , Felipe Coloma , Ricardo Velásquez , Laura Hernández , Paulina Vásquez , Simone A. Kasemann","doi":"10.1016/j.gr.2024.12.002","DOIUrl":"10.1016/j.gr.2024.12.002","url":null,"abstract":"<div><div>The Chollay-Piuquenes batholith (CPB) represents voluminous Lower-Middle Triassic magmatism on the western margin of Gondwana. It crops out in the Chilean Frontal Cordillera (28°30′S–30°30′S), covering ∼2,400 km<sup>2</sup>. It is composed of the Chollay and Piuquenes plutonic complexes, that were emplaced over a 16 Myr interval, with magma production rates ranging from 6 to 7.5 km<sup>3</sup>/Myr km<sup>−1</sup>. The batholith lithologies vary from diorites to syenogranites, with a predominance of monzogranites and granodiorites. It was previously interpreted as an anorogenic, post-collisional magmatism, originated from crustal anatexis in a rifting continental margin (Pre-Andean Cycle). This field and geochemical study proposes that CPB is likely a subduction-related batholith constructed in a convergent retreating margin. This interpretation is consistent with the Triassic geotectonic context proposed for western Gondwana. Moreover, the extensional context for the CPB emplacement is inferred from the contemporaneous development of forearc and back-arc basins, and from geochemical signals indicating Mesozoic crustal thinning along the margin. The CPB rocks exhibit subalkaline, meta- to peraluminous, calc-alkaline to alkaline-calcic affinities, enrichment in LILE relative to HFSE, depletion in Nb-Ta, Ti, Sr, and P, and Pb enrichment. The rocks display flat REE patterns (La<sub>N</sub>/Yb<sub>N</sub>: 3.40–13.78) and Al-in-Hbl barometer calculations (1.7–1.8 ± 0.6 kbar) suggest an epizonal emplacement. The Sr-Nd-Pb isotopic signature suggests a mixture of depleted mantle and continental crust, and not only crustal reworking, as the main magma-generating process. A comparative analysis of CPB samples with other well-known examples of both retreating and advancing margin batholiths allows the establishment of criteria to distinguish each tectonic context.</div></div>","PeriodicalId":12761,"journal":{"name":"Gondwana Research","volume":"139 ","pages":"Pages 81-103"},"PeriodicalIF":7.2,"publicationDate":"2024-12-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142797874","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":"Constraints on Earth’s atmospheric evolution from a gas-aqueous partition of fluid inclusion volatiles","authors":"Justin G. Park , Morgan F. Schaller","doi":"10.1016/j.gr.2024.12.003","DOIUrl":"10.1016/j.gr.2024.12.003","url":null,"abstract":"<div><div>Recent attention has been paid to fluid inclusions in surficial minerals for their ability to capture and preserve aliquots of ancient atmospheric gas. Through mechanical or thermal decrepitation, the volatiles trapped in these multiphase inclusions can be analyzed by mass spectrometry, providing direct constraints on the composition of the Earth’s ancient atmosphere. It is often assumed that this measured gas composition reflects directly the atmosphere under which the minerals precipitated. However, when the effects of gas solubility are neglected, the interpreted atmosphere is likely to be erroneous, reflecting a mixture of gas and brine. Here, we present a novel technique and computer code, MAGPI (Method for Atmospheric Gas Partitioning from fluid Inclusions), to partition the atmospheric volatiles between the gas and aqueous phases present at the time of inclusion formation and volatile entrapment. The N<sub>2</sub>/<sup>40</sup>Ar ratios of the released gases are used to calculate the volume fractions of the gaseous and aqueous phases present at the time of entrapment, which allows the observed gas ratios to be corrected to accurately reflect the composition of the atmosphere under which they formed. We validate our method on contemporary halite fluid inclusions, and then apply it to existing data from a suite of Tonian (815 Ma) halite and gypsum evaporites from the Browne Formation, Australia, and the Minto Inlet Formation, Canada. The results of our partition indicate that the Tonian atmosphere contained 92.83 ± 0.70 % N<sub>2</sub>, 6.62 ± 0.71 % O<sub>2</sub>, 0.47 ± 0.01 % Ar, and 0.08 ± 0.07 % CO<sub>2</sub>, which is consistent with other proxy and model reconstructions of the Neoproterozoic atmosphere. These results demonstrate the importance of phase chemistry in fluid inclusion gas analyses and provide a fundamental framework for future studies of Earth’s atmospheric evolution through inclusion gases.</div></div>","PeriodicalId":12761,"journal":{"name":"Gondwana Research","volume":"139 ","pages":"Pages 204-215"},"PeriodicalIF":7.2,"publicationDate":"2024-12-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142884646","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":"Differential lithospheric evolution during craton destruction: Insights from Mesozoic mafic magmatic suites with transitional features in the North China Craton","authors":"Fei Xue , M. Santosh , Sung Won Kim","doi":"10.1016/j.gr.2024.11.010","DOIUrl":"10.1016/j.gr.2024.11.010","url":null,"abstract":"<div><div>During the Mesozoic, the North China Craton (NCC) especially the eastern part underwent significant destruction of its cratonic roots. During ∼125–120 Ma, the source of magmatism shifted from an ancient enriched lithospheric mantle to a juvenile depleted asthenospheric mantle. While this geochemical change is clear in the eastern NCC, it is unclear whether a similar shift occurred in the central NCC or if the lithospheric evolution differed across the craton. Mafic magmatic suites are key to understanding the evolution of cratonic lithospheric mantle, especially by analyzing their geochemical and isotopic transitions. This study examines the Mesozoic Laiyuan ultramafic–mafic intrusions in central NCC, classified into gabbro, gabbroic diorite, and cumulate suites (pyroxenite and hornblendite). Zircon U-Pb dating indicates gabbroic rocks formed between 136–124 Ma and cumulated between 130–129 Ma. These rocks also display similar isotopic signatures, including zircon Hf isotopes ranging from −24.9 to −7.8 and −28.3 to −15.9, (<sup>87</sup>Sr/<sup>86</sup>Sr)<sup>i</sup> ratios from 0.705945 to 0.706335 and 0.705692 to 0.706038, and ε<sub>Nd</sub>(t) values from −16.1 to −12.8 and −15.8 to −12.5, respectively. Geochemical and isotopic data suggest an enriched lithospheric mantle source influenced by subduction-related metasomatism with minimal crustal contamination. The gabbroic and ultramafic layers represent residual melts and cumulates from a common source, respectively. Geochemical data reveal a transition in the mantle source from ultramafic-mafic intrusions (∼140–124 Ma) to dolerite (∼125–117 Ma) and lamprophyre (∼115–110 Ma), indicating lithospheric thinning and asthenosphere upwelling. This gradual transition in the central NCC contrasts with the rapid change in the eastern NCC, reflecting different lithospheric evolution processes: thermo-mechanical erosion in the central NCC and lithospheric delamination in the eastern NCC. These findings highlight diverse mechanisms of cratonic destruction across the NCC.</div></div>","PeriodicalId":12761,"journal":{"name":"Gondwana Research","volume":"139 ","pages":"Pages 118-135"},"PeriodicalIF":7.2,"publicationDate":"2024-12-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142841530","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}
Muhammad Amir Raza , Abdul Karim , M.M. Aman , Mahmoud Ahmad Al-Khasawneh , Muhammad Faheem
{"title":"Global progress towards the Coal: Tracking coal reserves, coal prices, electricity from coal, carbon emissions and coal phase-out","authors":"Muhammad Amir Raza , Abdul Karim , M.M. Aman , Mahmoud Ahmad Al-Khasawneh , Muhammad Faheem","doi":"10.1016/j.gr.2024.11.007","DOIUrl":"10.1016/j.gr.2024.11.007","url":null,"abstract":"<div><div>Coal remains a significant energy source globally, with the United States holding a substantial portion of the world’s coal reserves but it creates the dangerous effects of global warming. Despite its abundance, questions arise regarding the accessibility and environmental impact of coal reserves. Therefore, this research forecasted the future of coal reserves, coal prices, electricity from coal, carbon emissions and coal phase-out targets globally using the SARIMAX Python® model for the study period 2023 to 2050 by using the economic data from the year 1980 to 2022. It is found that, the global coal reserve capacity is 1.07 trillion tons with an average coal prices vary with region to region, ranging from US $130 per tone to US $206 per tone until 2050. The global production of electricity from coal will also increase from 10415.49 TWh in 2023 to 13316.57 TWh until 2040 and 15243.36 TWh until 2050 which ultimately enhances the production of carbon emissions, increases from 157,768 billion metric tons in 2023 to 188,535 billion metric tons until 2040 and 215,077 billion metric tons until 2050. Furthermore, this study undertakes and presented the country wise examination of coal phase out and it is found that in many countries 75% of coal will phase out by 2030 and 100% by 2040 for meeting the Intergovernmental Panel on Climate Change (IPCC) 1.5 <sup>0</sup>C targets. Therefore there is a dire need to shift towards cleaner energy sources, leading to a decline in coal-fired power generation and a trend towards coal phase-out.</div></div>","PeriodicalId":12761,"journal":{"name":"Gondwana Research","volume":"139 ","pages":"Pages 43-72"},"PeriodicalIF":7.2,"publicationDate":"2024-12-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142797875","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}
Bo Liu , Jingxuan Ma , Pengfei Li , Yangbaihe Hong , Wei Feng
{"title":"First boron isotopes in the southern Jilin TTG series uncover a Neoarchean oceanic arc in the eastern North China Craton","authors":"Bo Liu , Jingxuan Ma , Pengfei Li , Yangbaihe Hong , Wei Feng","doi":"10.1016/j.gr.2024.11.008","DOIUrl":"10.1016/j.gr.2024.11.008","url":null,"abstract":"<div><div>The Neoarchean evolution of the eastern North China Craton (NCC) is still controversial. This study presents the first B isotopes, together with zircon U-Pb-Hf isotopes and whole-rock geochemical analyses, for the TTG and dioritic series in the Baishan area of the southern Jilin region. LA-ICP-MS zircon U-Pb results uncover the Neoarchean magmatic activities, including granodioritic gneisses (2648 ± 10 Ma and 2622 ± 8 Ma), and quartz dioritic gneiss (2539 ± 7 Ma). The 2.65–2.60 Ga TTG series exhibit intermediate calc-alkaline characteristics, with relatively lower Th/La ratios (0.11–0.41) and positive zircon ε<sub>Hf</sub>(t) values (+3.73 to +7.93), suggesting that the TTG series were likely derived from partial melting of mafic lower crust. By contrast, the 2.54 Ga dioritic series show positive Zr, Hf and Eu anomalies, with relatively lower Nb/Zr ratios (0.013–0.028) and ε<sub>Hf</sub>(t) values (+2.00 to +5.49), indicating that they were possibly produced by mixing of the mantle-derived magma and crustal melts. Importantly, the 2.65–2.60 Ga TTG series are characterized by positive whole-rock δ<sup>11</sup>B values of +4.11 to +15.08 ‰, resembling the Izu-Bonin-Mariana oceanic arc and South Sandwich Island arc volcanic rocks. The formation of these TTG rocks is attributed to <sup>11</sup>B-rich fluids released by subducted oceanic slab and subsequent metasomatism of the subarc mantle wedge. Unlike the oceanic arc TTG series, the 2.54 Ga dioritic series exhibit lighter whole-rock δ<sup>11</sup>B values of −4.23 to −4.50 ‰, reflecting an arc-continental collision induced by slab breakoff and mantle-derived magma upwelling. Integrated with previous studies, it suggests that the subduction-collision process in the eastern NCC resulted from the co-evolution of oceanic arc and continental margin arc.</div></div>","PeriodicalId":12761,"journal":{"name":"Gondwana Research","volume":"139 ","pages":"Pages 243-259"},"PeriodicalIF":7.2,"publicationDate":"2024-11-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143133271","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}
Yuanlin Chen , Huan Li , Shangyi Gu , Gary G. Lash , Chaoyang Zheng , Liuan Duan , Fan Yang
{"title":"Pulsed atmospheric oxygenation recorded by Mo isotopes and Ce anomalies during Lomagundi Event from Jingshan Group marble of North China Craton","authors":"Yuanlin Chen , Huan Li , Shangyi Gu , Gary G. Lash , Chaoyang Zheng , Liuan Duan , Fan Yang","doi":"10.1016/j.gr.2024.11.006","DOIUrl":"10.1016/j.gr.2024.11.006","url":null,"abstract":"<div><div>The Lomagundi Carbon Event (LE), the large, long-lived Paleoproterozoic positive carbon isotope excursion, is traditionally associated with a significant increase in atmospheric oxygen. However, the magnitude and extent of atmosphere–ocean oxygenation during this critical period of Earth’s history remain poorly constrained. Here, we present molybdenum isotope data and Ce anomaly values of Paleoproterozoic Jingshan Group marble samples deposited coincident with the peak of LE. Analyzed samples are characterized by near-modern seawater δ<sup>98</sup>Mo<sub>carb</sub> values (maximum = 2.13 ‰ ± 0.05), crustal Ce anomalies (average = 1.03), and δ<sup>98</sup>Mo<sub>carb</sub> values (average = 0.41 ‰). The great variation of Mo isotope values displayed by samples recovered from a thin stratigraphic interval likely reflect the existence of a small Mo reservoir during LE. We suggest that Mo removal from poorly oxygenated oceans under ferruginous conditions was responsible for the contraction of the Mo oceanic reservoir. Mo concentrations and isotope values of deposits coincident with this time interval appear to have been controlled by iron and manganese oxides shuttle. Placed in the context of Earth’s oxygenation history, our findings suggest that O<sub>2</sub> <!-->levels of the atmosphere–ocean system remained much less (1 % PAL) than the present level with occasional episodes of increased or pulsed atmospheric oxygen during the peak of LE.</div></div>","PeriodicalId":12761,"journal":{"name":"Gondwana Research","volume":"139 ","pages":"Pages 32-42"},"PeriodicalIF":7.2,"publicationDate":"2024-11-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142797877","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}
Claudio Andrade , Paulo M. Vasconcelos , Joan Esterle , Tracey Crossingham , Kasia Sobczak , Heinz-Gerd Holl , Suzanne Hurter , Corey Wall , James L. Crowley
{"title":"Tracing regional unconformities in intracratonic basins with high-precision zircon CA-TIMS geochronology","authors":"Claudio Andrade , Paulo M. Vasconcelos , Joan Esterle , Tracey Crossingham , Kasia Sobczak , Heinz-Gerd Holl , Suzanne Hurter , Corey Wall , James L. Crowley","doi":"10.1016/j.gr.2024.11.009","DOIUrl":"10.1016/j.gr.2024.11.009","url":null,"abstract":"<div><div>New high-resolution ID-TIMS geochronology of zircon from tuff horizons reveals a regionally traceable temporal hiatus of ∼ 3–10 Ma in sedimentation along the contact between the Middle-Upper Jurassic Walloon Coal Measures (WCM) and the Upper Jurassic Springbok Sandstone (SS), Surat Basin, Australia. Undecompacted sedimentation rates of 15–65 <span><span>m.Ma</span><svg><path></path></svg></span><sup>−1</sup> in the WCM drop to apparent sedimentation rates of 0 to 7 <span><span>m.Ma</span><svg><path></path></svg></span><sup>−1</sup> near the WCM-SS transition, rising again to 15–51 <span><span>m.Ma</span><svg><path></path></svg></span><sup>−1</sup> during SS deposition. U-Pb geochronology identifies a hiatus – either a cessation in sedimentation or an erosional event defining a regional unconformity – not discernable from sedimentary features, highlighting the need for high-resolution geochronology in defining key bounding surfaces in sequence stratigraphy of intracratonic basins. Determining the exact position of lithological contacts and characterizing petrophysical properties of units below and above the WCM-SS transition are particularly important in quantifying connectivity between the gas-bearing units below with regional aquifers above the unconformity. As exploration for coal-seam and shale gas in intracratonic sedimentary basins expands globally, identification of major stratigraphic transitions through high-resolution geochronology will help assessing the economic potential and environmental vulnerabilities of such systems.</div></div>","PeriodicalId":12761,"journal":{"name":"Gondwana Research","volume":"139 ","pages":"Pages 73-80"},"PeriodicalIF":7.2,"publicationDate":"2024-11-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142797887","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"The congruence of dual gaps in economic growth on regional sustainability","authors":"Yumeng Luo, Xiyao Liu, Meixi Chen, Yuhuan Xia","doi":"10.1016/j.gr.2024.11.005","DOIUrl":"https://doi.org/10.1016/j.gr.2024.11.005","url":null,"abstract":"The pursuit of economic development poses substantial environmental challenges, and achieving both economic and sustainable development are difficult goals to balance. Based on China’s unique political structure, government officials serve as central decision-makers in regional development. The policy choices of these officials are constrained by the official promotion tournament system. We examined the impact of gaps in the economic development goals of Chinese prefecture-level city governments on the sustainable development of regions using panel data for Chinese cities from 2003 to 2019. We analyzed the (in)congruence of the following two gaps: 1) the gap between the economic development of a city in the current and previous year, and 2) the gap between the average economic growth rate of other cities in the same province and the actual economic growth rate of a city. The results show that when there is incongruence between these two gaps (e.g., economic development surpasses expectations but falls short of the provincial average), green innovation within the region increases considerably. Our study integrates resource allocation theory and promotion tournament theory, expanding the boundaries of the theory of promotion tournaments for officials and the examination of motivations for green innovation. In addition, our findings not only benefit the Chinese government but also provide insights for governments worldwide to rationally allocate resources toward a cleaner and more sustainable future.","PeriodicalId":12761,"journal":{"name":"Gondwana Research","volume":"47 1","pages":""},"PeriodicalIF":6.1,"publicationDate":"2024-11-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142797876","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}
Oktay Özkan , Hephzibah Onyeje Obekpa , Stephen Taiwo Onifade , Andrew Adewale Alola
{"title":"Probing environmental sustainability aspects of resource efficiency, renewable energy usage and globalization","authors":"Oktay Özkan , Hephzibah Onyeje Obekpa , Stephen Taiwo Onifade , Andrew Adewale Alola","doi":"10.1016/j.gr.2024.10.016","DOIUrl":"10.1016/j.gr.2024.10.016","url":null,"abstract":"<div><div>Given the pace of economic expansion arising from energy usage among other social and economic factors, emerging economies such as Turkey are increasingly becoming the focus for a net zero future. Therefore, the current attempt considers the drivers of environmental sustainability via load capacity factor (LCF) in the context of resource efficiency, renewable energy utilization, and globalization for Turkey over the period 1982 to 2019. By employing series of empirical tools that include cross-quantilogram method, quantile-on-quantile regression, quantile regression approaches, and the nonparametric quantile Granger causality approach, the result shows there is statistically significant evidence of quantile-to-quantile dependence among the trio of (resource efficiency, renewable energy utilization, and globalization) and LCF such that the dependence it reflects some levels of positive directional predictability, thus showing that these indicators are important drivers of environmental sustainability in Turkey. Furthermore, for the quantile-on-quantile regression results, there are statistically significant and positive effects of (i) resource efficiency on LCF across its conditional quantiles of distribution, (ii) renewable energy utilization on LCF and is mostly visible at the lower quantile up to the upper middle quantiles of renewable energy utilization (0.05–0.65), and (iii) globalization on LCF across the lower to upper middle quantiles. With the other empirical approaches providing similar results, the outcome of this investigation offers specific policy insight into resource circularity and energy efficiency.</div></div>","PeriodicalId":12761,"journal":{"name":"Gondwana Research","volume":"139 ","pages":"Pages 16-31"},"PeriodicalIF":7.2,"publicationDate":"2024-11-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142797878","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Gang Wang , Kun Zhao , Jingxuan Zhang , Shengxian Zhu , Chaochao Xing , Xianguo Lang
{"title":"Glacial fluctuations in the Cryogenian Marinoan Snowball Earth","authors":"Gang Wang , Kun Zhao , Jingxuan Zhang , Shengxian Zhu , Chaochao Xing , Xianguo Lang","doi":"10.1016/j.gr.2024.10.015","DOIUrl":"10.1016/j.gr.2024.10.015","url":null,"abstract":"<div><div>The Marinoan glaciation represents the pinnacle of glacial severity in Earth’s geological history. Deep-water glacial deposits have revealed a complex interplay of at least two glacial advance-retreat cycles. However, the extent to which these glacial episodes are mirrored in shallow-water settings has received less attention. To shed light on this, we undertook an exhaustive lithofacies analysis of three shallow-water sections within the Nantuo Formation in South China. Our findings delineate six distinct lithofacies within the Nantuo Formation: massive diamictite, crudely stratified diamictite, pebbly sandstone, massive sandstone, dropstone-bearing laminated siltstone/mudstone, and laminated mudstone/siltstone. The vertical successions of these lithofacies have allowed us to identify two facies associations indicative of glacial dynamics; they are the ice-grounding line fan facies association and the ice-distal facies association. By juxtaposing our findings with the facies analysis of three deep-water sections, we have established a lateral correlation, confirming the presence of at least two glacial advance and retreat cycles in shallow-water environments. Each glacial advance is marked by the presence of inversely graded massive diamictite, indicative of ice-proximal, glaciomarine conditions. In contrast, each retreat phase is characterized by a fining-upward sequence from siltstone to mudstone, interspersed with dropstones, signifying ice-distal, glaciomarine settings. This study not only underscores the dynamic character of the Marinoan snowball Earth glaciation but also suggests that the glacial oscillations observed in deep-water environments have counterparts in shallow waters. It provides evidence that the scale of the Marinoan glacial fluctuations was not confined to the deep ocean but extended to encompass the entire basin, offering a more comprehensive understanding of the Earth’s climatic and glacial history during this critical period.</div></div>","PeriodicalId":12761,"journal":{"name":"Gondwana Research","volume":"139 ","pages":"Pages 1-15"},"PeriodicalIF":7.2,"publicationDate":"2024-11-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142756902","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}