T. Torsvik, H. Svensen, B. Steinberger, D. Royer, D. Jerram, Morgan T. Jones, M. Domeier
Most hotspots, kimberlites, and large igneous provinces (LIPs) are sourced by plumes that rise from the margins of two large low shear-wave velocity provinces in the lowermost mantle. These thermochemical provinces have been quasi-stable for hundreds of millions years and plume heads rise through the mantle in about 30Myr or less. LIPs provide a direct link between the deep Earth and the atmosphere but environmental consequences depend on both their volumes and the composition of the crustal rocks they are emplaced through. LIP activity can alter the plate tectonic setting by creating andmodifying plate boundaries and hence changing the paleogeography and its long-term forcing on climate. Extensive blankets of LIP-lava on the Earth’s surface can also enhance silicate weathering and potentially lead to CO2 drawdown, but we find no clear relationship between LIPs and postemplacement variation in atmospheric CO2 proxies on very long (>10 Myrs) time-scales. Subduction flux estimates correlate well with zircon age frequency distributions through time. This suggest that continental arc activity may have played an important role in regulating long-term climate change (greenhouse vs. icehouse conditions) but only the Permo-Carboniferous icehouse show a clear correlation with the zircon record.
{"title":"Mantle Convection and Surface Expressions","authors":"T. Torsvik, H. Svensen, B. Steinberger, D. Royer, D. Jerram, Morgan T. Jones, M. Domeier","doi":"10.1002/9781119528609","DOIUrl":"https://doi.org/10.1002/9781119528609","url":null,"abstract":"Most hotspots, kimberlites, and large igneous provinces (LIPs) are sourced by plumes that rise from the margins of two large low shear-wave velocity provinces in the lowermost mantle. These thermochemical provinces have been quasi-stable for hundreds of millions years and plume heads rise through the mantle in about 30Myr or less. LIPs provide a direct link between the deep Earth and the atmosphere but environmental consequences depend on both their volumes and the composition of the crustal rocks they are emplaced through. LIP activity can alter the plate tectonic setting by creating andmodifying plate boundaries and hence changing the paleogeography and its long-term forcing on climate. Extensive blankets of LIP-lava on the Earth’s surface can also enhance silicate weathering and potentially lead to CO2 drawdown, but we find no clear relationship between LIPs and postemplacement variation in atmospheric CO2 proxies on very long (>10 Myrs) time-scales. Subduction flux estimates correlate well with zircon age frequency distributions through time. This suggest that continental arc activity may have played an important role in regulating long-term climate change (greenhouse vs. icehouse conditions) but only the Permo-Carboniferous icehouse show a clear correlation with the zircon record.","PeriodicalId":12504,"journal":{"name":"Geophysical Monograph Series","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2021-06-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78314328","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-01-16DOI: 10.1002/9781119564485.CH3
A. Barker, Elin Rydeblad, Sónia Silva
The Cape Verde archipelago is a group of Ocean Islands in the Central Atlantic that forms two chains of islands trending Northwest and Southwest. Several of the islands are considered to be volcani...
佛得角群岛是大西洋中部的一组海洋岛屿，形成了西北和西南方向的两个岛屿链。有几个岛屿被认为是火山。
{"title":"Magma Storage at Ocean Islands","authors":"A. Barker, Elin Rydeblad, Sónia Silva","doi":"10.1002/9781119564485.CH3","DOIUrl":"https://doi.org/10.1002/9781119564485.CH3","url":null,"abstract":"The Cape Verde archipelago is a group of Ocean Islands in the Central Atlantic that forms two chains of islands trending Northwest and Southwest. Several of the islands are considered to be volcani...","PeriodicalId":12504,"journal":{"name":"Geophysical Monograph Series","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2021-01-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89085247","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Hydrogeology, Chemical Weathering, and Soil Formation","authors":"","doi":"10.1002/9781119563952","DOIUrl":"https://doi.org/10.1002/9781119563952","url":null,"abstract":"","PeriodicalId":12504,"journal":{"name":"Geophysical Monograph Series","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2021-01-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76811764","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Large igneous provinces (LIPs) have occurred episodically throughout Earth’s history, with the most severe events causing profound disturbances to Earth’s climate and biosphere that likely influenced the course of metazoan evolution. One environmental perturbation caused by LIP emplacement is a change in global oceanic redox conditions. The uranium (U) and molybdenum (Mo) isotope systems are relatively established tracers of global oceanic redox conditions, particularly for the extent of anoxic and euxinic seafloor, whereas the thallium (Tl) isotope system is emerging as a tracer for the extent of well‐oxygenated seafloor characterized by manganese (Mn) oxide burial. In this review, we discuss how these metal isotope systems can be used to infer changes to global oceanic redox conditions through the cascade of environmental perturbations caused by LIP emplacement, focusing on the three events (Cenomanian‐Turonian, Toarcian, and Permian‐Triassic) that have received the most attention. Existing isotope mass‐balance models for these metals indicate an expansion of oceanic anoxia and euxinia (by ~1 to 2 orders of magnitude greater than the modern ocean) accompanied LIP emplacement during these events. Future studies, ideally utilizing a multi‐isotope approach on the same samples and coupled with improvements in oceanic metal isotope mass balances and modeling, are expected to provide more precise and accurate estimates of the spatiotemporal extent of oceanic anoxia/euxinia expansion and how this relates to the magnitude, location, and style of LIP events. 13 1 Department of Earth and Environmental Sciences, University of Waterloo, Waterloo, Ontario, Canada 2 School of Earth and Ocean Sciences, Cardiff University, Cardiff, UK 3 Department of Earth, Ocean and Atmospheric Science and National High Magnet Field Laboratory, Florida State University, Tallahassee, Florida, USA 306 LARGE IGNEOUS PROVINCES balance models to link and infer changes in the global extent of seafloor covered by oxic versus anoxic (euxinic and noneuxinic) waters. For ancient LIP events with negligible open‐ocean seafloor records, changes in global oceanic redox conditions must be inferred from the metal isotope ratios of continental margin sedimentary rocks. Differences in marine input/output fluxes, ocean residence times, and isotope fractionation mechanisms for Mo, U, and Tl mean that each metal provides its own perspective on changes in oceanic redox conditions during LIP emplacement. Because Mo is highly insoluble in sulfidic environments and is thus enriched in euxinic sediments (Helz et al., 1996; Erickson & Helz, 2000; Scott & Lyons, 2012), Mo isotope data from euxinic organic‐rich mudrocks are typically used to infer the global extent of seafloor where dissolved sulfide occurs in the water column and sediments (e.g., Arnold et al., 2004; Dahl et al., 2011; Goldberg et al., 2016). Uranium is insoluble in its reduced form and, in contrast to Mo, does not require dissolved s
大型火成岩省(lip)在整个地球历史上偶尔发生，最严重的事件对地球气候和生物圈造成了深刻的干扰，可能影响了后生动物的进化过程。LIP就位引起的一个环境扰动是全球海洋氧化还原条件的变化。铀(U)和钼(Mo)同位素系统是全球海洋氧化还原条件的相对成熟的示踪剂，特别是对于缺氧和缺氧海底的范围，而铊(Tl)同位素系统正在成为以锰(Mn)氧化物埋藏为特征的良好氧合海底范围的示踪剂。在这篇综述中，我们讨论了这些金属同位素系统如何通过LIP侵位引起的一系列环境扰动来推断全球海洋氧化还原条件的变化，重点讨论了三个最受关注的事件(Cenomanian - Turonian, Toarcian和Permian - Triassic)。这些金属的现有同位素质量平衡模型表明，在这些事件期间，伴随着LIP侵位的海洋缺氧和缺氧的扩大(比现代海洋大1到2个数量级)。未来的研究，理想地利用多同位素方法对相同的样品，再加上海洋金属同位素质量平衡和模型的改进，有望提供更精确和准确的估计海洋缺氧/缺氧扩张的时空范围，以及这与LIP事件的大小、位置和类型的关系。13 1滑铁卢大学地球与环境科学系(加拿大安大略省滑铁卢)2卡迪夫大学地球与海洋科学学院(英国卡迪夫)3佛罗里达州立大学地球、海洋与大气科学系和国家高磁场实验室(塔拉哈西，佛罗里达州)306个大火成岩省平衡模式，以联系和推断缺氧与缺氧(含氧和非含氧)水域覆盖的海底全球范围的变化。对于具有可忽略的开放海洋海底记录的古代LIP事件，必须从大陆边缘沉积岩的金属同位素比率推断全球海洋氧化还原条件的变化。Mo、U和Tl在海洋输入/输出通量、海洋停留时间和同位素分异机制方面的差异，意味着每种金属对LIP放置期间海洋氧化还原条件的变化提供了自己的视角。因为Mo在硫化物环境中高度不溶，因此在含氧沉积物中富集(Helz et al.， 1996;Erickson & Helz, 2000;Scott & Lyons, 2012)，富氧有机质泥岩的Mo同位素数据通常用于推断水柱和沉积物中溶解硫化物的海底全球范围(例如，Arnold et al.， 2004;Dahl et al.， 2011;Goldberg et al.， 2016)。铀在还原态下是不溶的，与钼不同，它不需要溶解的硫化物来结合和掩埋在沉积物中(Morford & Emerson, 1999;Algeo & Tribovillard, 2009)。尽管存在这种地球化学差异，但由于对缺氧海洋环境中同位素分异因素和U去除机制的知识差距，尚不完全清楚U同位素是否最适合作为一般海洋缺氧(缺氧和非缺氧)全球范围的示踪剂，或者更具体地说，是否适合作为海洋缺氧全球范围的示踪剂(Stylo et al.， 2015;Hood等人，2016;Andersen等人，2017;Brown et al.， 2018;Cole et al.， 2020)。然而，富有机质泥岩和碳酸盐岩的U同位素数据作为追踪显生宙缺氧事件期间全球海洋氧化还原变化的工具，已经获得了突出的地位。来自富氧有机质泥岩的铊同位素组成已被用于推断富氧海底的程度，因为在富氧环境中，Tl对Mn氧化物的吸附与已知最大的海洋Tl同位素分选有关(Nielsen et al.， 2011;《孔雀与月亮》，2012;Owens et al.， 2017a)。Tl较短的海洋停留时间以及这种金属的海洋质量平衡对Mn氧化物埋藏通量的敏感性意味着，在显生宙缺氧事件开始时，Tl的海水同位素组成将比Mo或U更快地响应区域/全球海洋脱氧(Ostrander etal .， 2017;他们等人，2018)。本章首先回顾了这三种同位素系统的现代海洋物质平衡(图13.1;数据报告约定见表13.1)。然后讨论了这些同位素系统作为显生宙LIP重大事件期间全球海洋氧化还原变化的示踪剂的应用。未来的利用将最终包括时间等效岩石上的多种同位素系统，以破译与LIP事件及其气候后果相关的整体全球氧化还原结构。13.2. 氧化还原敏感金属同位素系统作为全球海洋氧化还原指标13.2.1。
{"title":"Large Igneous Provinces","authors":"Brian Kendall, Morten B. Andersen, J. Owens","doi":"10.1002/9781119507444","DOIUrl":"https://doi.org/10.1002/9781119507444","url":null,"abstract":"Large igneous provinces (LIPs) have occurred episodically throughout Earth’s history, with the most severe events causing profound disturbances to Earth’s climate and biosphere that likely influenced the course of metazoan evolution. One environmental perturbation caused by LIP emplacement is a change in global oceanic redox conditions. The uranium (U) and molybdenum (Mo) isotope systems are relatively established tracers of global oceanic redox conditions, particularly for the extent of anoxic and euxinic seafloor, whereas the thallium (Tl) isotope system is emerging as a tracer for the extent of well‐oxygenated seafloor characterized by manganese (Mn) oxide burial. In this review, we discuss how these metal isotope systems can be used to infer changes to global oceanic redox conditions through the cascade of environmental perturbations caused by LIP emplacement, focusing on the three events (Cenomanian‐Turonian, Toarcian, and Permian‐Triassic) that have received the most attention. Existing isotope mass‐balance models for these metals indicate an expansion of oceanic anoxia and euxinia (by ~1 to 2 orders of magnitude greater than the modern ocean) accompanied LIP emplacement during these events. Future studies, ideally utilizing a multi‐isotope approach on the same samples and coupled with improvements in oceanic metal isotope mass balances and modeling, are expected to provide more precise and accurate estimates of the spatiotemporal extent of oceanic anoxia/euxinia expansion and how this relates to the magnitude, location, and style of LIP events. 13 1 Department of Earth and Environmental Sciences, University of Waterloo, Waterloo, Ontario, Canada 2 School of Earth and Ocean Sciences, Cardiff University, Cardiff, UK 3 Department of Earth, Ocean and Atmospheric Science and National High Magnet Field Laboratory, Florida State University, Tallahassee, Florida, USA 306 LARGE IGNEOUS PROVINCES balance models to link and infer changes in the global extent of seafloor covered by oxic versus anoxic (euxinic and noneuxinic) waters. For ancient LIP events with negligible open‐ocean seafloor records, changes in global oceanic redox conditions must be inferred from the metal isotope ratios of continental margin sedimentary rocks. Differences in marine input/output fluxes, ocean residence times, and isotope fractionation mechanisms for Mo, U, and Tl mean that each metal provides its own perspective on changes in oceanic redox conditions during LIP emplacement. Because Mo is highly insoluble in sulfidic environments and is thus enriched in euxinic sediments (Helz et al., 1996; Erickson & Helz, 2000; Scott & Lyons, 2012), Mo isotope data from euxinic organic‐rich mudrocks are typically used to infer the global extent of seafloor where dissolved sulfide occurs in the water column and sediments (e.g., Arnold et al., 2004; Dahl et al., 2011; Goldberg et al., 2016). Uranium is insoluble in its reduced form and, in contrast to Mo, does not require dissolved s","PeriodicalId":12504,"journal":{"name":"Geophysical Monograph Series","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2021-01-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78268142","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Crustal Magmatic System Evolution","authors":"M. Masotta, C. Beier, S. Mollo","doi":"10.1002/9781119564485","DOIUrl":"https://doi.org/10.1002/9781119564485","url":null,"abstract":"","PeriodicalId":12504,"journal":{"name":"Geophysical Monograph Series","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"91295377","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-11-07DOI: 10.1002/essoar.10504686.1
P. Jarvis, M. Pistone, Alexia Secretan, J. Blundy, K. Cashman, H. Mader, L. Baumgartner
The mixing and mingling of magmas of different compositions are important geological processes. They produce various distinctive textures and geochemical signals in both plutonic and volcanic rocks...
{"title":"Crystal and Volatile Controls on the Mixing and Mingling of Magmas","authors":"P. Jarvis, M. Pistone, Alexia Secretan, J. Blundy, K. Cashman, H. Mader, L. Baumgartner","doi":"10.1002/essoar.10504686.1","DOIUrl":"https://doi.org/10.1002/essoar.10504686.1","url":null,"abstract":"The mixing and mingling of magmas of different compositions are important geological processes. They produce various distinctive textures and geochemical signals in both plutonic and volcanic rocks...","PeriodicalId":12504,"journal":{"name":"Geophysical Monograph Series","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2020-11-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78750035","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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