Developing continuous volcano-stratigraphies across the South Atlantic Transect: NERC UK-IODP Moratorium support for Aled Evans - IODP Expedition 393

开发横跨南大西洋横断面的连续火山地层：NERC UK-IODP 暂停支持 Aled Evans - IODP Expedition 393

• 批准号: NE/X00631X/1
• 负责人: Damon Teagle
• 金额: $ 6.97万
• 依托单位: University of Southampton
• 依托单位国家: 英国
• 项目类别: Research Grant
• 财政年份: 2022
• 资助国家: 英国
• 起止时间: 2022 至 无数据
• 项目状态: 已结题
• 来源: https://gtr.ukri.org/projects?ref=NE%2FX00631X%2F1
• 关键词: Developing; continuous; volcano; stratigraphies; across

Mid-Ocean Ridges are the most extensive magmatic system on Earth, producing 75 per cent of the planet's volcanism with the resulting processes governing the architecture of at least two thirds of the surface of our planet. A representative stratigraphic record of the order, eruption style, and extent of mid-ocean ridge lava flows is required to understand seafloor spreading, a fundamental process in plate tectonics. As access to ocean crust is restricted to scientific ocean drilling and the use of submersibles, physical and chemical information on the nature of upper ocean crust is limited to recovered rock. However, during scientific ocean drilling, the proportion of recovered rock compared to the length drilled is both generally low and highly variable. These recovered samples have been shown to reflect a bias towards stronger, more competent lithologies, with weaker, more incompetent rock types underrepresented. This highlights that recovered physical samples from scientific expeditions display only a partial representation of reality. Integration of recovered physical drill cores with quantitative geophysical wireline logging data can provide representations of the volcanic stratigraphy at drilled sections of mid-ocean ridges. The unification of a physical but incomplete dataset, with a complete but abstract quantitative dataset, provides constraints on biases within recovered samples. An understanding of the bias reflected in recovered samples is essential to avoid inaccurate estimations of key planetary processes such as the extent of heat, chemical, and mass exchange between ocean crustal rocks and seawater. The understanding and quantification of these exchanges is necessary in evaluating the role of mid-ocean ridges on long-term global geochemical cycles (e.g., C, H2O) and the wider habitability of the planet. International Ocean Discovery Program (IODP) Expeditions 390 and 393 will drill a transect of six sites across the South Atlantic, recovering ocean crust formed at the Mid-Atlantic Ridge between 7 and 61 million years ago. I will integrate observations of physically recovered core samples with quantitative geophysical wireline logging data from these drillholes to reconstruct the volcanic history along a transect of the aging western flank of the southern Mid-Atlantic Ridge . The resulting stratigraphy will provide an essential foundation for subsequent investigations and quantifications of planetary processes at mid-ocean ridges.

洋中脊是地球上最广泛的岩浆系统，产生了地球上75%的火山活动，由此产生的过程控制着我们地球表面至少三分之二的结构。要了解板块构造的一个基本过程——海底扩张，就需要有关于海中脊熔岩流的顺序、喷发方式和范围的代表性地层记录。由于对海洋地壳的接触仅限于科学的海洋钻探和使用潜水器，因此关于上层海洋地壳性质的物理和化学信息仅限于回收的岩石。然而，在科学海洋钻探过程中，回收岩石与钻探长度的比例通常很低，而且变化很大。这些回收的样品显示出对更强、更强的岩性的偏爱，而更弱、更弱的岩石类型的代表性不足。这突出表明，从科学考察中获得的实物样本只能部分反映现实。将回收的物理岩心与定量地球物理电缆测井资料相结合，可以提供中洋脊钻探剖面的火山地层表征。物理但不完整的数据集与完整但抽象的定量数据集的统一提供了对恢复样本内偏差的约束。了解回收样品中反映的偏差对于避免对关键行星过程（如海洋地壳岩石和海水之间的热、化学和质量交换的程度）的不准确估计至关重要。在评估大洋中脊对长期全球地球化学循环（例如C、H2O）的作用以及地球更广泛的可居住性方面，了解和量化这些交换是必要的。国际海洋发现计划（IODP）的390和393探险队将在南大西洋的六个地点进行取样，以恢复700万至6100万年前在大西洋中脊形成的海洋地壳。我将把物理回收的岩心样本的观察结果与这些钻孔的定量地球物理电缆测井数据结合起来，沿着大西洋中脊南部老化的西侧样带重建火山历史。由此产生的地层学将为海洋中脊的行星过程的后续调查和量化提供必要的基础。

项目成果

South Atlantic Transect

南大西洋横断面

• 发表时间: 2024
• 期刊: Proceedings of the International Ocean Discovery Program Expedition reports
• 作者: Coggon, R.M.;Teagle, D.A.H.;Sylvan, J.B.;Reece, J.;Estes, E.R.;Williams, T.J.;Christeson, G.L.
• 通讯作者: Christeson, G.L.

Expedition 393 Preliminary Report: South Atlantic Transect 2

• DOI: 10.14379/iodp.pr.393.2023
• 发表时间: 2023-01
• 期刊: International Ocean Discovery Program Preliminary Report
• 作者: D. Teagle;J. Reece;R. Coggon;J. Sylvan;G. Christeson;T. Williams;E. Estes

Expedition 390 Preliminary Report: South Atlantic Transect 1

• DOI: 10.14379/iodp.pr.390.2022
• 发表时间: 2022-10
• 期刊: International Ocean Discovery Program Preliminary Report
• 作者: R. Coggon;J. Sylvan;D. Teagle;J. Reece;G. Christeson;E. Estes;T. Williams