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Testing for the Pulse of the Iceland Plume: IODP EXP.395

测试冰岛羽流的脉动：IODP EXP.395

基本信息

批准号：
NE/W002167/1
负责人：
Bramley Murton
金额：
$ 4.8万
依托单位：
NATIONAL OCEANOGRAPHY CENTRE
依托单位国家：
英国
项目类别：
Research Grant
财政年份：
2021
资助国家：
英国
起止时间：
2021 至无数据
项目状态：
已结题

来源：
https://gtr.ukri.org/projects?ref=NE%2FW002167%2F1
关键词：
Testing Pulse Iceland Plume IODP

项目摘要

Do mantle plumes have a pulse? Does intraplate volcanism fluctuate and is that determined by mantle dynamics deep-within the interior of the earth? How do these changes impact the inhabited surface of the planet, its climate and life support systems? These are some of the questions we aim to address in IODP Exp. 395.Oceanic islands and plateaus provide strong evidence that significant fluxes of mass and energy are transferred from the Earth's interior to its surface by processes that are independent of the normal plate tectonic cycle. Whereas today, mid-ocean ridges account for ~95% of the mass and energy flux from the mantle, in the past, the contribution from hotspot volcanism has been as high as 50%. Such pulses of magmatism are implemented in climate change, mass extinctions, geomagnetic field anomalies and higher rates of seafloor spreading, hydrothermal activity, and continental break-up. Yet these pulses of excessive volcanism are episodic across a range of time scales. Understanding these, their periodicity and processes, are essential if we are to gain an insight into mantle dynamics and Earth evolution.In this proposal, we aim to test hypotheses for the origin and affects of the hotspot responsible for the formation of the Iceland plateau. Through its interaction with the adjacent, slow-spreading Reykjanes Ridge, we aim to recover a record of Icelandic hotspot volcanism and its variability over the past 35Ma. Specifically IODP Exp.395 will investigate whether hotspot mantle upwells beneath Iceland and advects laterally along the ridge. Fluctuations in melt production from the Iceland hotspot are indicated by a nested suit of diachronous V-shaped ridges that form the flanks of the Reykjanes Ridge. By sampling across these V-shaped ridges, we will explore whether they are caused by fluctuations in the hotspot mantle flux, temperature or composition. In addition, we will investigate the chemical aging of oceanic crust as it is affected by an adjacent hotspot.Study of the Iceland-Reykjanes Ridge couplet is widely recognised as a type example of hotspot-ridge interaction. The outcome of this study will be a greater understanding of mantle hotspot dynamics and their impact on ocean basin evolution, the surrounding land masses, climate and ocean circulation.

地幔柱有脉动吗？板内火山活动是否波动？这是由地球内部深处的地幔动力学决定的吗？这些变化如何影响地球上有人居住的表面、气候和生命支持系统？这些是我们旨在在 IODP Exp 中解决的一些问题。 395. 海洋岛屿和高原提供了强有力的证据，表明大量的质量和能量通量是通过独立于正常板块构造循环的过程从地球内部转移到其表面的。如今，大洋中脊约占地幔质量和能量通量的 95%，而在过去，热点火山活动的贡献高达 50%。这种岩浆脉冲会在气候变化、大规模灭绝、地磁场异常以及海底扩张、热液活动和大陆破裂等方面发生。然而，这些过度火山活动的脉冲在一系列时间尺度上都是间歇性的。如果我们要深入了解地幔动力学和地球演化，了解这些及其周期性和过程至关重要。在这项提议中，我们的目标是检验有关冰岛高原形成的热点的起源和影响的假设。通过它与邻近的、缓慢扩张的雷克雅内斯山脊的相互作用，我们的目标是恢复冰岛热点火山活动的记录及其在过去 35 Ma 的变化。具体而言，IODP Exp.395 将调查热点地幔是否在冰岛下方上升并沿山脊横向平流。雷克雅内斯山脊两侧的一套历时 V 形山脊的嵌套表明了冰岛热点熔体产量的波动。通过对这些 V 形山脊进行采样，我们将探讨它们是否是由热点地幔通量、温度或成分的波动引起的。此外，我们还将研究海洋地壳受邻近热点影响时的化学老化。冰岛-雷克雅内斯海岭联体的研究被广泛认为是热点-海脊相互作用的典型例子。这项研究的结果将是更好地了解地幔热点动力学及其对洋盆演化、周围陆地、气候和海洋环流的影响。