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.

地幔李有脉冲吗？内部火山爆发是否会波动，这是由地幔动力学在地球内部深处确定的吗？这些变化如何影响地球的居住地，其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.海岛和高原提供了有力的证据，表明质量和能量的明显通量通过与正常板块构造循环无关的过程从地球内部转移到其表面。而今天，大海山脊占地幔的质量和能量通量的〜95％，而过去，热点火山的贡献高达50％。这种岩浆作用的脉冲是在气候变化，大规模灭绝，地磁野外异常和海底扩散率，水热活动和大陆分裂的速度中实施的。然而，在各种时间尺度上，这些过度火山的脉冲是偶发的。如果我们要深入了解地幔动态和地球的进化，那么了解它们的周期和过程至关重要。在此提案中，我们旨在测试负责冰岛高原形成的热点的起源和影响的假设。通过与相邻的，慢速播放的雷克雅尼斯山脊的互动，我们旨在恢复过去35mA中冰岛热点火山的记录及其可变性。具体来说，IODP Exp.395将调查冰岛下方的热点地幔上升，并沿着山脊横向前进。冰岛热点的熔体生产的波动是由嵌套的直觉V形脊的嵌套西服，形成了Reykjanes Ridge的侧面。通过在这些V形山脊上进行采样，我们将探索它们是否是由热点地幔通量，温度或组成的波动引起的。此外，我们将研究海洋壳的化学老化，因为它受到相邻热点的影响。这项研究的结果将是对地幔热点动力学及其对海盆进化，周围土地肿块，气候和海洋循环的影响。