Structure and evolution of Axial Volcanic Ridges: Constraining the architecture, chronology and evolution of ocean ridge magmatism

轴状火山脊的结构和演化：制约洋脊岩浆作用的结构、年代和演化

基本信息

批准号：
NE/G00126X/1
负责人：
Bramley Murton
金额：
$ 10.52万
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：
2008
资助国家：
英国
起止时间：
2008 至无数据
项目状态：
已结题

来源：
https://gtr.ukri.org/projects?ref=NE%2FG00126X%2F1
关键词：
Structure evolution Axial Volcanic Ridges

项目摘要

Mid-ocean ridges (MORs) are the loci of the most voluminous volcanism on our planet, the products of which have generated 60% of the Earth's surface crust. Unlike its sub-aerial counterpart, MOR volcanism is hidden from view beneath several kilometres of water, leaving the processes largely unknown. For many MORs, this volcanism forms axial volcanic ridges (AVRs), a few kilometres wide and tens of kilometres long, which appear episodic or cyclic in their evolution. Although the processes that generate AVRs, their episodicity, effusion rates and links to melt extraction from the Earth's mantle are the focus of much speculation, little is actually known in sufficient detail to unravel their evolution. This is largely because we have not had the tools capable of studying volcanic architecture, sampling volcanic stratigraphy or determining age relationships between erupted units at the fine scale required. In recent years a new generation of submersible instruments has been developed that now allow us to image to sub-metre resolutions and to collect samples to similar precision, and hence to address AVR genesis directly. Recent developments in dating techniques, coupled with improvements in the precision of geochemical analyses, are now providing the means to test many of the models describing MOR volcanism. Here, we propose a detailed study using the high-resolution tools now available to unravel the complex processes of MOR volcanism. We will use measurements of the variation of the Earth's magnetic field strength, variations in sediment accumulation, and radiomentric dating (including newly-developed uranium series dating) of young basalts, to estimate precise ages. The complexity of the study requires collaboration across different laboratories and between different continents. By pooling our resources in this international programme, our study will yield new insights into the time scales, eruption rates, lava volumes and interaction between the volcanoes and their underlying mantle source. These insights are essential if we are to understand this key component of the Earth System / and hence its relationship to Earth evolution as a whole.

海脊（MORS）是我们星球上最庞大的火山症的基因座，其产物产生了地球表面的60％。与其次生式同行不同，莫尔火山污染被隐藏在几公里的水下，这使得过程在很大程度上未知。对于许多摩尔人来说，这种火山主义形成了轴向火山脊（AVR），几公里宽，数十公里，它们的演变似乎是偶发性的或循环的。尽管产生AVR的过程，它们的发作性，积液速率以及与地球地幔熔体提取的链接是许多猜测的重点，但实际上几乎没有足够的详细知名度以揭示其进化。这主要是因为我们还没有能够研究火山结构，采样火山地层或确定所需良好规模爆发单位之间的年龄关系的工具。近年来，已经开发了一种新一代的潜水仪器，现在使我们能够成像以亚米为单位的分辨率，并以类似的精度收集样品，从而直接解决AVR Genesis。现在，约会技术的最新发展以及地球化学分析精确度的改进，现在正在提供测试许多描述MOR火山的模型的手段。在这里，我们提出了一项详细的研究，使用现在可用的高分辨率工具来揭示Mor火山症的复杂过程。我们将使用对地球磁场强度的变化，沉积物积累的变化以及年轻玄武岩的放射性约会（包括新发达的铀序列约会）的测量值，以估计精确的年龄。研究的复杂性需要在不同的实验室和不同大陆之间进行协作。通过将我们的资源汇集在该国际计划中，我们的研究将产生有关时间尺度，喷发率，熔岩量以及火山及其基本地幔来源之间的相互作用的新见解。如果我们要了解地球系统的这一关键组成部分，并且因此与地球演化的整体关系相关，那么这些见解至关重要。