NSFGEO-NERC: Data Mining the Deep: Combining Geochemistry and Imaging Spectroscopy to Quantify Deep Hydrothermal Circulation at Mid-Ocean Ridges

NSFGEO-NERC：深海数据挖掘：结合地球化学和成像光谱学来量化大洋中脊的深部热液循环

• 批准号: NE/W007517/1
• 负责人: Damon Teagle
• 金额: $ 31.04万
• 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: 2021
• 资助国家: 英国
• 起止时间: 2021 至 无数据
• 项目状态: 未结题
• 来源: https://gtr.ukri.org/projects?ref=NE%2FW007517%2F1
• 关键词: NSFGEO; NERC; Data; Mining; Deep

Ocean crust is formed at mid-ocean ridge spreading ridges and covers more than 60% of the surface of Earth. Because of the plate tectonic cycle and subduction, the ocean crust is geologically young, on average less than 70 million years old and all is less than 200 million years; much younger than the old rocks that make up the continents. Heated seawater circulates within the ocean crust from the ridge axes until it gets consumed in subduction zones. During this circulation, these seawater-derived fluids react with the rocks forming new minerals, and key elements and molecules such as water, CO2, K, Mg are exchanged between seawater and the ocean crust. These interactions between fluids and the rock are a major - but not yet quantified - contributor to seawater chemistry, and through subduction the composition of the interior of Earth. A key challenge is that ocean drilling has not sampled the deepest ocean crust many kilometers below the seafloor. However, in the past few years, the International Continental Scientific Drilling Program's Oman Drilling Project has drilled a few kilometers of oceanic crust and the uppermost mantle in Oman, where tectonics have pushed this critical portion of Earth's crust onto the continent. In this project, scientists at Caltech will work with colleagues at the Universities of Southampton and Plymouth in the UK to investigate these drill core to work out how much exchange there has been between seawater and the deep ocean crust. We will take an innovative approach that combines detailed but traditional laboratory analyses with a novel technique, micro-imaging spectroscopy, which allows us to use the reflectance of infrared light to determine the mineralogy of the entire drill core at a spatial resolution of less than one millimeter. This research will achieve major advances in our understanding of deep circulation of fluids within the ocean crust through objective characterization at a scale and sampling completeness previously impossible. It will yield insights into the contribution of fluid-rock reactions to global geochemical cycling and seawater chemistry as well as constraining the role of deep fluid circulation in cooling and alteration of the lower oceanic crust. We will build a website with a core viewer to disseminate mineral maps of the drill cores to the broader scientific community and for educational use in classes.

洋壳形成在大洋中脊扩张的海脊上，覆盖了地球表面的60%以上。由于板块构造旋回和俯冲，洋壳在地质上很年轻，平均不到7000万年，全部不到2亿年；比组成大陆的旧岩石年轻得多。加热的海水从海脊轴线在洋壳内循环，直到被俯冲带消耗。在这种循环过程中，这些来自海水的流体与形成新矿物的岩石发生反应，水、二氧化碳、钾、镁等关键元素和分子在海水和洋壳之间进行交换。流体和岩石之间的这些相互作用是海水化学的主要贡献者，但尚未量化，并通过俯冲作用影响地球内部的组成。一个关键的挑战是，大洋钻探没有对海底下许多公里处最深的洋壳进行采样。然而，在过去的几年里，国际大陆科学钻探计划的阿曼钻探项目已经在阿曼钻探了几公里的洋壳和最上面的地幔，那里的构造将地壳的这一关键部分推到了大陆上。在这个项目中，加州理工大学的科学家将与英国南安普顿大学和普利茅斯大学的同事合作，调查这些钻芯，以计算出海水和深海地壳之间的交换程度。我们将采取一种创新的方法，将详细但传统的实验室分析与微成像光谱学这一新技术相结合，该技术使我们能够使用红外光的反射比在低于一毫米的空间分辨率下确定整个钻芯的矿物学。这项研究将通过在以前不可能的规模和采样完整性的客观描述，在我们对洋壳内流体的深部循环的理解方面取得重大进展。它将深入了解流体-岩石反应对全球地球化学循环和海水化学的贡献，以及限制深部流体循环在下部洋壳冷却和改造中的作用。我们将建立一个有核心浏览者的网站，向更广泛的科学界传播钻芯的矿物图，并在课堂上用于教育用途。

项目成果

Listvenite Formation During Mass Transfer into the Leading Edge of the Mantle Wedge: Initial Results from Oman Drilling Project Hole BT1B

• DOI: 10.1029/2021jb022352
• 发表时间: 2022-01
• 期刊: Journal of Geophysical Research: Solid Earth
• 作者: P. Kelemen;Juan Carlos de Obeso;J. Leong;M. Godard;K. Okazaki;A. Kotowski;C. Manning;E. Ellison;M. Menzel;J. Urai;G. Hirth;M. Rioux;D. Stockli;Romain Lafay;A. Beinlich;J. Coggon;N. Warsi;J. Matter;D. Teagle;M. Harris;K. Michibayashi;E. Takazawa;Zaher Al Sulaimani

Initial Results From the Oman Drilling Project Multi-Borehole Observatory: Petrogenesis and Ongoing Alteration of Mantle Peridotite in the Weathering Horizon

阿曼钻井项目多孔观测站的初步结果：风化层中地幔橄榄岩的岩石成因和持续蚀变

• DOI: 10.1029/2021jb022729
• 发表时间: 2021
• 期刊: Solid Earth
• 影响因子: 3.4
• 作者: Kelemen P

Geochemical Profiles Across the Listvenite-Metamorphic Transition in the Basal Megathrust of the Semail Ophiolite: Results From Drilling at OmanDP Hole BT1B

• DOI: 10.1029/2021jb022733
• 发表时间: 2021-12-01
• 期刊: JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH
• 影响因子: 3.9
• 作者: Godard, M.;Carter, E. J.;Kelemen, P. B.
• 通讯作者: Kelemen, P. B.

Geochemical Characterization of the Oman Crust-Mantle Transition Zone, OmanDP Holes CM1A and CM2B

阿曼壳幔过渡带、OmanDP 孔 CM1A 和 CM2B 的地球化学特征

• DOI: 10.1029/2021jb022694
• 发表时间: 2022
• 期刊: Solid Earth
• 影响因子: 3.4
• 作者: Kourim F

Active near-surface mobilisation of slab-derived geochemical signatures by hyperalkaline waters in brecciated serpentinites

角砾蛇纹岩中超碱性水对板片衍生的地球化学特征的主动近地表动员

• DOI: 10.1016/j.chemgeo.2023.121822
• 发表时间: 2024
• 期刊: Chemical Geology
• 影响因子: 3.9
• 作者: Evans A