Water-rock reaction on Mars - as seen through Earth analogues

火星上的水-岩石反应——通过地球类似物看到的

• 批准号: 1949161
• 金额: --
• 依托单位: The Open University
• 依托单位国家: 英国
• 项目类别: Studentship
• 财政年份: 2017
• 资助国家: 英国
• 起止时间: 2017 至 无数据
• 项目状态: 已结题
• 来源: https://gtr.ukri.org/projects?ref=studentship-1949161
• 关键词: Water; rock; reaction; Mars; seen

This project will use mineralogy and mass spectrometry to understand water-rock interactions, mineral formation, element mobility and volatile budgets in mafic rocks from Germany. These rocks are analogues for clay formation processes on Mars and on Early Earth. With a focus on the most recent finding of an impact-generated hydrothermal system by the Mars Exploration rover Opportunity at Endeavour crater, and the discovery of mudstones on at Gale Crater by the Mars Science Laboratory rover, understanding the detailed volatile and element pathways in aqueous alteration is more important than ever. Working at two universities with vibrant and internationally recognized research communities, and collaborating with Germany, this project is set out to create a more in depth understanding of processes on Mars - with potential for the application to the Early Earth.Mafic and ultramafic rocks make up large parts of Mars and Earth. On Earth, they form the magmatic component of the ocean floors and at the mid-ocean ridges provide well-studied sites for the study of hydrothermal alteration1. However they are also found on the continents where they are subject to a very different, i.e., less saline, alteration environment. Alteration products formed in continental environments are less well studied than the marine counterparts yet are highly relevant to understanding processes on Mars. The similarities are in weathering, diagenesis and subsurface fluid processes. The heavy noble gases (Ar, Kr, Xe) provide trace volatiles in such environments, whose sources, pathways and sinks have been intensely investigated in meteorites for the typical components found in them2, but have not yet been investigated in detail for water-rock interaction based processes3. This study offers an opportunity to make inroads into our understanding of alteration and its effect on the evolution of volatile budgets and element mobility on early Mars, and the early Earth. In detail, this project will seek to 1. Provide a detailed mineralogical and geochemical account of the nature of alteration of mafic rocks from a range of environments from the Variscan in Germany (Odenwald/Saxothuringian Zone, and Lahn Dill Syncline/Rhenohercynian Zone) and - if desired - the UK, to deduce the specific alteration conditions (e.g. temperature, fluid chemistry).2. Pioneer the measurement of heavy noble gas signatures of minerals within alteration phases to understand the pathways and host minerals of volatiles. 3. Collate geochemical data to test and refine existing hydrothermal models to quantify the concentrations of elements acting as nutrients in the hydrothermal fluid and the environmental conditions for microbial life.This work will pioneer the combination of detailed mineralogical with heavy noble gas investigations by applying a method which is well established in meteorite research. This work aims to understand the element mobility, alteration mineral formation conditions and volatile reservoirs in rocks relevant to the evolution of early Mars and Earth. It will help to assess the effects of such alteration on the habitability of the surface and subsurface of these two terrestrial planets in the Noachian/Hadean times, the time to which we can track back the beginning of life on Earth.

该项目将使用矿物学和质谱分析来了解来自德国的镁铁质岩石中的水-岩相互作用、矿物形成、元素流动性和挥发性收支。这些岩石类似于火星和早期地球上的粘土形成过程。随着火星探测漫游车机遇号在奋进陨石坑发现撞击产生的热液系统的最新发现，以及火星科学实验室漫游车在盖尔陨石坑发现的泥岩，了解水蚀变中详细的挥发性和元素路径比以往任何时候都更加重要。该项目在两所拥有国际知名研究团体的大学开展，并与德国合作，旨在更深入地了解火星上的过程，并有可能应用于早期地球。镁铁质和超镁铁质岩石构成了火星和地球的大部分。在地球上，它们构成洋底的岩浆成分，在大洋中脊，它们是研究热液蚀变的良好场所1。然而，他们也发现在大陆上，他们受到一个非常不同的，即，盐份减少，环境改变。大陆环境中形成的蚀变产物的研究不如海洋环境中的蚀变产物，但与了解火星上的过程高度相关。相似之处在于风化作用、成岩作用和地下流体作用。重稀有气体（Ar，Kr，NH3）在这种环境中提供痕量挥发物，其来源，途径和汇已在陨石中发现的典型成分中进行了深入研究2，但尚未详细研究水-岩石相互作用的过程3。这项研究提供了一个机会，使我们的理解的变化及其对早期火星和早期地球的挥发性预算和元素流动性的演变的影响。具体而言，该项目将寻求1.对来自德国华力西期（奥登瓦尔德/Saxothurin带和Lahn Dill向斜/Rhenohercynian带）和英国（如果需要）的一系列环境的镁铁质岩石的蚀变性质提供详细的矿物学和地球化学说明，以推断具体的蚀变条件（例如温度、流体化学）。率先测量蚀变阶段矿物的重惰性气体特征，以了解挥发物的路径和宿主矿物。3.整理地球化学数据，测试和完善现有的热液模型，以量化热液中作为营养物的元素的浓度和微生物生命的环境条件，这项工作将开创性地采用陨石研究中公认的方法，将详细的矿物学调查与重惰性气体调查相结合。这项工作旨在了解与早期火星和地球演化有关的元素活动性，蚀变矿物形成条件和岩石中的挥发性储层。这将有助于评估这种变化对诺亚纪/冥古宙时期这两个类地行星表面和地下可居住性的影响，我们可以追溯到地球上生命开始的时间。