Life on the Rocks: Microbes, Mines, and Martians

想象一下，在恐龙出现之前，动植物还没有进化的世界。火山在那里孕育出新的陆地，并向无氧大气中喷发有毒气体。在那里，大陆刚刚诞生，海洋几乎没有生命，只有微小的单细胞生物。但是有什么吃的呢？看得更深一点。在海底深处的裂缝和缝隙中，海水向下渗入岩石，被加热，剥离的金属后来集中在稠密的黑烟喷流中，这些烟从矿化的烟囱中冒出来，像畸形的尖顶进入黑暗中。随着这些烟囱的生长，它们有时会在自己的重量下坍塌，形成的土堆短暂地暴露出它们闪闪发光的丰富的金属硫化物，然后它们很快就会在寒冷、氧化、含盐的海水中生锈。在这些又深又暗又多水的地方，发现了微生物，它们栖息在硫化物土丘和下面的玻璃熔岩中，从这种不太可能的食物来源中提取营养。熔岩在海底火山持续喷发，这些火山在海底形成山链，就像棒球上的接缝。在这些动态环境中，地球、水文和大气之间发生了全球显著的化学、生物和热通量。新地壳的形成和古老地壳在俯冲带重新并入地幔，可能是板块构造旋回中最基本的组成部分。这些过程控制着地球的地貌以及地壳和地幔的化学和热演化。拟议研究的指导原则是在数十亿年的时间尺度上调查地球和行星材料中的水-岩石-微生物过程。这一领域处于跨学科研究的前沿。我的团队使用一种多学科的方法，结合地球化学、矿物学、岩石学和成像技术来研究现代和古代的热液系统。我们的工作重点是地球和行星材料。我们利用新的地球化学技术对水-岩石-微生物相互作用的生物地球化学效应进行了开创性的研究，以检测微生物的生物特征并限制经历了变形和变质的岩石的环境条件。这已被进一步应用于导致金属在地壳中堆积并创造经济矿藏的地球化学过程。最近，我们应用我们的尖端技术来量化和限制陨石的产生和改变。尽管乍一看，这些话题似乎有些不同，但它们是密不可分的。贯穿所有这些过程并将它们联系在一起的主题是水-岩石-微生物在地质时代的相互作用。这项研究的结果将引起学术和应用研究人员和从业者的兴趣和重要性，其影响将使社会从经济和基本理解中受益。

Picture a world before the dinosaurs when plants and animals hadn't evolved yet. Where volcanoes gave birth to new land and spewed toxic gases into an oxygen-free atmosphere. Where the continents were just being born and where the oceans were almost free of life except for tiny single-celled organisms. But what was there to eat? Look a little deeper. In the cracks and crevices deep beneath the seafloor, seawater seeps down into the rocks, gets heated, and strips metals that are later concentrated in jets of dense black "smoke" that exit through mineralized chimneys rising like misshapen spires into the darkness. As these chimneys grow they sometimes crumble under their own weight, forming mounds that briefly expose their glistening riches of metal sulphides before they quickly rust in the cold, oxidized, salty seawater. In these deep, dark, watery places microbes have been found that colonize the sulphide mounds and glassy lavas beneath, extracting nutrients from this unlikely food source. Lavas continuously erupt at undersea volcanoes that form mountain chains beneath the sea like seams on a baseball. These are dynamic environments where globally significant chemical, biological, and heat fluxes occur between the geo-, hydro-, and atmosphere. The formation of new crust and the reincorporation of aged crust into the mantle at subduction zones are perhaps the most fundamental components of the plate tectonic cycle. These processes control the physiography of the Earth and the chemical and thermal evolution of the crust and mantle. The guiding principle of the proposed research is the investigation of water-rock-microbial processes in Earth and planetary materials over timescales of billions of years. This field is at the forefront of interdisciplinary study. My group uses a multidisciplinary approach combining geochemical, mineralogical, petrological, and imaging techniques to study modern and ancient hydrothermal systems. Our work focuses on both Earth and planetary materials. We have pioneered research on the biogeochemical effects of water- rock-microbial interactions using novel geochemical techniques to detect microbial biosignatures and constrain environmental conditions in rocks that have undergone deformation and metamorphism. This has been further applied to geochemical processes that lead to metal accumulations in the crust and create economic ore deposits. More recently, we have applied our cutting-edge techniques to quantify and constrain the creation and alteration of meteorites. Although these topics may at first glance seem to be somewhat disparate they are inextricably intertwined. The theme that runs through all these processes and ties them together is that of water- rock-microbial interactions through geological time. Outcomes of this research will be of interest and importance to both academic and applied researchers and practitioners with impacts that will benefit society from both an economic as well as basic understanding.