Life on the Rocks: Microbes, Mines, and Martians

想象一下恐龙出现之前的世界，那时动植物还没有进化。在那里，火山产生了新的土地，并向无氧大气中喷出有毒气体。那时大陆刚刚形成，海洋里除了微小的单细胞生物几乎没有生命。但是有什么吃的呢？再看深一点。在海底深处的裂缝和裂缝中，海水渗入岩石，被加热，并剥离金属，然后集中在密集的黑色“烟”中，这些“烟”从矿化的烟囱中喷出，像畸形的尖塔一样上升到黑暗中。随着这些烟囱的生长，它们有时会在自身的重量下坍塌，形成土丘，短暂地暴露出它们闪闪发光的丰富金属硫化物，然后在寒冷、氧化、含盐的海水中迅速生锈。在这些深、暗、有水的地方发现了微生物，它们在硫化物丘和玻璃状熔岩下面定居，从这个不太可能的食物来源中提取营养。熔岩在海底火山中不断喷发，形成了海底山脉，就像棒球上的接缝一样。这些是动态环境，在地球、水文和大气之间发生具有全球意义的化学、生物和热通量。在俯冲带，新地壳的形成和旧地壳与地幔的重新合并可能是板块构造旋回的最基本组成部分。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。这个领域处于跨学科研究的前沿。我的小组采用多学科方法结合地球化学、矿物学、岩石学和成像技术来研究现代和古代热液系统。我们的工作重点是地球和行星材料。我们率先研究了水-岩石-微生物相互作用的生物地球化学效应，使用新颖的地球化学技术来检测微生物生物特征，并限制岩石中经历变形和变质作用的环境条件。这已被进一步应用于导致金属在地壳中积聚和创造经济矿床的地球化学过程。最近，我们运用我们的尖端技术来量化和限制陨石的形成和变化。虽然这些话题乍一看似乎有些不同，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贯穿地质时代的水-岩石-微生物相互作用。本研究的结果将引起学术和应用研究人员和实践者的兴趣和重要性，其影响将从经济和基本理解中受益于社会。

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.