Life on the Rocks: Microbes, Mines, and Martians

想象一下恐龙出现之前的世界，那时植物和动物还没有进化。在那里，火山孕育了新的陆地，并向无氧的大气中喷出有毒气体。那里的大陆刚刚诞生，那里的海洋几乎没有生命，只有微小的单细胞生物。但是有什么吃的？再深入一点。在海底深处的裂缝和缝隙中，海水渗入岩石，被加热，剥离金属，然后集中在密集的黑色“烟雾”中，这些烟雾通过矿化的烟囱排出，像畸形的尖顶一样上升到黑暗中。随着这些烟囱的生长，它们有时会在自身重量的作用下崩溃，形成土丘，短暂地暴露出它们闪闪发光的金属硫化物，然后在寒冷、氧化、咸的海水中迅速生锈。在这些深邃、黑暗、多水的地方，发现了微生物，它们在硫化物土丘和下面的玻璃状熔岩中定居，从这个不太可能的食物来源中汲取营养。熔岩不断地在海底火山喷发，在海底形成山脉，就像棒球上的接缝。这些是动态环境，在地球，水和大气之间发生全球显著的化学，生物和热通量。新地壳的形成和老地壳在俯冲带重新并入地幔可能是板块构造旋回最基本的组成部分。这些过程控制着地球的自然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调查数十亿年时间尺度内地球和行星材料中的水-岩石-微生物过程。该领域处于跨学科研究的前沿。我的团队使用多学科方法，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-微生物相互作用的地球化学效应，使用新的地球化学技术检测微生物生物特征，并限制发生变形和变质的岩石中的环境条件。这一点已被进一步应用于导致金属在地壳中积聚并形成经济矿床的地球化学过程。最近，我们已经应用我们的尖端技术来量化和限制陨石的产生和改变。虽然这些主题乍一看似乎有些不同，但它们是不可分割地交织在一起的。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期的水-岩石-微生物相互作用。这项研究的结果将是学术和应用研究人员和从业人员的兴趣和重要性，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.