EAGER Collaborative Research: The Basalt-Hosted Biosphere Observatory at North Pond, Advanced Instrumentation for Transformative Science

该奖项是根据2009年《美国复苏和再投资法案》(公法111-5)提供资金的。该项目的近期目标是获得并建造两个仪器包，作为中大西洋海岭微生物实验(MARME)计划的一部分，这两个仪器包将与IODP钻孔观测站对接，称为软木塞。这一国际方案利用新的跨学科方法来阐明海洋次表层的水文、地球化学和微生物成分之间的联系和交换率。这些工具包对于实现Marme的总体目标至关重要，该目标是在北纬22度大西洋中脊西侧的一个孤立的沉积“池塘”下的7-8 Ma玄武岩基底内原位确定微生物群落的来源和性质。北池塘的微生物群落将根据其水文地球化学环境进行表征。之所以选择这个地点，是因为1)玄武岩基底足够年轻(10 Ma)，可以容纳活跃的微生物；2)基岩上的沉积物覆盖层足够深，可以很好地穿透钻头；3)该地点以前在DSDP和ODP段期间已经钻探过几次，因此存在关于该系统的水文和地球化学信息。这个项目是对结晶岩中深层生物圈的更大规模的多学科研究，该研究解决了以下重要问题：1)年轻山脊两侧微生物群落的性质？2)这种环境中微生物生长的机制？3)微生物在氧化和还原条件下矿物风化中的作用？4)细菌群落的接种物来源？5)海底水文地质如何影响微生物群落的组成和生理？通过使用长期海底观测站可以最有效地解决这些问题，这些观测站允许在钻探的初始干扰后重建现场的流体、热和化学条件。这个项目是一个更大的研究工作的一部分，该工作分为三个主要阶段，包括作为第一阶段的现场调查，该阶段于2009年1月完成。钻探探险将是第二阶段，在此期间，将安装3个密封的钻孔观测台，作为IODP赞助的邮轮(IODP 677提案，完整)的一部分。该项目将直接支持第三阶段，即部署和回收海底仪器包，以便与软木对接，该阶段将1)通过监测地层流体压力和温度来测量系统中的流体流量，以及2)部署GeoMICROBE Sling，用于在1年半的时间尺度上从软木内特定深度层收集流体样本，进行微生物和地球化学分析。压力和温度测量提供了现场水文和热条件的基本约束，所有现场微生物和模拟实验都是根据这些条件设计的。更广泛的影响：Marme项目和相关的IODP钻探将是自IODP第201次会议以来对深海生物圈进行的最大规模的协调调查，该次会议侧重于海洋沉积物。该项目将利用新颖的多学科方法，大大促进我们对中大西洋海脊基底岩石中的深层海洋生物圈的了解。与海洋沉积物相比，玄武岩基底对获取用于微生物分析的高质量样品提出了更多挑战，使用科克天文台进行这类研究对于推动这一学科的发展至关重要。因此，该项目符合IODP的许多主要科学目标。该项目奠定的基础将为今后以观测站为基础的深层生物圈调查提供必要的基础设施和动力。它将支持众多本科生和研究生研究项目，并促进亚洲、北美和欧洲三大洲的合作研究和教育交流。

This award is funded under the American Recovery and Reinvestment Act of 2009 (Public Law 111-5). The immediate goals of this project are to acquire and build two instrument packages that will be interfaced with IODP borehole observatories, known as CORKs, as part of the Mid-Atlantic Ridge Microbiological Experiments (MARME) program. This international program utilizes novel interdisciplinary approaches to elucidate the linkages and rates of exchange between the hydrological, geochemical and microbiological components of the oceanic subsurface. The instrument packages are essential for achieving the over-arching goals of MARME to determine the origin and nature of microbial communities in situ within basaltic basement of 7-8Ma age below an isolated sediment "pond" on the western flank of the Mid-Atlantic Ridge at 22N, known as North Pond. The microbial communities of North Pond will be characterized in the context of their hydrogeochemical environment. This site was chosen because 1) the basaltic basement is suitably young ( 10 Ma) to harbor active microorganisms, 2) the sediment cover over the basement rock is sufficiently deep to permit good penetration of the drill bit, 3) the site has been drilled several times before during DSDP and ODP legs, thus information exists regarding the hydrology and geochemistry of the system. This project feeds into a much larger multi-disciplinary study of the deep biosphere within crystalline rocks that addresses important questions such as 1) nature of microbial communities in young ridge flanks? 2) mechanisms of microbial growth in such environments? 3) What is the role of microbes in mineral weathering under oxidizing and reducing conditions? 4) source of inoculum for this bacterial community? 5) How microbial community composition and physiology is affected by the subseafloor hydrogeology? Questions as these are most effectively addressed through the use of long term subseafloor observatories, which permit in situ fluid, thermal, and chemical conditions to re-establish after the initial disturbance from drilling. This project is one part of a much larger research effort that is divided into three major phases, including a site survey as the first phase, which was completed in January, 2009. The drilling expedition will be the second phase, during which 3 sealed borehole observatories will be installed as part of an IODP-sponsored cruise (IODP 677 Proposal, Full). This project will directly support the third phase, which is to deploy and recover seafloor instrumental packages to be interfaced with the CORKs that will 1) measure fluid flow in the system by monitoring formation fluid pressures and temperatures, and 2) deploy a GeoMICROBE Sled for collecting fluid samples from specified depth horizons within the CORKs for microbiological and geochemical analyses over 1 ? 5 year time scales. The pressure and temperature measurements provide the basic constraints of the in situ hydrological and thermal conditions from which all of the in situ microbiological and modeling experiments are designed. Broader Impacts: The MARME project and associated IODP drilling would be the largest coordinated investigation of the deep marine biosphere since IODP leg 201, which focused on marine sediments. This project will utilize novel and multidisciplinary approaches that will significantly advance our understanding of the deep marine biosphere in the basement rocks of the Mid Atlantic Ridge. Relative to marine sediments, the basaltic basement poses more challenges for obtaining quality samples for microbiological analysis, and the use of CORK observatories for such studies is essential to move this discipline forward. As such, this project meets many of the primary scientific objectives of the IODP. The foundation laid by this project will provide the necessary infrastructure and momentum for future observatory-based investigations of the deep biosphere. It will support numerous undergraduate and graduate research projects, and foster collaborative research and educational exchange across three continents, Asia, North America and Europe.