LEXEN: Development of the Capability to Measure Proxies forMicrobial Activity within Oceanic Crust (Collaborative Research)

9729673凯尼格这项研究提出了一项计划，通过检测与这些次表层微生物群落有关的特定代谢产物，来检验这样一种假设，即在离轴海脊两侧的海洋上地壳岩石中，有大量的微生物生物圈生活在水-岩石界面下数百米处。这些诊断出的有机化合物应该伴随着已知在地壳上部岩石内循环的热液流体，最终在裸露岩石的扩散喷口处排放到上面的海水中。我们还将检测和鉴定(核糖体RNA分子探针)任何与液体排放相关的细胞生物量。为了测试山脊侧面地下生物圈假说，我们建议建立一个仪表化的“生物毯”，通过相对较小的清扫柱聚焦从这些扩散喷口区域发出的向上涌出的液体，作为代谢(有机碳)产物的陷阱。拟议的仪表式毯子还将测量热液向海水喷发时的上升流温度和速度。生物毯的开发将分为几个阶段：最初的仪器组件测试和流体采样将利用“软木”ODP1026b孔方便的阀门管道系统，该孔记录了65摄氏度的流出流体；随后的完整原型仪器将部署在海脊侧面暴露的露头(Baby Bare，卡斯卡迪亚盆地)和大洋中脊扩展中心(Endeavour Segment)的有源扩散通风口上，该中心的通量很高，流体的任何成分的信噪比都很大。直接探测到生活在较老的海脊侧翼地区的海底以下的广泛生物群落，将极大地改变我们对生物生产力和全球碳收支的估计，并对我们对地球的哲学观点产生深远影响。***

9729673 Kenig This research suggests a program to test the hypothesis that there is a substantial microbial biosphere living within the oceanic upper crustal rocks of the off-axis ridge flanks, hundreds of meters below the water-rock interface, by detecting specific metabolic products which are associated with these sub-surface microbial communities. These diagnostic organic compounds should accompany the hydrothermal fluid that is known to circulate within the upper crustal rocks and eventually discharges into the overlying seawater at diffuse vent sites in exposed rock outcrops. We will also detect and phylogeneticallv characterize (ribosomal RNA molecular probe) any cellular biomass associated with fluid discharges. To test the ridge flank subsurface biosphere hypothesis, we propose to build an instrumented "bio-blanket" that focuses up-welling fluid emanating from these diffuse vent areas through relatively small scavenging columns that serve as traps for metabolic (organic carbon) products. The proposed instrumented blanket would also measure up-welling temperatures and velocities as the hydrothermal fluid vents into seawater. The development of the bio-blanket will be in several stages: initial instrument-component tests and fluid sampling will exploit the convenient valved- plumbing system of the "corked" ODP Hole 1026B, which has documented 65 C outflowing fluids; subsequent complete prototype instruments will be deployed over active diffuse vents at both an exposed outcrop at a ridge flank site (Baby Bare, Cascadia Basin) and a mid-ocean ridge spreading center (Endeavour Segment), where flux rates are high and the signal-to-noise ratio of any component of the fluid is quite large. The direct detection of a wide-spread biological community, living within the sub-surface ocean floor in the older ridge flank regions, would dramatically alter our estimates of biological productivity and the global carbon budgets, and have a profound impact on our ph ilosophical view of the earth. ***