BE/CBC: Geobiology and the Emergence of Terraced Architecture during Carbonate Mineralization

目的和方法：这项建议的目的是确定如何要求特定活微生物和/或微生物群落的生物多样性和活性来创建在高温和低温碳酸盐泉水沉积中普遍观察到的梯形结构。这些结果将提供碳酸盐沉淀过程中微生物-水-矿物相互作用的基本知识，这是更准确地重建地球和其他星球上微生物生命历史所必需的。该项目通过将地质学研究、微生物rDNA和基因分析以及定量建模相结合来推进生物复杂性领域，以提供碳酸盐阶地形成的详细地质生物学描述。该项目的综合多学科研究和教育方面满足了为未来的地球生物学和生物复杂性研究培养人才的国家需求。该项目由一个独特的跨学科研究团队领导，该团队在地质学、微生物学和物理学方面具有专门知识。项目的里程碑包括：1)进行原位结晶实验，以确定微生物在紫外线照射下沉积的钙华的形态和化学成分，这是一种杀菌技术，将使泉水流出的其他基本物理和化学条件保持相对不变；2)记录方解石晶体生长形式、分布和化学与微生物形态、多样性和代谢活动之间的关系；3)使用随机微分方程对碳酸盐阶地形成进行定量模拟，以描述地质和生物过程的综合影响。猛犸象温泉是世界上最适合进行拟议研究的自然实验室。尽管二氧化碳脱气和温度下降对泉水化学有很大影响，但最近对钙华晶体形态和同位素化学的重大生物控制已被定量记录。猛犸象温泉独一无二的提供：1)高达5毫米/天的降水速率，允许在生物和物理影响的条件下进行短期的原位结晶实验；2)一个地点的高到低温碳酸盐沉淀的全部光谱；3)长期熟悉研究地点的皮·S，他手中有所有必要的研究许可；4)世界上唯一一个易于进入的温泉综合体，在其自然状态下受到保护。智力价值：主要解决的问题是，梯田碳酸盐建筑的存在是否是微生物活动存在的初步证据。这项研究的结果将有助于鉴定现代和古代其他高温和低温阶地碳酸盐泉水沉积中受微生物影响的结晶作用。定量建模中使用的技术提供了从物理和生物角度对重大地质特征的基本原理的理解。同样重要的是，这项研究的结果将建立一个系统和定量的工具包，以确定碳酸盐沉积过程中的微生物影响，可用于地球和其他星球上其他各种重要的陆地、海洋和埋藏环境。广泛的影响：这种对生物和地质过程之间相互作用的系统水平的理解以及由此产生的概念方法将提供从研究生到K-12以及普通公众的所有级别的学习机会。培训生物复杂性研究人才的计划将包括本科生、研究生和博士后，与意大利锡耶纳大学的国际学生交流，基于网络的地球生物学课程开发，以及在伊利诺伊州开发正式的地球生物学课程。该项目通过博物馆展示、小册子和黄石国家公园峡谷和猛犸象温泉游客中心的解释性步道标志，提高公众对生物复杂性研究的必要性的认识，每年将有300多万公园游客观看和使用这些温泉中心。

ABSTRACTObjectives and Methods: The goal of this proposal is to determine how the biodiversity and activity of specific living microbes and/or microbial communities are required to create the terraced architectures universally observed in high-temperature and low-temperature carbonate spring deposits. Results will provide a fundamental knowledge of microbe-water-mineral interactions during carbonate precipitation that are needed to more accurately reconstruct the history of microbial life on earth and other planets. This project advances the field of biocomplexity by combining geological studies, microbial rDNA and gene analyses and quantitative modeling to provide a detailed geobiological account of carbonate terrace formation. The integrated multidisciplinary research and educational aspects of this project meet a national need to train personnel for future geobiology and biocomplexity studies.The project is headed by a unique interdisciplinary research team with specific expertise in geology, microbiology, and physics. Project milestones include:1) performing in situ crystallization experiments to determine the form and chemistry of travertine deposited when the microbes have been UV-irradiated, a sterilization technique that will leave the other fundamental physical and chemical conditions of the spring drainage outflow relatively unchanged; 2) documenting associations between calcite crystal growth form, distribution and chemistry with microbial form, diversity and metabolic activity; and 3)quantitative modeling of carbonate terrace formation using stochastic differential equations to describe the combined effects of geological and biological processes.Mammoth Hot Springs is the most appropriate natural laboratory in the world for conducting the proposed research. Although CO2 degassing and decreasing temperatures strongly influence the spring water chemistry, significant biological controls on travertine crystal form and isotope chemistry have recently been quantitatively documented.Mammoth Hot Springs uniquely offers:1) precipitation rates as high as 5 mm/day that allow short-duration in situ crystallization experiments in a regime of coupled biological and physical influences;2) the full spectrum of high-to low-temperature carbonate precipitates at one site;3) long-term familiarity of the study site by the PI 's who have all required research permits in hand; and 4)the only easily accessible hot spring complex in the world protected in its natural state.Intellectual Merit: The main question addressed is whether the presence of terraced carbonate architecture is prima facie evidence for the presence of microbial activity. Results from this study will permit the identification of microbiologically influenced crystallization in other modern and ancient high-temperature and low-temperature terraced carbonate spring deposits. The techniques employed in the quantitative modeling provide a first principles understanding of significant geological features from a physical and biological perspective. Of equal importance, the results from this study will establish a systematic and quantitative toolkit to identify microbial influence during carbonate deposition that can be used in a wide variety of other important terrestrial, marine, and burial environments on earth and other planets.Broader Impacts: This systems-level understanding of the interaction between biological and geological processes and resultant conceptual approaches will provide learning opportunities at all levels from postgraduate to K-12, as well as to the general public. The program to train personnel in biocomplexity studies will include undergraduates, graduate students, and postdocs, international student exchange with the University of Siena in Italy, web-based curriculum development for Geobiology courses, and the development of a formal Geobiology program at Illinois. This project enhances public awareness of the need for biocomplexity studies through museum displays, brochures, and interpretive trail signs for the Canyon and Mammoth Hot Springs Visitor Centers in Yellowstone National Park, which will be seen and used by over 3 million park visitors each year.