Collaborative Research: Antiquity of Life in Salt Deposits? A Rb-Sr Age-Dating Study

该项目旨在验证地质证据，证明微生物可以在充满盐水的岩盐晶体包裹体中存活10^8年。这项研究的目标是获得两种古代岩盐包裹体的绝对辐射年龄，其中微生物已经被培养出来：新墨西哥州二叠纪萨拉多地层的晶体和巴西白垩纪Muribeca蒸发岩的“chevrons”。这样的定年将消除人们对流体包裹体年龄的怀疑，这些包裹体中提取了所谓的二叠纪和白垩纪微生物。获得岩盐中盐水包裹体的绝对年龄对地球上细菌的长期生存和天体生物学具有深远的意义，并可能为未来探索火星和太阳系其他部分的生命提供技术。据称是世界上最古老的生物体，孢子形成细菌Virgibacillus sp. Permian菌株2-9-3，是从250 Ma Permian Salado组的岩盐水泥中的盐水包裹体中培养出来的。对这些样品中的单个盐水包裹体进行Rb-Sr测年将明确确定在Salado盐沉积时，Virgibacillus sp. 2-9-3是否被困在流体包裹体中。从白垩纪Muribeca组原生雪佛龙岩盐的盐水包裹体中培养了古细菌菌株。用Rb-Sr法对这些白垩纪岩石层中的卤水包裹体定年，可以确定产生新发现的嗜盐古菌的卤水包裹体的年龄是否为100 Ma。从这项资助中获得的信息作为在国家会议上的报告和期刊文章分发给研究界。研究结果在宾厄姆顿大学每年为研究生/本科生举办的地球生物学研讨会上，以及德克萨斯大学与人合作教授的分析地球化学课程中都有说明。首席研究员参加了K-12学生的夏季丰富计划，在环境中进行实地和实验室工作，包括显微镜和环境扫描电子显微镜观察各种样品，包括盐中的盐水包裹体。一个关于盐水包裹体中微生物生命和保存的网站介绍了该项目的最新研究成果。(与Riciputi/0418651/ university；田纳西州诺克斯维尔)

Lowenstein0418758This project seeks to verify geological evidence that microorganisms can survive inside the brine-filled inclusions of halite crystals for periods of 10^8 years. The goal of the research is to obtain absolute radiometric ages of brine inclusions from two ancient halites from which microorganisms have been previously cultured: crystals from the Permian Salado Formation, New Mexico and "chevrons" from the Cretaceous Muribeca evaporites of Brazil. Such dating will remove doubts about the ages of the fluid inclusions from which the purported Permian and Cretaceous microorganisms were extracted. Obtaining absolute ages of brine inclusions in halite has profound implications for long-term bacterial survival on Earth and for astrobiology, and may contribute techniques to future exploration for life on Mars and other parts of the solar system.The purported world's oldest living organism, the spore-forming bacterium Virgibacillus sp. Permian strain 2-9-3, was cultured from a brine inclusion in halite cement of the 250 Ma Permian Salado Formation. Rb-Sr dating of individual brine inclusions from these samples will establish unequivocally whether Virgibacillus sp. 2-9-3 was trapped in a fluid inclusion at the time of deposition of the Salado salts. Archaeal strains have been cultured from brine inclusions from primary chevron halite of the Cretaceous Muribeca Formation. Dating brine inclusions in these Cretaceous halites by Rb-Sr methods will ascertain with certainty whether the brine inclusions that yielded the newly discovered halophilic Archaea are 100 Ma in age.The information obtained from this grant is disseminated to the research community as presentations at national meetings and as journal articles. The results are illustrated in a geobiology seminar offered each year to graduate/undergraduate students at Binghamton, and in an analytical geochemistry course co-taught at UT. The Principal Investigator participates in a summer enrichment program for K-12 students with field and laboratory work on microorganisms in the environment, including microscope and Environmental Scanning Electron Microscope viewing of an assortment of samples including brine inclusions in salt. A website on microbial life and preservation in brine inclusions features current research from this project.(Collaborative research with Riciputi/0418651/Univ. Tennessee at Knoxville)