HR: 1400h
AN: B13B-10    [Abstracts]
TI: Putative Bioalteration Textures Hosted Within Impact Melt Glasses From the Ries Crater, Germany
AU: * Sapers, H M
EM: hsapers@uwo.ca
AF: University of Western Ontario, 1151 Richmond Rd Dept. of Earth Sciences, London, ON N6A 5B7, Canada
AU: Osinski, G R
EM: gosinski@uwo.ca
AF: University of Western Ontario, 1151 Richmond Rd Dept. of Physics and Astronomy, London, ON N6A 5B7, Canada
AU: Osinski, G R
EM: gosinski@uwo.ca
AF: University of Western Ontario, 1151 Richmond Rd Dept. of Earth Sciences, London, ON N6A 5B7, Canada
AU: Banerjee, N R
EM: neil.banerjee@uwo.ca
AF: University of Western Ontario, 1151 Richmond Rd Dept. of Earth Sciences, London, ON N6A 5B7, Canada
AB: Impact cratering is a ubiquitous geological process on solid bodies. Any hypervelocity impact into a H₂O- rich target has the potential to generate hydrothermal systems [1]. Recent research has suggested that such impact-induced environments may be conducive to microbial colonization [e.g., 2]. Bioalteration of terrestrial basaltic glasses produces characteristic tubular and granular aggregate textures. Such bioalteration textures preserved in Archean greenstone belts constitute one of the oldest records of life on Earth [3]. Our examination of glasses from the Ries crater in Germany has revealed tubular textures with remarkably similar morphologies to those seen in volcanic glasses. The hyperthermophilic root of the 16S phylogenic tree of life suggests an essential role for thermophilic environments in the origin or the early evolutionary history of life on Earth. Previous work has associated primitive life on Earth with submarine volcanic activity suggesting that submarine hydrothermal settings may have played an essential role in the origin of life [e.g., 4]. Impact-induced hydrothermal systems share many characteristics with submarine volcanic hydrothermal systems including the presence of chemical and thermal energy for microbial metabolism. Interestingly, the Late Heavy Bombardment period, during which life purportedly arose on Earth, was characterized by a high impact flux. Thus, impact-generated habitats were likely much more common on Earth than submarine hydrothermal systems suggesting the former as a more statistically probable habitat for the origin of life. Here we present preliminary data characterizing the putative bioalteration structures hosted within the Ries impact glasses. Establishing the biogenecity of the alteration structures observed in these glasses may have significant astrobiological implications: impact glasses share many similarities with volcanic glasses, however, fundamental differences make impact glasses unique geochemical systems [5]. The bulk compositions of impact melts are diverse, reflecting heterogeneities in the target lithologies. Furthermore, impact melts often display heterogeneity on multiple scales. Given the probable ubiquity of impact glasses in hydrothermal settings throughout the Solar System, it is important to understand the biological components and potential of such systems. Impact derived endolithic habitats are being considered as possible locations for life on early Earth [6] and on the surface of other planets such as Mars [7]. Understanding the geomicrobiology of impact craters on Earth is critical in furthering the search for life on Mars. Studies constraining the biogeochemistry of impact craters may not only yield insight into early life and the origin of life on Earth, but furthermore, may comprise a potential habitat for life and past life on other terrestrial planets such as Mars. References: [1] M.V. Naumov (2005) Geofluids, 5, 165-184. [2] C.S. Cockell, P. Lee (2002) Biological Reviews, 77, 279-310. [3] Banerjee et. al. (2007) Geochim. Cosmochim. Acta. 71, A58. [4] Staudigel et al. 2008. ES Rev. 89(3-4) 156-178. [5] Osinski G. R. (2003) MAPS 38(11), 1641-1667. [6] F. Westall, R.L. Folk (2003) Precambrian Res. 126. [7] Cockell C. S., et al. (2005) MAPS 40(12), 1901-1914
DE: 0448 Geomicrobiology
DE: 0450 Hydrothermal systems (1034, 3017, 3616, 4832, 8135, 8424)
DE: 3625 Petrography, microstructures, and textures
DE: 5215 Origin of life
DE: 5420 Impact phenomena, cratering (6022, 8136)
SC: Geological Association of Canada [GA]
MN: 2009 Joint Assembly