A test of the biogenicity criteria established for microfossils and stromatolites on quaternary tufa and speleothem materials formed in the “Twilight zone” at Caerwys, UK

Brasier, A. T.; Rogerson, M. R.; Mercedes-Martin, R.; Vonhof, H. B.; Reijmer, J. J. G.

Abstract

© 2015, Mary Ann Liebert, Inc. The ability to distinguish the features of a chemical sedimentary rock that can only be attributed to biology is a challenge relevant to both geobiology and astrobiology. This study aimed to test criteria for recognizing petrographically the biogenicity of microbially influenced fabrics and fossil microbes in complex Quaternary stalactitic carbonate rocks from Caerwys, UK. We found that the presence of carbonaceous microfossils, fabrics produced by the calcification of microbial filaments, and the asymmetrical development of tufa fabrics due to the more rapid growth of microbially influenced laminations could be recognized as biogenic features. Petrographic evidence also indicates that the development of "speleothem-like" laminae was related to episodes of growth interrupted by intervals of nondeposition and erosion. The lack of any biogenic characteristics in these laminae is consistent with their development as a result of variation in the physicochemical parameters that drive calcite precipitation from meteoric waters in such environmental settings.

Citation

Brasier, A. T., Rogerson, M. R., Mercedes-Martin, R., Vonhof, H. B., & Reijmer, J. J. G. (2015). A test of the biogenicity criteria established for microfossils and stromatolites on quaternary tufa and speleothem materials formed in the “Twilight zone” at Caerwys, UK. Astrobiology, 15(10), 883-900. https://doi.org/10.1089/ast.2015.1293

• Journal Article Type: Article
• Acceptance Date: Sep 18, 2015
• Publication Date: 2015-10
• Deposit Date: Oct 27, 2015
• Publicly Available Date: Nov 23, 2017
• Journal: Astrobiology
• Print ISSN: 1531-1074
• Electronic ISSN: 1557-8070
• Publisher: Mary Ann Liebert
• Peer Reviewed: Peer Reviewed
• Volume: 15
• Issue: 10
• Pages: 883-900
• DOI: https://doi.org/10.1089/ast.2015.1293
• Keywords: Microfossil; Stromatolite; Biogenicity; Carbonate; Tufa; Speleothem
• Public URL: https://hull-repository.worktribe.com/output/380371
• Publisher URL: http://online.liebertpub.com/doi/10.1089/ast.2015.1293
• Additional Information: Authors' accepted manuscript of article published in: Astrobiology, 2015, v.15, issue 10. Final publication is available from Mary Ann Liebert, Inc., publishers http://dx.doi.org/10.1089/ast.2015.1293