Advanced two- and three-dimensional insights into Earth’s oldest stromatolites (ca. 3.5 Ga): prospects for the search for life on Mars

Hickman-Lewis, K. et al. (2023) Advanced two- and three-dimensional insights into Earth’s oldest stromatolites (ca. 3.5 Ga): prospects for the search for life on Mars. Geology, 51(1), pp. 33-38. (doi: 10.1130/g50390.1)

Abstract

Paleoarchean stromatolites are among the oldest compelling evidence for life. We present advanced two- and three-dimensional (2-D and 3-D) reconstructions of the morphology, mineralogy, trace element geochemistry, and taphonomy of permineralized stromatolites from the lowermost horizons of the ca. 3.5 Ga Dresser Formation, Pilbara, Western Australia. Rare earth element plus yttrium compositions suggest a restricted paleodepositional setting influenced by marine influxes; this contrasts with other Dresser stromatolites, which developed around terrestrial hot springs. Mineral phase relationships and positive Eu anomalies denote syndepositional hydrothermal influence and silicification promoting high-fidelity microstructural preservation. Although no primary kerogen is preserved, numerous 2-D and 3-D morphological characteristics denote a biogenic origin, including the onlap of sedimentary layers onto stromatolitic topography, fine-scale undulatory laminations, non-isopachous laminations with crestal thickening, laminoid fenestrae, and subvertical pillar-like fabrics interpreted as microbial palisade structure; these features suggest that the stromatolite ecosystem was dominantly phototrophic. The deep iron-rich weathering profile of the Dresser stromatolites makes them pertinent analogues for potential microbialites in altered carbonates on Mars. Were similar putative biogenic macro-, meso- and micromorphologies identified in habitable Martian settings by rover imaging systems, such materials would be compelling targets for sample return.

• Item Type: Articles
• Additional Information: Funding for this study came from the UK Space Agency, the Centre National d’Études Spatiales, and the Centre National de la Recherche Scientifique. Access to Elettra Sincrotrone was enabled by Central European Research Infrastructure Consortium support to Hickman-Lewis.
• Status: Published
• Refereed: Yes
• Glasgow Author(s) Enlighten ID: Smith, Dr Caroline
• Authors: Hickman-Lewis, K., Cavalazzi, B., Giannoukos, K., D’Amico, L., Vrbaski, S., Saccomano, G., Dreossi, D., Tromba, G., Foucher, F., Brownscombe, W., Smith, C.L., and Westall, F.
• College/School: College of Science and Engineering > School of Geographical and Earth Sciences
• Journal Name: Geology
• Publisher: Geological Society of America
• ISSN: 1943-2682
• ISSN (Online): 1943-2682
• Published Online: 04 November 2022
• Copyright Holders: Copyright © 2022 The Authors
• First Published: First published in Geology 51(1): 33-38
• Publisher Policy: Reproduced under a Creative Commons License