A new window into Early Archean life: Microbial mats in Earth's oldest siliciclastic tidal deposits (3.2 Ga Moodies Group, South Africa)

Abstract

Research Article| April 01, 2006 A new window into Early Archean life: Microbial mats in Earth's oldest siliciclastic tidal deposits (3.2 Ga Moodies Group, South Africa) Nora Noffke; Nora Noffke 1Department of Ocean, Earth and Atmospheric Sciences, Old Dominion University, 4600 Elkhorn Avenue, Norfolk, Virginia 23529, USA Search for other works by this author on: GSW Google Scholar Kenneth A. Eriksson; Kenneth A. Eriksson 2Department of Geosciences, Virginia Polytechnic Institute and State University, Blacksburg, Virginia 24061, USA Search for other works by this author on: GSW Google Scholar Robert M. Hazen; Robert M. Hazen 3Carnegie Institution, Geophysical Laboratory, 5251 Broad Branch Road NW, Washington, DC 20015, USA Search for other works by this author on: GSW Google Scholar Edward L. Simpson Edward L. Simpson 4Department of Physical Sciences, University of Pennsylvania, Kutztown, Pennsylvania 19530, USA Search for other works by this author on: GSW Google Scholar Author and Article Information Nora Noffke 1Department of Ocean, Earth and Atmospheric Sciences, Old Dominion University, 4600 Elkhorn Avenue, Norfolk, Virginia 23529, USA Kenneth A. Eriksson 2Department of Geosciences, Virginia Polytechnic Institute and State University, Blacksburg, Virginia 24061, USA Robert M. Hazen 3Carnegie Institution, Geophysical Laboratory, 5251 Broad Branch Road NW, Washington, DC 20015, USA Edward L. Simpson 4Department of Physical Sciences, University of Pennsylvania, Kutztown, Pennsylvania 19530, USA Publisher: Geological Society of America Received: 26 Sep 2005 Revision Received: 30 Nov 2005 Accepted: 05 Dec 2005 First Online: 09 Mar 2017 Online ISSN: 1943-2682 Print ISSN: 0091-7613 Geological Society of America Geology (2006) 34 (4): 253–256. https://doi.org/10.1130/G22246.1 Article history Received: 26 Sep 2005 Revision Received: 30 Nov 2005 Accepted: 05 Dec 2005 First Online: 09 Mar 2017 Cite View This Citation Add to Citation Manager Share Icon Share Facebook Twitter LinkedIn MailTo Tools Icon Tools Get Permissions Search Site Citation Nora Noffke, Kenneth A. Eriksson, Robert M. Hazen, Edward L. Simpson; A new window into Early Archean life: Microbial mats in Earth's oldest siliciclastic tidal deposits (3.2 Ga Moodies Group, South Africa). Geology 2006;; 34 (4): 253–256. doi: https://doi.org/10.1130/G22246.1 Download citation file: Ris (Zotero) Refmanager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search Search Dropdown Menu toolbar search search input Search input auto suggest filter your search All ContentBy SocietyGeology Search Advanced Search Abstract Newly discovered sedimentary structures produced by ancient microbial mats in Early Archean sandstones of the 3.2 Ga Moodies Group, South Africa, differ fundamentally in appearance and genesis from Early Archean stromatolites and bacterial cell fossils preserved in chert. Wrinkle structures, desiccation cracks, and roll-up structures record the previous existence of microbial mats that effectively stabilized sediment on the earliest known siliciclastic tidal flats. In thin-section, the sedimentary structures reveal carpet-like, laminated fabrics characteristic of microbial mats. Negative δ13C isotope ratios of −20.1 to −21.5 ± 0.2‰ are consistent with a biological origin for the carbon preserved in laminae. The biogenicity of the sedimentary structures in the Moodies Group is substantiated by comparative studies on identical mat-related features from similar tidal habitats throughout Earth history, including the present day. This study suggests that siliciclastic tidal-flat settings have been the habitat of thriving microbial ecosystems for at least 3.2 billion years. Independently of controversial silicified microfossils and stromatolites, the newly detected microbially induced sedimentary structures in sandstone support the presence of bacterial life in the Early Archean. You do not have access to this content, please speak to your institutional administrator if you feel you should have access.