Precambrian Research 146 (2006) 35–44 Spatial and temporal distribution of microbially induced sedimentary structures: A case study from siliciclastic storm deposits of the 2.9 Ga Witwatersrand Supergroup, South Africa Nora Noffke a,∗ , Nic Beukes b , Jens Gutzmer b , Robert Hazen c a Old Dominion University, Department of Ocean, Earth & Atmospheric Sciences, 4600 Elkhorn Avenue, Norfolk, VA 23529, USA b Paleoproterozoic Mineralization Research Group, Department of Geology, University of Johannesburg, P.O. Box 524, Auckland Park 2006, South Africa c Geophysical Laboratory, Carnegie Institution of Washington, 5251 Broad Branch Road NW, Washington, DC 20015, USA Received 6 October 2005; received in revised form 3 January 2006; accepted 5 January 2006 Abstract Microbially induced sedimentary structures (MISS) arise from the interaction of microbial mats with the physical sedimentary dynamics of shallow-marine settings. The structures occur in siliciclastic deposits of Paleo-Archean age to modern, where they record biostabilization and baffling, trapping and binding of photoautotrophic microbenthos. In the Brixton Formation, Witwatersrand Supergroup, South Africa, erosional remnants and pockets, wrinkle structures, and oscillation cracks include carbon- and pyrite- rich filament-like textures that resemble modern trichomes of cyanobacteria. C-isotope ratios of -22 ± 0.1‰ indicate potential photoautotrophy. The MISS occur at the turning points of regression–transgression, and are restricted to a specific sedimentary facies characterized by 2–20 cm thick fine sandstone beds predominantly composed of quartz. The sandstone beds display ripple marks, which record moderate hydraulic reworking. This spatial and temporal distribution of MISS in the Brixton Formation is consistent with occurrences of those structures in comparable environments throughout Earth history. © 2006 Elsevier B.V. All rights reserved. Keywords: Microbially induced sedimentary structures; Archean; Stratigraphy; Microbial mat; Siliciclastic; Basin analysis 1. Introduction Microbially induced sedimentary structures (MISS) constitute the siliciclastic counterparts to stromatolites. Whereas stromatolites are formed by microbial mats mediating the precipitation of mineralic substances in hypersalinar shallow-marine milieus, MISS arise from the interaction of the benthic microbial communities ∗ Corresponding author. E-mail address: nnoffke@odu.edu (N. Noffke). with the predominant physical sedimentary dynamics of non-chemical, siliciclastic environments (Noffke et al., 2001b, 2003a). How do MISS form? In studies in modern shallow- marine environments, erosion triggers biostabilization, that is active sediment fixation by microbial mats (defi- nition in Paterson, 1994; Noffke et al., 2003a; quantifi- cation in Noffke and Krumbein, 1999). In the case of deposition, the microbial mats react by baffling, trap- ping, and binding (classical study Black, 1933, quan- tification in Noffke and Krumbein, 1999; Noffke et al., 2003a). Those biotic-physical interactions create a great 0301-9268/$ – see front matter © 2006 Elsevier B.V. All rights reserved. doi:10.1016/j.precamres.2006.01.003