The Fortescue Group contains little-metamorphosed sediments deposited in marine and continental (fluvial and lacustrine) environments between 2775-2630 Ma, preserving a detailed record of environmental conditions and biological processes during the Neoarchean. The Tumbiana Formation of this group was deposited at 2720 Ma, during an episode of increased volcanic activity and tumultuous change in global geological and biological systems. It is well-known for its preservation of a large delta 13C anomaly and remarkably well-preserved, diverse and abundant stromatolites, as well as much of the earliest evidence many modern geobiological cycles, including some of the earliest evidence for oxygenic photosynthesis. Microbialites of the Tumbiana Formation offer clues to the biological affinities of some microbialite-constructing microorganisms at this time, and strongly imply the presence of motile and filamentous organisms occupying an ecological niche that is today occupied by cyanobacteria. I will discuss recent findings relating to informative microbialite morphologies of the Tumbiana Formation. In addition, I will introduce stromatolitic units of the 2.74 Ga Kylena Formation and 2.63 Ga Jeerinah Formation, Fortescue Group, and discuss how the study of these units is providing us with an improved understanding of the timing and significance of evolutionary events recorded in the Tumbiana Formation.
|Number of pages||1|
|Publication status||Published - 2012|
|Event||International Geological Congress (34th : 2012) - Brisbane, Australia|
Duration: 5 Aug 2012 → 10 Aug 2012
|Conference||International Geological Congress (34th : 2012)|
|Period||5/08/12 → 10/08/12|
Flannery, D., Hoshino, Y., Walter, M., Van Kranendonk, M., & George, S. (2012). A Record of life in changing Neoarchean environments of the Fortescue Group, Pilbara region, Western Australia. 1655. Abstract from International Geological Congress (34th : 2012), Brisbane, Australia.