Advanced

The 2.1 Ga old Francevillian biota : Biogenicity, taphonomy and biodiversity

El Albani, Abderrazak; Bengtson, Stefan; Canfield, Donald E; Riboulleau, Armelle; Bard, Claire Rollion; Macchiarelli, Roberto; Pemba, Lauriss Ngombi; Hammarlund, Emma LU ; Meunier, Alain and Mouele, Idalina Moubiya, et al. (2014) In PLoS ONE 9(6).
Abstract

The Paleoproterozoic Era witnessed crucial steps in the evolution of Earth's surface environments following the first appreciable rise of free atmospheric oxygen concentrations ∼2.3 to 2.1 Ga ago, and concomitant shallow ocean oxygenation. While most sedimentary successions deposited during this time interval have experienced thermal overprinting from burial diagenesis and metamorphism, the ca. 2.1 Ga black shales of the Francevillian B Formation (FB2) cropping out in southeastern Gabon have not. The Francevillian Formation contains centimeter-sized structures interpreted as organized and spatially discrete populations of colonial organisms living in an oxygenated marine ecosystem. Here, new material from the FB2 black shales is... (More)

The Paleoproterozoic Era witnessed crucial steps in the evolution of Earth's surface environments following the first appreciable rise of free atmospheric oxygen concentrations ∼2.3 to 2.1 Ga ago, and concomitant shallow ocean oxygenation. While most sedimentary successions deposited during this time interval have experienced thermal overprinting from burial diagenesis and metamorphism, the ca. 2.1 Ga black shales of the Francevillian B Formation (FB2) cropping out in southeastern Gabon have not. The Francevillian Formation contains centimeter-sized structures interpreted as organized and spatially discrete populations of colonial organisms living in an oxygenated marine ecosystem. Here, new material from the FB2 black shales is presented and analyzed to further explore its biogenicity and taphonomy. Our extended record comprises variably sized, shaped, and structured pyritized macrofossils of lobate, elongated, and rodshaped morphologies as well as abundant non-pyritized disk-shaped macrofossils and organic-walled acritarchs. Combined microtomography, geochemistry, and sedimentary analysis suggest a biota fossilized during early diagenesis. The emergence of this biota follows a rise in atmospheric oxygen, which is consistent with the idea that surface oxygenation allowed the evolution and ecological expansion of complex megascopic life.

(Less)
Please use this url to cite or link to this publication:
@article{6b720ce7-3730-4016-918f-75ed8be37a24,
  abstract     = {<p>The Paleoproterozoic Era witnessed crucial steps in the evolution of Earth's surface environments following the first appreciable rise of free atmospheric oxygen concentrations ∼2.3 to 2.1 Ga ago, and concomitant shallow ocean oxygenation. While most sedimentary successions deposited during this time interval have experienced thermal overprinting from burial diagenesis and metamorphism, the ca. 2.1 Ga black shales of the Francevillian B Formation (FB2) cropping out in southeastern Gabon have not. The Francevillian Formation contains centimeter-sized structures interpreted as organized and spatially discrete populations of colonial organisms living in an oxygenated marine ecosystem. Here, new material from the FB2 black shales is presented and analyzed to further explore its biogenicity and taphonomy. Our extended record comprises variably sized, shaped, and structured pyritized macrofossils of lobate, elongated, and rodshaped morphologies as well as abundant non-pyritized disk-shaped macrofossils and organic-walled acritarchs. Combined microtomography, geochemistry, and sedimentary analysis suggest a biota fossilized during early diagenesis. The emergence of this biota follows a rise in atmospheric oxygen, which is consistent with the idea that surface oxygenation allowed the evolution and ecological expansion of complex megascopic life.</p>},
  articleno    = {e99438},
  author       = {El Albani, Abderrazak and Bengtson, Stefan and Canfield, Donald E and Riboulleau, Armelle and Bard, Claire Rollion and Macchiarelli, Roberto and Pemba, Lauriss Ngombi and Hammarlund, Emma and Meunier, Alain and Mouele, Idalina Moubiya and Benzerara, Karim and Bernard, Sylvain and Boulvais, Philippe and Chaussidon, Marc and Cesari, Christian and Fontaine, Claude and Chi-Fru, Ernest and Ruiz, Juan Manuel Garcia and Gauthier-Lafaye, François and Mazurier, Arnaud and Pierson-Wickmann, Anne-Catherine and Rouxel, Olivier and Trentesaux, Alain and Vecoli, Marco and Versteegh, Gerard J M and White, Lee and Whitehouse, Martin and Bekker, Andrey},
  issn         = {1932-6203},
  language     = {eng},
  month        = {06},
  number       = {6},
  publisher    = {Public Library of Science},
  series       = {PLoS ONE},
  title        = {The 2.1 Ga old Francevillian biota : Biogenicity, taphonomy and biodiversity},
  url          = {http://dx.doi.org/10.1371/journal.pone.0099438},
  volume       = {9},
  year         = {2014},
}