An Akouemma hemisphaeria Organic Macrofossils Colony Hosting Biodiversity Assemblage on the Seafloor of Okondja Basin (Gabon) dated at 2.2 GaEdou-Minko A1*, Moussavou M1, Sato T2*, Tchikoundzi C1, Sawaki Y3, Ndong Ondo S1, Ortega R4, Maire R5, Kaestner A6, Mbina Mounguengui M1, Roudeau S4, Fleury G7, Carmona A4, de Parseval PH8, Makaya Mvoubou1, Musavu Moussavou B1, Ogandaga Agondjo M1, Sasaki O9 and Maruyama S2
- *Corresponding Author:
- Edou-Minko A
Université des Sciences et Techniques de Masuku, BP. 901 Franceville, Gabon
E-mail: [email protected]
- Sato T
Earth-Life Science Institute (ELSI), Tokyo Institute of Technology
2-12-1 O-okayama Meguro-ku, Tokyo 152-8551, Japan
E-mail: [email protected]
Received date: January 19, 2017; Accepted date: February 06, 2017; Published date: February 10, 2017
Citation: Edou-Minko A, Moussavou M, Sato T, Tchikoundzi C, Sawaki Y, et al. (2017) An Akouemma hemisphaeria Organic Macrofossils Colony Hosting Biodiversity Assemblage on the Seafloor of Okondja Basin (Gabon) dated at 2.2 Ga. J Geol Geophys 6: 281. doi: 10.4172/2381-8719.1000281
Copyright: © 2017 Edou-Minko A, et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
A colony of silico-carbonate Akouemma nodules found in Akou River sedimentary formations of the Palaeoproterozoic Okondja Basin consists of two groups, spheroidal (ovoid) nodules and elongated nodules. These nodules, which consist of two hemispheres separated by a median disc, are composed essentially of micro-quartz associated with calcite of extra-polymeric substance (EPS) type, clay minerals, organic carbon and oxides and sulphides of iron. They contain tubular microfossils, pluricellular clusters, microorganisms and vesicles, and have undergone considerable deformation by mutual lateral compression in tabular beds. They were interpreted as biogenic nodules hosting microorganisms.
We provide the following additional supporting evidence: Akouemma nodules exhibit internal fibro-radial fabrics initially composed of fibres and carbon particles; the initially well-organized structures are decaying and are in particles and fragments that are dispersed in the undeformed siliceous mass. These internal fabrics are strongly highlighted by Al- K- (Ti)-rich clay minerals that are often in close association with fibres and carbon particles. They had likely a vegetative reproduction by duplication.
We infer that the Akouemma nodules are macrofossils of sessile soft-plastic body organisms. These macrofossils, recently dated at 2.2 Ga, are designated “Akouemma hemisphaeria” and bring a new vision to the “large colonial organisms” found in the Franceville Basin.