The Franceville Basin is a 1.6–2.1 billion year old sedimentary basis in

Gabon Gabon (; ; snq, Ngabu), officially the Gabonese Republic (french: République gabonaise), is a country on the west coast of Central Africa. Located on the equator, it is bordered by Equatorial Guinea to the northwest, Cameroon to the north ...

. It contains unmetamorphosed sediments. It is notable for containing the

Francevillian Biota The Francevillian biota (also known as Gabon macrofossils or Gabonionta) is a group of 2.1-billion-year-old Palaeoproterozoic, macroscopic organisms known from fossils found in Gabon in the Palaeoproterozoic Francevillian B Formation, a black sha ...

, which is likely the oldest

multicellular life A multicellular organism is an organism that consists of more than one cell, in contrast to unicellular organism. All species of animals, land plants and most fungi are multicellular, as are many algae, whereas a few organisms are partially uni ...

known. A natural fission reactor formed there about 800-900 million years ago.

Geology

The Franceville Basin cover approximately 25,000 km² and is made up of unmetamorphosed sediment derived mainly from eroded Mesoarchaean tonalite–trondhjemite–granodiorites. It is over a kilometer thick, with various sources claiming 2.5-4 kilometers as the maximum depth. Around 800-900 mya a natural fission reactor formed. The resulting fission by-products were held in place by a clay layer.

References

Geology of Gabon {{Gabon-geo-stub

Geology

See also

References