Primeval 5 – Proterozoic Eon

 

Approximately 2.3 billion years ago things changed on the Earth, when cyanobacteria began producing oxygen on a massive scale(1)D. T. Flannery and R.M. Walter (2012) “Archean tufted microbial mats and the Great Oxidation Event: new insights into an ancient problem” Australian Journal of Earth Sciences, Volume 59, Number 1, Pages 1–11 causing the Great Oxidization, also known as the Oxygen Catastrophe. The atmosphere was changed from the former Archean atmosphere rich in methane, into the Proterozoic atmosphere similar to our current atmosphere and rich in oxygen. This new atmosphere did not have the ability to trap heat the way the earlier atmosphere did, and the Earth cooled into an ice age that is believed to have lasted 300 million years, generally regarded as the longest period of glaciation in the existence of the Earth. This early glaciation marked the beginning of the Proterozoic Eon, which lasted until the current Phanerozoic Eon began 542 million years ago. The oldest fossils of multi-cellular life date to the early Proterozoic Eon,(2)Abderrazak El Albani et al. (2014) “The 2.1 Ga Old Francevillian Biota: Biogenicity, Taphonomy and Biodiversity” Public Library of Science ONE, Volume 9, Number 6, Page e99438 and could have been involved in the Great Oxidization as they do date to the Huronian Glaciation.

franconville-biota

Francevillian Lifeform

It is possible the Great Oxidization was caused by an intelligent visiting species, although it is not required to explain the event; panspermia or evolution could equally explain the Great Oxidization. The rapid emergence of large multi-cellular lifeforms in the new biosphere is more difficult to explain, as they appear during the Huronian glaciation. By 2.1 billion years ago the Francevillian biota, large flatend disks with spherical central masses of up to 12 cm (4.7 inches) were living on our frozen world, presumably under the ice-sheets. These creatures do not appear to be related to later crustaceans (trilobites), or reef building creatures (archaeocyathids). It is plausible that these creatures could have been seeded in the Earth’s oceans to serve as a food source for an alien civilization. If so then this civilization likely caused the destruction of the Archean biosphere, and the Huronian Glaciation in order to farm the Earth.

The Proterozoic Eon was an Age of Ice, as it saw the worse the Ice-Ages the world have ever known. In addition to the 300 million long Huronian Glaciation, there was the 60 million year long Sturtian glaciation, and the 15 million year long Marinoan glaciation. During the Marinoan glaciation it is believed that the entire planet could have been frozen all the way to the equator due to the fact that all the continental mass comprised the super-continent Rodinia which was located in the equatorial region. This period is known as Snowball Earth.(3)J. L. Kirschvink (1992) “Late Proterozoic low-latitude global glaciation: The snowball Earth” in J. W. Schopf and C. Klein The Proterozoic Biosphere: A Multidisciplinary Study Pages 51–52

References   [ + ]

1. D. T. Flannery and R.M. Walter (2012) “Archean tufted microbial mats and the Great Oxidation Event: new insights into an ancient problem” Australian Journal of Earth Sciences, Volume 59, Number 1, Pages 1–11
2. Abderrazak El Albani et al. (2014) “The 2.1 Ga Old Francevillian Biota: Biogenicity, Taphonomy and Biodiversity” Public Library of Science ONE, Volume 9, Number 6, Page e99438
3. J. L. Kirschvink (1992) “Late Proterozoic low-latitude global glaciation: The snowball Earth” in J. W. Schopf and C. Klein The Proterozoic Biosphere: A Multidisciplinary Study Pages 51–52