The Paleoproterozoic is the first of the three sub-divisions of the Proterozoic occurring between 2500 to 1600 million years ago. This is when the continents first stabilized. This is also when the atmospheric oxygen increased. Cyanobacteria were responsible for the increase.
The significant increase in atmospheric oxygen was poisonous to almost all life that existed at this time; before this time all was ananerobic, that is, the metabolism of life depended on a form of cellular respiration that did not require oxygen. The presence of large amounts of free oxygen is poisonous to most anaerobic bacteria, and at this time most life on Earth died out. The only life that survived was either life that was resistant to the oxidizing and poisonous effects of oxygen, or life that spent most or all of its life-cycle in an oxygen-free environment.
Paleoproterozoic sedimentary and volcanic rocks are currently interpreted as rift-related marine basin fill deposited unconformably on the drowned Archean platform margin.
The Flin Flon Belt (FFB) is in the juvenile internal zone of the Trans-Hudson Orogen and consists of Paleoproterozoic volcanic, plutonic and minor sedimentary rocks.
The Paleoproterozoic Lynn Lake and Rusty Lake greenstone belts occur in the interior (Reindeer) zone of the Trans-Hudson Orogen, that is, in the zone formed as new ocean floor, or in oceanic to continental volcanic arcs and related marine and continental sedimentary basins.
However, the Paleoproterozoic volcanosedimentary succession that includes the Serra do Navio Formation is widely believed to be similar in origin and laterally equivalent to the Birimian Supergroup in West Africa.
Paleoproterozoic laterites, red beds and ironstones of the Pretoria Group with reference to the history of atmospheric oxygen.
The sedimentary manganese ore bed is interbedded with iron-formation of the Hotazel Formation of the Early Paleoproterozoic Voëlwater Subgroup of the Transvaal Supergroup.
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