History of Earth - Proterozoic Eon (PaleoProterozoic Era)

		PROTEROZOIC
		THE PROTEROZOIC EON (PaleoProterozoic Era) 2.5 to 1.6 Billion Years Ago
		The Long Age of Planetary Maturation The Earth 'comes of age' - the oxygen atmosphere forms.
Then God said, ". . . I give every green plant for food." - Genesis 1:29-30
Archean				Meso- Proterozoic
\|-----------------\| Paleo-Geography
Continents stabilize; begin to consolidate Oxygen atmosphere forms Metals 'rust' out of the oceans; oceans turn blue. 'Banded Iron' rock formations created as free oxygen oxidizes the metal on the surface and in oceans. All land is barren, lifeless desert
Life
"Oxygen Catastrophe" - Earth's first extinction event Oxygen-intolerant archean microbes wiped out or driven into hiding Green cyanobacteria stromatolites (below) thrive and dominate in coastal waters. Their relentless photosynthesis pumps more and more oxygen into air.
			Cyanobacterial stromatollites in the Early Proterozoic (Source: K.M. Towe, NASA)
	Green cyanobacteria took almost a blllion years to create our oxygen atmosphere. (Source: M. Clayton, Univ. WI, Madison)
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SOURCES: University of California Museum of Paleontology - Tour of Geologic Time Wikipedia - Geologic Time Scale Palaeos - Geological Time IInternational Commission on Stratigraphy By Corey Zak - CORZAK INTERACTIVE

THE PROTEROZOIC EON (PaleoProterozoic Era)
2.5 to 1.6 Billion Years Ago