|WikiProject Geology||(Rated Start-class, High-importance)|
The Proterozoic Era was definitely from 2.5 billion years ago to 600 mya. There was an oxygen build-up on Earth and there were the first multi-cellular life forms on our planet.
I completley agree too!!!
I made some changes in keeping with accepted stratigraphic nomenclature. I also reworded the third paragraph (for the better, I hope), added a blurb on the Cyrogenian and Ediacaran Periods and added some links. I am teaching a course in Historical Geology this semester (first time in 15 years) and am finding Wikipedia very useful in filling in all of the picky little facts that I need for my lectures but have long since forgotten! Jay Gregg
Oxygen Atmosphere When?
From the article: "The transition to an oxygenated atmosphere during the Mesoproterozoic."
The Build-up of Oxygen
"most accumulation ceased after 1.9 billion years ago, either due to an increase in oxygen or a more thorough mixing of the oceanic water column.(Stanley 324)" right, accumulation stoped at 1.9 Gyr and the second part of the sentence is fine but how an increase in Oxygen can stop accumulation ? - phe 10:09, 14 January 2008 (UTC)
- hmm,I guess it's an increase of oxygen in see water ? - phe 10:16, 14 January 2008 (UTC)
- What that section means is that BIF probably stopped accumulating because all the unoxidized iron that could react, did; for instance, if you added a great excess of acetic acid (vinegar) to calcium bicarbonate (baking soda), once the soda fully reacted with the necessary amount of acid to form sodium acetate, you'd eventually just end up with a whole of unreacted acid carrying a tiny bit of sodium acetate in solution. Same deal here; an excess of oxygen would eventually "use up" the iron so it was "free" to accumulate without getting bound up in iron oxide.Erimus (talk) 05:24, 18 January 2008 (UTC)
- I understand chemical sink but I'd trouble to get a consistent figure between this section and Oxygen Catastrophe which show an increase around 1.85 Ga then accumulation stopped in atmosphere, so new chemical sink was available which replaced BIF. That's unclear from the section in this article. - phe 09:19, 18 January 2008 (UTC)
In the references, #7 is an LPSC abstract about the Tharsis rise on Mars. I assume there is a typo in the link. Can someone please fix the reference? Proterovenus (talk) 20:24, 18 April 2010 (UTC)proterovenus