Talk:Precambrian
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I have reverted the page to remove the comment "Because it makes up roughly seven-eights of the earth's history, reffering to it as a singular time period is misleading." From the opening paragraph. If there is a debate about whether it ought to be called a 'time period' or not, then that ought to be mentioned in the article (with opposing views, if there are any, mentioned) it has no place in the opening paragraph, which is merely a summary of what the article is about. Cheers --Monk Bretton 16:52, 15 Feb 2005 (UTC) (PS there is only on f in referring).
I understand. bad idea.vvv
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[edit] Copyvio
The section labelled Precambrian era is a cut and paste job from the Columbia Electronic Encyclopedia.[1] I'll remove it. Matt 16:27, 18 February 2006 (UTC)
- other contributions by Megaman1188
- http://www.nps.gov/blca/webvc/geo_pre.htm probably PD-usgov (yes, sitenotice says so.)
- The former link is copyrighted, but the latter is in public domain because it is a governmental source and no copyright is explicitly mentioned on the page. I'm not familiar with the Columbia Encyclopedia, but I suspect its information copied from the National Park website. Therefore the text probably didn't violated copyright. However, Wikipedia is not a public domain text dump, so considerable rewriting is needed before the text could be readded. (PS. I fixed Megaman1188's contributions link.)--Jyril 19:19, 18 February 2006 (UTC)
[edit] oldest rocks
An edit from April 26th of this year correctly cites some research on zircon crystals from 4400 million years ago. But attributing that age to existing "rock beds" (identified as a little older than 3800 Ma in the prior edit) is somewhat misleading, because the zircons are detrital -- they're grains that eroded out of pre-existing rocks. Those older rocks no longer exist, only the zircons do, so the oldest existing rock beds still only date to around 3800 Ma. I'll clarify this in the paragraph about the Hadean Eon. Cephal-odd 17:03, 26 December 2006 (UTC)
[edit] Age
It says that earth is 4.5 million years old here, however I usualy seeit as 4.5 billion years old someone please clarify and correct if needed.
- It says 4500 million years, which is the same as 4.5 billion - if there is a place "4.5 million" is used, please point it out. Thanks. Cheers Geologyguy 01:15, 3 March 2007 (UTC)
[edit] typo?
I might just be really ignorant, but in the opening paragraph there seems to be a terrible typo... the evolution of abundant macroscopic hard-shelled fossils. I didn't know that fossils could evolve ??? --DragonGuyver 04:03, 8 March 2007 (UTC)
- Fixed. Thanks. Geologyguy 04:05, 8 March 2007 (UTC)
