Wednesday, July 12, 2006

Cambrian Complaining part 2

Just a brief note to link an illustration of exactly how variable the age correlations for the Cambrian have been over the past 80 years.
http://earth-time.org/evolving_timescale.gif

3 comments:

yami mcmoots said...

Nice! If only it crammed on the details of when the ages changed, vs. when they picked new fossil-appearances to define the eras...

Remotely Mars said...

Interesting. I had no idea these dates were so fluid through time.... I now resent our sed/strat guy making us memorize dates even more!

Lab Lemming said...

If you're really curious, check out the papers. I suspect that the main problem is correlating the strata. The Neoproterozoic is notorious for not having any ash layers where you need them; I suspect the same was true of the Cambrian for a while. On the other hand, the Cryogenean confusion is what keeps my paychecks coming; if it was easy, I wouldn't be able to keep getting paid for shovelling zircons into the mass spectrometers.