I'm a geochemist. My main interest is in-situ mass spectrometry, but I have a soft spot in my heart for thermodynamics, poetry, drillers, trees, bicycles, and cosmochemistry.
Tuesday, May 05, 2009
Geochronological goofiness
Why does the Eoarchean come before the Paleoarchean, when the Eocene comes after the Paleocene?
It's a confusion of vowels in prefixes: Eo(s)=dawn, Pal, Pale, Paleo= ancient or old. Eoarchean=dawn of the Archean, which is older than Paleoarchean= "old" archean. Eocene=dawn of the recent (time or life), which is younger than Paleocene= "old(er)" dawn of the recent. The fact that "eo" constitutes the first two letters of eos and the last two letters of paleo creates ambiguity of just what the prefixes are and what they are modifying. Shorter version: there is no "dawn" in Paleoarchean, even though it looks like there is.
And because I can't leave well enough alone- especially when I can say someting silly- I would point out that if you wanted to name a period of time between the end of the Hadean and Eoarchean, you might call it the Paleoeoarchean: the ancient dawn of the Archean. A bit before that might be the Eopaleoeoarchean. And so on, ad inifinitum. E-I-E-I-O! ; )
It's a confusion of vowels in prefixes: Eo(s)=dawn, Pal, Pale, Paleo= ancient or old. Eoarchean=dawn of the Archean, which is older than Paleoarchean= "old" archean. Eocene=dawn of the recent (time or life), which is younger than Paleocene= "old(er)" dawn of the recent. The fact that "eo" constitutes the first two letters of eos and the last two letters of paleo creates ambiguity of just what the prefixes are and what they are modifying. Shorter version: there is no "dawn" in Paleoarchean, even though it looks like there is.
ReplyDeleteAnd because I can't leave well enough alone- especially when I can say someting silly- I would point out that if you wanted to name a period of time between the end of the Hadean and Eoarchean, you might call it the Paleoeoarchean: the ancient dawn of the Archean. A bit before that might be the Eopaleoeoarchean. And so on, ad inifinitum. E-I-E-I-O! ; )
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