Thanks, Et'. I'd read through two of your three last weekend.
Here's the phrase that's out there on the Internet:
"The name Hadean was coined by geologist Preston Cloud for the
pre-Isuan sequence whose record may not be preserved on Earth but is better known from Moon rocks."
But I cannot find 'pre-Isuan sequence' defined anywhere.
I'm investigating the Hadean Era, the first geologic period of the Earth's existence, even though we have very few rocks from the period, most being Moon rocks and meteorites that are as old as 4.5 Ga. There's controversy in the theories about the Hadean Era--just how long the Earth was hot; whether it can be proven that the Earth went through long 'snowball' periods during the era; why we have no actual geological evidence from this first era--and whether we might have such evidence. I read one research project out of Stanford last weekend in which the molten heat of Hadean Era Earth had been questioned--the Sun's heat at that time having been cooler than it is today. Interesting study.
But nowhere can I find the term 'pre-Isuan' defined--and it's only mentioned in conjunction with Preston Cloud's having named the first era 'Hadean' (after 'Hades' or place of great heat
).
So that's that. Looks like a trip to the library today is in the offing.
