I can't find the pre-Isuan sequence defined anywhere. Have googled--three hits, but no explanation other than what I already knew: the sequence is part of the Hadean Era.

Have checked Onelook.com. Neither pre-Isuan nor Isuan is defined.

Checked Brittanica online. Nada.

Does this mean I'm going to have to go to a 3D library and actually find something in a book? Aggggghhhhhh! I'm being facetious--I love libraries.

Anyway, if anybody knows what the sequence is exactly--what occurred during the sequence specifically, many thanks.