I'm sure you've all seen that banded iron tiger eye stuff from Australia:
(pic from Mindat)
Does anyone know with confidence anything about it - especially the age and formation name?
I find various info online, some of which conflicts. Some say Archean, 2.7by, some say Early Proterozoic... and is it currently accepted as Nimingarra Formation or what? Can anyone find a stratigraphic column showing where this stuff is situated? I can't. I just want the basic info about it, but from a more trustworthy source than the usual websites that get their info from who-knows-where. I know some of you are good at finding literature on sundry subjects.
I understand there are two sites in Western Australia that the stuff we find in lapidary shops/etc is likely to be from (see mindat). I don't suppose there's a way to tell which spot the piece you've got came from. If both sites are the same formation I guess it doesn't matter much.
And is it stromatolitic, or just sediments containing precipitated iron/iron oxide?