# TIL

37 thoughts
last posted Jan. 23, 2018, 10:28 a.m.

8 earlier thoughts

0

Iron oxides are not only abundant, they globally occur on a geologic scale in large, layered "Banded Iron Formations"; what I was taught about these seems to still be the conventional wisdom, namely that they're a highly visible side effect left over from when the biosphere discovered photosynthesis.

28 later thoughts