Archean meteorite impact evidence from the Fig Tree Group in Barite Valley, Barberton Greenstone Belt, South Africa - Mountain Beltway - AGU Blogosphere
http://blogs.agu.org/mountainbeltway/2016/10/26/archean-meteorite-impacts-in-barberton/
During the Archean eon of geologic time, the Earth was young, and had characteristics that were both similar to what we find in the modern planet,
and also seemed to have some striking differences. Examples of the former: gravity, oceans, and metamorphism. Examples of the latter: a different
atmospheric mix of gases, an absence of plate tectonics, and a much hotter internal temperature (of which the komatiites are one signature).
Something else that was apparently quite different was regular bombardment by large extraterrrestrial impactors – the early, messy solar system was
still in the process of cleaning itself up by gravitationally merging previously isolated bodies. Large meteorite impacts would of course create
a crater at the site of the impact, but continual resurfacing on the planet due to the rock cycle makes it less likely to preserve their large region-
scale forms. We’ll have better luck if we consider the sedimentary record of those impacts. What sedimentary signatures would a really big impact have
on its neighboring or more distant regions?
