What is "paleoarchean"

The Paleoarchean (; also spelled Palaeoarchaean (formerly known as ' early Archean')) is a geologic era within the Archaean. It spans the period of time —the era being defined chronometrically and not referenced to a specific level in a rock section on Earth. The name derives from Greek "Palaios" ancient. The oldest ascertained life form ( fossilized bacteria in microbial mats, old, found in Western Australia) is from this era. The first supercontinent Vaalbara formed during this period.

During this era, a large asteroid, about wide, collided with the Earth about 3.26 billion years ago, creating the features known as the Barberton greenstone belt.