from The American Heritage® Dictionary of the English Language, 4th Edition
- adj. Variant of Archean.
from Wiktionary, Creative Commons Attribution/Share-Alike License
- adj. of, or relating to the geologic eon from about 3,800 to 2,500 million years ago; comprises the Eoarchean, Paleoarchean, Mesoarchean and Neoarchean eras; marked by an atmosphere with little oxygen, the formation of the first continents and oceans and the emergence of simple life
- proper n. the Archaean eon.
Sorry, no etymologies found.
The area coloured terra cotta surrounding Hudson Bay like a great horse-shoe is known as the Archaean Protaxis, composed of preCambrian rocks, the ancient back bone of the continent.
This rocky highland stretches from a little north of the St. Lawrence River to Hudson Bay, around which it laps in the form of a V, and so is known as the Archaean V or shield.
He states that what is known as the Archaean protaxis, or that rugged, rocky region which stretches away from the St. Lawrence River, expanding to the northwestward, and occupying a large part of Northern Ontario, has produced and is constantly producing, a group of what may be called unique, or at least comparatively rare, economic minerals.
Stromatolite reef from the Early Archaean era of Australia.
The oldest rocks of Victoria Land are apparently banded gneiss and gneissic granite, which may be taken as Archaean.
As regards Kaiser Wilhelm Land, the Gaussberg is a volcanic cone mainly composed of leucite-basalt, but its slopes are strewn with erratics presumably transported from the south and these include gneiss, mica-schist and quartzite, apparently Archaean.
In the Graham Land region there seems to be a fundamental rock closely resembling the Archaean.
The mounds in the foreground are stromatolites, colonies of photosynthetic bacteria which have been found as fossils in Early Archaean rocks of South Africa and Western Australia.
Stromatolites increased in abundance throughout the Archaean, but began to decline during the Proterozoic.
If you were able to travel back to visit the Earth during the Archaean, you would likely not recognize it is the same planet we inhabit today.
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