Algonkium
The Algonkian , like the Eozoic , is an outdated term for the Proterozoic , the uppermost, youngest chronostratigraphic unit of the Precambrian . It was named after the settlement area of the Algonquin Indians in North America in 1889 by Charles Walcott . In 1892 the unit was separated from the Cambrian .
The layers of the Algonkiums overlap discordant the archaic Lauren tables mountain-building , and are of the Cambrian Assyntischen Orogenese on Gondwana superimposed. At that time Gondwana was probably part of the crumbling supercontinent Rodinia and the briefly forming Pannotia .
Usable rocks of the Algonkian are granite, ores and slate. The development of life was characterized by blue-green algae, molluscs and sponges. The term Algonkische revolution is probably for the radical faunal between Ediacaran biota and the Cambrian explosion from 542 mya .