pohjakausi
Pohjakausi refers to the geological period of the Precambrian eon that falls after the Archean and before the Proterozoic. It is a less commonly used term compared to its divisions, the Paleoproterozoic, Mesoproterozoic, and Neoproterozoic eras. The Precambrian itself is the earliest part of Earth's history, spanning from the formation of the planet approximately 4.5 billion years ago up to the beginning of the Cambrian period, about 541 million years ago. The Precambrian is generally divided into the Hadean, Archean, and Proterozoic eons.
The term pohjakausi, if used, would encompass the significant geological events that occurred during this vast