Siderian
From Palaeos
| Proterozoic eon 2,500-542 | |||||||||
|---|---|---|---|---|---|---|---|---|---|
| Paleoproterozoic era 2,500-1,600 | Mesoproterozoic era 1,600-1,000 | Neoproterozoic era 1,000-542 | |||||||
| Siderian 2,500-2,300 | Rhyacian 2,300-2,050 | Orosirian 2,050-1,800 | Statherian 1,800-1,600 | Calymmian 1,600-1,400 | Ectasian 1,400-1,200 | Stenian 1,200-1,000 | Tonian 1,000-850 | Cryogenian 850-630 | Ediacaran 630-542 |
The Siderian Period of the Paleoproterozoic Era:
2,500 to 2,300 Mya
Ingress here
The Siderian (from Greek sideros, "iron") is the first geologic period in the Paleoproterozoic Era and lasted from 2500 Ma to 2300 Ma (million years ago). Instead of being based on stratigraphy, these dates are defined chronometrically.
Abundance of banded iron formations (BIFs) peaked early this period. BIFs were formed as anaerobic algae produced waste oxygen that combined with iron, forming magnetite (Fe3O4, an iron oxide). This process cleared iron from the oceans, presumably turning greenish seas clear. Eventually, without an oxygen sink in the oceans, the process created the oxygen-rich atmosphere of today.
Huronian glaciation began in the Siderian 2400 Ma and ended in the late Rhyacian 2100 Ma.
