Siderian
The Siderian (IPAEng|saɪˈdɪəriən, _el. sideros, meaning "iron") is the first
geologic period in thePaleoproterozoic Era and lasted from 2500 Ma to 2300 Ma (million years ago). Instead of being based onstratigraphy , these dates are defined chronometrically.Abundance of
banded iron formation s (BIFs) peaked early this period. BIFs were formed as anaerobicalgae produced wasteoxygen that combined withiron , formingmagnetite (Fe3O4, aniron 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. This event is known as theOxygen Catastrophe .The
Huronian glaciation began in the Siderian 2400 Ma and ended in the lateRhyacian 2100 Ma.References
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Siderian — 1. adjective Of a geologic period within the Paleoproterozoic era from about 2500 to 2300 million years ago. 2. noun The Siderian period … Wiktionary
Geologic time scale — This clock representation shows some of the major units of geological time and definitive events of Earth history. The Hadean eon represents the time before fossil record of life on Earth; its upper boundary is now regarded as 4.0 Ga.[1] Other… … Wikipedia
Neoproterozoic — era 1000 542 million years ago Key events in the Neoproterozoic view • edit … Wikipedia
Mesoproterozoic — era 1600 1000 million years ago Key events in the Mesoproterozoic view • edit … Wikipedia
Cryogenian — Period 850–630 million years ago … Wikipedia
Orosirian — The Orosirian ( /ˌɒrɵˈ … Wikipedia
Huronian glaciation — The Huronian glaciation (or Makganyene glaciation) extended from 2400 Mya to 2100 Mya, during the Siderian and Rhyacian periods of the Paleoproterozoic era, triggered by the oxygen catastrophe, which oxidised the atmospheric methane (a greenhouse … Wikipedia
Geology of the North Sea — Contents 1 Tectonic structure 2 Precambrian 3 Finnmarkian, Athollian, Caledonian Orogenies … Wikipedia
Cambrian — For other uses, see Cambrian (disambiguation). Cambrian Period 542–488.3 million years ago … Wikipedia
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