Siderian

Common card · No. 273988

The Siderian ( ) is the first geologic period in the Paleoproterozoic Era and Proterozoic Eon. It lasted from 2500 to 2300 million years ago (Ma), spanning 200 million years, and is followed by the Rhyacian Period. Instead of being based on tectonic layers, these dates are defined chronometrically. Most continental activity in this period revolved around the breakup of the supercontinent Kenorland. While this event mainly occurred in the North American craton, volcanic intrusions and dike swarms appeared in plates pertaining to Northwestern Europe, South Africa, and Australia in connection to Kenorland's rifting. In the ocean, emissions from hydrothermal vents contributed to the production and crystallization of minerals, along with varying concentrations of sulfur and iron. While this sedimentation circulated in the ocean, the amounts deposited on the ocean floor contributed to the development of banded iron formations, along with a diverse range of ores such as pyrite and magnetite. Cyanobacteria...

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