# Cryogenian

> second period of the Neoproterozoic Era

**Wikidata**: [Q507402](https://www.wikidata.org/wiki/Q507402)  
**Wikipedia**: [English](https://en.wikipedia.org/wiki/Cryogenian)  
**Source**: https://4ort.xyz/entity/cryogenian

## Summary

The Cryogenian is a geologic system that spans from approximately 720 million to 635 million years ago[1]. It represents a major division of the Neoproterozoic Era within the geologic time scale.This system is characterized by extreme glacial conditions, often referred to as "Snowball Earth" events, during which ice covered much of the planet[1]. The Cryogenian's boundaries are defined by global stratigraphic markers, reflecting significant climatic and environmental changes.


## References

1. [Source](https://zenodo.org/records/10659112)
2. International Chronostratigraphic Chart 2023/09
3. [Source](https://stratigraphy.org/ICSchart/CGMW_ICS_colour_codes.xlsx)
4. Freebase Data Dumps. 2013
5. BabelNet
6. KBpedia