c. 720000000 BCE–c. 635000000 BCE
Cryogenian glaciations
Climate & environment · Paleoclima · Glaciaciones · Registros geológicos
Geological records place the Sturtian and Marinoan glaciations within the Cryogenian Period, roughly 720 to 635 million years ago. The ice extent and the degree to which the planet may have been ice-covered remain under study; this entry marks a stratigraphic interval, not a uniform climatic state.
Precision, calendar, and review
- Start
- year · approximate
- End
- year · approximate
- Calendar and convention
- Historical-era years; the source calendar is not identified. No conversion of days is assumed.
- Year zero
- The scale goes from 1 BCE to 1 CE without year zero. Changing era names changes labels only.
- Documentary review
- Date not recorded
Reading the date: duration of a process.
Sources
- gcmd.earthdata.nasa.gov (opens in a new tab)
Source provenance and scope
- Publication date
- Pending verification: the source could not be accessed
- Bibliographic date checked
- 2026-09-23
The correspondence between this reference and individual claims has not yet been itemized.
This record is an editorial synthesis. Consult the sources to check claims and their limits. Chronological relationships alone do not establish causation.