System (stratigraphy)
A sequence of rock layers that were laid down in the same geological period / From Wikipedia, the free encyclopedia
A system in stratigraphy is a sequence of strata (rock layers) that were laid down together within the same corresponding geological period. The associated period is a chronological time unit, a part of the geological time scale, while the system is a unit of chronostratigraphy. Systems are unrelated to lithostratigraphy, which subdivides rock layers on their lithology. Systems are subdivisions of erathems and are themselves divided into series and stages.
More information Segments of rock (strata) in chronostratigraphy, Time spans in geochronology ...
Segments of rock (strata) in chronostratigraphy | Time spans in geochronology | Notes to geochronological units |
---|---|---|
Eonothem | Eon | 4 total, half a billion years or more |
Erathem | Era | 10 defined, several hundred million years |
System | Period | 22 defined, tens to ~one hundred million years |
Series | Epoch | 34 defined, tens of millions of years |
Stage | Age | 99 defined, millions of years |
Chronozone | Chron | subdivision of an age, not used by the ICS timescale |
Close