Relationship To Earth's Geologic Time Scale
Since little or no geological evidence on Earth exists from the time spanned by the Pre-Nectarian period of the Moon, the Pre-Nectarian has been used as a guide by at least one notable scientific work to subdivide the unofficial terrestrial Hadean eon. In particular, it is sometimes found that the Hadean eon is subdivided into the Cryptic era and Basin Groups 1-9 (which collectively make up the Pre-Nectarian), and the Nectarian and Lower Imbrian. The first lifeforms (self replicating RNA molecules, see RNA world hypothesis) may have evolved on earth around 4 bya during this era.
| Hadean Eon | |||
|---|---|---|---|
| The Hadean doesn't have any recognizable subdivisions categorized by the International Commission on Stratigraphy. The following subdivisions represent one proposal that is loosely based on the lunar geologic time scale. | |||
| Cryptic | Basin Groups | Nectarian | Lower Imbrian |
Read more about this topic: Basin Groups
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