The Cryptic era is an informal term for the earliest geologic evolution of the

Earth Earth is the third planet from the Sun and the only astronomical object known to Planetary habitability, harbor life. This is enabled by Earth being an ocean world, the only one in the Solar System sustaining liquid surface water. Almost all ...

and

Moon The Moon is Earth's only natural satellite. It Orbit of the Moon, orbits around Earth at Lunar distance, an average distance of (; about 30 times Earth diameter, Earth's diameter). The Moon rotation, rotates, with a rotation period (lunar ...

. It is the oldest (informal) era of the

Hadean eon The Hadean ( ) is the first and oldest of the four geologic eons of Earth's history, starting with the planet's formation about 4.6 billion years ago (estimated 4567.30 ± 0.16 million years ago set by the age of the oldest solid material ...

, and it is commonly accepted to have begun close to about 4.533 billion years ago when the Earth and Moon formed, and lasted to about 4.15 billion years ago. No samples exist to date the transition between the Cryptic era and the following Basin Groups era for the Moon (see also

Pre-Nectarian The pre-Nectarian period of the lunar geologic timescale runs from 4.533 billion years ago (the time of the initial formation of the Moon) to 3.920 billion years ago, when the Nectaris Basin was formed by a large impact. It is followed by the Necta ...

), though sometimes it is stated that this era ended 4150 million years ago for one or both of these bodies.Harland, Walter Brian '', et al.'' (1989) ''A Geologic Time Scale 1989'' Cambridge University Press, Cambridge, UK, Fig. 1.7 on page 10
/ref> Neither this time period, nor any other Hadean subdivision, has been officially recognized by the

International Commission on Stratigraphy The International Commission on Stratigraphy (ICS), sometimes unofficially referred to as the International Stratigraphic Commission, is a daughter or major subcommittee grade scientific organization that concerns itself with stratigraphy, strati ...

. This time is cryptic because very little

geological Geology (). is a branch of natural science concerned with the Earth and other astronomical objects, the rocks of which they are composed, and the processes by which they change over time. Modern geology significantly overlaps all other Earth s ...

evidence has survived from this time. Most geological landforms and rocks were probably destroyed in the early bombardment phase, or by the continued effects of plate tectonics. The Earth accreted, its interior differentiated and its molten surface solidified during the Cryptic era. The proposed collision that led to the formation of the

occurred also at this time. The oldest known minerals are from the Cryptic era.

References

External links

"Cryptic" Geowhen Database
*01 Geologic time scales of Earth Lunar geologic periods {{geochronology-stub

See also

References

External links