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 harbor life. While large volumes of water can be found throughout the Solar System, only Earth sustains liquid surface water. About 71% of Earth's surfa ...

and

Moon The Moon is Earth's only natural satellite. It is the fifth largest satellite in the Solar System and the largest and most massive relative to its parent planet, with a diameter about one-quarter that of Earth (comparable to the width of ...

. It is the oldest (informal) era of the

Hadean eon The Hadean ( ) is a geologic eon of Earth history preceding the Archean. On Earth, the Hadean began with the planet's formation about 4.54 billion years ago (although the start of the Hadean is defined as 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 Basin Groups refers to 9 subdivisions of the lunar Pre-Nectarian geologic period. It is the second era of the Hadean. Definition The motivation for creating the Basin Groups subdivisions was to place 30 pre-Nectarian impact basins into 9 relativ ...

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 referred to unofficially as the "International Stratigraphic Commission", is a daughter or major subcommittee grade scientific daughter organization that concerns itself with stratigr ...

. This time is cryptic because very little

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

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