The Precambrian began with the formation of planet Earth and lasted until about 570 million years ago.
The first thing we are going to do is determine the etymological origin of the term Precambrian . In this sense, we can say that it is the result of the addition of the Latin prefix “pre-”, which means “before”, and Cambrian, which derives from the Latin word “Cambria”, which refers to the original natives of what today it would be Wales.
The Precambrian is one of the periods on the geology time scale. This is the first stage in the history of the planet, which begins with the formation of the Earth and extends about 570 million years ago. When it appears written with a lower case letter, the term refers to what is linked to said period.
During the Precambrian , primary life forms began to emerge. This period lasted between 4,000 and 5,000 million years, until the Cambrian began. Due to the age, the low amount of fossils found and the orogenic modifications, it is very difficult to develop studies on these years.
Precambrian Division
The Precambrian is considered to be divided, in turn, into three periods:
-Hadic Eon, phase that took place in the period between 4,500 and 3,800 million years. In it, a great meteorite bombardment occurred and the Earth, the Moon and the lithosphere were formed.
-Archaic Eon, covers the phase between 3,800 and 2,500 million years. The first continents emerged and plate tectonics began.
-Proterozoic Eon, dated between 2,500 and 540 million years ago. In this phase the first continents give shape to Pangea I, the first eukaryotic cells appear and the Ozone Layer is formed.
It is estimated that the Moon developed during the Precambrian.
Main events of the period
Among the most notable events that occurred in the Precambrian are the appearance of Ediacaran organisms and the first sponges , the division of the supercontinent known as Rodinia , the emergence of Columbia , the oxygenation of the atmosphere and even the development of our satellite. natural (the Moon ) through the collision between the Earth and a planet called Theia .
In addition to everything stated above, we cannot ignore other important events that are considered to have taken place at the stage in question:
-The hydrosphere was formed as well as the atmosphere itself.
-The first continental nuclei emerged, which were called cratons.
-It hosted a great glaciation.
-There were glacial periods that alternated with others of a desert nature, let's put it that way.
-This period is significant due to the fact that it currently occupies 88% of Earth's History.
Other characteristics of the Precambrian
The Precambrian was a period of great geological modifications. Experts have determined that volcanic activity sent carbon dioxide and water vapor into the proto-atmosphere , causing temperatures to drop. From then on, the rocks began to solidify. Water vapor was also key to the development of the oceans.
With the oxygenation of the atmosphere in the Precambrian , on the other hand, the ozone layer was formed about 1.8 billion years ago, protecting living organisms from the sun's ultraviolet rays.