Through research on rocks and fossils, scientists estimate that the Earth has approximately 4 billion of years, during this entire period it went through great transformations, a process classified as eras geological. The different geological eras correspond to large intervals of time, divided into periods. The alternation of geological eras was established through significant changes in the earth's crust, being, therefore, classified into five distinct geological eras: Archeozoic, Proterozoic, Paleozoic, Mesozoic and Cenozoic.
Archeozoic
The Archeozoic geological era is characterized by the formation of the earth's crust, in which crystalline shields and magmatic rocks appeared, in which we find the oldest relief formations. This period began approximately 4 billion years ago.
Proterozoic
It is estimated that this geological era began about 2.5 billion years ago and ended 550 million years ago. During this period there was intense volcanic activity, a fact that promoted the displacement of magma from the interior of the Earth to the surface, giving rise to large deposits of metallic minerals, such as iron, manganese, gold, etc. In the geological era of the Proterozoic there was a great accumulation of oxygen in the atmosphere. It was also characterized by the emergence of the first advanced single-celled life forms.
Paleozoic
The Paleozoic era prevailed from 550 to 250 million years ago. During this period, the earth's surface underwent major transformations, including the emergence of mountainous areas such as the Scandinavian Alps (Europe). This geological era is also characterized by the occurrence of sedimentary and metamorphic rocks, the formation of large forests, glaciations, the appearance of the first insects and reptiles.
Dinosaurs emerged in the Mesozoic era
Mesozoic
The Mesozoic era began about 250 million years ago, it was marked by intense volcanism and consequent lava flow in various parts of the globe. It was also characterized by the sedimentation process of the seabed, which originated a large part of the oil deposits known today. Other features of this geological era are: division of the great continent of Pangea, emergence of large reptiles, such as the dinosaur, emergence of mammalian animals, development of flowers in plants.
Cenozoic
This geological age is divided into two periods: Tertiary (approximately 60 million years ago) and Quaternary (1 million years ago).
- Tertiary: Characterized by the intense movement of the Earth's crust, a fact that gave rise to modern folding, with the highest mountain ranges on Earth, such as the Andes (South America), the Alps (Europe) and the Himalayas (Asia). In this geological era, birds, several species of mammals, as well as primates arose.
- Quaternary: Geological era that began about 1 million years ago and continues to the present day. The main occurrences in this period were: great glaciations; current formation of continents and oceans; emergence of man.
By Wagner de Cerqueira and Francisco
Graduated in Geography
Source: Brazil School - https://brasilescola.uol.com.br/geografia/eras-geologicas.htm
