The geologic era is a unit of time in Earth’s history, defined by important geomorphological events that took place during a specific period of time. This time cycle is a predecessor of the Archaic Era.
Each era is characterized by different types of rocks, fossils and eventsbeing an effective way of dividing the existence of the planet into more manageable units for its study and understanding.
Definition and meaning of the geological age
The Earth’s history is divided into several eras, each of which is characterized by unique geomorphological and biological events that took place in that time period. These eras are defined by significant changes in the geological structure, climate, ocean patterns, life, and ecosystems on the planet.
Geological eras represent an effective way of categorize and understand the evolution of the world and its history, and allows us to see how geotechnical and biological forces have shaped our planet and its ecosystem over time.
What are the characteristics of the geological age of the earth?
each era has specific features that distinguish it from others. These are defined by changes in events that took place during that particular period. Some of the important features of geologic eras include:
- The types of rocks and minerals that were formed during that era.
- tectonic events, such as the formation of mountains or the opening and closing of oceans.
- The evolution and diversification of species, including the emergence of new life forms and mass extinctions.
- Changes in Earth’s climate and environment, such as glaciation or desertification.
These characteristics can be studied and analyzed by geologists, paleontologists and other scientists. Questions like “What are the eras that the Earth has?”, “How do these stages end?”, “How many eras are there?” Geographers have already been able to answer them, managing to better understand the history of the Earth and its evolution over time.
How are the geologic ages divided?
These are categorized into smaller modules called periods, which, in turn, are separated into even smaller units known as ‘epochs’. Each is characterized by unique geological events.
For example, the Paleozoic era is divided into six phases: the Cambrian, the Ordovician, the Silurian, the Devonian, the Carboniferous and the Permian. Each of these periods is characterized by different events, such as the Cambrian explosion, the formation of Pangea in the Permian, and the mass extinctions in the Ordovician and Permian.
Similarly, the Mesozoic era is divided into three periods: the Triassic, the Jurassic and the Cretaceous. Each of which is characterized by the evolution and diversification of dinosaurs, the appearance of the first mammals and flowering plants. Plus, of course, a meteorite that wiped out the dinosaurs and many other species.
Finally, the Cenozoic era split into two periods: the Tertiary and the Quaternary, the Tertiary, in turn, is divided into five epochs: the Paleocene, the Eocene, the Oligocene, the Miocene and the Pliocene. During this era, the evolution and diversification of mammals took place, including the appearance of the first primates and hominids, and great changes in the Earth’s climate and geography.
What are the types of geological eras?
By containing so much information about the history of the planet, These are divided into three categories, and together they form the Phanerozoic eon, a geological time scale. Next we explain the division of the geological era:
- Paleozoic: This era covers a period of time extending since a few 541 M years to about 252 M years. During the Paleozoic era, the evolution and diversification of life occurred. In addition, the first multicellular, invertebrate, and vertebrate organisms arose. Continents also formed and mass annihilations occurred, including the Permian-Triassic mass extinction, which wiped out around 95% of marine species.
- Mesozoic: This geological era covers a period of time that extends from about 252 M years ago to about 66 M years ago. During the Mesozoic era, Occurred the evolution and diversification of dinosaurs and other reptiles, as well as the appearance of flowering plants and the first mammals. There was also a great mass extinction at the end of the era, wiping out the dinosaurs and many other species.
- Cenozoic: This geological era covers a period of time extending since a few 66 million years to the present. During the Cenozoic era, the evolution and diversification of mammals took place, including the appearance of the first primates, hominids, and human life, as well as the development of modern life as we know it today. There were also great changes in the Earth’s climate and geography, including the formation of the Alps and the Andesand the glaciation of the poles.
What is the Mesozoic geological era?
Also known as the ‘Age of Dinosaurs’, it was a era that began 252 million years ago and ended 66 M years ago. It is divided into three periods: Triassic, Jurassic and Cretaceous.
During the Mesozoic era, there were significant changes in geological structure of the Earth, including the formation of the Andes mountain range and the separation of the continents that formed the Atlantic and Indian oceans. The Earth’s climate was hot and humid, the polar areas were not covered by ice.
The Mesozoic era was also a time of great diversification and evolution of life, especially the dinosaurs, which dominated the Earth for most of this era. Also the first mammals appearedalthough they were small and nocturnal, and flowering plants.
The end of the Mesozoic era was marked with a mass extinction which wiped out the dinosaurs, as well as many other species. This is believed to have been caused by an asteroid or comet impact on Mexico’s Yucatan Peninsula, causing the disappearance of around 75% of Earth’s species.
How do geological ages end?
Processes that occur over a long period of time culminate in the end of the ages, rather than ending them suddenly. However, there are certain events that mark the end of an era and the beginning of another.
One of the most important events that mark the end of an era is a mass extinction. During the history of the planet, there have been several that have caused the disappearance of a large number of species and have altered the Earth’s ecosystems.
For example, the mass extinction that occurred at the end of the Cretaceous period, about 66 million years ago, marked the end of the Mesozoic era and the beginning of the Cenozoic era. This mass extinction is believed to have been caused by an asteroid or comet impact, and resulted in the demise of the dinosaurs and many other species.
Another event that marks the end of a geological era is a change in plate tectonics. Their movements cause the formation of new mountain ranges, the opening or closing of oceans and the separation or union of continents.
These changes have a significant impact on weather patterns and in Earth’s ecosystems, they can mark the end of one geological era and the beginning of another.