General, Research, Technology

A brief excursion: how do scientists understand the eras of the planet?

Cenozoic, Mesozoic, Paleozoic ...As soon as scientists themselves are not confused in the eras of our planet? Over its 4.6 billion years of existence, the Earth has gone through a huge number of changes, particles of which are preserved in the ancient layers of the earth's surface. In order to classify the time periods of the history of our planet, experts have developed a special system that divides geological time into several units, each of which is characterized by its unique flora and fauna, climate and other important characteristics, reports In order to make it easier for you to understand the nuances of the main periods of the history of the Earth, Hi-News has prepared for you a short excursion on the chronology of the planet.

Our Earth has already survived 5 different eras, each of which completely mutated the planet

What is the difference between Cenozoic and Mesozoic?

Fossils are considered the most convenient toolto study the geological period of the planet for several reasons. Due to the fact that life was probably on the planet about 90% of earthly existence, the history of the Earth is parallel to the history of living organisms. In addition, fossils are also useful in analyzing environmental changes, which, like nothing else, reflect the main events in the history of the planet.

One of the important moments in the history of the Earth wasthe transition from the Mesozoic era to the Cenozoic about 65 million years ago. The most significant event of this period was the fall of a giant asteroid, which ultimately killed the dinosaurs that reigned for many millions of years. The consequences of just one day seriously affected the evolution of life on the planet, opening up the possibilities for the onset of a new era - the Holocene, which became a real golden age for mammals and flowering plants.

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In order to estimate the difference between the Mesozoic andCenozoic, scientists most often use a special layer of rock for analysis, helping researchers estimate its age. Thus, the unusually high levels of iridium present in the earth's crust during the Mesozoic era most often indicate the period that separated the Mesozoic from the Cenozoic.

The last dinosaurs of the planet died in the last period of the Mesozoic era

Recent advances in geochronology, orrock dating, allow geologists to measure radioactive decay and with high probability to calculate the exact ages of geological events. In order to accurately calculate the age of rocks, scientists have to compare the proportions of certain isotopes that can tell about the era in which they formed.

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So, the analysis of isotopes can tell that duringIn the early periods of the Archean era, the planet was actively formed in the form in which we know it: a dense atmosphere full of carbon dioxide hung over the Earth, and while the lifeless oceans kept separate pools on the surface of the young planet. A few million years after the rapid evolution, when a solid core had already formed on the Earth, the first microorganisms began to appear on the third planet, gradually filling the atmosphere with oxygen. It is precisely the remains of ancient bacteria that were first discovered in Australian fossils that speak of the turbulent youth of our planet.

After the end of the Archean era, it was replaced bycalled pterose, marked by the appearance of the first multicellular organisms with a nucleus and capable of sexual reproduction. The third geological era of the Earth became the Paleozoic, whose unique warm climate contributed to the growth of giant ferns and horsetails, the remains of which we still use as fuel - for example, in the form of fossil coal.

Paleozoic - one of the most turbulent eras in the history of the Earth

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Despite the fact that the most active period forlife’s development passed about 250 million years ago, our Cenozoic era can also be unique in its own way, and this time thanks to man. Thus, many scientists argue that the active influence of man on the planet deserves the proclamation of a new era - the anthropocene, which the whole scientific world does not agree with the wording. According to some scholars, capitalocenosis can more accurately convey those social systems that have had a huge impact on the planet since the industrial revolution.