The planet earth has gone through much abuse and punishment in the past. Formed approximately 4. 5 billion years ago, the earth has undergone multiple catastrophic asteroids erasing species after species. Due to geologic evidence, it is estimated over 90 percent of all life that had ever lived in this planet have been extinct. No more than the past 500 million years alone, 50-90 percent of all organisms on earth were wiped out of the geological timeline without any warning.
This little blue planet has been through bombardments of asteroids, devastating earthquakes, volcanoes that resulted in a total wipeout of entire civilizations. plate tectonics, solar flares, reversal of the magnetic fields and magnetic storms, continental drifts that literally broke apart a massive singular continent, worldwide floods, hundreds and thousands of meteorites, ice ages, cosmic radiations, and god knows what else.
Through all of this the planet still stands and in turn explains the evolution of this planet throughout the geologic timeline. Based on the system of chronological measurement based on the planet’s stratigraphy, we can determine the earth’s age through radioactive dating which is the process of using an elements half-life decay rate of meteorites that show they all have nearly the same radiometric age of 4. 56 billion years thus is can be reasonably inferred that the solar system (earth included) is about that age.
Although due to the very nature of our dynamic and continuously changing earth, the wear and tear of erosion and weathering has eliminated a lot of the original rocks that inhabited the planet making the actual age of the earth theoretical than actual fact. In the beginning, there was light. Well specifically, the sun. Formed gradually from a disc-shaped matter of debris and gas left by the formation of the sun, the earth was literally a ball of fire at first.
Completely molten due to extreme temperatures caused by friction from constant damages from space and volcanoes, the outer layers of this ball of fire eventually cooled to form a crust once water was introduced into the atmosphere. Almost 50 million years after the formation of the earth, the moon which was believed to be part of the earth before a planet-sized body collided into it, was formed. What was once a part of the earth, the moon is currently the only natural satellite encircling the planet. Its gravitational force is responsible for the production of ocean tides and in turn takes part in the geological processes of the earth.
As the earth continually cooled to the point of forming a thin crust, the water vapors eventually upgraded into massive storm clouds bringing more and more water down onto the earth until it eventually formed a sea. During the span of several hundred millions of years, the earth has gone through constant shaping and reshaping where eventually the giant supercontinent broke apart forming the continents that are currently formed today. Through fossilized evidence it can also be inferred that the earth has gone through major climate changes and through these changes we use it to define certain geological time periods in history.
During periods of warm climates, specifically during the Jurassic and Cretaceous periods, fossils of plant and animal life were left behind where the materials built up during the course of millions of years leaving us with what is now fossil fuel. Seen from the other side, during period of frigid weather where much of the earth’s surface was covered in layers of ice more popularly known as the ice ages. Proof of this is again in the fossils of woolly mammoths frozen in place perfectly preserved by the ice.
When broken down, Precambrian comprised approximately 90% of the entire geologic timeline. When dividing the Precambrian era into eons, Hadean occurred during the time the solar system was undergoing its formation. The time of Archean was when the Earth’s crust started to cool thus continental plates were starting to form. During the Proterozoic eon, it is believed that the earliest-known continent, Rodinia started to begin breaking apart and it also when the first known process of glaciation occurred. Currently, the Phanerozoic eon is the most recently known in the geologic timescale.
It spans to approximately 550 million years during which the continents have started to drift about creating what is known as Pangaea which later on split into the continents they are today. The Phanerozoic eon divides into three subsections of era in what is known as the Paleozoic, Mesozoic, and Cenozoic which is broken down again into subsections of periods and epochs. During the Paleozoic era, landmass was split up smaller continents and is the time Pangaea was formed. The Mesozoic era spanning from 250 to 65 million years ago was when Pangaea started to break up and was the time of the reptiles.
Sea creatures and evolutionary splits between dinosaurs and lizards started appearing . During the time period, the earth was warm and modern mammals and birds started to form, specifically during the cretaceous period. Subsequently, during the end of the cretaceous period, a mass extinction of approximately 90% of land and marine species were wiped out. Cenozoic was the time of the mammals, more specifically the appearance of placental type mammals. During this time period was when the formation of the Rocky’s and Himalayan mountains were formed.
Earth was now a 24 hour long day and modern mammals started to appear during the Eocene epoch. It wasn’t until around 6 million years ago that the first bi-pedal hominids started to evolve. There is no certainty with what the geological timeline would look like long after we’re gone, but through geological and biological means we can have a grasp or clue on what’s to come. Everything from the chemical reactions on the earth’s surface, the rate of cooling and heating, and the gravitational influenced our planet has with space and help determine what we can do to avoid future disasters.
Even though the human race is only a speck of dust in the timeline, we are the only species alive that are able to do anything to survive any upcoming catastrophes as futile as it may or may not be. Technological advances may give us more information on our geological history which in turn can tell us something about the present and maybe the future. Whether we make a difference or not, the planet is always resilient as evidence has proved. 4. 5 billion years and the planet still stands, it’s the people that are screwed.
