How Was the Geological Time Scale Developed?
The geological time scale’s development dates back to 1815. The connection between the fossils and the rock was estimated by a builder, William Smith. He noticed that the fossils were not only some kind of material and minerals, but had some connection with the rocks. This triggered the beginning of the development of the Geological Time Scale. The beginning of the geological scale’s development started when geology was being introduced in the world as another form of logical science.
William Smith started noticing the fossils and observing them carefully. He saw that the fossils have their connection with the layers of the soil. The correlation between the two started being observed by many scientists of those times. The book called ‘Origin of the species’ by Charles Darwin led the scientist believe more in the relationship between the fossils and the rock.
It was then that everyone found out that the rocks were also made up of fossils. It was also discovered that the fossils were once a form of life and were not mere materials and leftover minerals. The rocks that were formed in different time periods were given separate names and the different layers of soil were given their names and were classified separately. All this happened around the middle of nineteenth century and was then called the geological time scale.
This classification of the rocks and the soil layers was based on varying time periods and eras. The geological time scale says that the very first era hadn’t had any fossils. This era was called Precambrian and marks the very beginning. The second era is called Paleozoic era. This is the beginning of the ancient times. Then came the Mesozoic era called the middle era or the middle life. After this came the modern era or the modern life, called the Cenozoic.
These eras are further divided in to sub eras. They were named after the places where the fossils were found. For instance, Permian era was named after Russia’s Permian Kingdom and after Devonshire in England; Devonian Period was given its name. Every name given to each era has some history attached to it. The names given to them were not mere fancy sounding or highly complicated names but their history denotes the relevance of their names.
Cretaceous period is another sub era which was named so because it was discovered in England where chalk cliffs existed. The word from where this name has been borrowed is Creta, meaning chalk. The Pleistocene Epoch of the Cenozoic Era means most recent as its name has been derived from the Greek names for these two words. In this era most of species can still be found in flesh and bones. The Eocene epoch that comes before the Pleistocene Epoch has only a maximum of 5 percent species still alive. This denotes how recent the Pleistocene era is.
Books like ‘Theory of the Earth’ by James Hutton helped a lot in the discovery of the geological time scale. The principle of Uniformitarianism was hinted in this book which was later excelled by Sir Charles Lyell, a British geologist. These people hence are also big contributors towards the discovery of the time scale apart from Charles Darwin, through his book and William Smith through his observation.
The technology of radioactive dating, scientist can now estimate the age of a fossil almost absolutely accurately. In this process, the geological time scale gives a big contribution. The epoch and eras help in indicating the exact fossil age. This helps in knowing other major developments is specific eras and the life then.