How was the geological time scale developed?
The geological time scale has its origins in 1815, when a canal builder named William Smith noticed a relationship between layers of rock and the fossils to be found within them. At this time, fossils were thought to be either diabolical artifacts or inorganic mineral arrangements, but these fossils were the key to the advent of the geological time scale. Being a canal builder, Smith looked at rocks quite frequently. He began to associate certain fossils with certain layers. The field of geology was flourishing at the time, directing attention towards the matter. Scientists around the world began to observe the layer-fossil correlation, but it was not until the mid-19th century that Darwin’s Origin of Species was published and the theory of evolution began to gain credibility. Evolutionarily speaking, it became clear why different layers of rock contained different fossils. The fossils were organisms that lived at varying time periods. The rock layers and the time periods at which they
