👉 Poseidonian is a term used in the context of the geological formation known as the Pliocene, which occurred between 3.87 and 2.5 million years ago. It refers to an early stage of the Earth's history when the planet was primarily covered by water ice, with many of its features remaining undisturbed. The term is often used in geology to describe a period of time that saw a significant increase in volcanic activity and erosion rates compared to the subsequent Ple