The Eurasian Plate is one of the largest tectonic plates on Earth, and its age varies across different regions. The oldest parts of the Eurasian Plate are estimated to be around 2.5 to 3 billion years old. These ancient regions are primarily found in the Baltic Shield and the Siberian Craton.
The plate itself is a combination of several smaller plates that have merged over billions of years. The process of plate tectonics has continuously shaped and reshaped the Eurasian Plate, leading to the formation of mountain ranges, basins, and other geological features.
In summary, while the Eurasian Plate as a whole is not of a uniform age, its oldest components date back to the Archean Eon, making them some of the oldest geological formations on our planet.