Eridanos (geology)

The name Eridanos, derived from the ancient Greek Eridanos, was given by geologists to a river that flowed where the Baltic Sea is now. Its river system is also known as the "Baltic River System".

The Eridanos began about 40 million years ago in the Eocene. By about 12 million years ago in the Miocene, the Eridanos had reached the North Sea area, where sediments carried by the river built an immense delta. The Eridanos disappeared in the early Middle Pleistocene, about 1 million years ago, when the Ice Age glaciers excavated the Baltic Sea bed.

The Neogene uplift of the South Swedish Dome deflected Eridanos river from its original path across south-central Sweden into a course south of Sweden in the Pliocene.