Eridanos (geology)

The Eridanus (also Eridanus ) is a hypothetical river that originated in what is now the Baltic Sea in the Middle Eocene, about 40 million years ago. The river disappeared during the Pleistocene.

Origin of the name

The name comes from the river Eridanus back in Greek mythology. As a " hypothetical flow" of Eridanus is referred to as geological findings ( eg sediments, which indicate deposition in a delta ) suggest the existence of such a river, direct detection (eg, an erosion valley ) but is not present.

In the Eocene

The Eridanus dewatered in the Eocene areas of the subcontinent, the parts of the present-day Scandinavia and Russia comprised approximately to the Urals. In this sub-continent grew up during a period of 10 to 20 million years of so-called " amber forest " which offered the resin for the Baltic amber. To the south of this area there was a marginal sea of ​​the Atlantic Ocean. During the Priabonium ( in the Upper Eocene ) of this flow resulted in an extended, at least 115 km wide delta ( Chłapowo Sambia - delta ) approximately in the area where today is located the Gulf of Gdansk (Baltic Sea). From the sediments that was deposited in the Eridanus its delta, was among other things the so-called Blue Earth, in which is by far the largest part of the occurrence of Baltic amber. However, it will also be argued that the amber deposits are to be explained in this area primarily by Meerestransgression and not or only to a small extent by river transport.

In the Pleistocene

In the Lower Pleistocene, about 2 million years ago, the river reaches a length of about 2,700 kilometers, was so similar in length to the present Danube. He sprang in Lapland, flowed through the territory of present-day Gulf of Bothnia, on through the area in which extends the Baltic Sea today, to Western Europe, where it resulted in a delta, its size is compared with those of today the Amazon or the Mississippi River. Sediment discoveries in the Netherlands and studies on sediments from the underground of the North Sea helped to reconstruct the main tributaries of the Eridanus, and brought the finding that the flow at the latest during the Cromer complex dried up ( Cromer interglacial period about 700,000 years ago).

Relationship between Eridanus and Baltic Urstrom

It is also represented in the literature of the opinion that only the drainage system in the Eocene, in which the Baltic amber was transported to the territory of present-day Gulf of Gdansk, can be described correctly with the mechanism introduced by Barbara Kosmowska - Ceranowicz term " Eridanus ". Subsequent drainage systems in the area of ​​today's Baltic Sea in the period of the Miocene to the Pleistocene had arisen independently thereof and applicable as " Baltic Urstrom 'or by " Baltic main stream ".