The World during the Middle and Late Ordovician

[ Ordovician Globe ]

During the later Ordovician, the continents were in very different positions than you find them today. The continents have only assumed their present locations on the globe in the last few ten's of million years. The process which moves the continents around the surface of the Earth is called "Plate Tectonics," and is a refinement of the earlier ideas of continental drift.

North America roughly straddled the equator. It was rotated about 45 degrees clockwise from its present orientation. Much, if not all, was covered by ocean. The map shows North America separated from other continents; an alternative theory places it very near the west coast of South America. (The positions of the plates during the Ordovician has been determined by the remnant paleomagnetism in the rocks deposited at the time. Paleomagnetism can only determine the paleolatitude, and paleolongitude must be determined from other, indirect evidence.)

Southern Europe, Africa, South America, Antarctica and Australia were bonded together into a supercontinent of Gondwana, and was in position over the South Pole. Western and Central Europe were separate from the rest of Eurasia, and were rotated about 90 degrees counterclockwise from their present orientation, and was in the southern tropics.

The map above shows the situation during the Middle Ordovician, several millions of years before the strata covered here were deposited. In the interim, Europe and North America moved steadily towards each other, until in they collided towards the end of the Ordovician.