divorse dating - Ordovician dating


During the Orodovician period, most of the land on earth was in the form of one super continent, Gondwana, which consisted of what is now Southern Europe, Africa, South America, Antarctica, and Australia.Climate The beginning of the Ordovician period had a climate that was extremely hot.The Ordovician is best known for its diverse marine invertebrates, including graptolites, trilobites, brachiopods, and the conodonts (early vertebrates).

The craton of Siberia-Kazakhstan lay east of Laurentia, along and slightly north of the Equator.

The Iapetus Ocean separated these two landmasses on the south from the Baltica craton, which included present-day Scandinavia and north-central Europe.

Lapworth’s proposal was resisted in Britain into the 1890s and, despite subsequent widespread international usage, was not officially adopted there until 1960.

The Ordovician is divided into three epochs: Early Ordovician (485.4 million to 470 million years ago), Middle Ordovician (470 million to 458.4 million years ago), and Late Ordovician (458.4 million to 443.8 million years ago). Although the positions of these continents are frequently updated with new evidence, current understanding of their position is based on paleomagnetic evidence, fossil markers, and climatically sensitive sediments, such as —made up of most of present-day North America, Greenland, and part of Scotland—straddled the Equator and was rotated approximately 45° clockwise from its present orientation.

This is likely due to high levels of carbon dioxide, which would then produce a greenhouse effect, warming the earth.