Scottish Agates - The Geology
The Cambrian Period
543 to 490 mya
| The Cambrian Period is recognised as the time when life appeared in abundance in the seas of the world. At that time there was no life on the land. That had to wait until the end of the Silurian Period some 100 million years later. All the life in the seas in the Cambrian was invertebrate and included Trilobites. These were small arthropods that lived in shallow seas including the Iapetus Ocean. Fossils from these early forms of life can be found in Cambrian rocks in Sutherland. |
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| The Cambrian Earth - This map shows the newly formed supercontinent of Gondwana near the south pole. The continents were being flooded by shallow seas. In these seas life was abundant and animals with hard shells first made an appearance, this was the "Cambrian explosion of life". During this time Scotland continued to move northwards from about 60 degrees below the equator in the early Cambrian to nearer the equator in the late Cambrian [See the Red Arrow]. [Copyright C.R. Scotese, Paleomap Project] |
In the early Cambrian Scotland was still far south near the South Pole and lay on the southern margin of a continent called Laurentia. Scotland lay partially on the continental margin and in the surrounding shallow seas. In these seas sand and mud was washed in by rivers to the north leading to the formation of sandstones, limestones and mudstones. These rocks can be found around Assynt, south of Durness and on the Isle of Skye. |
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