Rift Valley Essay

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Register to read the introduction… New crust is generated as plates pull away from each other and can either cause sea floor spreading or new land to be created. An example of a continental rift valley is the Eastern African Rift Valley which is being formed as the Eastern African plate is moving away from the main Africa plate in a north-easterly direction. Plates move apart due to convection currents in the lithosphere. As the crusts move away from each other the crust thins, tension in the lithosphere causes the plate to thin as it starts to split. As sections of the crust move apart, areas of the crust drop down between parallel faults to form rift valleys. Inward facing scarp slopes that are created in the Eastern African Rift Valley reach heights of 600m above the valley floor. Rift valleys give us an understanding of plate theory as the effect of convection currents can clearly be seen by their …show more content…
Coal reserves have been found in Antarctica, 500km from the South Pole. Due to the current climate of Antarctica only feasible explanation behind this discovery is that there has been a change in latitude throughout the continent. This supports the idea that Antarctica has not always been located at the South Pole where it is impossible for plants to grow. It is believed that when Antarctica was part of the supercontinent Gondwanaland, forests and swamps were formed which then lead to the formation of coal as the pressure from layers of sand, sediment, and plant and animal remains forced out water from the layers to leave behind coal. In the same way that fossil discovery supports continental drift and tectonic plate theory, the discovery of coal reserves supports these theories in the same …show more content…
Similar rock types and structure have been found on the two sides of the Atlantic. The sequences of sedimentary and igneous rocks from the Appalachian Mountains of North America match those from the Caledonian Mountains of Scotland. Geologists believe that because of the similarities in rock type and rock sequence, both the Appalachian Mountain range and the Caledonian Mountain range were part of the same ancient mountain range known as the Central Pangaean Mountains which were formed when the North American plate and the Eurasian Plate collided. This belief can be used to support and explain plate tectonics theory which could be deemed necessary for our understanding of the

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