DiverginGeology of Icelandg plates and hot-spot
Plate tectonics, seafloor-spreading, hot-spot and volcanism are some keywords regarding the geological processes in Iceland The North-Atlantic Ocean began opening about 60 million years ago. During that period the North American plate and the Eurasian plate has moved east and westwards, approximately by 1 cm per year in each direction. This process is still lasting today. At the plate boundaries magma has welled up and constantly created new basaltic sea floor.
But this flow of magma at the Mid-Atlantic-Ridge does not build up islands in the several thousands of meters deep ocean. The existence of Iceland points to another important fact: A so called hot-spot, the Iceland plume, is located near the Mid-Atlantic-Ridge in the North Atlantic and it is believed to have caused the formation of Iceland itself. A hot-spot (also “mantle plume”) is an upwelling of abnormally hot rock within the Earth's mantle.
Because of the plates, drifting east and westwards, it is plausible, that Iceland has a larger spreading to these directions than to the North-South. So we can infer that the east and the west are Iceland’s oldest parts, where we find the oldest rocks. In the middle of the island the the country is a geologically young land and extremely active, having many volcanoes. And of course, there are also many solfataras, hot springs and geysers in Iceland, including Geysir, from which the English name is derived.