Geologists believe that Iceland formed because of an unusual geological coincidence.
Iceland is one of the few places in the world where a mid-ocean ridge is exposed above sea level. A mid-ocean ridge forms along the boundary of two oceanic plates, which are spreading slowly apart. As the gigantic plates move apart cracks, called fissures, form and provide a path for molten rock to move to the surface. Along the axis of the mid-ocean ridge is usually a rift valley such as the valley at ingvellir . Geologists think that Iceland is above sea level because at this one place on Earth, the position of the mid-ocean ridge coincides with the position of a hotspot.