 Igneous rocks which arose from this hotspot have been found on both sides of the Mid-Atlantic Ridge, which originated 57–53 million years ago ("Ma"), around the time North America and Eurasia separated and sea floor spreading began in the Northeast Atlantic.Geologists can determine plate motion relative to the Icelandic hotspot by examining igneous rocks throughout the Northern Atlantic region.This is possible because certain rocks attributable to hotspot volcanism can be interpreted as volcanic traces left by the Iceland hotspot.