The geology of Iceland is unique. Situated on the divergent boundary between the Eurasian plate and the North American plate, it also lies above a hotspot, the Iceland plume. The plume is believed to have caused the formation of Iceland itself, the island first appearing over the ocean surface about 16 to 18 million years ago.  Upwelling commenced in the early Tertiary and sea bed core evidences 55 million year old rock.  The result is an island characterized by repeated volcanism – Surtsey, a new volcanic island was formed in 1967. Geothermal phenomena such as geysers are a great natural resource