what type of rock makes up most of iceland
Iceland can be divided into three zones based on the age of the basaltic rocks. Tertiary flood basalts make up most of the northwest quadrant of the island. This stack of lava flows is at least 3,000 m thick.celand formed by the coincidence of the spreading boundary of the North American and Eurasian plates and a hotspot or mantle plume â an upsurge of abnormally hot rock in the EarthÂ´s mantle.