Geological map of Iceland. Map of Iceland showing a number of geological features including volcanoes (red triangles) glaciers (white) and eruptive fissures (magenta lines). Iceland lies on the Mid-Atlantic Ridge (red line), the spreading boundary between the North American (left) and Eurasian (right) plates, and has been formed by successive eruptions of volcanic rock. The map is colour-coded according to when the volcanic rock was laid down; Holocene sediments (yellow), late Quaternary (pink), late Tertiary-early Quarternary (purple) and Tertiary (grey/blue).