Divided into 3 parts. Part 1 contains general legend, the geology of the Arctic and Antarctic regions (Polar projections), and explanatory notes. Parts 2 & 3 (Mercator projection on a scale of 1:25,000,000 at the equator), can be centred on the Atlantic, illustrating the expansion of the ocean depths and the drifting of continents from the dorsal median; or centred on the Pacific, showing the ocean circled by zones of subduction associated with volcanism in an arch shape. Accompanied by a simplified legend in English and French and a representation of polar zones.