FAMOUS GEOLOGISTS/Suess 239 Figure Map showing divergent branching (Virgation) of the Rocky Mountains, from the first volume (1885) of Suess’ Das Antlitz der Erde To convey the complexity of the structures of folded mountain chains, Suess often used the term ‘Virgation’, meaning the rodlike spreading out, or dispersion, of the individual branches towards their forelands Such an order also meant that a region that was the ‘hinterland’ for one branch served as the ‘foreland’ for another Translation of the key: A, Archaean rocks and granite; p, Palaeozoic; tj, Triassic and Jurassic; cr, Cretaceous; t, Tertiary; cross hatching, younger lava; a, Quaternary and alluvium