Two revolutions in the Earth Sciences

Two great revolutions have shaken the field of the geological sciences since World War II, one involving the solid Earth and the other involving the ice ages. The former came after a long and gradual preparation that extended across a century. The latter came abruptly, after a long period of stasis during which little conceptually new had emerged. The former did not demolish anything - it was only the logical conclusion of a long process of discovery. The latter demolished a canon that had become a dogma held true for half a century. The reactions of the scientists to the two revolutions are a study in contrast: instant acceptance of the former versus laggard and reluctant acceptance of the latter.