There are strong discrepancies in reckoning of the number of glaciers between The Urantia Book and current science. The time of the third glacier according to the book corresponds to the first according to the reckoning of geologists.  750,000 years ago the Siberian glacier was making its southernmost march, compelling early man to move southward, back toward the lands of his origin.  Land elevation produces glaciers.  No other terrestrial activity apart from glaciers leaves such characteristic evidence on the topography.