Inter-glacial. Ice-sheet melted here; Depression, but generally probably not more ice in not to the present level. (Longest epoch arctic regions than now. Deep channels cut in the of this era.) bed-rocks by the Fluvial and lacustrine Delaware, Susquehanna, deposits of this time, Potomac, and other with those of the first rivers. The Appomattox Glacial epoch, were deposits much eroded. eroded by the second glaciation. Relative length of this epoch made known by McGee from study of this region. First Glacial. Begun by high continental Continental elevation; uplift, cool climate and erosion of Delaware and snow-fall throughout the Chesapeake Bays, and of year, producing Albemarle and Pamlico ice-sheet. Much glacial Sounds. Plentiful erosion and snow-fall on the southern transportation; till and Appalachian Mountains; stratified deposits. snows melted in summer, Ended by depression of and heavy rains, land; return of warm producing broad climate, with rain; final river-floods, with melting of the ice. deposition of the Isthmus of Panama Appomattox formation. probably submerged (Gulf Stream smaller), and again in second Glacial epoch. _Changes in Altitude and Climate, during the Quaternary Era._ Mississippi Basin and Cordilleran Region. Europe and Asia. northward.