50 Uphwn — Review of the Quaternary Era, 



Succession of Epochs, Glacial and Fluvial Deposits, and 



Epochs. 



Eastern Provinces and 

 New England. 



Rise of the land to its present 

 height, or somewhat higher, soon 

 after the departure of the ice. 

 Recent or Rivers eroding their glacial flood- 



Terrace. plains, leaving remnants as ter- 

 races. Warmer climate than 

 now, probably due to greater 

 (Mostly within the G-ulf Stream, formerly permit- 

 period of tradi- ted southern rnollusks to extend 

 tional and writ- to Gulf of St. Lawrence, now 

 ten history-) represented by isolated colonies. 



Middle and Southern 

 Atlantic States. 



Continued subsidence of coast 

 at New York and southward* 

 and rise of the mountainous belt, 

 by displacement along the fall 

 line of the rivers. Much erosion 

 of the Columbia formation since 

 culmination of second Glacial 

 epoch; sedimentation in bays, 

 sounds, and estuaries. 



Land depressed under ice- 

 weight; glacial recession; con- 

 tinued deposition of upper till 

 and deep flood-plains of gravel, 

 sand and clay (modified drift). 

 Champlain. Terminal moraines marking 

 pauses or re-advance during 

 (Close of the general retreat of ice. Marine 

 second Glacial submergence 150 to 230 feet on 

 epoch.) coast of Maine, to 520 feet in 



Gulf and valley of St. Lawrence. 



Less subsidence in latitude of 

 New York and southward than 

 at north; lower Hudson valley, 

 and part of its present subma- 

 rine continuation, above sea 

 level. Gravel and sand deposits 

 from englacial drift in Delaware 

 and Susquehanna valleys, enclos- 

 ing abundant human imple- 

 ments at Trenton. N. J. 



Second 

 Glacial. 



Second great uplift of the land, 

 3,000 to 4,000 feet higher than 

 now ; snowfall again all the 

 year; ice probably two miles 

 thick on Laurentide highlands, 

 and extending somewhat farther 

 south here than in first glacia- 

 tion. Lower till (ground mor- 

 aine), and upper till (englacial 

 drift). Terminal moraines, 

 kames, osars, valley drift. 



Renewal of great continental 

 elevation (3,000" feet in latitude 

 of New York and Philadelphia), 

 of excessive snowfall and rains, 

 and of widespread fluvial depos- 

 its, the Columbia formation, on 

 the coastal plain, during early 

 part of this epoch. Implements 

 of man at Claymont, Delaware. 



Inter- 

 glacial. 



(Longest epoch 

 of this era.) 



First 

 Glacial. 



Ice-sheet melted here ; proba- Depression, but generally not 

 bly not more ice in Arctic regions to the present level. Deep chan- 

 than now. nels cut in the bed-rocks by the 



Fluvial and lacustrine deposits Delaware, Susquehanna, Poto- 

 of this time, with those of the mac and other rivers. TheAppo- 

 first Glacial epoch, were eroded mattox deposits much eroded, 

 by the second glaciation. Relative length of. this epoch 



made known by McGee from 

 study of this region. 



Begun by high continental up- 

 lift, cool climate and snowfall 

 throughout the year, producing 

 ice-sheet. Much glacial erosion 

 and transportation; till and 

 stratified deposits. Ended by de- 

 pression of land; return of warm 

 climate, with rain; final melting 

 of the ice. Isthmus of Panama 

 probably submerged (Gulf 

 Stream smaller), and again in 

 second Glacial epoch. 



Continental elevation ; erosion 

 of Delaware and Chesapeake 

 bays, and of Albemarle and Pam- 

 lico sounds. Plentiful snowfall 

 o n the southern Appalachian 

 mountains ; snows melted in 

 summer, and heavy rains, pro- 

 ducing broad river-floods, with 

 deposition of the Appomattox 

 formation. 



