1:7.6 PROCEEDINGS OK COLUMBUS MEETING. 



4:12(1207). Monomoy point ; looking northward from Monomoy lighthouse, cape 

 Cod, Mass. Monomoy is a long sand-bar formed by the conflict of wind and 

 tidal currents south of the elbow of cape Cod. It.- surface is at present 

 covered by shifting sand-dunes with very sparse vegetation (W. M. D.). 



433 (120!i). The Powder hole: Monomoy lighthouse; from the lighthouse. 



434(1244). Mount Desert island; from Green mountain. Mount Desert contains 

 the highest land on the Atlantic coast of the United States. Its east and 

 west mountain range marks the location of a great granite intrusion in ancient 

 crystalline and Paleozoic i ?) rocks ; the present height of the range above the 

 adjacent surface being due to the superior resistance of its rocks to denuda- 

 tion and not to upheaval. The range is now deeply dissected by transverse 

 valleys, and these are deepened by glacial action. The fjord-like quality of 

 the coast and the outlying islands indicate a submergence of the region since 

 the valley system attained its present form (W. M. 1).). 



435 (1246). Mount Desert island ; looking southwestward from Green mountain. 



4:;ii. Eagle lake, Mount Desert island ; looking northwestward. Eagle lake lies in 

 one of the transverse valleys by which the granitic range of mount Desert is 

 deeply dissected. In the distance the narrow arm of the sea by which the 

 island is separated from the mainland may lie seen (W. M. D.). ' 



4.">7 (1241). Mount Desert island : Bar Harbor; looking southwestward from Green 

 mountain. 



4M8 (1245). Mount Desert island : Bar Harbor; looking south westward from Green 

 mountain. 



439 (1228). Mount Desert island: Bass Harbor lighthouse. 



440 (1375). Entrance to harbor of Saint John, X. B. ; looking inland. This harbor 



is entered through a narrow gateway of rock in which the tidal currents or 

 "falls "are very rapid. This view shows the "falls" at ebb tide (W. M. D.). 



441 (13741. Locality same as 440 ; " falls " at flood tide. 



442(1308). Low tide in the basin of Minas ; Nova Scotia. Excellent illustrations 

 of mud Hats and tide-water gullies on the slopes (W. M. D.i. 



443 (1399). Low tide in the basin of Minas; X. S. 



444(1311). Hudson river; looking northward from West Point. The crystalline 

 Highlands of the Hudson are cut across by a deep and narrow gorge, by 

 which the open upper valley of the Hudson is drained. The whole region 

 once stood lower, and was then worn down to a lowland of denudation 

 whose remnants are now seen in the relatively even sky-line of the High- 

 lands. The denudation of this lowland was completed in tin 1 later part of 

 Cretaceous time. Somewhere in Tertiary time an elevation raised the low- 

 land to about its present altitude, the uplift being greater in the north than 

 in the south. In this slanting upland the Hudson cut down its valley, and 

 the valley widened by the wasting of its sides. The depth of the valley is 

 dependent simply upon the height to which the old surface was uplifted; 

 the breadth of the valley depends upon the hardness of the rocks in which 

 it was sunk. North of the Highlands the rocks are relatively weak ; there 

 the valley is wide. The Highlands are of hard rocks, and there the valley 

 is narrow. The great volume of the present Hudson river is due to a slight 



depression of the land, whereby sea water is allowed to li 1 the valley for 



150 miles from its mouth, as far as Albany. The Hudson proper above 

 Albany is comparatively a small stream (W. M. D.). 



445(1315). Hudson river; looking southward past Poughkeepsie. Since the gen- 

 eral elevation by which the Hudson cut its gorge through the Highlands 

 and opened its wide valley from Newberg to Albany and beyond, there has 

 been a later elevation of a less amount by which the valley-lowland above 

 Newberg has been trenched by the river to a depth of 200 or 300 feet. Since 

 then a slight depression has flooded the river with sea water, thus giving it 

 a volume unduly great for its moderate drainage area. This view shows the 

 Highlands in the distance. The valley-lowland of Tertiary denudation forms 

 the sky-line of the foreground and middle distance. The trench cut into 

 this lowland makes the center of the view, and in this trench the sea water 

 is now admitted by the depression of the country (W. M. D.). 



