TITLES AND ABSTRACTS OF PAPERS 89 



submerged trench. Delta filling has gone on rapidly since the fiord was ex- 

 posed by glacial retreat. 



In Muir Inlet the eastern bay near Adams Glacier, 132 to 315 feet deep, has 

 the submerged hanging valley relationship to the main fiord, with a discordance 

 of about 600 feet. North of the ice-front of 1892 the depth of water is 936 to 

 1,152 feet. Only 21 years ago the ice was 2,500 feet thick at the site of the 

 terminal cliff of Muir Glacier in 1913, 9 miles north of the ice-front of Reid's 

 time. 



Judging by (a) the exhumed forest floor discovered in 1913 near Muir 

 Glacier, (h) the stumps of trees there and in Tarr Inlet, and (c) the drumlin- 

 like shapes of ice-sculptured outwash gravels, the main work of glacial erosion 

 was performed during the ancient, prolonged ice-flood stage rather than the 

 modern, brief advance, which buried the lately exhumed forests and which 

 probably had its maximum between 1794 and 1814. From this it is argued 

 that vast lapse of time is necessary for the sculpture of fiords and of sub- 

 merged hanging valleys, which in Glacier Bay are believed to have been carved 

 chiefly by ice rather than running water, and produced with the land essen- 

 tially at its present level. 



Presented in full without notes. The paper was discussed by Messrs. 

 N. H. Winchell and H. F. Eeid. 



BURIED GORGE OF THE HUDSON RIVER AND GEOLOGIC RELATIONS OF 

 HUDSON SYPHON OF THE CAT SKILL AQUEDUCT 



BY W. O. CROSBY 



(Abstract) 

 Physiographic history: 



The Cretaceous peneplain. , 



The Miocene baselevel. 



The Pliocene baselevel. 



The Pliocene gorge of the Hudson. 



The Pleistocene elevation. 



The Pleistocene gorge of the Hudson. 



Glaciation and glacial erosion. 



Glacial and postglacial deposits. 



Bedrock geology: , 



Nature of the bedrock. 

 Joint structure. 



Thrust faults and shear zones. 

 Transverse faults. 

 Recent faulting. 

 Gorge of the Hudson not a graben. , 



Storm-King-Breakneck section of the gorge: 

 Contours. 

 Depth. 

 Deposits. ^ 



