PALEOZOIC PHYSIOGRAPHY OF THE SOUTHERN ADIRONDACK^ 701 



EARLY PALEOZOIC PHYSIOGRAPHY OF THE SOUTHERN ADIRONDACKS 

 BY WILLIAM J. MILLER 



(Abstract) 



Some of the more important points regarding the southern Adirondack region 

 brought out in this paper are the following : 



1. The early Paleozoic sea encr^ .ched on a more or less well developed pene- 

 plain in the Adirondack region, tnis peneplain being moderately rugged in the 

 northeastern and eastern portions ; less so in the southern portion ; and very 

 smooth in the southwestern portion, such a difference in character of the 

 peneplain no doubt being due to the fact that the southwestern portion longest 

 remained above sealevel. 



2. When the early Paleozoic sea encroached on the region it did not set up 

 embayments or estuaries in the pre-Cambrian rock area, except possibly to 

 some extent on the eastern side, as shown by the peneplain character of the 

 pre-Cambrian rock surface, the typical marine character of the deposits in the 

 Paleozoic rock outliers, and the downfaulted structure of the outliers. 



3. The region was never completely submerged during the Paleozoic era. 

 though at the time the maximum submergence during the Trenton a compara- 

 tively small land-mass remained. 



4. The land areas varied considerably in extent from time to time, but the 

 principal area of unsubmerged pre-Cambrian rock ran in a northeast-southwest 

 direction through the southern Adirondack region and most likely continued 

 through the northern region. 



5. This prominent northeast-southwest structural belt or axis of elevation, 

 occupying practically the same position as the present main axis of elevation 

 of the mountains, has played an important part in the geological history of 

 northern New York. 



LEVEL OF MAXiMUM PRECIPITATION AS A FACTOR IN THE GLACIATION 



OF MOUNT RAINIER 



BY F. E. MATTHES " 



(Abstract) 



A study of the present distribution of ice on Mount Rainier and of the 

 sculptural features indicative of the former extent of its ice cover seems to war- 

 rant the inference that that mountain carried on its broad summit but little, If 

 any, more snow during the last glacial epoch than it does today. On its Ranks, 

 however, the ice was formerly much thicker than now. while the profound 

 valleys radiating from its base were occupied by glaciers of considerable ex- 

 tent. But these great ice-streams were ool merely prolongations of the swollen 

 Rainier glaciers. As the topography aboul the base of the volcano Indicates, 

 they originated Independently at relatively low levels, for the most part in 

 cirques, at altitudes between t,000 and 6,000 feet -al the same levels, In other 

 words, at which the other valley glaciers of the last Glacial epoch had their 

 origin throughout the Cascade Range. The Rainier glaciers, therefore, were 



Introduced by M. R. Campbell. 



XLVIJI— Bull. Geol. Soc. Am.. Vol. 124. lftlU 



