30 NEW YORK STATE MUSEUM 



worn cobbles form a steep slope nearly to the 800 foot contour 

 line but 1 have not been able to distinguish this deposit from 

 waterworn material deposited in the presence of the glacier 

 and worked over by it. It is not discriminated from the general 

 local drift coating on the accompanying map. 



South of Deer pond and thence southeastward along the curv- 

 ing contour of the tianks of the Adirondacks I have not been able 

 to iind traces of wave action above 680 feet along the northern 

 margin of the Altona Hat rock or spillway, above 070 to 075 feet 

 in the region west of West Ohazy, and above 640 feet at the 

 southern limit of the map. 



Water may have stood at a higher level with waves beating 

 against the flat rocks but these bared surfaces would have 

 yielded little material for making recognizable beaches. The 

 680 foot level is very indistinct or locally wanting along the 

 eastern margin of the Altona flat rock area in the southern 

 part of Tine ridge where the stripped rocks descend to lower 

 levels than usual. The absence of definite beaches therefore 

 between Deer pond and Altona does not necessarily mean the 

 absence of wave action within the zone ait which it might be 

 expected if it is granted that these supposed wave-made deposits 

 marked a former water level now tilted to the southward. 



The falling off in level of this tracing of highest beaches is 

 as much as 110 feet at least between Gannon Corners and the 

 southern margin of the quadrangle. In an air line in a north- 

 west and southeast direction this amounts to a rise on the 

 north at the rate of about 6.5 feet to the mile, or if we neglect 

 any possible east west tilting, and compare the two localities 

 in a north and south direction, the rate of tilting is about 7^ 

 feet to the mile. 



The rather persistent beach at the 680 foot contour on the north 

 side of the Altona flat rock extending in an east by south direc- 

 tion for about 3 miles lies at a very large angle to the evident di- 

 rection of tilting and this fact will account for the approximate 

 uniformity of level which the water lines there show. 



These estimates of the degree of tilting involve the supposition 

 tluil the highest lines are parts of one water level. There are 

 good reasons lor thinking this not the case. It is evident that 



