FOURTH REPORT OF THE DIRECTOR I9C7 25 



Distribution of the drift. Some facts have already been given 

 in the description of the glacial lobes. No general estimates of the 

 thickness of the drifts are offered. These it is believed are sure 

 to be delusive. It may be said in a general way that in the Adiron- 

 dack portion of the area the drift is apt to be thick in the valleys 

 and it is generally thin on the slopes and summits as would be ex- 

 pected. In the Sacandaga basin south of Northville and over the 

 region of the Great Vly the drift is of unknown thickness and out- 

 crops are rare. Naturally the drift is very massive along the belt 

 of the interlobate moraine, and south of this moraine extending 

 from about West Perth eastward for 7 or 8 miles there is a broad 

 flat topped plateaulike mass of till sometimes showing sandy phases. 

 The north edge of this region is near Broadalbin and the south near 

 Perth, the ridge averaging perhaps 3 to 4 miles in width. It is on 

 the high ground between the Mohawk and Sacandaga basins and it 

 is seen as a conspicuous profile from all high points south of the 

 Mohawk river. It is historic in the sense of having carried the 

 ancient highway of Johnstown to Saratoga. It is conjectured that 

 it has been a great overridden moraine of an earlier age but this 

 suggestion is offered doubtfully and with hesitation. South of this 

 region toward the ]\Iohawk river, especially in the region between 

 Galway c-nd Amsterdam the drift is thin. Around Johnstown east- 

 ward and westward it is comparatively massive. So is it also at 

 many points in the Mohawk valley. South of the Mohawk it inclines 

 to be thick near the river but averages thin wherever the glacier 

 overrode the higher sandstones which lie south of the black shales. 

 An exception, however, appears several miles about Charleston Four- 

 corners where the geological map shows almost no outcrops and 

 where the drift must be comparatively massive. An interesting belt 

 of drumlins exists in the vicinity of Gloversville and Johnstown. 

 At Johnstown these drumlins make up a large part of the territory, 

 show altitudes of from 50 to 150 feet and are the most conspicuous 

 elements in the topography. The same is true northward and north- 

 westward of Gloversville to the base of the Adirondacks. A few 

 of these drumlins are peculiarly massive and noble in proportion, 

 making an aggregate of great ellipsoid swells which command the 

 attention of the observer. The same forms are found eastward 

 of Gloversville and along the road from Gloversville to Mayfield and 

 curiously these forms In some cases emerge among the sands of the 

 interlobate moraine. Some of these are seen between Gloversville 

 and Broadalbin, the sands sweeping around the base of the drumlins 

 and in some cases partly up on one side or one end. Many of the 



