EVIDENCES OF RECENT ELEVA TION 23 



the island. Excepting the valley bottoms, which are filled with 

 quantities of unusually large and well-rounded bowlders, this belt 

 has been stripped of its loose material in the form of glacial drift ; 

 consequently the bare and naked rock is exposed on the hilltops. 

 The attack of the agencies of weathering upon the surface of 

 this area has been in progress, more or less, ever since the rock 

 was exposed, but the effect is far less than that over the areas 

 above an elevation of 300 feet. This would naturally follow, 

 since it will be shown that up to this elevation the waters have 

 but recently subsided or fallen. By far the larger quantity of 

 loose materials which are scattered here and there over this 

 zonal surface is rounded and waterworn. Mechanical weath- 

 ering has in places shown its effect, and angular masses are 

 seen scattered about somewhat sparingly, in the form of small 

 talus deposits. This zone will embrace at least three-fourths of 

 the total land area of that part of the island visited. 



The second zone has its lowest level and beginning at the 

 300-foot elevation and includes all the surface above, including 

 an area which is not continuous, being merely the tops and 

 sides of the hills for two-thirds of their distance downward. In 

 this zone the bedrock is seldom seen, but is covered to an 

 unknown depth with very large and loose angular blocks ; in a 

 few places, however, the bedrock outcrops at the surface in the 

 shape of small knolls of somewhat decayed rocks. These 

 angular rocks are clearly derived from the local gneisses, pre- 

 sumably largely, if not entirely, by frost action. In some cases 

 they are weathered to a thoroughly crumbled condition. The 

 scarcity of glacial bowlders in this angular mass was very strik- 

 ing, yet a few, which proved in each instance to be of foreign 

 source were seen. 



Along the sides, at an elevation of from 50-75 feet above 

 the valley bottom, which was 220 feet above the sea, were noted 

 patches of pebbles and bowlders, mostly the latter. These 

 were deposited in small channel ways which had been carved by 

 temporary streams flowing down the valley sides. Fully a half 

 dozen of these were seen at different places on the same hill- 



