4l8 NEW YORK STATE MUSEUM 



another a mile northeast of the mouth of Eighteenmile creek and 

 about 5 miles southwest of Oswego. 



In cross-section view the concentric bedding decreases in con- 

 vexity passing downward toward the bottom of the drumlin. In 

 other words, the bedding near the base of the drumlin is quite 

 horizontal or slightly arched ; and the arching increases with hight 

 until near the top the layers are parallel with the drumlin pro- 

 file. In some instances, particularly toward Oswego, the sections 

 exhibit a superficial bed, estimated at 10 to 20 feet thick, of a 

 lighter color and yellowish shade, and apparently less compact 

 than the deeper blue-gray till. This superficial bed weathers into 

 smoother or more uniform faces, instead of the projections, pinna- 

 cles, towers, or battlemented forms of the deeper and harder till. 



A good test, and a confirmation, of the concentric structure is 

 found in the oblique and the nearly longitudinal sections. A glance 

 at plates 7 and 8 will show how the lake erosion is cutting the drum- 

 lins at very different angles. It is found that' the stratification 

 exposed in these different sections has the direction which would 

 correspond to a concentric bedding. In sections approaching the 

 longitudinal the bedding is quite straight and declines parallel with 

 the crest of the drumlin toward the tail of the hill. In general the 

 upper beds are parallel with the cliff profile and have the curvature 

 appropriate to the angle of the section. 



The application of these facts of drumlin structure to the problem 

 of drumlin origin will be found in a later chapter. To facilitate the 

 study of the subject by any one who wishes to examine the drumlin 

 sections for himself the following notes and directions are supplied. 



West of Sodus bay (the Pultneyville sheet) the cliffs are partly 

 morainal and only two good drumlin sections occur, one of them 

 being shown in plate 46. East of Sodus bay the lake shore is 

 included in the Sodus bay sheet, reproduced in plate 8, and the 

 Oswego sheet, partly shown in plate 7. These maps show approxi- 

 mately the angle of the wave cutting with reference to the drum- 

 lin axes. 



The drumlins which display the bedded structure in the clearest 

 manner are, taken in order eastward : Lake bluff (using the local 

 names) [pi. 44] ; Cline's bluff, 1 mile east of Lake bluff ; Blind Bay 

 bluff, 1^ miles east of East bay [pi. 45] ; two cliffs either side of 

 Juniper pond, which lies 2 miles beyond Fairhaven bay; and the 



