152 Agricultural Experiment Station, Ithaca, N. Y. 



flows in the old drift-iilled valleys and then the shale wall is changed 

 to one of till, in which the boulder clay is sometimes one or two 

 hundred feet deep, as is the case in parts of the gulf near Westfield. 



As the ice withdrew, with a south-facing front, it naturally in- 

 terfered with all north-tlowing streams. It formed a dam and 

 caused many reversals of drainage. The St. Lawrence valley 

 was occupied by the ice when the front had retreated north of the 

 escarpment which partly encloses the grape belt. Therefore these 

 north-flowing streams could not drain by the present outlet, but 

 were pounded back and forced to take another place of outflow, and 

 this was of course the lowest point in the enclosing hills, a point 

 which was naturally higher than the present outlet. While the 

 lake was held at its upper place of outflow it was building the upper 

 beach, which has been called Sheridan beach. The outflow of this 

 lake was then at Fort Wayne, Ind., into the Wabash, and the beach 

 may be traced continuously to this outlet. However, in the east 

 this beach comes to an end just south-east of Silver Creek ; and near 

 its eastern end there is a tract of moraine.* 



To the southward of the town of Hamburg, on the road to New 

 Boston, there is another morainic belt, and a second beach, which 

 can be quite continuously traced from west of Silver Creek nearly 

 to Hamburg, begins to disappear as this town is neared. The last 

 place at which it could be distinctly determined is near Eden 

 Church, southwest of Hamburg ; but a third beach from the top 

 passes directly through Hamburg, and has been found to disappear 

 near Crittenden. In each case, as the moraine is approached, the 

 beach becomes less distinct and finally can be traced no farther. 



This shows that while these beaches were being built at their 

 respective levels, the ice was standing at different places and was 

 bringing materials which were being laid down at its front in the 

 form of moraines. At first the ice front passed near Silver Creek 

 and then the upper beach was made, while the outflow of the lake 

 was past Fort Wayne. Then the edge of the ice withdrew for a 

 distance until some lower outlet was formed, and again to a still 

 lower, more northern point, when another and still lower outlet was 



*This moraine has not been traced, so that nothing can be stated con- 

 cerning its extension; but it appears in quite distinct development about 

 two miles east of Silver Creek, extending nearly to the town. 



