70 H. L. FAIRCHILD — ICE EROSION THEORY A FALLACY 



Drumlin-belt filling. — The heaviest deposit of drift in central New 

 York is that belt lying north of the Finger lakes and which carries one 

 of the most remarkable areas of drumlins in the world. It has not been 

 recognized as morainal for the reason that it is so low-lying as to be 

 buried or leveled b,y lake action. It forms the blockade to all the north 

 and south valleys, both those with lakes and those without lakes today. 

 The Flint and Bristol (Ganargua) valleys held shallow postglacial lakes 

 which have been changed to swampy tracts. 



The belt of drift lies deepest over the east and west outcrop of the soft 

 Salina shales and north of the outcrop of the Helderberg-Corniferous 

 limestones. It was all beneath the glacial waters of lake Warren and 

 the slowly falling waters succeeding the Warren (Hyper-Iroquois) ; and 

 all the area of the Sodus-Cayuga depression was under lake Iroquois 

 during all the life of the latter (see plate 21). 



It may be suggested that a large portion of this drift was rubbed into 

 the valleys along the Salina outcrop during the early stages of the ice 

 sheet, and thereby saved the more southerly part of the valleys (now 

 occupied by the lakes) from great filling. The outcrop or low escarp- 

 ment of the limestones was the most obdurate barrier which the ice en- 

 countered on the Ontario plain. The drumlins were probably formed 

 during the closing stages of the ice. The lakes have spread their silts 

 over the lowlands and partially buried even the drumlins, while vegetal 

 deposits have continued the filling, and form the vast peat marshes of 

 the Montezuma swamps and along the Seneca river. 



Buried valleys. — The writer is not able to fully prove that the val- 

 leys are graded in rock and are merely dammed by drift, but all the 

 available facts point to this, and it is believed that borings will so prove 

 it. The assumption that any of the lakes have a rock barrier on the 

 north is without any warrant in knowledge or in sound reasoning. 



From the foot of the Finger lakes northward to near the Ontario shore 

 the valleys are buried quite out of view beneath the drumlin-belt drift 

 filling, but they partly reappear in the depressions along the Ontario 

 shore. If the reader will spread before himself in order the Macedon, 

 Pultneyville, Sodus bay, and Oswego sheets of the state topographic 

 map he will see that the Ontario shore from Irondequoit bay eastward 

 to Sodus bay, a distance of about 25 miles, has no embayments. The 

 Medina rocks are here visibly continuous, and no large streams ever 

 traversed this belt of land. They were diverted either westward to the 

 Genesee (Irondequoit gulf) or eastward to the Seneca-Sodus valley. At 

 Sodus bay is a great break in the shoreline, and a broad valley intersects 

 the rock strata. This ancient valley is not less than 2 miles wide, but 



