290 F. Leverett — Correlation of Moraines 



rect this owes its peculiar topography and structure to the 

 presence of lake water beneath the ice-margin. This portion 

 of the moraine has an altitude but slightly below the level of 

 the Yan Wert beach, consequently the water was shallow and 

 incapable of buoying up the ice-sheet and producing icebergs. 

 The result was what might be anticipated under such condi- 

 tions of deposition, a variable structure produced by the 

 motion of waters under the edge of the melting ice-sheet, and 

 an uneven surface molded by the inequalities of its base and 

 margin. It may be suggested that the moraine received its 

 sandy deposits from a lake that, covered it after the ice had 

 retreated. It seems improbable, however, that such was the 

 case, (1) because the sandy deposits are not in the form of a 

 beach nor in any way connected with a well defined beach, 

 but are in sharp knolls similar to the clay knolls of the 

 moraine ; (2) because the sand in places graduates into clay of 

 glacial origin showing contemporaneous deposition with it ; (3) 

 because the basins and depressions are so sharp and of such a 

 form and arrangement as to forbid the idea that the wave 

 action had been long exerted on them ; (4) the portion of the 

 moraine northwestward from where the Leipsic beach crosses 

 affords a clear illustration of the effect of an open lake on the 

 moraine, its surface being smooth and its sand either a uniform 

 coating or aggregated into forms clearly referable to wave or 

 wind action. It is fortunate that the lake in its later stages 

 fell short a few feet of reaching its earlier maximum stage and 

 thus left unmodified a portion of what appears to be a lake- 

 deposited moraine. So far as I am aware no cases of a moraine 

 demonstrably formed in lake water have been reported from 

 other parts of the glaciated district, but it is not improbable 

 that other instances will be found when attention is directed 

 more closely to this subject, if they have not already been 

 observed by other students. It is quite probable that in por- 

 tions of this moraine farther north, there will be found other 

 places similar to that just described. My studies were not 

 carried north of the Putnam and Henry County line. 



Summing up the phenomena of this district it appears (1) 

 that the Yan Wert ridge terminates near Findlay, Ohio, and 

 that east from there the Blanchard moraine is its correlative ; 

 (2) that the Blanchard moraine from near the meridian of 

 Findlay northwestward, was deposited in lake water. The 

 beach as well as the morainic phenomena therefore support 

 the hypothesis that the lake bounded by the Yan Wert beach 

 was of glacial age. 



