LATER MORAINES OF LAKE MICHIGAN, SAGINAW, AND HURON-ERIE LOBES. 291 



advancing and in the receding phase of the invasion. Moreover, it occurred, in all probability, 

 twice in each of the great ice invasions that overspread the basins of Lakes Huron and Erie, 

 for the observed disposition of the pre-Wisconsin drift, especially in the interlobate tracts 

 in central and southeastern Michigan and in the western peninsula of Ontario, indicates the 

 existence of Saginaw, Huron, and Erie ice lobes then in forms substantially identical with 

 those of the last ice sheet. The troughs, lying with their axes in the line of ice movement at 

 the last maximum, in all probability held the same relation to the maxima of each of the earlier 

 invasions, and, in so far as they have been made by ice erosion, they may be in part a product 

 of each of the invasions. 



In Monroe County Sherzer reports three sets of stria? at Stony Point and Brest and two 

 sets at each of the following places: Sissung Quarry, Point aux Peaux, Monroe, Maybee, 

 Dundee, and Ottawa Lake. The latest striae at Sibleys (N. 29° W.) are readily recognized in 

 all these localities, and it is interesting to note that they incline more and more toward the 

 west with increasing distance south from Sibleys, until at Ottawa Lake they run west or slightly 

 south of west. This deflection is distinctly expressive of a lobe spreading northwestward, 

 westward, and southwestward from a central point in the western basin of Lake Erie; and the 

 striae seem best interpreted as recording the spreading of one lobe at a particular stage and 

 time. 



The sets of striae have another significance which is worthy of note. As Sherzer states, 

 three sets at Sibleys are quite distinct from each other, the intermediate courses between each 

 pair of contiguous sets being only sparsely represented. This seems to mean that a given set at 

 this locality was made, not while the ice front was in active retreat, changing its alignment and 

 shifting the courses of the lines of flow to the margin, but while the ice front was stationary or 

 maintaining one position steadfastly. It is therefore concluded that each set of stria? stands for 

 a pause in the retreat of the ice front, and hence corresponds to or is the correlative of a terminal 

 moraine. From this point of view it seems probable that the striae running N. 29° W. at Sibleys 

 are correlatives of a moraine of the Lake Erie lobe which is itself the correlative or complement 

 of the Birmingham moraine of the Lake Huron lobe and in part also of the Detroit interlobate 

 moraine. Where no notable change of frontal alignment took place between the pauses in the 

 retreat, the direction of the striae might remain unchanged, and so represent more than one 

 moraine. Such preservation of frontal alignment is generally maintained along the axis of a 

 lobe; and the striae running N. 29° W. at Sibleys, being nearly on the axis of the small sublobe 

 which reached northwest from the mouth of Detroit River, may represent pauses of the ice 

 front corresponding to all of the slender moraines from the Birmingham to the Mount Clemens. 



CORRELATIVES IN OHIO, NEW YORK, AND ONTARIO. 



By Frank B. Tayior. 

 GENERAL CORRELATION. 



It seems certain that the group of slender moraines sweeps across the Maumee Valley 

 from the Detroit interlobate moraine to the shores of the glacial lakes in eastern Ohio, Pennsyl- 

 vania, and western New York. A number of the slender moraines are known to pass beneath 

 the Maumee shores and they are believed to emerge east of Cleveland, where Mr. Leverett has 

 mapped a number of moraines constituting his escarpment system. 1 Mr. Leverett shows others 

 emerging farther eastward in Pennsylvania and New York. 



The later moraines of the same series in Michigan sweep northeastward and northward 

 through Ontario, emerging northwest of London. Thence they run northward and eastward 

 around the upper edge of the highland south of Georgian Bay and, bending in wide curves, return 

 southward on the east side, passing across the eastern end of Lake Erie. The writer has 

 traced parts of all of those in Ontario, 2 and in all these localities the strength and character 

 and general relations of these moraines show a strong resemblance to the system of slender 

 individuals which is so well displayed in the eastern limb of the Saginaw lobe. 



i If on. U. S. Geol. Survey, vol. 41, pp. 651-672, Pis. XV and XVIII. 



2 The moraine systems of southwestern Ontario: Trans. Canadian Inst., vol. 10, 1913, pp. 1-23, with map. 



