LATER MORAINES OF LAKE MICHIGAN, SAGINAW, AND HURON-ERIE LOBES. 269 



The Mayville moraine has a great development of knob and basin topography in western 

 Watertown Township in association with the esker trough leading south from Murphys Lake. 

 The rest of this moraine to the east line of Dayton Township has a strong swell and sag topog- 

 raphy but includes many basins, some of them on its highest parts. 



The Owosso moraine has a rather mild swell and sag topography as far as a point north of 

 Mayville, except along its outer border, where it has knobs and basins in association with the 

 gravels of the Butternut border drainage line. Farther northeast, on the high ground of Fremont 

 and Dayton townships, it has a varied expression, mainly swell and sag, but with knobs and 

 basins along its front, especially southeast of Cat Lake. 



In areas where it has little relief, the Juniata moraine is mainly swell and sag, but in each 

 of the three areas where it has strong relief it has more or less knob and basin topography, espe- 

 cially in the largest high area in northern Fremont Township. 



Near Marlette the Mayville moraine shows mostly swell and sag topography on the ridges, 

 but in some places it has many basins and on its inner border many swampy hollows. 



The Deanville moraine is a smooth ridge along its front but is bordered by scattered irregu- 

 lar knolls for a mile or two on its eastern side. 



The ill-defined morainic belt running east through southern Koylton has mainly a swell and 

 sag topography, but has also a considerable number of basins and many swampy recesses on its 

 inner side. This expression continues nearly to Omard, but beyond that the form of the Yale 

 moraine is mainby swell and sag to the kame area in the central part of Speaker Township, where 

 knob and basin topography and kames are developed in connection with the overriding of the 

 large transverse ridge. 



The ill-defined morainic belt running southeast from Kingston and the high area just west 

 has some knobs and manj r basins. 



The interlobate region in northwestern Sanilac County has a broad swell and sag topography 

 with a moderate development of drumlin-like forms in the eastern part. 



Almost all the scattered ridges in western Sanilac County are low swells. Some, however, 

 are sharp and narrow, but these more or less resemble eskers. 



The transverse stony ridges are mainly smooth, with only mild swell and sag forms, but 

 where their tops bear kames they are rougher and have many basins. Where they are crossed 

 by the moraines they have also a mixed topograph}-. 



STRUCTURE OF THE DRIFT. 

 COMPOSITION. 



The moraines of the district are composed mainly of stony clay, the proportion of bowlders 

 and pebbles being considerably greater than in the moraines west of Lapeer County. The more 

 pronounced interlobate deposits in central Lapeer Countj r , especially those south of the Imlay 

 channel between Oregon and Imlay townships, contain a very large share of coarse materials. 

 The moraines hi this interval approach more nearly the interlobate type, in which more or less 

 concentration of coarse sediments is characteristic. The moraines in Marathon and Watertown 

 townships also contain much coarse material, but the group of moraines that sweep through 

 southern Tuscola County around into Sanilac, eastern Lapeer, and northwestern St. Clair coun- 

 ties are more largely composed of clay. Except in their higher parts, the Owosso and Juniata 

 moraines are composed largely of clay with very little coarse material. 



The transverse ridges are composed mainly of very stony till, bowlders being generally very 

 plentiful upon them. Considerable quantities of gravel and sand are associated with these 

 ridges in places, especially upon the tops of the larger ones in Washington and Elk townships. 



No very extensive sand or gravel deposits were found. The outwash apron in Watertown 

 and Marathon townships is the largest. Two or three smaller ones occur in central Lapeer 

 County. 



