(',(',() THE GEOLOGY OP MINNESOTA. 



I [lh:c till and moraim-s. 



ries of Richland and Wheeling the elevation is due mainly to the under- 

 lying Hudson River and Trenton rocks which probably exist in their full 

 thickness, although there is still a great thickness of blue till in these 

 townships, the surface being smooth or broadly undulating. 



Moraines and morainic belt*. 



The chief morainic accumulation in the county appears in the town- 

 ship of Webster and in the northwestern part of Forest. The surface here 

 is very rough, generally exhibiting conspicuous ridges that have an approxi- 

 mate north and south direction, rising from 75 to 125 feet above the valleys, 

 one of the highest points observed being in sec. 16, which is approximately 

 1150 feet above the sea. These ridges, and all the drift in the township, 

 consist essentially of blue till, with disseminated Cretaceous debris. Yet, 

 east of the hilly region, in some places on the Dodd road, considerable 

 gravel deposits are seen, the result of drainage from the ice at the same 

 time that it was bringing forward the drift itself. Toward the west further 

 while the surface is rolling and perhaps is to be considered as included in 

 the same general moraine, extending across the township of Wheatland, 

 the hills rise only from fifty to seventy-five feet above the numerous lakes 

 and long peat marshes. 



The general direction of this very rough portion of the county is a 

 little south of southwest, occupying the eastern part of Erin, the whole of 

 Shieldsville, and the western two-thirds of Morristown, leaving the county 

 on the south side of lake Sakata. In Shieldsville, and in western Erin, 

 where this high rolling surface attains apparently its greatest avenigo 

 elevation, the highest hills become, rather, elevated plateaux, and the 

 roughness of the surface pertains to their margins and lies somewhat lower 

 than these higher flats. This flatness is due either to the existence of the 

 Trenton formation, or to the lack of copious drainage at the time of depo- 

 sition of the original till sheet. The southwest part of Morristown is very 

 rough, with 75-80 feet between the hills and valleys, the higher points 

 being 1150 to 1175 feet above the sea. 



Both toward the east and west from this rolling tract the contour of the immediate surface 

 is less rolling or becomes simply undulating, and in some places might be denominated flat. Such 

 flat tracts are found in the northeastern part of Forest, including the western part of Uridgewater. 

 The northern and central parts of Wells are undulating, but the northeastern is broken again with 

 other moraiuic surfaces. 



