616 GLACIAL FORMATIONS OF ERIE AND OHIO BASINS. 



The only conspicuous gravel ridge observed is the Hartland esker. 

 This ridge lies on a very level till plain in the northeast part of Hartland 

 Township, Huron Count}^ its southern end being near the east-to-west 

 center road, and 1^- miles east of Hartland Center, and its length, about 2 

 miles. The trend is nearly due north to south, but the ridge winds 

 slightly, varying 20° or more from a due north-south line. The general 

 height is 10 to 12 feet, but in places a height of 20 feet is attained. 

 The width, including slopes, is only 75 to 125 yards. It is a continuous 

 ridge, except for a gap near the middle a few yards in width. Two basins 

 were observed on the crest of the ridge, one of whicli is fully 10 feet in 

 depth and contains a small pond. The northern half of the ridge is sharper 

 and higher and contains coarser material than the southern half 



The largest exposure noted in the esker is at a gravel pit in the 

 noi'thern half near the schoolhouse referred to above. It is opened at a 

 place where the ridge makes a sharp curve from a south-southeast course 

 to one west of south. It has been worked back from the outer side of the 

 curve to the inner, the best exposures being at points which show the 

 structure of the inner curve. There is a confused mass of cobble, gravel, 

 and sand, with slight clay admixture, and onlj indistinct lines of bedding. 

 These, so far as made out, are nearl}" horizontal. On the outer curve of 

 the ridge the bedding appears to be more distinct than on the inner. 

 Several slight exposin-es occur between this large pit and the souther^ end 

 of the ridge. They usually show a thin bed of sandy clay at the surface, 

 which is sparingly interspersed with pebbles, beneath which is gravel of 

 medium coarseness. Residents state that the wells along this portion of 

 the ridge frequently strike a bed of sand which yields some water, after 

 which they enter till near the level of the bordering plain. 



There is no fan or gravel plain at the south end of this esker, but on 

 the contrary, it ternnnates abruptly in the till plain. About 2 miles south, 

 however, is found the northern end of the spur of the Defiance moraine 

 described above, which lies along the east side of Vermilion River, and 

 since this spur is composed mainly of gravelly knolls and is so nearly in 

 line with the esker, it is thought that it may have been formed by the same 

 glacial stream which formed the esker, the interval of 2 miles between the 

 esker and the spur having been unfavorable for the production either of an 

 esker or of gravelly knolls. Just how the glacial waters deposited such 



