BLANCH ARD OR DEFIANCE MORAINE. 615 



Wellington, where numerous wells have penetrated 75 to 110 feet of drift. 

 Aside from this there were but few places found where the drift exceeds 

 50 feet. One is at W. H. Todd's, 2 miles north of Florence, in Erie County, 

 where rock is struck at a depth of 77 feet. A mile south of this well is 

 a sandstone hill which rises to a height of 40 to 50 feet above the well 

 mouth. Another is in Hartland Township, Huron County, at a school- 

 house and at the base of the Hartland esker. This well has a depth of 75 

 feet and does not reach the rock. Around the northern end of the esker 

 the drift has a thickness of only 10 to 20 feet. A gas well in Rocky River 

 valley, at Columbia Center, Lorain County, ' passed through 40 feet of 

 drift. The well mouth is 20 to 25 feet below the level of the bordering till 

 plain. At Brunswick Center, Medina County, Gr. B. Babcock has a well 

 50 feet deep which did not reach rock, but rock comes to the surface just 

 north of the village at a higher level than the well mouth. 



STRUCTURE OF THE DRIFT. 



The drift is mainly till, though the valleys, as already indicated, 

 contain considerable silt beneath the till, and there are thin sheets of sand 

 and gravel on the uplands interbedded with the till. It is from these slieets 

 of sand and gravel that the wells are usually obtained, the abundance or 

 scarcity of good water depending upon their thickness and extent. The till 

 ordinai'ily contains a large amount of clay, but in the midst of the sandstone 

 hills of northwestern Lorain and eastern Erie counties it is of a sandy 

 nature, furnishing a good illustration of the effect of the local rocks upon 

 the structure. 



BOWLDERS. 



The number of bowlders on this inner border tract is not great, though 

 in certain limited districts they abound. One such district is crossed on the 

 road from Strongsville to Columbia Center. Another is in eastern Seneca 

 County, along the east-west center road in Thompson Township west of 

 the center. Perhaps other similar places occur within the limits of this 

 district, but they have not been noted. 



THE HAR'ILAND ESKEK. 



Aside from the beds of assorted material which are interbedded with 

 the till, there are occasional surface deposits of gravel or sand in the form 

 of knolls and ridges, and also in plane tracts. 



