366 GLACIAL FORMATIONS OF ERIE AND OHIO BASINS. 



The presence of buried oxidized tills and of sand and gravel deposits 

 between till sheets can not, in the writer's opinion, be cited as demonstra- 

 tive evidence of retreats and advances of the ice sheet unless accompanied 

 by other and more certain lines of evidence, such as peat beds or soils, 

 leached and eroded surfaces, etc. Their occurrence seems rather a problem 

 demanding investigation than a line of evidence from which conclusions 

 can be drawn. 



In the western limb of the moraine no extensive natural exposures 

 wei'e observed; we pass, therefore, to the data afforded by well records, 

 beginning the discussion at the northern end of the eastern limb of the 

 morainic loop. 



The following record of drift, ^^enetrated in a gas-well boring at the 

 Buckeye Portland Cement Works, near Harper, was furnished by Gr. W. 

 Bartholomew, jr., treasurer of the company. The well mouth is about 

 1,260 feet above tide, and the well is situated in the valley of Rush Creek, 

 about 1 mile east of Harper station, at the edge of a marshy tract. 



Section of drift beds in a gas horing near Harper, Ohio. 



Feet. 

 Blue clay : 15 



Gravel (water stood 7 feet below well mouth) 20 



Clay 20 



Gravel (water stood 15 feet above well mouth) 10 



Clay 20 



Gravel (water stood 17 feet above well mouth) 95 



Yellowish and brown bowlder clay (probably Illinoian) 65 



Helderberg limestone at 245 feet. 



Bartholomew reports that a well for water was bored about a mile 

 north of this gas well. It penetrated 100 feet of drift before reaching a ' 

 water-bearing gravel, thus presenting a marked contrast to the upper 100 

 feet in the gas well. On the bordering uplands the rock surface reaches in 

 places an altitude of 1,400 feet, or nearly 500 feet above the rock floor in 

 Rush Creek Valley. 



A well for water at Benjamin Easton's, near the Hogue Summit, east 

 of Bellefontaine, is reported by the driller, J. A. Hartzler, of Bellefontaine, 

 to have penetrated 350 feet of drift, of which the upper 60 or 70 feet is 

 largely gravel, while the remainder is mainly blue till. No Devonian shale 

 was encountered, the first rock being the Helderberg limestone. The alti- 

 tude of the well mouth is about 50 feet below that of the Hogue Summit, 

 or 1,490 feet above tide. The well Avas not a success in the yield of water, 



