MAIN MORAINIC SYSTEM IN THE GRAND RIVER LOBE. 461 



111 the vicinity of Edenburg- several wells were drilled at the time of 

 the oil excitement of 1861 to 1864. They showed the existence of a broad 

 deep valley there that in places extends 175 to 200 feet below the lowland 

 tract along the river, or to a level scarcely 600 feet above tide. The 

 significance of this deep excavation is discussed on pp. 150-151. 



Near Mount Jackson, on the uplands west of Beaver River, at an 

 altitude about 1,200 feet above tide. White notes ^ wells 40 feet deep as 

 not reaching rock, and also^ drift 30 feet thick on the uplands bordering 

 Beaver River near Wampum at an altitude 275 feet above the stream. The 

 latter point is very near the southern margin of the drift. 



Near New Galilee the Pittsburg, Fort Wayne and Chicago Railroad 

 has a large gravel pit, a brief description of which is given by Wliite.^ 

 It has a depth of 60 feet and exposes "rounded bowlders of granite, lime- 

 stone, sandstone, etc., together with fragments of coal and much coarse sand, 

 filling up the intervals between the bowlders and also occurring in irregular 

 lenticular masses by itself" The top of this pit is stated by White to be 

 130 feet above Little Beaver River. In the publication referred to. Pro- 

 fessor White considered it a remnant of a terrace, but in a subsequent report * 

 he considers it independent of Little Beaver River. His later decision is 

 sustained by the fact that the moraine-headed terrace on this creek is but 

 15 to 20 feet above the stream at the point where it leaves the moraine. 



In Columbiana County, Ohio, no wells showing a large amount of 

 drift have come to the writer's knowledge. The general thickness on the 

 uplands is as great as in western Pennsylvania, and it is probable that some 

 of the valleys are deeply filled with drift. 



In Mahoning County, Ohio, heavy drift deposits are exposed along the 

 south bluff of Mahoning River, the thickness in jDlaces being as great as 

 75 feet. In the river valley several deep wells have been made which show 

 a variable thickness of drift. Two borings at Niles were reported by 

 Fosliay to penetrate a large amount of drift; one at the Niles Rolling Mill 

 has 190 feet, striking rock at a level about 170 feet below the river bed; 

 the other at a farm house north of the city is 175 feet deep and does not 

 reach rock, though it terminates at a level about 150 feet below the river. 



Between Niles and the State line no borings in the Mahoning- Valley 



^Second Geol. Survey Pennsylvania, Kept. Q^ p. 8. ^Ibid., Kept. Q'', p. 14. 



2 Ibid., Kept. Q^E^ , nbid., Kept. Q', p. 17. 



