460 GLACIAL FORMATIOMS OF ERIE AND OHIO BASINS. 



In Neshannock Valley east of Mercer the drift iu an oil boring made 

 several years ago was thought by citizens of Mercer to be fully 100 feet in 

 thickness. In the valley of Neshannock Creek at Leesburg, in southern 

 Mercer County, White reports^ a well which penetrated 90 feet of sand 

 and silt, reaching a level 80 feet below the creek. 



In the west part of Newcastle Mr. Davison has a well 150 feet deep 

 which extends to a level 50 feet below the Shenango River and does not 

 reach rock ; it is principally through till, but has some quicksand interstrat- 

 ified. In the north part of Newcastle there are heavy deposits of gravel 

 which have a capping of till a few feet thick, some excavations showing a 

 depth of 50 to 60 feet of gravel. The top of the gravel is about 900 feet 

 above tide, or 115 to 120 feet above the level of the Shenango River. In the 

 southern part of the city, on the east side of the river, many exposures of the 

 drift are made in grading streets. They show an interbedding of till and 

 gravel, the beds lying in oblique attitudes, rising usually towai'd the south. 

 In one exposure the till is interbedded with a fine sand, and both are arched 

 and disturbed. In this exposure considerable variation in the color of the 

 till is displayed, some of it being a very dark blue, while both above and 

 below it there is a yellow or brown till. In one exposure a thin bed of blue 

 till rises toward the south and thins out, finally disappearing at a level about 

 15 feet above the northern end of the exposure, 2 or 3 rods distant. There 

 are also exposures where poorly assorted gravel, cobble, and small bowlders 

 are imbedded together in a matrix of sand. In the extreme south end of 

 the city large gravel pits are opened, in one of which the following peculiar 

 exposure was found : There is assorted material next the bluff's, the lower 

 portion of which grades horizontally into till in the direction of the vallej", 

 and this till is overlain by gravel in contorted beds, as if disturbed by the 

 ice sheet after deposition; yet this upper gravel has a nearly plant? surface 

 like a terrace. 



White reports^ a well in Newcastle, near the mouth of the Neshan- 

 nock, made by Reis, Brown, and Bergher, which penetrated (1) gravel 15 

 feet, (2) blue mud and quicksand 125 feet, and here struck "slate." The 

 altitude of the well mouth is 803 feet above tide. Mention is also made in 

 a general way ^ of several deep drift sections from near the junction of the 

 Mahoning and Shenango and along Beaver River. 



' Second Geol. Survey Pennsylvania, Kept. Q^ p. 83. ^ Ibid., Kept. Q^ p. 184. '' Ibid., Kept. Q^ pp. 

 13-18. 



