626 



CHARLES BUTTS 



The peculiar dimpling of the bedding surfaces shown in Fig. 7 is 

 said to be characteristic of the Nunda beds in New York. In the 

 fourth cut, 7,750 feet west of the station, a few bands up to i foot 

 thick of compact or shaly, chocolate-colored rock occur, and similar 

 rock is exposed in a cut along the incline No. 10 on the old Portage 

 Railroad. These layers may be the attenuated representatives of 

 the Oneonta phase of sedimentation in eastern New York. The 



Fig. 6 



thickness of the formation measured along the Pennsylvania Rail- 

 road appears to be about 1,400 feet. 



In Blair County the bottom of the Nunda formation is sharply 

 marked by the top of the Genesee shale. The top of the formation 

 is, however, very indefinite. No persistent and easily recognized 

 stratum separates the Nunda from the succeeding Chemung forma- 

 tion, nor is there any distinct lithologic change to mark the boundary. 

 The rocks of the one merge into those the other by imperceptible stages. 

 The boundary, as established by the writers, rests on a paleontologic 

 basis. All the beds above the Genesee, and below the horizon at 



