THE DEVONIAN SECTION NEAR ALTOONA, PA. 621 



OLIIl DAY5BURG QUAQRANGLE 



Fig. 3 



micaceous shale. Bands of fine-grained, bluish sandstone occur, 

 but they are infrequent and rarely a foot thick. These sandstone 

 layers are often very uniform in thickness, and are divided by joint- 



