170 Annals of the Carnegie Museum. 



vertical distance between* the two layers in question is 120 feet and 

 the minimum is 76 feet. The strata actually exposed measure 85 feet 

 6 inches, thus showing that the minimum is too small, and the inter- 

 val has been assumed to be slightly above the average between the 

 two figures, and has been placed at 100 feet. Absolute accuracy is not 

 claimed for any of the measurements on account of the varying dip 

 and the physical difficulties of making the measurements on the steep 

 sides of the cuts. 



6. The Mahoning sandstone is rather thin-bedded and seems to 

 yield readily to weathering. This sandstone and the Cow Run sand- 

 stone seem to have been confused with the Buffalo in previous work. 



5. The Upper Freeport coal is being actively mined on the eastern 

 side of Dry Ridge between the old and new railroad tracks. The coal 

 is reported to be very good, but contains a couple of "binders" 

 which have to be picked out. It has been prospected on the eastern 

 side of the anticline, but is not being mined there at present. 



Section at the Grapeville Anticline. 



The crest of the next anticline west of the Fayette anticline crosses 



the Pennsylvania Railroad between Grapeville and the cutting just east 



of the station at Jeannette. In the bank of Brush Creek at Oakford 



Park, a mile north of the railroad and northeast of Jeannette, the 



Upper Freeport coal, three feet thick, is exposed. Fourteen feet of 



sandy shale and 44 feet of heavy-bedded Mahoning sandstone rest 



upon it. The section in the railroad cut at Jeannette is interesting in 



comparison with the similar portion of the section at Donohoe, It is 



as follows : 



Section at Jeannette, Pa. 



II. Yellow and gray sandy shale with plant remains. At the base 



and three feet above the base are thick layers of sandstone. 



Mason shale horizon. 11 ft 11 ft. 



10. Gray clay-shale. 2 ft 13 ft. 



9. Coal. 10 in. Mason 13 ft. 10 in 



8. Gray structureless clay. 14 ft 27 ft. 10 in. 



7. Gray sandy shale with nodules. 21 ft 48 ft. 10 in. 



6. Very carbonaceous shale, almost coal. May be the horizon of 



the Upper Gallitzin. i ft. 6 in 50 ft. 4 in. 



5. Thin-bedded black shale, with great numbers of specimens of 



Carbonic ola 2^\A Spir or bis. i ft 51 ft. 4 in. 



4. Gray shale and thin layers of limestone which contain fresh-water 



invertebrate fossils. 4 ft. 6 in 55 ft- lo in. 



