ALLEGHENY FORMATION OF WESTERN PENNSYLVANIA BASINS 97 



shale. All of the limestones are here. In the central and northwestern 

 parts of the county the whole interval from the Van port down is filled 

 with sandstone, mostly massive, but the normal condition exists in the 

 north central part, where one finds the Middle and Lower Kittanning, 

 55 feet apart, and the Scrubgrass, or Upper Clarion, directly underlying 

 the Vanport limestone, is 35 feet above the Brookville, which rests on the 

 Homewood sandstone. The coal beds of the Kittanning and Clarion 

 groups, though persistent and at times of workable thickness, rarely 

 yield good coal. The Lower Freeport, somewhat variable in thickness, 

 is important, as it yields good coal, while the Tipper Freeport, equally 

 persistent, is of little value. The Vanport limestone changes in the 

 northwest part of the county into cherry limestone, and then into cal- 

 careous sandstone. Eastwardly it thins out and seems not to extend 

 beyond the middle of the county. Of the other limestones the Johnstown 

 cement is present in sections showing its place, the Lower Freqport is very 

 irregular, and the Upper Freeport, persistent in the east and south, is 

 apparently absent in the middle and northwest portions. The great 

 sandstones are represented usually by shale.* 



Indiana county is south from Jefferson and its larger part lies west 

 from Chestnut hill. A narrow area exposing the Allegheny stretches 

 along the west slope of that ridge from Jefferson county to the Cone- 

 maugh river, whence it extends southwardly across Westmoreland and 

 Fayette into West Virginia. 



Near the Jefferson border the Upper Freeport shows the structure so 

 often observed in the Second basin and is 5 feet 2 inches thick, but yields 

 worthless coal. The interval to the Lower Freeport is 75 feet and both 

 limestones are present. The Upper Kittanning at 50 feet lower shows at 

 one locality the feature observed already in that bed as well as in the 

 Lower Freeport and to a somewhat less extent in the Middle Kittanning, 

 thus: 



Feet. Inches. Feet. Inches. Feet. Inches 



Bony coal or cannel.... 13 8 3 12 



Coal, good but friable... 2 7 2 7 2 7 



The upper division has 21 to 24 per cent of ash and the lower 1.6, while 

 the sulphur is practically the same in both, .621 to .654. This "pot" of 

 thick cannel embraces only a few acres. The Johnstown cement lime- 

 stone is here with the Gorman coal bed 3 feet thick and 2 feet below the 

 limestone. The Lower Freeport farther south is very irregular; the 

 Vanport was not seen by Mr Piatt, but Mr Bichardson has recognized it 



* W. G. Piatt: Jefferson (H 6), pp. xxx-xxxii, 100, 111, 187, 190, 199. 

 X — Bull. Geol. Soc. Am., Vol. 17. 1905 



