102 J. J. STEVENSON CARBONIFEROUS OF APPALACHIAN BASIN 



the same as in the last. The interval between Upper Kittanning 

 (Darlington) and Lower Kittanning in western Armstrong varies from 

 95 to 117, that between Lower Freeport and Lower Kittanning remaining 

 the same, while in central Butler, Doctor Chance's section shows about 

 85 feet to the bottom of the Lower Kittanning, differing little from the 

 interval in these measurements by Doctor White. The Lower Kittan- 

 ning is from 3 to 11 feet thick and one of its benches yields good coal; 

 the other beds are without value. The Butler and Kittanning sand- 

 stones are massive. In the southwest corner of the county the Freeport 

 coal beds are 45 feet apart and the Darlington (Upper Kittanning) is 

 145 feet below the Upper Freeport. The Freeport sandstone is massive 

 and the Upper Freeport limestone is present in most of the sections. 



On the Connoquenessing the Freeport coals are of little value and are 

 55 to 80 feet apart. The interval from the Lower bed to the Darlington 

 varies from 43 to 70 feet, the smaller interval being on the western border, 

 where the Darlington is barely 125 feet below the LTpper Freeport. At a 

 few miles north from this exposure a coal bed, known as the Eichenaur 

 and commonly supposed to be a' local bed, is seen at 115 feet below the 

 Upper Freeport. It is variable, cannel on top, coal below, but changing 

 into bituminous shale. This is very like the L T pper Kittanning (Darling- 

 ton), which in the neighboring township of Forward is only 120 feet 

 below the Upper Freeport. The Freeport and Butler sandstones are 

 usually massive along the Connoquenessing valley. A boring in Forward 

 township shows the whole interval from the Home wood sandstone up to 

 what may be the Middle Kittanning coal bed filled with sandstone. The 

 Freeport limestones appear in most' of the sections, none of which goes 

 down to the place of the Vanport. The coal beds are poor and of no 

 economic importance, though the Lower Freeport and Upper Kittanning 

 (Darlington) are mined for local use.* 



The northern border of the Allegheny formation, owing to shallowing 

 of the synclinals, falls southwardly toward the west, so that in Mercer 

 county, west from Venango and Butler and extending to the Ohio line, 

 one finds rocks higher than the Vanport (Ferriferous) limestone only in 

 the southeast corner near the Butler line. Doctor White's sections show 

 the Lower Kittanning at 45 feet above the Vanport limestone and at the 

 same distance below a coal bed termed the Darlington locally. The 

 Darlington of Mercer is not the same with the Darlington of southern 

 Butler ; that of Mercer is the Middle Kittanning ; that of southern Butler 

 is the Upper Kittanning. The Mercer County measurements are only 



* I. C. White: Southern Butler (Q), pp. 90, 92, 94, 95, 110, 111, 112, 117, 119, 120, 

 130, 133, 135-139. 



