VI. SOME SECTIONS IN THE CONEMAUGH SERIES BE- 

 TWEEN PITTSBURGH AND LATROBE, PENNSYLVANIA. 



By Percy E. Raymond. 



During the last few years the Pennsylvania Railroad has made many 

 new cuttings in straightening and improving its main line in western 

 Pennsylvania, and some of these excavations between Pittsburgh and 

 Latrobe have exposed strata which could not be well seen in the ex- 

 posures previously available for study. The two big cuts between 

 Donohoe and Beatty near l.atrobe in Westmoreland County are par- 

 ticularly interesting as they expose a nearly continuous section about 

 450 feet in thickness, permit the identification of the various horizons, 

 and correct some errors into which previous workers have been led by 

 the incomplete exposures available at the time the surveys were made. 



In the Report of the Second Geological Survey of Pennsylvania, 

 Volume KK, Dr. Stevenson gave two sections, one east from Georges 

 Station and including the strata in the tunnel through Dry Ridge, and 

 one west from Beatty. In neither of these sections are the horizons 

 identified except in relation to the Pittsburgh coal, and in each there 

 are a number of concealed intervals. The sections which are here 

 given serve to supplement and to some extent to explain the older 

 sections. 



The big cut through Dry Ridge just east of the station at Donohoe 

 is on the western side of the Fayette anticline, and the dip is strongly 

 northwest. In the middle of the cut it is about i foot in 16. The 

 dip becomes less as the summit of the anticline is approached, but all 

 the strata of the Conemaugh series below the Cow Run sandstone and 

 thirty to forty feet of the strata of the Allegheny series are brought up 

 above the level of the railroad track before the dip changes. Just be- 

 yond the semaphore, a mile and a half east of Donohoe, the dip 

 changes to the southeast. From that point there are no good ex- 

 posures until the western end of the big cut west of Beatty is reached. 

 There the strata from just below the Pine Creek limestone to the clay 

 on top of the Birmingham shale are exposed. In the low cuttings 

 east of this big cut the Morgantown sandstone and the Clarksburg 



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