' Beaver County, Pennsylvania. 17 



is taken out than suffices to supply the needs of those min- 

 ing ; and when from any cause it becomes inconvenient to 

 work at an opening any longer, it is deserted and allowed 

 to fall down, to the great detriment of the property. 



The Ferriferous Limestone is of interest, both because of 

 its fossils and of the variations in its thickness and quality. 

 On Trough Run it is only eight inches thick; two miles 

 below, on Rippling Run, it is eight feet; while on the other 

 side of the river, and directly opposite the latter locality, it is 

 only one foot. Traced northward, fifteen miles from New 

 Brighton, it is found to be twentj'-five feet thick at Wam- 

 pum. Opposite the bridge over Block House Run, near 

 New Brighton, it is seven feet thick. From it, at this 

 locality, a very good hydraulic cement was manufactured by 

 the Pittsburg and Eric Canal Co., which was used by them 

 in building their locks. At Wampum it is extensively 

 quarried to supply the iron-furnaces at Pittsburg, Alleghany, 

 and other cities in the vicinity. Everywhere it is richly 

 fossiliferous, and from various localities the following species 

 have been obtained : Productus JSfebrascensis, P. semi-retic- 

 ulatus, P. longispinus, Spirifer linealus, Sjjirifer sp. ( ?) , 

 Athyris sublilita, several species of Platyceras, Pleurotomaria 

 turbinella, P. Grayvilliensis, P. perJiumerosa, Polyphemop- 

 sis peracuta, Polyp he mopsis sp. (?), Euomphalus rugosus, 

 LophophyUum proliferum. 



The Clarion Coal is finely exposed in the vertical cliffs 

 above New Brighton and below Trough Run, presenting a 

 black band, which is conspicuous for some distance alono- 

 the river. It never exceeds eighteen inches in thickness, 

 but is said to be of remarkably fine quality. 



The Droohville Coal is traceable with some difficulty. In 

 a small gully, emptying into the Beaver River, opposite New 

 Brighton, this seam is double, the two parts separated by 

 four feet of shale. The bed is of no economic value. 



The Shale, No. 7, is fossiliferous. On Trough Run I ob- 

 tained from this stratum the following species : Productus 

 jult, 1874. 2 Ann. Ltc. Nat. Hist., Vol. xi. 



