white] CUMBERLAND TO THE OHIO RIVER. 281 



*' fossil ore n (d) was once mined here, and has the same appearance and 

 fossils as m Mew York and Pennsylvania. 

 Salina scries, ( VI) thickness 680 feet. 



Feet. 



(«) Red shales and thin, light-colored Limestones with marly shales S00 



(6) Water lime, a bed of dark, magnesian limestone, from which the famous 

 "Cumberland cement" has long been manufactured; finely exposed at 

 the quarry along the Weal Virginia Central and Pennsylvania railroads 



in Cumberland, thickness 30 



(c) Gray and yellowish, thin-bedded, sparingly fossiliferous, impure limestones. 350 



Lower Helderberg series ( IT), thickness about 350 feet. 



Massive gray and dark-colored limestones, many of the layers quite 

 pure, and a splendid flux for iron ores, richly fossiliferous; finely exposed 

 at Cumberland, and from there southwestward to Keyser, a distance 

 of 24 miles, 



Oriskany sandstone ( FIT), thickness 75 to 100 feet. 



A coarse, dirty yellow, calcareo-siliceous rock, highly fossiliferous 

 (mostly casts); makes Knobby Mountain, which starts at Cumberland 

 and trends away to the southwest: often forms great dill's along the 

 Baltimore and Ohio Railroad, between Cumberland and Keyser; one 

 of these just east from Keyser is known as Bull Neck, and here the 

 railroad passes across the Oriskany in a cut through a sharp syncline, 

 making a tine exposure of the rock and its fossils. The high cliff just 

 opposite Keyser, across the Potomac River from the Baltimore and 

 Ohio station, is made by this rock, and is known as Queens Point. 

 From Cumberland eastward this stratum is quite massive and often 

 forms ridges 1,000 to 1,200 feet high. 



At Cumberland the Baltimore and Ohio Railroad, main line, turns 

 southwestward, following up the North Potomac River, and hence 

 runs along the strike of the rocks to Keyser, 24 miles from Cumberland, 

 so that not only the Oriskany sandstones, but all of the other beds 

 below it, down to the Medina white sandstones, are frequently seen 

 between the two points. 



The Oorniferous Limestone appears to be absent entirely from the 

 Alleghany Mountain region, since although a thin, earthy limestone 

 (Selinsmove) is present a few feet above the Oriskany at many points, 

 it evidently belongs to the Marcellus epoch of the Hamilton. 



Hamilton shahs, ( 17//). A series of black slates, olive shales, and 

 dark gray sandy beds, with an earthylimestone near the base, all quite 

 fossiliferous. These beds underlie t he station site .in Cumberland, and 

 are partially exposed just east from it in acutting; also exposed in the 

 vicinity of Keyser. 



These rocks make valleys wherever they extend, and hence are 

 usually covered up and concealed from view by soil and detrital mat- 

 ter, so that the exact thickness can not be determined, but estimating 



