278 GEOLOGICAL EXCUB8ION TO THE ROOKY MOUNTAINS. 



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this distance the track crosses, more or less obliquely, 

 several rather low and Hat tol.ls of CTpper Silurian and 

 Devoni&D strata, and finally reaches 



Cumberland. Although it contains but 13,000 inhabi 

 hints, this is the largest place in Maryland, next to Balti- 

 more. It has considerable importance as the center of the 

 coal industry of western Maryland and from the- manufac- 

 tureof Portland cement of exeellentquality. Geologically, 

 Cumberland is important because it affords one of the most 

 complete sections of the entire Paleozoic series to be found 



anywhere within the Appalachian System. This is not seen 



to the best advantage along the railroad line, which here 



eiders upon a southwesterly course, hut by following up 

 Wills Creek and Jennings Hun, which head in the Krost 

 burgcoa] basin. On the west side of the town rises an 

 abrupt K to S. ridge, Wills Mountain (fig. 6). This is com- 

 posed of red layers of the lower Medina (IV), capped by 

 the massive, white bed of the Same horizon, which forms 

 an anticlinal fold whose eastern Hank dips gently east 

 while its western plunges downward nearly vertically. ( >n 

 the east side of this axis, in the city itself, may be seen in 

 succession Clinton, Niagara (V), Salina, Belderberg (VI), 

 Oriskany (VII), and Hamilton beds (VIII). all Idled with 

 their characteristic fossils. On the west side of the 

 mountain, owing to its abrupt downward plunge, the series 

 is still more complete and extends, within a short horizon- 

 tal distance (8 miles), to the top of the Coal Measures. 



Above Cumberland the road follows the, river in a south- 

 west direction as far as Keyser. parallel with the, strike of 

 the beds, and along the west base of Knobby Mountain. 

 This mountain is made of Salina and Belderberg beds, 

 capped by Oriskany sandstones, which are visible in the 

 cliffs. On the right (west) can be seen the first range of 

 the Alleghany Mountains, which is capped by the I'otts- 

 ville conglomerate (millstone grit), the Mountain lime- 

 stone, Pocono sandstone and Chemung beds forming the 

 intervening slopes, while the valley at the base is in Ham- 

 ilton shale. 



At Bradys, in limestone concretions of the Ilelderberg 

 limestone, have been found beautifully and curiously de- 

 veloped crystals of celestite. 14 



On the left, before entering the town of Keyser, are quar- 

 ries in Ilelderberg limestone, and on the right, el ill's of 



