414 MINING INDUSTRY. 



The formation overlying this calcareous shale is a granular, siliceous 

 limestone ; much of it is completely metamorphosed into beds of hard, com- 

 pact chert, frequently interstratified in their layers with the more calcareous 

 beds. The purer calcareous beds often contain masses and nodules of chert 

 imbedded within them. The top of Telegraph Peak is of the siliceous lime- 

 stone, the immediate summit being composed of a dull, brownish-red chert. 

 The thickness of the siliceous limestone formation is about 100 feet. 



The calcareous shale and siliceous limestone formations occur on the 

 summit of the Base Metal Range, the former covering the long gentle slope to 

 the northwest. (See Atlas-Plate 14.) Upon the east side of the anticlinal 

 fold, overlying the Devonian limestone, are found the shale and limestone, as 

 observed upon the west side. They appear along the east base of the Blue 

 Ridge. From there to the head of Applegarth Canon a few outcrops of the 

 siliceous limestone are found, but the greater part has been eroded off. Fol- 

 lowing the line of the axis of the fold, both formations are found, occurring 

 regularly along the east side of Treasure Hill, where the entire formation 

 appears to be compressed together and thrown up at a sharp angle. The dip 

 of the strata along the east side of the hill is from 32° to 37° to the east. 

 The formation next overlying the siliceous limestone is a black argillaceous 

 shale. The lower beds are quite hard and compact, but rapidly pass into 

 layers more laminated in structure, which, near the top, become quite arena- 

 ceous. Many of the beds carry narrow seams of bituminous matter. These 

 argillaceous shales have a thickness of about 600 feet. The depression, or 

 basin, in which Hamilton is situated, as well as the bottom of the Applegarth 

 Canon, is in this latter formation. At Wliite Pine streams of water and nat- 

 ural springs are quite rare ; nearly all of them occurring in this shale forma- 

 tion. At Hamilton a number of wells have been sunk, furnishing good water ; 

 the same may be said of Applegarth CaSon, where there are several natural 

 springs. 



Mokomoke Ridge has a general north and south trend. The geological 

 structure is very simple. The rocks are perfectly conformable, striking 

 with the trend of the ridge, and dipping at an angle of 22° to the east. The 

 above description does not, however, apply to the ridge, above the saddle, 

 connecting with Treasure Hill, along the southwest side of Mokomoke Moun- 



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