70 GEOLOGICAL REPORT. 



300 yards of the range of the shafts, where Sandstone is found 

 both on the top and sides. At the eastern extremity of the 

 ridge, the Magnesian Limestone is almost perfectly horizontal, 

 with no perceptible dip, until it approaches the Sandstone, when 

 it is seen dipping down for a short distance, at an angle of ten 

 or fifteen degrees, to the west. This Sandstone continues west 

 for about 600 feet, visible at points, both on the top and sides 

 of the ridge ; but no other rock was seen (excepting on the 

 south side, and near its base, where Dr. Shuniard measured a 

 brecciated mass, eighteen feet high, consisting of chert and 

 Magnesian Limestone, until passing a short distance west of the 

 range of shafts, where the Magnesian Limestone was again vis- 

 ible, with, at first, a dip of ten or fifteen degrees to the east ; 

 but a short distance further west, on the same ridge, it was 

 horizontal. In the Sandstone, whether exposed on the ridge, or 

 examined in the driftings, I found no appearance of stratifica- 

 tion. The surface of the ridge is so covered with soil, that it 

 is impossible to examine the eastern and western junctions of 

 the Sandstone, with the Magnesian Limestone ; but I infer, from 

 examination of the driftings in the mine, that the western junc- 

 tion is irregular, with a general course across the ridge of about 

 N., 20 "W. ; and that along this line, there is, in all probability, 

 a space, for some distance beneath the surface, filled witli the 

 debris of the two rocks. 



" Most of the mining done has been in a space, irregular, so 

 far as explorations have shown, the direction of which is across 

 and extending below the base of the ridge, and with a general 

 course of about north, twenty degrees west, and of an estimated 

 width of from forty to sixty feet, bounded on the east by Sand- 

 stone, and on the west by Magnesian Limestone. This, so far 

 as explored, is found filled with tumbling rock, clay, chert, 

 calc spar (semi-crystalline, and colored red by peroxide of iron), 

 masses of iron ore and copper ores. 



" From the vertical section, it will be seen that there are five 

 shafts, the deepest of which (engine shaft) is 115 feet, and in 

 which is the pump, worked by a steam engine. In sinking it, 

 tumbling rock, of a magnesian character, was found through 

 its entire depth, and it is cribbed from top to bottom. This 

 shaft is connected by a level, 145 feet in length, with a shaft 

 ninety feet deep, north of it, and thus connecting with the main 

 works in the north hill. At the time of my last visit this level 



