1847.] Geology of Letvis County. 319 



overlaid by the lead, which was in turn invested by calcareous 

 spar, in broad crystals, with curved faces. 



Occasionally surfaces, spangled with brilliant crystals of sul- 

 phuret of iron, were found in this part of the mine. The usual 

 crystaline forms of the spar were the six-sided prism with trihe- 

 drial pyramids; the slender pyramid, or dog-tooth spar, often 

 coated by sulphuret of iron, and the variety known as the nail- 

 head spar, formed by two low three-sided pyramids placed base 

 to base, without any intervening prism. 



In addition to the forms here mentioned, calcareous spar occurs 

 in a ravine, east of Martinsburgh village, crystalized in the pri- 

 mary form, wath cleavage parallel with the faces of the crystals. 

 They are of a straw color, about half an inch on a side, and quite 

 free from striffi. 



The " lead mines" were wrought for about two years, but never 

 with a success sufficient to cover any considerable portion of the 

 expenses; and after the erection of a furnace for reducing the ore, 

 and an unprofitable outlay of many hundred dollars, were finally 

 abandoned. 



The mania for mining speculation was not confined to the en- 

 terprise above mentioned; but several unsuccessful attempts were 

 made in various parts of the county to procure lead, " silver," and 

 other metals, in the Trenton limestone, but with the same result. 

 One of these excavations on Whetstone creek, about a quarter of 

 a mile east of the State road, deserves notice, from the beauty of 

 the specimens of calcareous spar which it afforded. These lined 

 the surface of the rock in its seams and crevices, and occasionally 

 detached masses of stone in these fissures were completely invest- 

 ed by them. A few crystals of galena, (silver!) and pyrites, 

 (gold!) were found at this locality. 

 "These results of mining enterprise, undertaken in the Trenton 

 limestone, would seem to indicate that this rock cannot be de- 

 pended upon as a metaliferous depository; and it is quite probable 

 that these veins do not extend down through the Birdseye, since 

 the latter rock is never found traversed by veins of spar, or ex- 

 hibiting any trace of the metals. Should such be the case, these 

 metals must have been derived from the rock itself, and separated 

 from its substance by their chemical attractions; a supposition 

 that is rendered more probable from their occurrence in successive 

 laminse upon the walls of the veins. 



The Trenton limestone occupies two terraces, extending through 

 the county, and nearly parallel with the river. They are, how- 

 ever, very irregular in outline, and occasionally broken by broad 

 valleys, that come down from the northwest. 



So irregular are these terraces of the rock, that in some places 

 they can scarcely be recognized, while in others they are united 



