174 LOWER SILURIAN OF CAPE BRETON — GILPIN 



hematite, but a further examination sliows that, perliaps, a few 

 inches of the rock has been partially replaced by iron oxide, and 

 that often yards away it has only enough iron in it to give a red 

 color. 



Traces of copper pyrites have been found at a few points in 

 these rocks, but there does not seem to have been any igneous 

 action paralleling that of the well-knoM'n copper fields of Lake 

 Superior, and bringing up the metal from lower depths. It may, 

 however, be found on further search that faults along- lines of 

 junction with the older rocks have permitted the accumulation of 

 workable bodies of copper ore in these measures. Iron pyrites 

 is not uncommon in layers of nodules, which at numerous places 

 have made small beds of l)Oo- iron ore, a mineral not of much 

 value until local furnaces are built. The soil overl3dng the 

 Silurian strata is general 1}^ thin and cold, and in many places 

 stony. Hitherto it has not attracted any appreciable amount of 

 farming except at some points in the Mira River Valley, where 

 presumably the present of limestone, &c., has given the soil some 

 little superiority. 



