108 



Less frequently what are called flots {notjlats) or irregularly 

 ramifying strings and sheets of ore, traverse the rock adjoining the 

 vein in planes ranging within a few degrees of the perpendicular to 

 the plane of the fault, in such a manner as occasionally to give rise 

 to a kind of stratified appearance. 



Our galena is generally met with in the form of the cube ; but 

 other forms belonging to the Cubic System are far from uncommon, 

 and beautiful examples of octahedral crystals, many of them of 

 large size, have been met with at Dufton, Helton, Murton, and 

 elsewhere. 



Galena occurs here and there through all the great upland tract 

 of Carboniferous rocks that extends away to the east and the 

 north-east from the Pennine Faults. It is worthy of remark that 

 hardly a trace of any lead ore has yet been detected in the portion 

 of the self-same Carboniferous rocks that occupies the low ground 

 of Edenside on the skirts of the Lake District, notwithstanding 

 that the beds of rock are, above a certain horizon, identifiable bed 

 for bed, and are in almost perfect agreement even in minute 

 particulars with the rocks wherein most of the ore has been 

 obtained in the more elevated tracts. Yet these same Carbon- 

 iferous rocks on the outskirts of the Lake District are traversed by 

 faults and smaller fractures in exactly the same way as are the 

 ore-yielding beds just mentioned. This would seem to prove that 

 the ore has not always been derived from the rock adjoining the 

 veins, if it has been so derived anywhere else. Here and there 

 the older rocks that compose the Lake District have yielded 

 galena ; but, although it is true that, in individual mines, very large 

 quantities of ore have been derived from veins traversing these 

 older rocks, the metalliferous veins occur in a more sporadic and 

 disconnected way, and the yield of ore is even more uncertain than 

 it is in the metalliferous part of the district occupied by rocks of 

 the Carboniferous Limestone series. 



In regard to the origin of the ore occurring in our district, a 

 series of observations extending over a mining area of several 

 hundred square miles, has led me to conclude that our ore dates 

 from comparatively recent times, geologically speaking ; and that 



