1869.] ULBICH — " NUGGETTY REEF." 333 



granite, dipping east at an angle of 18°, was again struck and sunk 

 into for 20 feet. But as it showed no change of any kind (being solid, 

 and nearly without joint or crack), further sinking was considered 

 useless, under the, no doubt well-founded, supposition that this last 

 granite represented the real massive formation of the rock, dipping 

 this way from the neighbouring surface-boundary, and not, as was 

 at first hoped, a strong vein or bar like those before described. The 

 only exceptional feature met with, whilst sinking the shaft through 

 the metamorphic sandstone underneath the fourth granite-vein, was 

 a vein of white " orthoclase " mixed with some quartz, which com- 

 menced at first quite thin right underneath the former vein, but 

 soon thickened to 3-4 inches, and was never lost for the whole 

 distance sunk, dipping nearly vertically through both the sandstone 

 and the granite. It sadly deceived the poor miners for a good while, 

 as they mistook the felspar for quartz, and considered the vein to be 

 a fresh " making " of the reef. After the shaft-sinking was dis- 

 continued, it was noticed that the relation of the fourth granite- 

 vein to the reef furnished strong evidence of the latter being faulted 

 by the former ; and a cross cut, starting right on the top of the 

 bottom floor of granite, was driven eastward in search of the faulted 

 portion, l^o signs of the reef being, however, met with after a dis- 

 tance of 70 feet was reached, this work has likewise been discon- 

 tinued, and it is now contemplated to cross-cut westward — a di- 

 rection which ought, in fact, to have been tried at first ; for, 

 according to the old mining rule, that the hanging portion of a 

 faulted lode has in most cases slid down in the direction of the dip 

 of the faulter, it is the most likely side on which the reef might be 

 regained (fig. 7). 



The four granite-veins described have, as mentioned in the be- 

 ginning, been observed in the mine of the Alliance Company ; in the 

 the neighbouring mine of the Speculation Company only the second 

 vein that dips in this direction (southward) has as yet been struck, 

 the first vein lying wholly in the Alliance Company's ground, and 

 the third and fourth occurring at a lower level than the workings 

 in this mine have reached. Lately, however, a granite-vein has 

 been struck in it at a depth of 200 feet, which is evidently quite 

 new, i. e. different from the other four veins, as it has only a 

 thickness of 1-2 feet, dips nearly vertically, and runs obliquely across 

 the reef. It is at present exposed in one drive only ; but as the 

 workings progress it will be interesting to observe whether it 

 stands in connexion with the second and third granite-veins, which 

 lie respectively above and below it. 



With regard to the mineral character of the granite of the veins, 

 as compared with that of the granite of the main mass in the imme- 

 diate neighbourhood, hardly any difference can be observed, except 

 that the vein-granite appears to be slightly more quartzose, and to 

 contain perhaps less mica than the other. It can scarcely be 

 doubted that the two lower granite -veins and the bottom floor are 

 still in connexion with the main mass, and would lead up to it if 

 followed northward ; whilst the other veins were originally so con- 



2 a2 



