The most easterly claim is called the Sampson, and from it has been shipped some rich ore, the claim producing the highest grade ore, I am told, of any mine on the vein. This claim is joined on the westward by the Morning Star, a deep cañon separating them. From the bottom of this cañon it is 800 feet to the summit of the mine, 1,500 feet farther west. The Morning Star Mine has been quite extensively opened by tunnels and shafts, but for several years past assessment work only has been done, as the ore which was found was too low grade to make shipping profitable.
The Meteor, Mammoth Chief, and Desert Queen succeed each other, respectively, going west. On the Mammoth Chief and Meteor, a great deal of work has been done; and it is claimed ore was shipped approximating $40,000 gross value. At any rate the owners have developed their claims and made a good living at the expense of the ore thus shipped from the vein. On the Meteor a shaft has been sunk a depth of 100 feet, at the bottom of which a drift 40 feet in length has been cut along the vein on an ore shoot which was followed down from the surface. At another point on this claim a shaft of 65 feet in depth has been sunk in ore. A drift at the bottom of this shaft is also in ore, 8 feet of which is exposed and the foot wall not yet reached.
The ore at this point is said to average 30 ounces. I was told that the average of the ore throughout the mine was about 25 ounces, ranging from 12 to 75 ounces, and occasionally much more. Numerous cuts, shafts, and drifts, some of them of considerable size, have been made along the vein on the Meteor and Mammoth Chief for a distance of 800 feet, and although these workings are not connected they have the appearance of being on one shoot of ore. One fact is very evident from an examination of the mine, and it is one of considerable importance. It is, that the ore is of better grade and occurs in greater quantity in the vicinity of the felsitic dike, which, though undoubtedly later than the vein itself, seems to have enriched the ore very materially. The largest shoot of ore I saw has formed very close to the point of intersection of the felsitic dike with the main vein. On the Desert Queen a long tunnel and several crosscuts have exposed ore bodies, some of which contained upwards of 200 ounces silver per ton.
The Imperial lode is one of the most promising veins of which I have any knowledge, but it requires considerable capital to properly and systematically open it. The rock is extremely hard, and the lack of wood and water are drawbacks which prevent the owners from working the mine as it should be worked. It would be difficult to find a vein offering greater natural advantages than are found here, excepting as to wood and water, both of which are obtainable under the usual conditions attending that problem on the desert. Water can be found in the dry lake 3½ miles distant by road, and 1,160 feet below the level of the cañons which cut the vein.
Coal may be delivered at Lavic Station, 5 miles from the lake, for about $9 or $10 a ton. The difficulties are no greater than at Calico, where they seem to have been overcome quite easily. Tunnels may be run in on the vein, getting average backs of about 350 feet above the bottom of the cañons.
Should ever this great vein be worked on a larger scale with abundant capital, a tunnel started at the lake will cut the vein at an average depth of 1,500 feet. Such a tunnel would probably be about 12,000 feet in length. The ore shoots seem to have an average width of about 5 feet as far as exposed, and none of the workings in ore have ever reached the bottom of a shoot. It is one of the most imposing looking veins I ever saw. On the Desert Queen the soft hanging wall has been eroded, leaving the vein standing exposed for fully 80 feet in height.
THE TIPTOP MINE.
About 4,000 feet south from the Imperial lode there is a mine of unusual character and interest, called the Tiptop. Originally a silver mine, it is now producing a high-grade copper ore, which is being shipped to Swansea, Wales.
The Tiptop was discovered in 1890, by the strong outcrop of an ore shoot. The country rock on both sides of the vein is quartz porphyry, similar to that inclosing the Imperial lode. The ore occurs along a fault plane, or rather a series of parallel faults, as the result of substitution of ore for the original rock. The faulting of the rocks has resulted in an extensive crushing and breaking up of the porphyry along the line of fracture, exposing large surfaces of rock, thus facilitating the deposition of mineral. As mentioned above, the faulting seems to have consisted of several fractures, nearly or quite parallel, between which the rock was crushed or ground to powder. In places this ore body would seem to possess well-defined walls, but moving in either direction along the strike of this zone the “wall” proves to be simply a faulting plane, beyond which ore again occurs. The result of these parallel fractures is to give to the deposit an appearance of banded structure, like that sometimes noticed in simple fissure veins. This apparently banded structure is entirely due to the planes of displacement.
