Elevation: 6,017 feet
The Kendall claim adjoins the Sandstorm on the north and, with the Argosy and Oregon claims, is the property of the Goldfield Kendall Mining Company. The principal workings are on the Kendall claim and on the same ledge as those of the Sandstorm. The mine was first worked by lessees, but was being operated by the company in 1905. The total production to the end of that year was about $100,000. Little work has been done on the Kendall of late years, and the following description applies to the mine as it was in 1905.
The main shaft of the Kendall mine is vertical, and at the end of 1905 was about 200 feet deep, with levels at 60 and 100 feet. Sinking was then in progress. Above the 60-foot level are some small tunnels and some irregular stopes and drifts. All the stoping at the time of visit had been done between the 60-foot level and the surface.
The Kendall shaft is sunk in Sandstorm rhyolite, which, as shown in Plate II, here forms a narrow strip between an area of Kendall tuff on the west and the Milltown andesite on the east. At a depth of about 135 feet the shaft passed into this tuff and continued in it for about 20 feet. It then passed into rhyolite of the intrusive Morena type, and continued in this rock to the bottom. The exact thickness of the tuff where it is penetrated by the shaft is not measurable, as the lagging of the shaft conceals the contacts. The general relation of these rocks is shown in section in figure 29 (see figure in gallery).
The tuff, as exposed at the surface, appears to pass beneath the Sandstorm rhyolite on the north, west, and south, but to be cut off on the east by a fault. (See PI. II.) This fault is well exposed on the 60-foot level, about 27 feet west of the shaft. There is not much brecciation of either rock, but the plane of movement is marked by a distinct gouge. The fault plane at this place dips about 40° E. It truncates the flow banding of the rhyolite, which dips about 25° W. The tuff probably rests upon Morena rhyolite about 150 feet below the surface. This rhyolite is doubtless intrusive into the tuff, but the contact has not been exposed except in the shaft.
On the 100-foot level a crosscut has been driven east through the Sandstorm rhyolite into the andesite, as shown in figure 29. The contact lies about 135 feet east of the shaft on this level, and appears to be the result of faulting. The andesite is soft and altered and is either tuffaceous or has been brecciated by movement. The faulting is probably local and is thought to represent minor displacement along a contact which originally was a rhyolitic surface over which the andesite flowed.
This same plane of movement, which dips about 35° E., is exposed in a tunnel just north of the main Kendall shaft. Near the mouth of this tunnel a shaft goes down through about 95 feet of andesite to the same contact. This shaft was not in good condition in 1905, but the dump indicated the presence of soft gouge like material at the base of the andesite and showed considerable pyritization of this rock in its lower part.
The Kendall ledge is the same as that of the Sandstorm mine. It is an indefinitely bounded zone of silicification in the effusive rhyolite. It was doubtful at the time of visit whether the ledge could be recognized at all below the point where the shaft enters tuff. The rhyolite in the bottom of the shaft contained much alunite, but this kind of alteration is so widespread in the Morena rhyolite as to be practically useless as a means of distinguishing typical ledge matter from country rock.
At the time of visit, near the end of 1905, no ore had been found below the 60-foot level.
Considerable rich ore was found by lessees at the surface, pockets of soft auriferous material having been gouged out from the hard, low-grade, siliceous part of the croppings. Subsequently ore was found, much as in the Sandstorm, in the form of small irregular bunches very erratically distributed through the ledge. The dependence of these rich bunches, however, upon transverse fissures was clearly shown, these fissures, which are neither regular nor persistent, having generally northwest-southeast trends.
The ore is entirely oxidized and no sulphide ore has yet been discovered beneath it. It is usually a soft mixture of kaolinite, quartz, limonite, and native gold, with abundant barite in crystals up to an inch or more in length. As in the Sandstorm mine, the barite crystals are usually implanted on silicified rhyolite with their free ends embedded in kaolinite or kaolinitic ore. No alunite has been noted in the Kendall ore, although this mineral is abundant in the bottom of the shaft.
Source: The Geology and Ore Deposits of Goldfield Nevada. USGS professional paper 66, 1906