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The Dayton iron deposit, in Lyon County, Nev., was studied and explored in 19^2 "by the Federal Geological Survey and the Bureau of Mines. It is a con tact-me tamo rphic deposit in partly metamorphosed and folded sedimentary beds of unknown geologic age, which are intruded by granitic rocks. Most of the ore is on and near the crest of a southward-plunging anticline. Magnetite is the main ore mineral, and is accompanied by pyrite, epidote, garnet, and unreplaced minerals of the original rocks. Hematite and limonite have been formed near the surface. Exploration has revealed two bodies of ore in the main part of the deposit. The larger is an irregular lenticular "body near the crest of the anticline. The other, which lies farther north, is in steeply dipping rocks and is of unknown shape. Still farther north are scattered smaller bodies of ore.The total reserves are estimated to "be about 5,500,000 long tons of ore containing more than UQ percent of iron and averaging U? percent, or 9,700,000 long tons of ore containing more than 30 percent of iron and averaging U3+ percent. Owing to the presence of pyrite, the sulfur content of the ore is about ^ percent.

Tin-bearing veinlets are exposed in a small area near Izenhood Ranch, 22 miles north of Battle Mountain, Nev. They occur in thick rhyolitic flows of Miocene (?) age, and wood tin, found in the gravels of arroyos that head in the surrounding rhyolite, presumably comes from-other veinlets not yet discovered. The exposed veinlets are about 20 feet in maximum length and a quarter of an inch in average thickness. Parallel and reticulating veinlets form lodes 4 to 6 feet thick and 15 or 20 feet long. Virtually no cassiterite is disseminated in the wall rock. The veinlets contain specularite, cassiterite, sanidine, andradite, cristobalite, tridymite, quartz, chalcedony, fluorite, and opal. All these minerals, except possibly cassiterite, together with topaz and pseudobrookite, are likewise present in cavities that are widely distributed in the rhyolite. The similarity of the mineral assemblage in the veinlets to that in the cavities indicates that the tin originated in the rhyolite magma, and spectrographic analyses indicate that the average rhyolite contains about 0.001 percent of tin. It is therefore believed that the incrustations were deposited in fumarolic vents along fissures formed by differential contraction during the cooling of the lavas. There is no record of any production of tin from the area. Possibly a few tons of the metal might be produced from the exposed veinlets by narrow stoping and hand sorting. No large body of rock in the area, however, contains even 0.2 of a pound of tin to the ton; and the amount of tin recoverable would be only a small part of that shown by assay, for not all of the tin is in grains of cassiterite large enough to be concentrated by ordinary methods. Placer deposits of commercial grade occur in small draws that head in the area where the veinlets are exposed, but as they are only a few inches thick and of small volume, they could yield only a few tons of cassiterite. There is a large area of alluvium in the valley bottom below the tin-bearing veinlets that has not been thoroughly sampled, but a few tests indicate that the tin content of the upper 40 feet is less than 0.1 of a pound to the cubic yard.