Abstract

Produced minerals in the Henry Mountains area include uranium, vanadium, coal, gold, silver, copper, and gemstones. Three are excluded from discussion here because they are discussed by others in this book. Non-produced commodities such as titanium, zirconium, molybdenum and clay are added. The commodities covered are those with less potential for significant future mineral production.

Lode deposits of gold, silver and copper are known near the apexes of the three largest peaks, but most production has been achieved in the Bromide Basin of Mt. Ellen. About 700 ounces of gold, 3000 ounces of silver and 17,500 pounds of copper have been produced since their discovery in 1889. Most ore came from thickenings or chutes along two north-south trending mineralized fissures. Fissure minerals include chalcopyrite, pyrite, limonite, malachite, azurite, chrysolcolla, hematite and rare molybdenite. In addition to the lode deposits, laccoliths and igneous-sedimentary contacts are locally mineralized with disseminated pyrite containing very small amounts of gold.

Gold placer deposits are found on the east side of Mt. Ellen in the fanglomerates and stream gravels on both sides of Crescent Creek. Only 300-500 ounces of gold have been recovered; limited water to work gravels, difficulty in recovering the fine flakes of gold, and irregular tenor are hindrances to economical production. A fossil placer containing titanium and zirconium has been discovered in the Ferron Sandstone (Cretaceous).

Clay is abundant in the sedimentary formations, but is mostly impure or otherwise unsuitable for special uses. In one area, however, clay has been discovered that is suitable for high- or super-duty refractory purposes. In the gemstone category, jasper, agate, petrified wood, dinosaur bone and jet have all been produced; the total value lies in a range 3 or 4 times that of the produced precious metals.