Silver Queen

Location: Idaho, United States (44.988, -113.559 approx.)

Commodities: rare earth elements; thorium

Deposit model: REE-Th bearing veins · Th-REE veins

Geology

“We conducted Phase I exploration activities in 2013 on the Lemhi Pass Project in the Silver Queen and Luck Horseshoe veins that included compliant geological mapping and channel sampling on these veins. The channel samples taken across the Silver Queen vein indicated rare earth mineralization that we believe warrants further exploration. We believe that the Lucky Horseshoe claim has limited potential for advanced exploration reserve discovery, but that other claims within the Lemhi Pass area are part of a trend that warrants further exploration.” (U.S. Rare Earths Inc. (2015b)) “The Lemhi Pass Project regional geology consists primarily of the Proterozoic metamorphosed Belt Supergroup of sediments that are well known in the region. These "metasediments" consist of very thick units of metamorphosed micaceous sandstones, siltstones, and mudstones of lake-basin origin and were deposited 1.4 billion years ago. These sediments have since been metamorphosed and subsequently thrust and block faulted. There are numerous block faults with normal movement surrounding and within the Project. Three named faults exist in the area: the Lemhi Pass Fault lies in the northern part of the project intersecting the Lucky Horseshoe Claims and the Bull Moose Fault and Dan Patch Faults are located in the northcentral part of the project. There are unnamed normal faults crossing the prospect.” (U.S. Rare Earths Inc. (2015b)) “The Project's rare earth mineralization is considered to be related and deposited in the early Cenozoic (Tertiary) time period and is structurally controlled along the northeast and northwest trending fractures and shear zones hosted in the prospect Belt Supergroup units.” (U.S. Rare Earths Inc. (2015b)) “East of the gulch, microcline becomes the most abundant gangue mineral. Goethite is the chief iron oxide in most places. This mineral occurs not only in veinlets but also forms dark-brown cubes and pyritohedrons—a pseudomorphous replacement of pyrite. Black shiny specularite is common and east of the gulch is more abundant than limonite. All samples contain minor amounts of magnetite, some of which is included in specularite. Part of the coloration is due to a black manganese oxide mineral. Brick-red thorite was the only thorium mineral noted. In addition, minor amounts of rutile, barite, apatite, jarosite, muscovite, fluorite, pyrite, and chalcopyrite were identified in some samples. The vein is highly brecciated and has at least two generations of minerals; the second set of minerals follows a set of fractures in early minerals and is in turn fractured. Eleven samples were taken from this vein, and they range from 0.12 to 2.91 percent ThO2 (pl. 2B; table 21).” (Staatz (1979)) “Approximately 15 feet north of the southern vein lies the south-central vein. This vein is parallel to the southern vein, striking N. 80deg W. and dipping 55deg SW. It is exposed only in the bottom of the main cut for a distance of 125 feet. Its thickness ranges from 0.7 to 2.0 feet. This vein is black and consists principally of limonite-stained calcite. Other common gangue minerals are white quartz and pink feldspar. The vein is colored by black shiny specularite and black manganese oxides. Limonite commonly occurs as dark-brown pyritohedrons, a pseudomorphous replacement of pyrite. Magnetite occurs but is generally included in the specularite. Red shiny thorite, the only thorium mineral noted, is common. Minor amounts of orange to tan striated rutile, white frosted apatite, brassy pyrite, and chalcopyrite were the other minerals identified. Three samples taken from this vein yielded 0.79-1.07 percent ThO2 (pl. 2B). One of these samples (MHS-66-72) was analyzed for base and precious metals. Only minor amounts of lead, zinc, and copper were noted; gold and silver were not detectable (table 21).” (Staatz (1979)) “The northern vein differs from the other three veins in being mainly quartz and specularite. It is thus more resistant and forms massive outcrops both east and west of the small gulch. A major part of the vein on this property lies under the dump of the main cut. On the Silver Queen 52B property this vein strikes approximately N. 85deg E. and dips steeply. It can be traced on the property for 810 feet but probably connects with a similar vein on the Lone Star No. 2 property on strike with it 0.5 mile to the west. This vein shows considerable thickening and thinning and ranges in thickness from 2.0 to 28 feet. The northern vein varies from white to dark purplish gray in color and is brecciated. In places white quartz is fractured and filled with later dark-purplish-gray vein material of quartz and specularite. In addition, in places this vein contains limonite and thorite. Thorium content, as indicated by its radioactivity, is erratic, much of the vein having only a minor amount of thorium but parts of the vein being fairly rich in thorium. Two samples were taken on abnormally highly radioactive parts of the vein (pl. 2B). They yielded 0.27 and 0.77 percent ThO2 (table 21).” (Staatz (1979)) “Four veins are exposed in and adjacent to the main cut. The northernmost vein is a massive quartz-hematite vein of erratic but generally low thorium content. This vein probably extends westward for 0.5 mile to the Lone Star No. 2 property. The other three are calcite-rich veins. The big cut was excavated mainly to expose the southern or largest of these three veins. The other two calcite-rich veins are only exposed in the central part of the floor of the main cut. A small northwest-trending fault down the small gulch east of the main cut offsets the quartz-hematite vein and largest calcite-rich vein about 140 feet to the northwest (pl. 2B). The largest calcite-hematite vein (southernmost vein) strikes N. 80deg W. and dips 34deg-55deg SW. It has been traced for 750 feet and ranges in thickness from 0.6 to 3.0 feet. This vein varies in color from brown to black and consists principally of limonite-stained calcite and lesser amounts of quartz and microcline.” (Staatz (1979)) “Eight feet north of the south-central vein is the north-central vein. This vein is only exposed for 40 feet in the floor of the main cut and probably does not continue far. It is 0.5-2.0 feet thick. The strike of the north-central vein is parallel to that of the south-central and southern veins; its dip was not observed. The north-central vein is black and calcite is the predominant gangue mineral. This vein is identical in appearance to the south-central vein and probably similar in composition. The one sample taken of this vein had 3.83 percent ThO2 (pl. 2B; table 21).” (Staatz (1979)) “The veins lie in a horst and are bounded both to the east and west by down dropped blocks of Challis Volcanics. A third fault, a northeast-trending cross fault that offset the horst faults, lies 700 feet to the northwest of the larger vein (pl. 1). If the veins extend far from the vicinity of the workings, then these faults might well limit their extent. The veins are generally black with some dark-brown spots and the gangue is chiefly quartz, although pink microcline is also abundant. The black color is due to numerous finely disseminated black shiny plates of specularite. Other iron oxide minerals include brown limonite, cherry-red hematite, and a little black magnetite. Reddish-brown shiny thorite is the only thorium mineral noted. The only other mineral identified was a minor amount of brown shiny rutile. Four samples were cut of the longer vein and one each of the shorter vein and of the intervening silicified country rock. The ThO2 content of the south vein ranged from 0.16 to 2.40 percent, that of the north vein and silicified country rock 0.22 and 0.05 percent, respectively (fig. 30; table 22). The total rare-earth content of one sample from the longer vein (sample 4911 D), as determined by X-ray fluorescence by the U.S. Bureau of Mines at Salt Lake City, Utah, was 1.60 percent.” (Staatz (1979))

Exploration and site history

• Discovery — Located in 1955 by J.A. Rucker; Owned by the Idaho Thorium Co. in 1957, the Nuclear Fuels and Rare Metals Corp in 1965, and the Joyce Corp. in 1970, 1955 (Staatz (1979))
• Discovery — Silver Queen 38A was located during the summer of 1954 by J.A. Rucker, and was one of more than 100 Silver Queen claims located by him in the mid 1950's in the Patte Creek drainage, 1954 (Staatz (1979))

Record imported from USGS USMIN ver. 4.0 (June 2019). Developments after that date appear on facility records, not here; see the methodology.