Honeycomb Hills Mining District, Juab County, Utah, USAi

Regional Level Types
Honeycomb Hills Mining District	Mine
Juab County	County
Utah	State
USA	Country

The Honeycomb Hill mining district is about 59 mi northwest of Delta in west-central Juab County. The area has no recorded production but has been prospected intermittently since the 1950s for lithophile elements including U, Be, Li, and rare earth elements (REE). The Honeycomb Hills is part of a low range of hills between the southern Deep Creek Range to the west and the Fish Springs Range to the east.
The Honeycomb Hills is an isolated series of rhyolite flow domes in the Basin and Range Province. Volcanic-hosted U mineralization was discovered in the Honeycomb Hills by H.P. Bertelsen in 1950, but grades are below typical ore grades (<0.1% U3O8). In 1961, C.R. Sewell discovered Be mineralization in the area while working for The Dow Chemical Company. Dow drilled a series of 15 exploration holes totaling 2930 ft and cut some dozer trenches. Assays reportedly ran from 0.05% to 0.85% Be (McAnulty and Levinson, 1964). Later, Anaconda held a property position in the district from 1977 to 1979 while exploring for uranium. ATW Gold Corp. acquired the Honeycomb Hills as a REE project in 2010. ATW Gold reported surface samples running up to 1000 ppm Be, 1690 ppm Li, 1270 ppm Rb, and 1043 ppm total rare earth oxides, but has dropped their property position.
The Honeycomb Hills is the westernmost Miocene to Pliocene (22 to 4 Ma) topaz rhyolite along the greater Deep Creek–Tintic mineral belt. This belt includes the famous Spor Mountain Be-F district 20 mi to the east. The Honeycomb Hills volcanic complex consists of a 40-ft-thick, Pliocene lithic, fluorite-bearing, air-fall (?) tuff, immediately underlain by older volcanic rocks, and overlain by two small coeval topaz rhyolite flow domes that erupted about 4.7 Ma. The rhyolite is gray, vesicular, strongly flow-banded, and contains about 40% phenocrysts of smoky quartz, sanidine, plagioclase, and biotite. Topaz crystals commonly line the vesicles. The rhyolite also contains globular topaz- and fluorite-bearing inclusions (Christiansen and others, 1986). Paleozoic carbonate rocks (Devonian?) lie beneath the rhyolite domes at an estimated depth of about 200 ft (McAnulty and Levinson, 1964). Low-grade Be, Li, Cs, and Rb occurs in an approximately 3-ft-thick zone in the uppermost tuff immediately underlying the capping massive Bell Hill (northwestern) rhyolite dome (McAnulty and Levinson, 1964). Some samples also contain anomalous Mo and Sn (Christiansen and others, 1986). Honeycomb Hills is also anomalous in Lu, Tb, Y, and Yb with a low light REE/heavy REE ratio (i.e., it is relatively enriched in heavy REE).