Leamington Mining District, Millard County, Utah, USAi

Regional Level Types
Leamington Mining District	Mining District
Millard County	County
Utah	State
USA	Country

The Leamington mining district is located about 22 mi northeast of Delta in Millard County and some small prospects are in adjoining portions of Juab County. The district was organized in 1886 and is a small Pb-Ag producer. Total district metal production at modern metal prices is estimated at $155,000. The Yellowstone underground mine is believed to be the largest producer.
The Leamington district is situated on the west flank of the northern Canyon Mountains of the Basin and Range Province. The Pb-Ag mineralization consists of disseminated to semi-massive galena replacements of brown, Fe-stained limestone of the Cambrian Howell Formation and as disseminated galena associated with coarse-grained, white calcite veins (USGS Model 22c). Much of the near-surface ore was oxidized to cerussite mixed with remnant galena in a gangue of calcite and ferruginous dolomite (Butler and others, 1920). The mineralization occurs along and adjacent to faults (Arbroath and Yellowstone mines), at intersections of faults and fissures (Yellowstone mine), and at intersections of fissures and bedding (Mine Hollow prospect). Ore guides include coarse-grained, rhombic calcite and brown, limonite-stained gray limestone. The vertical extent of the ore is probably less than 250 to 300 ft since adits driven to intersect the orebodies at depth have no ore on the dumps. Based on limited sampling, the ore contains high concentrations of Pb, Ag, and Mn and low concentrations of Cu, Ba, and Zn (Gloyn, 2004).
The Yellowstone mine workings consisted of a 200-ft-deep, 80° inclined shaft with levels at 50, 100, and 170 ft (Butler and others, 1920), now mostly caved, and a small 15- to 20-ft-deep incline to the west of the main shaft. The ore consists of small veinlets, replacements, and disseminations of galena in light-tan to orange-tan, Fe-stained Howell Limestone. Ore remaining on the dump consisted of Fe-stained limestone having stringers and veinlets of fine-grained galena, disseminated blebs of galena, and thin, coarse-grained, white calcite veinlets with minor galena at the vein margins. Select samples contain as much as 10% to 15% galena (Gloyn, 2004). Butler and others (1920) reported that small bodies of ore were stoped at the 50 ft level along a north-striking structure particularly where shattering occurred at the intersection with an east-trending fracture, and that some ore was mined on the 170 ft level from a zone containing veinlets of calcite and dolomite containing 3% to 4% Pb. Butler and others (1920) report that the mine was worked intermittently and produced a few carloads of hand-sorted ore with values of 30% to 65% Pb and up to 205 ppmAg.