Barometer Mine, Aniak Mining District, Bethel Census Area, Alaska, USAi

Regional Level Types
Barometer Mine	Mine
Aniak Mining District	Mining District
Bethel Census Area	Census Area
Alaska	State
USA	Country

Location: The Barometer Mine is in a short, unnamed, north-flowing gully that enters the flood plane of the the Kuskokwim River; it is about 0.5 mile west-northwest of the mouth of McCally Creek at an elevation of about 500 feet. The mine is labeled on the 1:63,360-scale USGS topographic map; it is in the NW1/4 sec. 6, T. 19 N., R. 45 W., of the Seward Meridian. The Barometer Mine is locality 19 of Miller and others (1989). The location is accurate.
Geology: The Barometer Mine was one of the first mercury-antimony lodes that was discovered in the Kuskokwim mineral belt (Bundtzen and Miller, 1997). It has been described in detail by Webber and others (1947), Cady and others (1955), Malone (1962), and Sainsbury and MacKevett (1965). The Barometer Mine is on the southwest limb of the northwest-trending Sleetmute anticline in a geological setting similar to that of the Red Devil Mine (SM028). The host rocks at the Barometer Mine are shale, siltstone and lithic sandstone of the Upper Cretaceous, Kuskokwim Group that have been intruded by mafic dikes and sills. The dikes and sills have been altered to a distinctive orange-weateing silica-carbonate rock (Cady and others, 1955; Sainsbury and MacKevett, 1965). The sedimentary rocks strike N45W and dip 55SW. Exposures are poor and the underground workings were caved prior to Sainsbury and McKevett's 1959 visit. Trenching completed in 1959 by Alaska Mines and Minerals, Inc. disclosed promising cinnabar-stibnite mineralization in altered dikes cut by bedding plane faults in a structural setting similar to the Red Devil Mine (Sainsbury and MacKevett, 1960; Herreid, 1962; MacKevett and Berg, 1963). According to Cady and others (1955), cinnabar is associated with stibnite and realgar in quartz-rich gangue near the silica-carbonate rocks. Ore mined in 1940 averaged about 1.20 percent mercury (Malone (1962). Production has been modest. About one flask was retorted in the early 1920s (Miller and others, 1989). A.C. Skidmore produced about 8 flasks of mercury in 1928 (Malone, 1962). Webber and others (1947) report that 10 flasks of mercury were produced in 1938 and 6 flasks in 1940. A total of about 25 flasks of mercury were produced from 1921 to 1940. In 1961, John Murphy and George Willis mined 50 to 75 tonnes of good surface ore, but the amount of mercury recovered is unknown (Jasper, 1961).
Workings: The Barometer deposit was discovered by Hans Halverson in 1921, who traced cinnabar float uphill from the base of a hill near the Kuskokwim River. In 1922, Halverson drove a 120-foot adit into the mineralized zone. In 1923, E.W. Parks purchased the claims and prospected on the surface. In 1931, Otto Rohlphs drove a crosscut in the adit, but dropped his option in 1932. The U.S. Bureau of Mines trenched the property in 1943 (Webber and others, 1947). Regular assessment work was conducted from 1941 to the mid 1950s (Jasper, 1961). More trenches were dug by Alaska Mines and Minerals, Inc. in 1959 and 1960 (Herreid, 1962). The property was visited in 1957, 1959, and 1988 by the U.S. Geological Survey (Sainsbury and MacKevett, 1960, 1965; Miller and others (1989).
Age: Undated; the nearby Fairview prospect (ARDF SM019) has a 40Ar/39Ar age of 72.6 Ma (Gray, Gent, and others, 1997).
Alteration: Silica-carbonate alteration of dikes and sills.
Production: Production has been modest. About one flask was retorted in the early 1920s (Miller and others, 1989). A.C. Skidmore produced about 8 flasks of mercury in 1928 (Malone, 1962). Webber and others (1947) report that 10 flasks of mercury were produced in 1938 and 6 flasks in 1940. In 1961, John Murphy and George Willis mined 50 to 75 tons of good surface ore, but the amount of mercury recovered from those efforts is unknown (Jasper, 1961). A total of about 25 flasks, about 1,900 pounds, of mercury were produced from 1921 to 1940 (Malone, 1962).

Commodities (Major) - Hg, Sb; (Minor) - As
Development Status: Yes
Deposit Model: Silica-carbonate mercury (Cox and Singer, 1986; model 27c).

Other Databases

Link to USGS - Alaska:	SM024

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References