Beryllium investigations at the Lost River Mine, Seward Peninsula, Alaska.
Berryhill-RV; Mulligan-JJ; Gnagy-WL
Juneau, AK: U.S. Department of the Interior, Bureau of Mines, OFR 1-65, 1965 Jan; :1-71
Bureau of Mines sampling indicates that beryllium minerals, principally chrysoberyl, occur associated with fluorite in an extensive zone of altered limestones at the Lost River Tin Mine, Seward Peninsula, Alaska. The fluorite-beryllium deposits occur as veins and replacements along numerous intersecting faults and fractures and along the walls of dikes. The sampling did not delimit either the horizontal or vertical limits of deposition. A 500-foot by 1,000-foot area adjacent to Lost River Mine was sampled because it contains many accessible altered limestone outcrops exposed during previous tin mining operations. The unweighted average grade of 124 vertical percussion-drill holes 5 feet deep in this area is 0.13 percent BeO. Diamond-drill core samples of altered limestone from various periods of drilling were collected and analyzed; 836 feet of altered limestone core drilled from the surface averages 0.12 percent BeO; 407 feet drilled from the 365 level in the Lost River Mine (365 feet below the main entry) averages 0.13 percent BeO. The few available samples of the cassiterite dike average 0.07 percent BeO.
Juneau, AK: U.S. Department of the Interior, Bureau of Mines, OFR 1-65