| Description |
Soil and stream sediment samples were kiln dried and sieved to less than 180 microns. The minus 180 fraction was split down to an 8.8 oz sample. Rock samples were crushed so more than 70 percent of the material passed through a screen with 0.08 in openings. The sample was then split down to an 8.8 oz sample that was pulverized until 85 percent passed through a 75 micron screen. Pan concentrate, placer, and sluice concentrate samples were dried and pulverized with out screening. All samples were fire assayed with either an ICP-MS finish if it was a soil or sediment sample or an ICP-AES finish, if it was a rock sample; to detect gold, palladium, and platinum. Suspected high-grade samples were analyzed using the same ICP-MS or ICP-AES methods but the instruments were calibrated to higher detection limits. Samples with gold and silver assay results that exceed their respective ICP analysis detection limits, at the discretion of the lab, were reanalyzed by fire assay with either a gravimetric finish, or by Atomic Absorption Spectroscopy (AAS). After the fire assay, a split of the sample pulp was partially dissolved in aqua-regia. The resulting solution was analyzed using a combination of ICP-MS and ICP-AES. AAS was used for samples when nonprecious metals of economic interest were over the ICP analysis detection limits. Elements of interest were antimony, arsenic, cadmium, copper, lead, mercury (cold vapor atomic absorption), nickel, and zinc. One sample (13185) that had more than 30% zinc, was reanalyzed by a volumetric titration method. Because barium, tin, and tungsten were resistant to the aqua-regia used in the ICP process, all samples, except pan concentrate and placer samples, were analyzed by XRF for those elements. |