NIOSHTIC-2 Publications Search
Statistical analysis of assay data from the Round Mountain silver prospect, Custer County, Colorado.
NTIS: PB 198 268 :1-32
A statistical analysis of silver assay data from rotary-drill-hole cuttings and diamond-drill-hole cores from the Round Mountain Prospect, Custer County, Colorado, Demonstrates several useful methods for estimating grades and tonnages of ore from the drilling of wide- spaced holes in disseminated deposits of precious metals. A new method of ore appraisal is introduced which estimates grade and tonnage of ore by calculating convex hulls (smallest convex polygons) for sample points with assay values above specified cutoff grades. Analyses of variance compare the consistency of data from rotary- and diamond-drill holes, from rotary-drill holes sampled at 2- and 4-foot intervals, from two methods of sample preparation, and from atomic-absorption and fire assaying. Evidently, data from the two types of drill holes, from holes sampled at the two intervals, and from different methods of preparation are in agreement. Atomic- absorption silver values are consistently lower than fire-assay silver values. Work done in cooperation with Round Mountain Associates.
IH; Report of Investigation;
NTIS Accession No.
NTIS: PB 198 268
Page last reviewed: May 5, 2020
Content source: National Institute for Occupational Safety and Health Education and Information Division