IC 9133 Estimation Of Remaining Lode Gold Endowment In Selected Mining Districts Of Alaska

The Bureau of Mines estimated the remaining lode gold endowment of eight mining districts in Alaska using historic production data. A log-arithmic model of cumulative tonnage of ore processed versus cumulative grade was applied to the following districts: Chichagof, Fairbanks, Homer, Hope-Seward, Juneau, Ketchikan, Prince William Sound, and Willow Creek. To assess the remaining endowment, a computerized production data base was compiled from Bureau records. These data were aggregated in 5-yr intervals for each district. Data were sorted in order of declining grade, and log cumulative grade was plotted against log cumulative tonnage. Linear regression was performed on the data for each district. The linear equation for each curve was used to predict remaining endowment at a limiting mining grade. Based on conservative extrapolation of the grade-tonnage curves, a substantial total endowment of 8,415,100 tr oz of gold remains in the eight districts. The districts with the greatest remaining endowment are the Juneau, Chichagof, Fairbanks, and Willow Creek Districts.