Disseminated flake graphite and amorphous graphite deposit types: an analysis using grade and tonnage models

CIM Bulletin, Vol. 83, No. 940, 1990

David M. Sutphin and James D. Bliss, U.S. Geological Survey

On the basis of differences derived from genetic, descriptive, and grade-tonnage data, graphite deposits are classified here into three deposit types: disseminated flake, amorphous (microcrystal-line), or graphite veins. Descriptive models have been constructed for each of these deposit types, and grade-tonnage models are constructed for disseminated flake and amorphous deposit types. Grade and tonnage data are used also to construct grade-tonnage models that assist in predicting the size and grade of undiscovered graphite deposits. The median tonnage and carbon grade of disseminated flake deposits are 240 000 tonnes and 9% carbon and for amorphous deposits, 130 000 tonnes and 40% carbon. The differences in grade between disseminated flake and amorphous deposit types are statistically significant, whereas the differences in amount of contained carbon are not.

Keywords: Graphite deposits, Industrial minerals, Descriptive models, Grade-tonnage models, Amorphous deposits, Disseminated flake deposits.