Soil Geochemistry above Deeply Weathered Porphyry Deposits in Unglaciated Terrain, Dawson Range, Central Yukon

Much of west-central Yukon escaped glaciation and is underlain by leached and oxidized, deeply weathered bedrock. Background and anomalous metal values in these soils are presumed to be lower than normal and therefore increase the challenge of interpreting soil geochemical surveys. It is suspected that the geochemical contrast between background and anomalous values can be maximized by sampling a particular soil horizon or analysing a specific size fraction. One hundred and sixteen samples were collected from soil profiles at ten sites above four porphyry-style mineral deposits - Antoniuk, Revenue, Nucleus and Casino in the Dawson Range of the Yukon-Tanana Terrane. B-horizon soils are locally clay-rich, thin and poorly developed. C-horizon soils are unconsolidated and very coarse grained. Bedrock samples from each site were crushed and analysed for comparison. All samples were analysed using the Au plus 32 (FA-AA and ICP) package which is a popular and economical method currently employed in most exploration programs. The results are generally consistent within the few samples taken at each deposit, but vary considerably overall, and probably reflect the variable physio-chemical…

Publisher

Government of Yukon

Resources

3

Catalogue metadata updated

2026-08-26