Enhanced interpretation of regional geochemical stream sediment data from Yukon: catchment basin analysis and weighted sums modeling

Geochemical data from regional geochemistry survey samples from Yukon have undergone exploratory data analysis and principal component analysis. The results of these analyses clearly demonstrate geological control on the distribution of a number of important commodity and mineral deposit pathfinder elements. Catchment basins have been delineated for the samples and the dominant simplified geological unit in each catchment basin used to level the geochemical data where appropriate. Levelling the geochemical data in this fashion generally fails to fully account for enrichments in many commodity and mineral deposit pathfinder elements in the bedrock due to practical limitations on the resolution of the mapping and knowledge of the relative contributions of different geological units, although the resulting data interpretation is an improvement on one based solely upon raw geochemical data. Weighted sums models have been generated for the deposit types that either exist within the individual map areas covered by this report or are considered by the authors to be of exploration significance. Separate catchment maps showing the distribution of stream water pH and the concentration of elements inferred to have accumulated through hydromorphic dispersion are also provided. An additional series of maps has been generated to display weighted sums models calculated using regression of commodity and mineral deposit pathfinder elements against those principal components containing the same elements that show the strongest spatial associations with bedrock geology. Both model types have been iteratively tested using known mineral occurrences in the relevant map areas and, for the most part, are compatible with the distribution of known mineralization where sampling coverage is adequate. Geochemical anomalies unrelated to known mineral occurrences are evident in both data sets and provide possible targets for further investigation.