CSA Global takes this opportunity to congratulate our team in Vancouver, Canada on their recently published report; “Mackie, R.A., Arne, D.C. and Pennimpede, C., 2017. Assessment of regional stream sediment catchment basin and geochemical data quality. Yukon Geological Survey, Open File 2017-4, 29 p.”
The Yukon Geological Survey (Department of Energy, Mines and Resources; Government of Yukon) generates, compiles, and provides geoscientific information pertaining to Yukon’s geology, mineral deposits and hydrocarbons. Products released by the Yukon Geological Survey are used by industry for mineral exploration and also provide the basis for land use planning initiatives.
Stream catchment areas digitized from existing regional stream sediment sample locations are assessed for quality and confidence of sample site location, catchment surface area (used as a proxy for downstream dilution), surface material type, slope angle and slope aspect. Rankings for each of these attributes are combined into quality indices to give an overall impression of reliability for each catchment that can be incorporated into mineral exploration targeting criteria and design of further sampling programs. Data from quality control samples included with each sample batch during a recent re-analysis program are also assessed for some key elements. Standard reference materials included in two separate re-analysis campaigns show slight shifts in bias even though the same analytical method was used in both instances. Some elements, particularly Au, show an unacceptable amount of scatter in repeat analyses of the standard reference materials indicative of a non-homogenous distribution of Au in the materials for the small sample mass (0.5 grams) used for analysis. Data precision is assessed using field and blind duplicate analyses for selected elements. The Au analyses show the poorest precisions, with data from Cu giving the best precision and data for As yielding intermediate precisions.
Above: Plan map showing a derived slope raster image and catchment basin outlines
ABOUT THE AUTHOR
Dennis has over (30) years’ experience in exploration in a wide range of environments in both the minerals and the petroleum industries, as an academic, and in geological surveys. In recent years he has been involved as a consultant in the development of exploration programs for precious and base metals exploration in Australia, North America, South America and the Middle East. Specifically, this has included contributing to exploration targeting reviews and understanding gold and base metals mineral systems, the design, management and interpretation of surficial geochemical surveys, the interpretation of lithogeochemical data, the preparation of QA/QC protocols, reviews of geochemical data quality, and contributions to NI43-101 and JORC/Valmin technical reports. He has published extensively in the areas of applied geochemistry, economic geology and thermal history analysis for tectonic and petroleum exploration applications.
PUBLISHED BY YUKON GEOLOGICAL SURVEY