| Title | Lithogeochemical facies of Athabasca Basin clastics, Saskatchewan - the use of PCA as a reconnaissance and mapping tool |
| Download | Downloads |
| |
| Licence | Please note the adoption of the Open Government Licence - Canada
supersedes any previous licences. |
| Author | Ramaekers, P; Bosman, S A; Card, C D |
| Source | Geological Survey of Canada, Open File 7790, 2016, 18 pages, https://doi.org/10.4095/297840  Open Access |
| Year | 2016 |
| Publisher | Natural Resources Canada |
| Document | open file |
| Lang. | English |
| Media | on-line; digital |
| File format | readme
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| File format | pdf; xlsx; rtf |
| Province | Saskatchewan |
| NTS | 64E; 64L; 64M; 74E; 74F; 74G; 74H; 74I; 74J; 74K; 74L; 74M; 74N; 74O; 74P |
| Area | northern Saskatchewan |
| Lat/Long WENS | -112.0000 -103.0000 60.0000 57.0000 |
| Subjects | geochemistry; sedimentology; lithogeochemistry; clastics; clastic facies; geochemical facies; sandstones; tuffs; clays; breccias; quartzarenites; uranium deposits; Athabasca Group; Athabasca Basin;
Manitou Falls Formation; Proterozoic |
| Illustrations | location maps; tables; plots |
| Program | Targeted Geoscience Initiative (TGI-4) Uranium Ore Systems |
| Released | 2016 04 07 |
| Abstract | This study illustrates how Principal Component Analysis (PCA) of lithogeochemical data may be used to identify and map lithogeochemical facies using a regional-scale database of ca. 40,000 samples. This
database also includes ca. 11,000 samples with enough stratigraphic data to permit this to be done in three dimensions to a rudimentary degree. The facies distribution by stratigraphy and deposystems furthers the understanding of depositional,
alteration history, and ore processes of the Athabasca Basin and its high-grade unconformity-related U deposits.
PCA permits distinction and mapping of detrital and alteration facies, separating uraniferous detrital facies from those related to
mineralization processes. The analysis helps to form working hypotheses about the ore systems in the basin, identify areas of further interest, as well as areas whose high U values suggest that they might be important, but which, in fact, are not
involved in the mineralization processes. Uranium bound in minerals released during partial dissolution techniques contributes less than a third of the U signal in the non-mineralized sandstone. Thus, immobile U not related to alteration can mask the
signal of hydrothermal U that still may be recognized by PCA. PCA also highlights potential large, but complex metal depleted zones around some of the major orebodies. If true, then the interpretation of low raw data element values or low U component
scores from PCA in a regional context is as important as the interpretation of high values. Samples from above or very near mafic intrusive suites in the basin show anomalously high and low values for some elements, as well as for a number of PCA
components. This suggests that the mafic intrusions generated hydrothermal systems of only limited extent.
Consistent with recent fluid-flow modelling, differences in alteration facies above and below the Wolverine Point Formation show that the
unit was an aquitard. Low levels of alteration facies in the basal unit in the Athabasca Basin imply that it was an aquifer in many areas. Both these observations reinforce long-standing field observations. |
| Summary | (Plain Language Summary, not published)
The Targeted Geoscience Initiative (TGI-4) is a collaborative federal geoscience program that provides industry with the next generation of geoscience
knowledge and innovative techniques to better detect buried mineral deposits, thereby reducing some of the risks of exploration. Using the Athabasca uranium geochemistry database (OF7495), this open file highlights geochemical variations related to
depositional and regional alteration facies in the Athabasca Basin to aid in exploration for unconformity-related uranium deposits. |
| GEOSCAN ID | 297840 |
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