Title | Multivariate statistical analysis of the REE-mineralization of the Maw Zone, Athabasca Basin, Canada |
Author | Chen, S; Hattori, K; Grunsky, E C |
Source | Journal of Geochemical Exploration vol. 161, 2016 p. 98-111, https://doi.org/10.1016/j.gexplo.2015.11.009 |
Year | 2016 |
Alt Series | Earth Sciences Sector, Contribution Series 20160021 |
Publisher | Elsevier BV |
Document | serial |
Lang. | English |
Media | paper; on-line; digital |
File format | pdf |
Province | Saskatchewan |
NTS | 74H |
Area | Key Lake; McArthur River |
Lat/Long WENS | -106.0000 -104.0000 58.0000 57.0000 |
Subjects | mathematical and computational geology; economic geology; mineral assemblages; rare earths; rock analyses, rare earth elements; uranium; uranium deposits; mineralization; mineral deposits; sedimentary
rocks; sandstones; analytical methods; statistical analyses; mineral exploration statistics; Phoenix Deposit; Maw Zone; Manitou Falls Formation; Read Formation; Athabasca Basin; Precambrian |
Illustrations | location maps; plots; tables; photomicrographs |
Program | Uranium Ore Systems, Targeted Geoscience Initiative (TGI-4) |
Abstract | To evaluate the relationship between the enrichment of rare earth elements (REEs) and U, we carried out a principal component analysis (PCA) of sandstones in the REE-rich Maw Zone in the Athabasca
Basin, Canada. The Maw Zone, a breccia pipe with surface exposure of 300 × 200 m, consists of highly silicified, hematitized, tourmaline-rich rocks with high REEs (up to 8.1 wt.% as total REE oxides). It is ~4 km southwest from the south end of the
Phoenix U deposits, however, rocks in the Maw Zone do not show high U (b7.8 ppm in most rocks). We used RQ-mode PCA to compute variable and object loadings simultaneously, which allows the displays of observations and the variables at the same scale.
PCA biplots of the Maw Zone data show that U is strongly correlatedwith V, Cr, Fe, Ni, Cu, Na, Li and Ba, but veryweakly correlatedwith heavy rare earth elements (HREEs)+Y, and inversely with light rare earth elements (LREEs) and P. Relative
enrichment of HREEs, Y, and P suggests xenotime as the predominant host of the HREEs. The grouping of LREEs + Sr + Th + P suggests the probable occurrence of monazite and/or aluminum phosphate-sulfate (APS) minerals. A mineralogical study confirmed
the common occurrence of xenotime and APS minerals. The positive association between U and Fe in the PCA plot in the Maw Zone suggests that U was transported by oxidized fluids. The absence of U mineralization in theMaw Zone is explained by lowU in
the oxidizing fluids, or a lack reducing fluids to precipitate U. The PC1 and PC2may reflect themajor element assemblages related to the REE mineralization. The comparison of the maps of PC scores and the concentrations of HREEs+ Y and P shows that
the scores of PCs are better indicating the hydrothermal REE mineralization. For prospecting HREEs, PC2 is more reliable than PC1 because PC2 has the largest variance of HREEs and the second largest variance of LREEs. |
GEOSCAN ID | 298709 |
|
|