|Title||Biogeochemical orientation survey over carbonatite-hosted deposit|
|Author||Simandl, G J; Fajber, R; Dunn, C E|
|Source||Joint annual meeting of the geological association of Canada-mineralogical association of Canada-society of economic geologists-society for geology applied to mineral deposits; abstracts; vol. 34, 2011
|Links||Online - En ligne|
|Alt Series||Earth Sciences Sector, Contribution Series 20120529|
|Publisher||Geological Association of Canada|
|Meeting||Joint Annual Meeting of the Geological Association of Canada-Mineralogical Association of Canada-Society of Economic Geologists-Society for Geology Applied to Mineral Deposits; Ottawa; CA; May 25-27,
|Media||paper; on-line; digital|
|Lat/Long WENS||-119.5000 -119.0000 52.2500 52.0000|
|Subjects||carbonatites; tantalum; niobium; minerals; rock analyses, rare earth elements; apatite; mineralization; tree sampling; Fir; White Spruce; detection; twigs; needles|
Geoscience Initiative (TGI-4), Rare-Metal Ore Systems|
|Abstract||This survey shows that coniferous trees are suitable sampling media in the exploration for carbonatites and related rare earth elements (REE), Ta, Nb, phosphate and fluorspar mineralization. |
four samples of twigs with needles from Subalpine Fir (Fir) and White Spruce (Spruce) were collected over the Upper Fir carbonatite and surrounding amphibolites and paragneisses. Twigs and needles were analyzed separately. Twigs were milled using a
Wiley mill and resulting pulps were digested in HNO3, then Aqua Regia and then analyzed by ICP-MS/ICP-ES. Twenty four samples of needles were ashed and submitted for ICPMS/ ICP-ES analysis after Aqua Regia digestion.
Light rare earth elements
(LREE), Y, Zr and P in both twigs and needles are good exploration vectors for carbonatite-related REE and apatite mineralization. Concentrations of heavy rare earths (HREE) are near or below the detection limit. The highest concentrations of REE are
detectable directly over the carbonatite. Chondrite-normalized plots of vegetation samples show negative Eu anomalies.
Ta is found in detectable concentrations only in twigs, in samples spatially related to carbonatite. Detectable Ta
concentrations range from 0.001 to 0.003 ppm. Nb concentrations range from 0.02 to 0.24 ppm Nb in Spruce twigs, 0.005 to 0.071 ppm Nb in Spruce needles (dry weights normalized), and 0.012 ppm to 0.030 ppm in Fir needles (dry weight
Spruce twig data show positive correlations between Fe, REE and Zr; and Nb correlates positively with Fe, Ti, Ce, and Nd. Fir twigs were not analysed.
Spruce needle data show strong positive correlation between P, Mg and Ti;
moderate correlation between P and Ca; and strong correlation between Nb and REE, Zr and Fe.
There are not enough Fir needle samples for formal statistical analysis; however, strong correlations between Fe and REE, Fe and Ti and also P and Zr are