|Titre||Biogeochemical orientation survey over carbonatite-hosted deposit|
|Auteur||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
|Séries alt.||Secteur des sciences de la Terre, Contribution externe 20120529|
|Éditeur||Association géologique du Canada|
|Réunion||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; mai 25-27,
|Document||publication en série|
|Media||papier; en ligne; numérique|
|Lat/Long OENS||-119.5000 -119.0000 52.2500 52.0000|
|Sujets||carbonatites; tantale; niobium; minéraux; analyses de la roche, éléments de terres rares; apatite; minéralisation; Détection|
|Programme||Étude des gîtes des métaux rares, Initiative géoscientifique ciblée (IGC-4)|
|Liens||Online - En ligne |
|Résumé||(disponible en anglais seulement)|
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.
Twenty 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
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 normalized).
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 suspected.