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TitreStream sediment orientation survey, Aley carbonatite niobium deposit, British Columbia, Canada
AuteurMackay, D A R; Simandl, G J
SourceBritish Columbia Geological Survey, Geofile no. 2014-05, 2014, 1 feuille
Année2014
Séries alt.Secteur des sciences de la Terre, Contribution externe 20120506
Documentpublication en série
Lang.anglais
Mediapapier
Formatspdf
ProvinceColombie-Britannique
SNRC94B/05
Lat/Long OENS-123.9250 -123.9233 56.4811 56.4000
Sujetséchantillons de sédiment de cours d'eau; géochimie des sédiments de cours d'eau; géochimie des éléments en trace; géochimie du cerium; géochimie du niobium; géochimie du tantale; géochimie du lanthane; géochimie du néodyme; géochimie de l'yttrium; géochimie de l'uranium; géochimie du thorium; géochimie du strontium; géochimie
Illustrationsanalyses; graphs; location maps; photographs
ProgrammeÉtude des gîtes des métaux rares, Initiative géoscientifique ciblée (IGC-4)
LiensOnline - En direct (9.3 MB)
Résumé(disponible en anglais seulement)
The Aley carbonatite-hosted deposit is the most important Nb resource in the British Columbia alkaline province. Portable X-ray fluorescence (pXRF) was used effectively to determine concentrations of carbonatite pathfinder elements (Nb, Ta, La, Ce, Pr, Nd, Y, Th, U, Ba, and Sr) in stream sediments. Investigation of sediments of the unnamed creek ("Al creek") draining the Aley carbonatite area, indicates that the +250?m, +125?m, and +63?m size fractions contain high concentrations of carbonatite pathfinder elements (Nb, Ta, La, Ce, Pr, Nd, U, and Th) relative to other size fractions. The +125?m fraction was chosen for systematic evaluation of the pathfinder element distribution in Al Creek sediments because it is suitable for chemical analysis and Quantitative Evaluation of Materials by Scanning electron microscopy (QEMSCAN). The same samples enriched in pathfinder elements are expected to contain minerals characteristic of carbonatites such as pyrochlore, columbite-(Fe), fersmite, monazite-(Ce), rare earth element (REE)-bearing fluorocarbonates, barite, and apatite. Optical microscopy, electron microprobe (EMP), laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS), and QEMSCAN studies of these samples are required to identify the most useful carbonatite indicator minerals and quantify their relative abundances with increasing distance from the deposit. The main objectives of this study are to: 1) determine if stream sediment geochemistry can be used effectively to explore for Aley type deposits; 2) establish the best stream sediment size fraction for indicator minerals that might point to Nb-bearing carbonatite deposits; 3) characterize the geochemical gradient of potential pathfinder elements (Nb, Ta, REEs, P, Ba, Sr, U, and Th) in sediments downstream from the deposit, and 4) evaluate the usefulness of pXRF analyses for preliminary assessment of indicator mineral and stream sediment studies.
GEOSCAN ID295092