GEOSCAN, résultats de la recherche


TitreThe use of statistical methods applied to multi-element geochemistry for phase discrimination in kimberlites - examples from the Star and Whiskey Kimberlites
AuteurGrunsky, E C; Kjarsgaard, B A; Kurszlaukis, S; Sellers, M
SourceL'Association géologique du Canada-L'Association minéralogique du Canada, Réunion annuelle conjointe, Recueil des résumés vol. 36, 2011 p. 1
Séries alt.Secteur des sciences de la Terre, Contribution externe 20100526
RéunionGeological Association of Canada / Mineralogical Association of Canada Annual Meeting; Ottawa; ON; 2011
Documentpublication en série
Mediaen ligne; numérique
ProvinceOntario; Saskatchewan
Sujetskimberlites; analyses géochimiques; analyses statistiques; méthodes statistiques; statistiques géochimiques; Kimberlite de Star ; géochimie
ProgrammeDiamands, GEM : La géocartographie de l'énergie et des minéraux
Résumé(disponible en anglais seulement)
The discrete eruptive phases of the Star kimberlite, Saskatchewan, and the Whiskey kimberlite, Ontario, Canada have been classified into distinctive groups using statistical methods applied to whole rock geochemical data. Based on the evaluation of petrography, mineralogy, major and trace element geochemistry, discrete kimberlite phases were constructed as geochemical groups. Multivariate statistical and cross-validation techniques including principal component analysis, k-means cluster analysis, analysis of variance, classification and regression trees were applied iteratively, to systematically refine the individual groups. Within the Star kimberlite, Ni, Si, Co, Mg and P contribute most to maximum discrimination between 5 recognized kimberlite phases. The Whiskey kimberlite can be subdivided into three distinct phases, defined by Ti, Al, Cr and Ni. The relationship between the geochemistry of the different kimberlite phases can be illustrated through graphical rendering of the statistical and classification procedures.
A portable hand-held X-ray fluorescence (XRF) spectrometer was used on crushed and powdered material from the three Whiskey kimberlite phases. The application of the same statistical methods to the powdered Whiskey kimberlite phases provided the similar phase discrimination results, thereby indicating that a portable XRF can be used to obtain geochemical signatures from which kimberlite phase discrimination can be carried out in the field.