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TitreAssessment of local spatial and analytical variability in regional geochemical surveys with a simple sampling scheme
AuteurGarrett, R G
SourceGeochemistry: Exploration, Environment, Analysis no. 13, no. 4, 2013 p. 349-354,
Séries alt.Secteur des sciences de la Terre, Contribution externe 20110233
ÉditeurGeological Society of London
Documentpublication en série
Mediapapier; en ligne; numérique
Formatspdf; html
Sujetsinterprétations géochimiques; analyses géochimiques; levés géochimiques; statistiques; méthodes statistiques; statistiques géochimiques; méthodes d'échantillonage; géochimie; géomathématique
Illustrationsdiagrams; screen captures; tables
ProgrammeGéosciences environnementales, Gestionnaire de programme
Diffusé2013 11 13
Résumé(disponible en anglais seulement)
A procedure is presented for estimating the relative contributions of geochemical survey, local sampling, and analytical variability to total survey variability.Additionally, F-tests for the statistical significance of the variance components are undertaken to assist in determining if the survey data are fit for purpose in mapping exercises. Based on triplicate analyses, where one of the field duplicates is split
to provide an analytical duplicate, the procedure is effective, both statistically and in terms of cost. Open Source, R, Analysis of Variance (ANOVA) software is available to undertake the statistical data investigation. Guidance rules are developed to help determine if the data should be transformed in order to satisfy the assumptions, normality and homoscedasticity, of the ANOVA method, and to accommodate the compositional, constant sum, nature of analytical geochemical data.