GEOSCAN, résultats de la recherche


TitreSuccesses and challenges in the application of multivariate statistics to multi element geochemical data
AuteurGrunsky, E C
Source 2013 p. 1
Séries alt.Secteur des sciences de la Terre, Contribution externe 20120168
RéunionInternational Geological Congress; Brisbane; AU; août 8, 2012
Mediaen ligne; numérique
Sujetsméthodes statistiques; statistiques; statistiques géochimiques; interprétations géochimiques; géochimie; géomathématique
ProgrammeBases de données couvrant les trois territoires (la télécartographie prédictive), GEM : La géocartographie de l'énergie et des minéraux
LiensAbstract - Résumé
Résumé(disponible en anglais seulement)
Processing geochemical data from geochemical surveys requires a systematic approach to effectively interpret the data in a meaningful way. Geochemical survey data, collected by mineral exploration and geological government surveys are typically comprised of many thousands of samples containing as many as 60 elements. When assembling large regional datasets from various sources, care must be taken to understand the nature of the sample media, methods of sample preparation, laboratory digestion procedures and analytical instrumentation methods. Effectively analyzing and assessing the information that exists in such datasets can benefit from the use of multivariate statistical procedures and spatial mapping of the results. Geochemical and geological processes can often be recognized through the use of data discovery procedures such as the application of principal component analysis. The use of classification and predictive procedures can be used to confirm lithologic variability, mineral ore zone alteration and zones of mineralization. Problems that have plagued the interpretation of multi-element geochemical data include the problem of closure, missing values, censoring and adequate spatial sample design amongst others. Of particular significance is the effect of stoichiometry within the logratio framework that has been used to deal with closed data. This presentation summarizes how geochemical data can be interpreted successfully along with some of the ongoing challenges that raise questions about the application of certain procedures. Examples are provided from Canada, Australia, USA and Indonesia.