Exploring the joint compositional variability of major components and trace elements in the Tellus soil geochemistry survey (Northern Ireland)

Raimon Tolosana-Delgado, Jennifer McKinley

Research output: Contribution to journalArticle

20 Citations (Scopus)
246 Downloads (Pure)

Abstract

The complexity of modern geochemical data sets is increasing in several aspects (number of available samples, number of elements measured, number of matrices analysed, geological-environmental variability covered, etc), hence it is becoming increasingly necessary to apply statistical methods to elucidate their structure. This paper presents an exploratory analysis of one such complex data set, the Tellus geochemical soil survey of Northern Ireland (NI). This exploratory analysis is based on one of the most fundamental exploratory tools, principal component analysis (PCA) and its graphical representation as a biplot, albeit in several variations: the set of elements included (only major oxides vs. all observed elements), the prior transformation applied to the data (none, a standardization or a logratio transformation) and the way the covariance matrix between components is estimated (classical estimation vs. robust estimation). Results show that a log-ratio PCA (robust or classical) of all available elements is the most powerful exploratory setting, providing the following insights: the first two processes controlling the whole geochemical variation in NI soils are peat coverage and a contrast between “mafic” and “felsic” background lithologies; peat covered areas are detected as outliers by a robust analysis, and can be then filtered out if required for further modelling; and peat coverage intensity can be quantified with the %Br in the subcomposition (Br, Rb, Ni).
Original languageEnglish
Article number76
Pages (from-to)263-276
Number of pages14
JournalApplied Geochemistry
Volume75
Early online date12 May 2016
DOIs
Publication statusPublished - Dec 2016

ASJC Scopus subject areas

  • Earth and Planetary Sciences(all)
  • Geochemistry and Petrology

Fingerprint Dive into the research topics of 'Exploring the joint compositional variability of major components and trace elements in the Tellus soil geochemistry survey (Northern Ireland)'. Together they form a unique fingerprint.

Cite this