Defining element associations and inferring geological processes from total element concentrations in Australian catchment outlet sediments: Multivariate analysis of continental-scale geochemical data

In this paper, the geochemical composition of surficial regolith is statistically analysed and compared to independent geoscientific datasets to infer processes governing regolith composition. Surface (0–10 cm depth) and sub-surface (∼60–80 cm depth) transported sediment samples from the National Geochemical Survey of Australia were analysed for total element content in both coarse (<2 mm) and fine (<75 μm) grain-size fractions. Multi-element total content data was obtained from mainly XRF and total digestion ICP-MS analysis, of which the 50 elements satisfying data quality criteria, plus Loss on Ignition, are used herein.Censored data (

Figure optionsDownload as PowerPoint slideHighlights
► Australia-wide geochemical dataset of catchment outlet sediments covers 6 M km2.
► Total element concentrations analysed by PCA after imputation and clr-transformation.
► Four first PCs account for 59% of variance.
► Element associations show lithology, weathering, etc. control regolith composition.
► Maps of PC distributions relate to ground, airborne and spaceborne datasets.