Climatic indications from soils and sands, and their lithified equivalents

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Sedimentary deposits are a significant resource for understanding Earth's changing climatic conditions through time and space. Specific atmospheric indicators are represented by 1) soil weathering profiles 2) the distribution of heavy mineral suites (minerals with densities >2.9), 3) proportions of stable detrital minerals, such as quartz, and 4) aluminosilicate (clay) minerals that are highly sensitive to weathering. Sands and sandstones are particularly favourable for componentry studies (i.e. minerals and rock fragments), whereas finer-grained fractions are useful for major and trace element geochemistry, and stable isotope analysis. The aim of this proposed research program is two-fold and involves, i) determining the climatic conditions that governed sediment formation and deposition at specific times in Earth history, and ii) examining how different climatic conditions in modern settings control sediment composition. This research program represents a consolidation of projects and analytical techniques that will contribute toward a clearer understanding of Earth's climatic evolution. The following projects are proposed: i) Distinguishing between Late Albian "normal" and "super" palesols in the Western Canada Sedimentary Basin, and their implications for climate conditions and marine transgression, ii) Climatic variations during the Late Cretaceous-Miocene Central Otago region, New Zealand as evidenced from multiple paleosols, iii) The distribution of trace elements in modern corestone-bearing soil profiles developed on basalt, and iv) The effects of climate on the composition and textures of modern arid and temperate alluvial fan deposits of Namibia and New Zealand. The samples will be analyzed using major and trace element geochemistry and stable isotope analysis, scanning electron microscopy, and cathodoluminescence spectroscopy. The proposed research program will fund two Ph.D. students, two M.Sc. students and one Post-doctoral Fellow. The research program is significant because the most important process governing sediment composition with respect to Earth's evolution is climate, as it directly affects the development of biota on our planet.