Earth Evolution: Surface Life and Climate
This broad theme involves the investigation of sedimentological, paleobiological, and climatological processes over geologic time. These processes operate within the Earth’s surface and near-surface realms. A variety of investigative techniques are employed, including field-based studies, stable isotope analysis, petrography, subsurface data analysis, major and trace element analysis, micro-imaging and numerical analysis.
These diverse techniques allow us to address a range of issues that include: sea-level change, biodiversity change, climate change, mass extinction, post-depositional processes, and lithosphere-atmosphere-biosphere interactions throughout Earth’s evolution.
The range and scope of research projects within the Earth Evolution theme is substantial, and there is major interaction and synergy between this and other research themes. However, Earth Evolution is distinguished by the fact that investigations inevitably involve the issue of change through time, whether over only a few hundred years to millions, or even billions of years.
Factors that control the composition of sedimentary deposits; tectonic setting, climate, provenance, transport, recycling, depositional environment, and diagenesis. Collaborative projects involve Precambrian sedimentary systems, Ordovician rocky shorelines, and modern beach grain composition and textures. Analytical techniques include trace element geochemistry, cathodoluminescence spectroscopy, petrography, SEM, and FTIR.
Stephen R. Hicock
Glacial and Quaternary geology in parts of Canada and Antarctica.
Ordovician-Silurian brachiopod taxonomy and diversity patterns through time; origin, radiation, mass extinction, and recovery of brachiopod faunas in the epicontinental seas of North America during the Ordovician and Silurian periods; paleoecolgy and environmental control on the evolution of brachiopod communities and faunas; comparative study of Ordovician-Silurian brachiopod faunas of North America and other regions – applications to global biodiversity patterns and paleobiogeography.
The use of O, H, C, and N isotopic ratios, including triple-isotope ratios of oxygen, and mineralogy to understand lower temperature lithosphere-biosphere-hydrosphere-atmosphere interactions. Large-scale fluid-rock interaction, diagenesis and alteration in sedimentary basins and other crustal rocks (Appalachian basin, Avalonia). Calibration and application of isotopic proxies (e.g., precipitation, lakewater, DIC, nitrate, cellulose, pollen, soil and sediment organic matter, shelly fauna, and teeth, bones, tusks and hair [collagen, keratin, amino acids, bioapatite phosphate and structural carbonate] of mammals – e.g., mammoths, mastodons, deer) for paleoecological and paleoclimatic reconstruction. Paleolimnology and glacial meltwater movement in the Great Lakes Basin over the last ~15,000 years (sediment cores: porewater, ostracodes, organic matter, diatoms, and clay mineralogy).
Clastic sedimentology and sequence stratigraphy of Cretaceous rocks in the Western Canada foreland basin, using data from outcrop In the Rocky Mountains coupled with a huge subsurface data base. Projects broadly address high-resolution sequence stratigraphy, paleogeographic evolution, causes, amplitude and timing of sea-level change, and sedimentary-tectonic interactions. Projects with colleagues in North America and Europe involve inter-regional correlation, molluscan biostratigraphy, high-precision U-Pb geochronology, carbon-isotope stratigraphy.
Taphonomic (post-mortem) factors that control the preservation of both hard and soft tissues of ancient organisms, including sedimentary dynamics, bioturbation, geomicrobiological processes and later effects of diagenesis. Paleoecology of invertebrate marine communities, reconstruction of ancient marine environments, and event stratigraphy. Collaborative projects include studies of the exceptionally preserved Mazon Creek biota (Carboniferous), and paleoecological and taphonomic aspects of Paleozoic mudrocks.
Development of stable-isotope biogeochemistry techniques to understand the interactions among the soil-plant-atmosphere continuum. Paleoclimate models based on the isotopic analysis of ancient plant materials (biogenic minerals and organic molecules) preserved in terrestrial soils are used to assess climate change and the evolution of biogeochemical cycles with implications for carbon sequestration, water resource availability, weathering rates, drought and fire frequency and ecosystem resilience in regions with high rates of natural or anthropogenic vegetation change.