Biotic and sedimentologic evolution of the Cambrian

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The 'Cambrian Explosion' half a billion years ago was a turning point for life on Earth: the appearance of animals, which gave rise to fossils of shells, spicules, skeletons, even sometimes soft tissues, plus new kinds of microbes, all of which caused profound ecological revolution in the marine realm. Sediment changed fundamentally due to processes of burrowing, pelletization, organic binding and bacterial decay. The first metazoan reefs appeared. We address these phenomena in an interdisciplinary way by combining sedimentology with paleontology in order to explore more fully this tremendous yet still mysterious evolutionary episode. The natural laboratory for us is mainly the splendidly exposed strata of the Cordillera and high Arctic, although we plan to recreate artificially some of the peculiar sedimentary features that are so distinct for this time. Our work on the bedrock geology is necessary documentation of an important component of Canada's natural history as well as critical background for natural resource exploitation. We do taxonomic work describing the trilobites, brachiopods, soft-bodied animals, corals and archaeocyathan and siliceous sponges, finding many new species, and we aim to elucidate in detail biological interactions such as predation. Our biostratigraphic data permit close temporal correlation and reveal patterns of diversification, extinction and phylogeny. Sedimentary features and paleoecology are used to compare the origin and evolution of facies and organo-sedimentary processes from the preceding Proterozoic through early Paleozoic time, and sporadically thereafter. Earthquake deformation structures are providing novel insight, and developing criteria to differentiate tsunami- versus storm-generated beds is ground-breaking. We are forging new ground with the Burgess Shale and various tropical carbonate reef, sand shoal, tidal flat and lagoonal deposits. We are employing geochemical data to reveal the source and processes of lithification of sediments and the tectonic history of the basins into which they were deposited.