Early neoproterozoic evolution of the Amundsen Basin

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The proposed research will investigate a 4 km-thick succession of sedimentary rocks known as the Shaler Supergroup that are well-exposed on northwestern Victoria Island, Northwest Territories. The precursor sediments were deposited in the Amundsen sedimentary basin nearly 1 billion years ago. The basin was situated within an ancient supercontinent, Rodinia, and records Earth's environmental history from the time of supercontinent amalgamation until its break-up about 250 million years later. The proposed detailed sedimentological, stratigraphic and geochemical studies will build upon previous research, leading to a greater understanding of larger-scale tectonic, geochemical and biological evolution during a poorly understood period of Earth's history. Questions that will be addressed include: 1) was the Amundsen basin part of a larger basin that was intermittently open to an exterior ocean? If the Shaler Supergroup represents deposition in a large basin within Rodinia, where are the correlative sedimentary strata from the other side of the basin that were separated when Rodinia broke apart? Such information, combined with that from parallel studies, will help us to reconstruct Rodinia. 2) What was the mechanism of subsidence in these interior basins and how does one explain the intermittent cycles of basin restriction and open ocean conditions that are observed? Further, what was the duration and mechanism of this cyclicity? 3) What was the ancient geography of north-western Canada at this time and how does that fit with paleogeographic models proposed for similar-age rocks on other continents (e.g. Australia, Siberia)?