Master of Science
Dr. Patricia Corcoran
The upper Gowganda Formation of the Huronian Supergroup contains glacially-induced, varve-like rhythmites composed of turbiditic micro-laminae that potentially preserve a detailed record of climatic conditions during the Paleoproterozoic Era. A sedimentological analysis of upper Gowganda Formation deposits enabled identification of eight lithofacies comprising a glaciogenic depositional environment: 1) diamictite, 2) contorted argillite, 3) interlaminated siltstone and sandstone, 4) interbedded siltstone and claystone, 5) sandstone, 6) siltstone, 7) interbedded coarse-grained and fine-grained siltstone, and 8) wavy argillite. Major, trace, and rare earth element analyses indicate that the rhythmites have undergone limited recycling and chemical alteration. Whole-rock δ18O values are consistent with an Archean gneiss provenance and support that chemical weathering and diagenesis were insignificant. Spectral analysis of four rhythmic couplet thickness records using the MTM Toolkit of Mann and Lees (1996) supports the hypothesis of annual deposition for the rhythmites.
Howe, Timothy S., "Investigating potential climatic cycles in glacially-influenced rhythmites of the upper Gowganda Formation using geochemical, sedimentological and spectral analyses" (2015). Electronic Thesis and Dissertation Repository. 3264.