Bekker, Andrey2020-04-212020-04-211998-02https://hdl.handle.net/11299/212452A Thesis submitted to the faculty of the Graduate School of the University of Minnesota by Andrey Bekker in partial fulfillment of the requirements for the degree of Master of Science, February 1998.The early Paleoproterozoic ocean and atmosphere experienced significant changes in climate and chemical composition. A global glaciation was followed by climatic amelioration. Chemical composition of the ocean, namely, carbon isotope values, changed dramatically during this time. Collected data support a glacial origin for the Headquarters and Vagner and possibly for the Campbell Lake Formations. Stable isotope values of limestones of the Vagner and Espanola Formations are similar, thereby strengthening correlation of the underlying glacial units. The Nash Fork Formation, based on carbon isotope values, was deposited at the end of the carbon isotope excursion. Study of carbonates of the Chocolay and Cobalt Groups showed similar carbon isotope values of the Gordon Lake Formation and the Kona Dolomite, supporting their correlation. Other carbonate units of the Chocolay Group that were considered correlative with the Kona Dolomite appear to have different carbon isotope systematics and are interpreted to be older.enPlan As (thesis-based master's degrees)Department of Earth and Environmental SciencesUniversity of Minnesota DuluthMaster of ScienceMaster of Science in GeologyThesis or Dissertation