View Item 
        •   Utrecht University Student Theses Repository Home
        • UU Theses Repository
        • Theses
        • View Item
        •   Utrecht University Student Theses Repository Home
        • UU Theses Repository
        • Theses
        • View Item
        JavaScript is disabled for your browser. Some features of this site may not work without it.

        Browse

        All of UU Student Theses RepositoryBy Issue DateAuthorsTitlesSubjectsThis CollectionBy Issue DateAuthorsTitlesSubjects

        Milankovitch cycles in REE+Y: A new geochemical tool for cyclostratigraphic analysis of BIFs

        Thumbnail
        View/Open
        Appie Haddouzi 4210026 - Guided Research Appendix v2.pdf (2.076Mb)
        Appie Haddouzi 4210026 - Guided Research Final Draft v2.pdf (924.3Kb)
        Publication date
        2020
        Author
        Haddouzi, A.
        Metadata
        Show full item record
        Summary
        Spectral analysis was performed on the UU BH-1 core containing the Kuruman banded iron formation (BIF) in order to identify the presence of Milankovitch cycles. We analysed the Fe/Mn which has been found to capture Milankovitch cycles, as well as the rare-earth element + Yttrium (REE+Y) record of a ~100m section of the core. Several recurring cycles were found across all proxies examined in the form of ~3.8m, ~5.2m, ~8.0m and ~19.5m cycles. The ~8.0m cycle was found to be a double ~3.8m cycle and together with the ~5.2m cycle explains nearly all elemental variations found throughout the stratigraphy. The ~19.5m cycle most likely functions as a modulation on the ~5.2m and ~8.0m cycles as the ~8.0m cycles were found to be most dominant with a weak ~19.5m cycle in the middle of the stratigraphy. REE+Y were able to capture a distinct signal throughout the entire stratigraphy, even in sections where Fe/Mn was incapable of capturing clear cycles. The REE+Y showed an antiphase relationship with Fe/Mn while Y/Ho and La were nearly in-phase with it. Y/Ho exhibited an exceedingly high coherence (0.71-0.91) with Fe/Mn at the period considered and was found to most directly respond to changes in continental input and thus climate. Due to the agreement between the cycles found in the Fe/Mn and REE+Y record we conclude that there is a direct climatological control on REE+Y in BIFs.
        URI
        https://studenttheses.uu.nl/handle/20.500.12932/36996
        Collections
        • Theses
        Utrecht university logo