| Summary: | The Chilean Margin region influences, and is influenced by, ocean-atmosphere, land-ocean, and surface-subsurface interactions. This area is home to the South Westerly Winds (SWW), whose strength and positions have broad implications for Southern Hemisphere and global climate through changes to precipitation, carbon dioxide, and heat storage. Existing regional records are limited by either time scale or resolution, which in turn limits our picture of a complex system. By creating a series of high-resolution Holocene records, we can assess SWW variability in response to various forcings and their relationship to global CO2. In this thesis I apply a multiproxy approach, including X-ray Fluorescence (XRF), stable isotope, and total organic carbon analyses among others, to reconstruct high resolution records of SWW migrations and Chilean Margin conditions during the Holocene and Pleistocene interglacial periods. High resolution, temporally extensive Chilean Margin records, can help us better understand how observed changes fit into the context of the South Pacific, the broader Holocene, and Pleistocene interglacial periods. The first chapter of my thesis focuses on solar forced centennial scale SWW variability. XRF analysis will be used to produce a ~2-year resolution aluminum record, a product of continental weathering in response to precipitation, representing SWW migration. It then ties resulting SWW migrations to Antarctic temperature variability using benthic δ13C data. Chapter 2 relies on productivity and nutrient consumption proxies to assess downstream effects of Southern Ocean biological pump inefficiency and, in doing so, helps solidify the leaky biological pump’s role in global atmospheric CO2 concentrations. Total organic carbon, Bromine XRF data, and bulk sediment nitrogen isotopes are included to obtain a full picture of nutrient availability and primary productivity along the Chilean Margin. Comparison with high and low latitude isotopic and primary productivity records constrains the fate of nutrients ...
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