Publication Date
2019
Document Type
Dissertation/Thesis
First Advisor
Scherer, Reed P.
Degree Name
M.S. (Master of Science)
Legacy Department
Department of Earth, Atmosphere and Environment
Abstract
The objective of this study was to assess the radiolarian assemblage of the Agulhas Current at International Ocean Discovery Program Expedition 361, Site U1479 (the most westward site), through the Mid-Pleistocene Transition (MPT). Samples between 1,000 to 777ka were utilized to (1) characterize the radiolarian assemblage, (2) observe whether the radiolarian assemblage is sufficiently distinctive to help discern the occurrence of the MPT in the Southern Ocean, and (3) determine whether changes in the radiolarian assemblage reflect a change or changes in ocean currents that may have occurred during the MPT.
Over 300 radiolarian species from 15 different families were identified in the relative abundance slides. Utilizing Tetrapyle octacantha, Lithomelissa thoracites, Phorticium clevei, Botryostrobus auritus/australis, and Cycladophora davisiana, the cyclicity of radiolarian assemblage peaks appeared to transition from obliquity- (~40ka) to eccentricity (100ka)- scaled cycles. Peaks in the abundance of these radiolarians were not tied directly to glacial/interglacial cycles as colder water taxa and subtropical taxa often had periods of overlap in spikes or drops in abundance. This suggests the mixing of the Agulhas Current with Atlantic and Antarctic waters, prominently the North Atlantic Deep Water and Antarctic Bottom Water, respectively, likely influenced relative abundances of radiolarians instead of purely glacial/interglacial intervals.
Recommended Citation
Bugbee, William Alberto, "Utilizing Radiolarian Assemblages to Track Changes in the Agulhas Current Through the Mid-Pleistocene Transition: IODP Site U1479" (2019). Graduate Research Theses & Dissertations. 6888.
https://huskiecommons.lib.niu.edu/allgraduate-thesesdissertations/6888
Extent
117 pages
Language
eng
Publisher
Northern Illinois University
Rights Statement
In Copyright
Rights Statement 2
NIU theses are protected by copyright. They may be viewed from Huskie Commons for any purpose, but reproduction or distribution in any format is prohibited without the written permission of the authors.
Media Type
Text
