Changes in the Miocene marine environment recorded by planktic foraminifera
Date
2025
Authors
Hawkey, Ivy
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Publisher
University of Victoria
Abstract
This research catalogued the distribution of marine microfossils (planktic foraminifera) at the end of the Miocene (4-6 million years ago (Ma)). Planktic foraminifera are single celled protists which produce a calcium carbonate shell. Due to their abundance, they create an excellent record of oceanic conditions of the past. The four samples used in this research were taken during the International Ocean Discovery Program (IODP) during Expedition 177 at Site 1088. This site is located on the Anghulas Ridge off the coast of South Africa. The samples were washed and prepared prior to this project. Individuals were grouped and counted by genus. The results of this research show that 6Ma the population of planktic foraminifera was dominated by genera which lived in the mixed layer, such as Globigerina and Globoturborotalita. By 4Ma, the population was dominated by genera which inhabit the deep thermocline, such as Neogloboquadrina and Globoconella. This indicates that the deep water became increasingly habitable as the Miocene ended, which could be due to ocean circulation shifts caused by the cooling surface temperature. Research into this topic is ongoing. Further research into this topic could consist of continuing abundance counts at Site 1088 across a longer period of time, or completing abundance counts at different sites.
Description
Keywords
planktic foraminifera, Miocene, climate change, cooling, ocean circulation, micropaleontology