Laurentide ice sheet meltwater influences and millennial-scale climate oscillations on the northwestern slope of the Gulf of Mexico during Marine Isotope Stage 6 and Termination II

• Main Author: O'Hayer, Walter Werley
• Other Authors: Droxler, Andre W., Dugan, Brandon
• Format: Thesis
• Language: English
• Published: 2009
• Subjects: Geochemistry; Ice Sheet
• Online Access: https://hdl.handle.net/1911/61948

Sub-Milankovitch climate oscillations are well documented phenomena in the Gulf of Mexico during Marine Isotope Stage (MIS) 3 and Termination I, however very little is known about equivalent events during older time intervals. Basin 4 is located on the northwest slope of the Gulf of Mexico and has provided a detailed record of late MIS 6 and Termination II. The results of this study show that the delta18O record of planktonic foraminifer G. ruber contains millennial-scale climate oscillations during MIS 6, a series of meltwater spikes, and a climate reversal during Termination II. Paired delta18O -- Mg/Ca data across these events reveal that the unusually large amplitudes in the delta 18O record cannot be explained by sea surface temperature (SST) or ice volume, but rather are a response to isotopically light glacial meltwater from the paleo-Mississippi river. This conclusion supports the studies of similar oscillations during Termination I and MIS 3.