Paleoenvironment and Paleoclimate of Coastal East Antarctica During the Middle Miocene : Particle Size Results of the ANDRILL Southern McMurdo Sound Project

• Main Author: Falk, Candice Joy
• Format: Text
• Language: unknown
• Published: Montclair State University Digital Commons 2009
• Subjects: Earth Sciences; Environmental Sciences; East Antarctica; McMurdo Sound; Antarc*; Antarctica
• Online Access: https://digitalcommons.montclair.edu/etd/1151; https://digitalcommons.montclair.edu/context/etd/article/2153/viewcontent/Falk_Thesis_2009_Redacted.pdf

The ANDRILL Southern McMurdo Sound (SMS) Project was carried out in December of 2007 by an international interdisciplinary team. The AND-2A core recovered the most complete Neogene stratigraphic record from Antarctica, spanning the past 20.2 million years. Analyzing particle size distributions of samples throughout the core can determine environmental conditions of the past, such as the advance or retreat of glaciers and the rise and fall of sea level. Over 300 samples were taken at approximately 3 m intervals from the 1138.54 m AND-2A core. Samples were processed and analyzed using a Malvern Instruments Mastersizer 2000, laser diffractometer which has the capability to measure sediments from 0.2 pm to 2000 pm. Statistical measures, such as the mean particle size, volume percent grain size, and distribution are analyzed to characterize the lithology, depositional environment and paleoclimate. The volume sand percent and sorting indicated a warming period during 15.6-15.7 Ma known as the middle Miocene climatic optimum (MCO) when ice-distal conditions existed, and a cooling period during 14.2-13.8 Ma known as the middle Miocene climatic transition (MMCT) that was ice-proximal. The MMCT is believed to have started the icehouse conditions in Antarctica that have existed for the past 14 million years. The changes in the particle size distribution give a better understanding of the hydrological processes and climate changes in Antarctica through the Neogene which will help predict future global environmental changes.