Presenter: Brooklyn Regan

Faculty Sponsor: R. Mark Leckie

School: UMass Amherst

Research Area: Geology and Earth Sciences

Session: Poster Session 4, 2:15 PM - 3:00 PM, 163, C3

ABSTRACT

Microfossils found in sediments from the Ross Sea continental shelf, Antarctica, provide details about Earth’s climate history and can help determine the extent of Antarctic Ice Sheet variability through time. We look at the Pliocene Epoch (5.33-2.56 Ma), a notably warm interval in Antarctica’s past that can serve as an analogue for our near-future climate. The West Antarctic Ice Sheet’s (WAIS) prominent variability due to ocean changes makes this region useful for understanding Earth’s climate evolution. Analyzing Pliocene marine microfossils from the Ross Sea allows us to add to Antarctica’s microfossil profile and interpret Antarctic glacial history. The sediment studied is from International Ocean Discovery Program Expedition 374 Site U1522. Microfossils such as diatoms, radiolarians, and foraminifera are found in various abundance throughout the cores. Sediment samples were processed and scanned at the >63-micron size fraction. Microfossils and materials including coal and glauconite were identified and counted in each sample. Counts inform us of oceanic trends in the Ross Sea through the Pliocene. Preliminary results of this study show that the early Pliocene had abundant radiolarians and few foraminifera which may suggest the dissolution of carbonate. A foraminifera peak, including planktic specimens at ~281 m may correlate with a warm water peak recognized at Site U1523 on the shelf edge at ~3.7 Ma. Additional peaks in components may indicate erosion and winnowing and the occurrence of Ross Sea Unconformity 2 at ~273 m. Further analysis of Site U1522 is necessary to understand the response of the WAIS to ocean changes.