Middle Miocene Paleoenvironmental Changes in the South Atlantic Region and its Impact on Planktic Foraminifera– A Multiproxy Reconstruction

Authors: Ravi Kiran Koorapati, Adriane Lam, Gilles Guerin, Jesse Yeon, Daisuke Kuwano, Damon Teagle, Julia S. Reece, Rosalind M. Coggon, Jason Sylvan, Trevor Williams, Emily Racz Estes, and the South Atlantic Transect IODP Expedition 390 & 393 Scientists

Field of Study: Science, Technology, Engineering, and/or Math

Faculty Mentors: Adriane Lam

Easel: 3

Timeslot: Midday

Abstract: The IODP 390/393 recovered sediments from Holes U1560A & U1583C spanning the Miocene Climate Optimum (MCO; 16.9–14.7 Ma), a time of warming followed by a period of cooling, the mid-Miocene Climate Transition (MMCT, 14.7–13.8 Ma). Previous studies from the Tasman Sea indicate Hadley Cell expansion and the westerlies’ pushed towards Antarctica, thus limiting sea ice formation during the MCO, whereas sea ice formation commenced with cells’ contraction across MMCT. This study investigates the atmospheric cells response across these periods from the South Atlantic. X-ray fluorescence (XRF) and natural gamma radiation (NGR) data indicate increased windiness over the sites, coinciding with the MCO at ~16 Ma, and the MMCT at ~14.5 Ma. This signal could indicate an expansion and subsequent contraction of the Hadley Cell. Stable isotope and foraminiferal biostratigraphy will be undertaken to decipher the response of the plankton community to concurrent atmospheric, oceanographic changes in the region.