26 Tech Fest Undergraduate Student Posters (Posters)

Tuesday, 14 March 2023
8:00 AM - 5:00 PM
Exhibition Hall 112

BENTHIC FORAMINIFERAL ANALYSES OF EQUATORIAL MID-PLEISTOCENE TRANSITION SEDIMENTS

Paper number: 26-2
Program: Theme Sessions
Time: 8:00 AM – 5:00 PM

Authors

Abstract

Samples from IODP Expedition 344 were collected to be processed for combined calcareous nannofossil and foraminiferal analyses over the Mid-Pleistocene Transition (MPT) which occurred between 1.25–0.7 million years ago. The samples from Site U1414, in the equatorial region off Costa Rica, contain excellent benthic foraminifera commonly associated with the mid-Pleistocene extinction event (Stilostomella Extinction Event referred to as SEE). The SEE includes >50 morphospecies and is well documented in DSDP and ODP sites, especially in the Southwest Pacific Ocean. The Stilostomella group has been noted to decrease in abundance and diversity in the late Pliocene with greater extinction rates having been documented between 0.7 and 1.2 Ma. The onset and duration of SEE events from the equatorial regions is only recorded at a couple of locations and comparisons of these and our study may provide a better understanding of the causes and impacts of the most recent benthic foraminifera extinction.

Here, we present foraminiferal ecology data and abundances throughout the MPT. Well-preserved specimens from these samples are used for stable carbon isotopic geochemistry. To determine microhabitat preferences of benthic foraminifera and assess their morphology and calcification with MicroCT scanning. MicroCT scanning was used in order to find volumes of the foraminifera tests. This data can be used to find patterns between individual foraminifera and how this relates to their depths and stable isotopic geochemistry. The findings of this project will provide initial observations and insights into the conditions prevailing at the equatorial region of the Southwestern Pacific during the MPT.

Geological Society of America Abstracts with Programs. Vol. 55, No. 1

doi: 10.1130/abs/2023SC-385046

© Copyright 2023 The Geological Society of America (GSA), all rights reserved. Permission is hereby granted to the author(s) of this abstract to reproduce and distribute it freely, for noncommercial purposes. Permission is hereby granted to any individual scientist to download a single copy of this electronic file and reproduce up to 20 paper copies for noncommercial purposes advancing science and education, including classroom use, providing all reproductions include the complete content shown here, including the author information. All other forms of reproduction and/or transmittal are prohibited without written permission from GSA Copyright Permissions.