Kimberly Steeh
Research Mentor(s): Katarina Keating
Mentor Department: Earth and Environmental Sciences
Authors: Kimberly Steeh, Katarina Keating, Nathan Sheldon
Session: Session 4 (1:00pm – 1:50pm)
Presentation Type: Poster 26
Abstract
Increasing atmospheric CO2 levels will bring unprecedented changes to the planet, and an understanding of how ecosystems functioned in past periods of high temperature and atmospheric CO2 may aid in developing strategies to mitigate some of the most extreme effects. This project compares atmospheric carbon isotopic composition values (d13Catm) from marine foraminifera, an established proxy source, during a period of elevated temperature in the Hoback Basin, Wyoming, to terrestrial sources of d13Corg, in order to assess their potential as d13C proxies, and therefore provide higher resolution data regarding carbon distribution during a period of global warming. Samples were collected from the Hoback and Pass Peak Formations in strata correlated to the upper Paleocene (~60-56 Ma) and lower Eocene (~54-50 Ma) Epochs. After sample size is determined by measuring total organic carbon in an elemental analyzer, d13Corg is evaluated using Cavity Ring-Down Spectroscopy (CRDS), and d13Catm is calculated using the methods developed by Farquhar et al., 1989. So far 121 out of 176 samples have been prepared for weighing and measurement, and 28 usable samples have been run in the CRDS. Additionally, some samples will need to be run a second time due to instrument malfunction. However, the data that have been returned are consistent with values obtained from marine foraminifera for the same time, and with expected values during a period of rapid global warming. An expansion of the timeframe being studied and additional sample types may further clarify the potential of terrestrial d13Corg sources as atmospheric proxies.
