Life in a Dead Ocean: Linking bacterial biomarkers to elemental analysis in the Permian – Triassic (PT) Extinction Event
Literature seminar abstract
A particular time frame of interest to geochemists is the period from the Late Permian to the Early Triassic, as that time frame includes the End-Permian extinction event that occurred around 252 million years ago, the largest known mass extinction event in earth’s history. However, the exact cause of this extinction is still unknown, with some possible contributing sources being volcanic activity, rising temperatures, ocean anoxia, and bacterial blooms.1 Inorganic analysis of rock samples is commonly used in geochemistry to analyze environmental conditions, identify extinction sources, and date samples, thus it has been used to analyze this event.2 Another method of analyzing this event is looking at bacterial and plant biomarkers left in the sediment. 3-4
There are a few issues with using both of these analytical methods. One of the main issues with analyzing this event with inorganic techniques is that the complexity of rock samples and the difficulty in analyzing them makes it hard to determine specific environmental factors. Analyzing biomarkers from these rock samples can help clarify certain environmental parameters due to certain bacteria having specific living conditions, and can give us a better idea of how the extinction progressed. However, the types of rock that can be analyzed with this method are limited. Rarely are both of these methods analyzed in a single paper, as they require very different methods of sample preparation and analytical instrumentation. This highlights a gap in the literature, as the question of whether the bacteria involved in this event impact or are impacted by the elements found at unusual concentrations in the sediment is unanswered. I propose a set of experiments in order to help clarify this gap in the literature.
(1) Knoll, A.; Bambach, R.; Payne, J.; Pruss, S.; Fischer, W. Earth and Planetary Science Letters, 2007, 256(3-4),295-313.
(2) Georgiev, S.; Stein, H.; Hannah, J.; Bingen, B.; Weiss, H.; Piasecki, S. Earth and Planetary Science Letters. 2011, 3-4, 389-400.
(3) Grice, K.; Cao, C. Q.; Love, G.; Bottcher, M. ; Twitchett, R.; Grosjean, E.; Summons, R.; Turgeon, S.; Dunning, W.;Jin, Y. Science. 2005, 5710, 706-709.
(4) Whiteside, J. and Grice, K. Annual Review of Earth and Planetary Sciences, 2016 , 44, 581-612.
Speaker: Allison A. Haase
Speaker Institution: Colorado State University
Event Date: 02-14-2018
Event Time: 4:00 PM
Event Location: Chemistry A101
Mixer Time: 3:45 PM
Mixer Location: Chemistry B101E
Host: D. Crans