Stable Isotope Paleoecology: Examining Changing Cenozoic Environments

My internship this summer, under the guidance of Dr. David L. Fox, focused on the use of stable isotope geochemistry to gain an understanding of organisms and environments from the later paleozoic.  My research approached this subject from several angles and I was variously involved in: collecting samples in the field, exploring field sites, processing and analyzing samples in the lab, and interpreting the results of those lab analysis. I also familiarized myself with the background literature relating to my research. My research essentially consisted of two discrete projects.

The first involved travel to Meade, Kansas in the southwest portion of the state. There, we explored and then collected sample from Pliocene paleosols. The goal of this project is to eventually describe the nature of the transition from a wooded environment to the characteristic 'great plains' of today. Using the isotopes of carbon and oxygen a picture of the plant community and the general climate can be drawn.This will help to establish if the transition took place along with a global change in plant communities or if the process had a more localized occurance.

The second project I was involved in was the processing of Siberian Wooly Mammoth (Mammuthus) tusks, also for analysis of the stable carbon and oxygen isotopes. I used a dental drill to collect powder samples and a mass spectrometer to analyize those samples. Interestingly our results suggested a warmer climate than had previously been inferred for siberian mammoths. This is perhaps because our samples came from Wrangel Island, which supported the last living population of mammoths 5000 years longer than they persisted on the mainland. The suggestion of my results is that my mammoth may be holocene in age. This would explain the unusual climatic signals.