Dr. Bradley Cramer has been granted an NSF Earth Sciences Postdoctoral Fellowship to carry out a research and education plan at the Kansas Geological Survey and the University of Kansas. The proposed research will undertake an investigation to significantly improve the Silurian timescale (444 to 416 million years ago) and better constrain our understanding of the rates of Paleozoic global climate change (542 to 251 million years ago). This project will integrate high-resolution biostratigraphy of conodonts and graptolites, high-resolution carbonate carbon isotope chemostratigraphy, new single grain zircon U/Pb age dates, and the Average Spectral Misfit (ASM) method of orbital tuning to produce a Silurian timescale with resolution and fidelity approaching that of modern global climate records. The proposed research will include study areas from the United States, the United Kingdom, Sweden, and Estonia.
The proposed research will increase the resolution of the Silurian portion of the Geologic Timescale by more than an order of magnitude, and when completed, will mark a significant improvement in our ability to tell time in the deep past, at the scale of thousands of years. Resolving the deep-time climate history of the Earth to such short timescales would allow over 500 million years of global climate change to be directly brought to bear on our understanding of the modern climate system and significantly improve our understanding of the natural variability within the ocean-atmosphere system. Research methods and results will be integrated into course material to be taught by the PI at the KU, Department of Geology, and both graduate and undergraduate students will be included in the field and laboratory portions of the proposed research to provide hands-on training for students.
Recalibrating the Silurian System This NSF Post-Doctoral Fellowship provided a wealth of new scientific information and helped advance Earth history research, but in addition has provided several potentially transformative contributions to both the scientific community and the public at large. From a purely technical view, this project has provided considerable improvement to our understanding of the timing and duration of major global change events during the Silurian Period which lasted from roughly 442 to 418 million years ago. This small slice of Earth History includes some of the largest and most dynamic changes within the global climate system, and now for the first time, we have been able to use modern, high-precision techniques to determine the rates and durations of some of these events. By doing so, we have begun to open the library of deep time Earth history to help improve our understanding of the natural variability within the global climate system. The research results from this study are transformative to the discipline in as much as they demonstrate global change events, particularly global ocean chemistry changes, occurred during the Silurian that are significantly faster than previous models have anticipated. This indicates that we are still in the process of trying to understand fully the intricate interactions within the global ocean-atmosphere-biosphere system. As with any good scientific enterprise, the completion of this fellowship has provided more questions than answers, and it has highlighted important new avenues for future research. The broader societal impacts of this fellowship rest in the training and primary research opportunities it provided for a range of students from high-school to PhD, but in addition, in a piece of technology referred to as the Digital Integrated Stratigraphy Project (DISP). Although the initial function of the DISP was as a permanent web-based digital resource for stratigraphy and the geoscience community, the DISP is also being developed as a tablet PC app available to the general public. Once primary work has been completed for a given location, the DISP will be able to provide the public the opportunity to take their tablet PC with them out to their favorite outcrop or major rock exposure and be able to interact with a 3D digital representation of the outcrop in front of them. The tablet PC app would allow the user to view the digital version of the outcrop and overlay a variety of data of their choice. If they wanted to know the formal names of the rocks, or the numerical ages of the strata, that data could be made available through the DISP app. As a result, the DISP provides an ideal platform to disseminate our modern understanding of Earth history to the population at large. The DISP is a technological component of the International Geoscience Programme (IGCP) Project 591 – The Early to Middle Paleozoic Revolution. IGCP 591 and the DISP were natural progressions from this post-doctoral fellowship, and were two of the results of this project. Overall, the primary objectives of this fellowship were accomplished, and in addition, several unanticipated new avenues of research have been opened as a result of this project.
