Earth Systems
Paleoclimate, paleoenvironments and the ancient biosphere

Disciplines: Stratigraphy; Sedimentology; Geochemistry; Paleontology

Faculty: Rick Lupia; Lynn Soreghan; Mike Soreghan; Steve Westrop; Rich Cifelli; Michael Engel; R. Douglas Elmore; John Pigott

A systems approach to Earth history emphasizes the interaction among the atmosphere, hydrosphere, lithosphere and the biosphere. The geologic record is a natural laboratory for studying global environmental change over long time periods.  An understanding of the linkages among the various systems provides insight into the mechanisms that produce major climatic and oceanographic changes, shifts in depositional systems, community replacement and mass extinction. Not only does this research provide a fresh perspective on the evolution of the Earth over the last 4.5 billion years, but also allows us to better evaluate the potential long-term impact of current anthropogenic global environmental change and potential biotic response.  An integrated, systems approach to the stratigraphic and fossil records also provides predictive tools for identifying distributions of hydrocarbon source, reservoir, and seal facies.

Paleoclimates.  Increasing levels of atmospheric greenhouse gases has heightened interest in pre-Quaternary time periods as analogs for near-future climate states. The climate system also plays a profound role in sediment generation and chemistry, sediment supply, depositional facies, ecosystem structure and ocean processes.  Thus, analysis of "alternative-Earth" paleoclimates provides a unifying theme in which to understand sedimentary, biological and even tectonic systems.  For example, the interplay between the tectonic history of the Himalayas and the origination and intensification of the Asian Monsoon may have affected atmospheric chemistry (CO2 drawdown) and altered ecosystems in East Africa.  These in turn may have spurred the evolution of our own species.  Research in the School of Geology and Geophysics concerns “deep time” climate change as well as Quaternary climate change in terrestrial and marine settings.  Approaches include sedimentological and inorganic and organic geochemical methods coupled with paleontological studies.  Linkages with colleagues in the College of Geographic and Atmospheric Sciences provide a firm foundation in climate science.

Paleoenvironments.  Environmental interpretation is a central theme for a variety of disciplines that deal with the Earth system. In paleontology, study of sedimentary rocks places fossils in their environmental context and also provides a record of changes associated with extinctions and other biotic events.  Sedimentary geology, ranging from basic field approaches of facies analysis, to sophisticated laboratory analyses, also provides critical data for unraveling the history of sedimentary basins and associated uplifts, as well as interpretation of changes in climatic or oceanographic conditions through time.  Development and application of sedimentary proxies for paleoclimatic and paleoceanographic reconstructions to anchor climate models is a burgeoning and especially exciting avenue of research. Refinements in environmental interpretation also aid our understanding of various aspects of petroleum geology, from the origin of source rocks to the geometries of reservoirs. Research in the School of Geology and Geophysics deals with these and other pure and applied research topics that involve sedimentary environments ranging from long-lived lakes to deep ocean basins. 

The Ancient Biosphere. Estimates indicate that more than 99% of all species that have ever existed are extinct. Paleontology—the study of fossils—is critical to a full understanding of the evolutionary history of life. The fossil record is also the primary source of information on long-term, large-scale patterns, such as evolutionary radiations (e.g., the “Cambrian Explosion” and the Cenozoic diversification of mammals) and mass extinctions. Geological applications of fossils include the development of time scales (biostratigraphy), tracking environmental change, and the interpretation of sedimentary environments. Students in the School of Geology and Geophysics work alongside their professors to conduct exciting and innovative research on paleontology of invertebrates, vertebrates (dinosaurs and mammals), and plants. At OU, we discover and describe new faunas and floras (systematics), investigate evolutionary relationships among taxa (phylogeny), study the process of fossilization (taphonomy) and how animals and plants lived and died (paleoecology), and analyze those data to document evolutionary radiations and mass extinctions. The Paleontology Option within the B.S. geology degree program allows students to take a range of courses designed to provide a broad understanding of both geology and biology. By emphasizing critical thinking and creativity, the Paleontology Option is appropriate for students interested in careers requiring careful observation and analysis and an understanding of the whole Earth system, with emphasis placed on preparation for graduate studies and careers in paleontology at universities, museums, and industry.