EARTH'S PAST CLIMATE: A GEOSYSTEMS APPROACH EMPHASIZING SEDIMENTARY GEOLOGY

Sedimentary rocks archive the record of Earth's surface processes– the ‘Critical Zone.' In sedimentary geology classes, we stress facies models and stratigraphic principles to understand deposition, to reconstruct environments, sea level changes and even plate tectonic settings. Recent developments in our abilities to read, date, and model Earth's deep-time sedimentary record, however, are enabling reconstruction and study of climate at unprecedented detail, and lend a new emphasis and even urgency to the study of sedimentary rocks.

A complete understanding of Earth's climate system demands an appreciation for the full spectrum of Earth's climate behavior. This is the concept underlying GeoSystems– an interdisciplinary, community-based effort intended to raise awareness of the importance of examining the wealth of ‘alternative-Earth' climatic extremes archived in the ancient rock record. GeoSystems emphasizes the ‘deep-time' perspective for understanding the complexities of Earth's atmosphere, hydrosphere, biosphere and lithosphere with climate as the nexus. The sedimentary record is thus critical, because it is our sole window to past behaviors of these systems, which include the most extreme climates known on the planet.

At OU, we team-teach a cross-college/departmental course in Earth's Past Climate that attracts students primarily from Meteorology, Geology and Science Education, and draws directly on the GeoSystems concept by virtue of the interdisciplinary approach. From our informal web searches, it appears to differ from many courses in paleoclimatology owing largely to the emphasis on ‘deep' time, which in turn demands equal attention paid to all of Earth's component systems, and a heavy dose of sedimentary geology– new territory for most Meteorologists. It is slash-listed in both Meteorology and Geology, and hence includes reviews of fundamental concepts in both, including Earth ‘systems' and cycles, but with sedimentary rocks as the core– the central database. ‘Crash'-course labs and field experiences engage the non-geologists in sedimentary geology. The last several weeks are spent exploring ‘extreme' Earth scenarios that, in this age of universal ‘biggie-sizing', seems to capture students' collective imaginations.