His Classroom is Outdoors

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Mar. 27, 2013

His Classroom is Outdoors

Geosciences professor Dan Lehrmann conducts research in South China and along a Central Texas river

Trinity University geosciences professor Dan Lehrmann conducts research in South China and along a Central Texas river

By Susie P. Gonzalez

SAN ANTONIO - For Trinity University geosciences professor Dan Lehrmann, fieldwork could mean guiding students down the Llano River in kayaks or taking them on hikes in a rural area of southern China. In either location or any of the other places where he ventures, he views fieldwork - especially if a discovery happens - as the excitement factor of his work.

"Fieldwork is what I love about geology in general," says Lehrmann, the Pyron Professor of Geosciences. He has spent 20 years studying the sedimentary evolution of south China and is now looking into reef complexes in Mason County along the Llano River in Central Texas as well as rocks near Lake Superior that represent ancient mountains and volcanic activity from some of the earliest history of the Earth.

When he says he is studying the "deep part of Earth's history," he means it. His work in China traces developments from 250 million years ago, the Llano outcrop dates back 500 million years, and the Lake Superior formations are from 3 billion years ago.

But the work has relevancy for the future, particularly in terms of how Earth systems fluctuations might have contributed to climate change, sea level fluctuations, or reef systems evolution, for example. Skimming the Llano River in kayaks, Lehrmann and his student researchers are studying what he describes as "really spectacular rocks" that are similar to and can provide a better understanding of hydrocarbon reserves in offshore Brazil. As a result, the central Texas work by Lehrmann, his students, and a team from Rice University has drawn recent funding support from four oil companies.

Lehrmann's work in China has been supported by the National Science Foundation, the American Chemical Society, and oil companies. A recent oil industry grant will allow him, his students, and colleagues from Stanford University to explore carbonate reef systems made of sedimentary deposits which might yield new insights on how to explore for oil in frontier basins. This latest China project will include mapping and developing 3-D models of the basin being studied.

In studying the area for nearly two decades, Lehrmann has detected patterns of climate change, sea level change, and related mountain-building episodes based on ancient tropical reefs as a dipstick to gauge environment conditions and the evolution of ocean basins. Now he is adding an analysis of sea water chemistry and what it might add to knowledge about rocks from that era.

Last summer, Dylana Watford, a senior from Brenham, Texas, and Jake Shultz, a senior from Wimberley, Texas, went to China with Lehrmann to learn first-hand about fieldwork.. "It was really helpful to be with Dr. Dan," Dylana says. "He has been doing fieldwork in China for many years so his expertise in the field and about China was invaluable. And of course it also helped that he speaks Chinese."

Watford and Shultz will be presenting results from their research at a Geological Society of America Conference in Austin next month, and they will be presenting at the American Association of Petroleum Geologists meeting in Pittsburgh in May.

Lehrmann recalled a kayaking trip along the Llano River with a Rice professor and graduate students as well as some oil company executives. While looking at one kind of reef system, a Trinity student discovered, by observation, a different kind of reefs in the Central Texas county. "It was fun and it showed that geology is visual," Lehrmann says. "You can make significant discoveries just doing fieldwork."

In addition to scenic study locales, geoscience is a growing and interdisciplinary field, Lehrmann says. "We use chemistry, physics, and biology and apply those principles to Earth systems. At Trinity, we talk about 'productive collisions among disciplines' - that's what geosciences is."

Courses taught

  • History and Evolution of Life

  • Physical Geology

  • Paleontology

  • Basin Analysis

Selected publications

Minzoni, M., Lehrmann, D. J., Payne, J., Enos, P., Yu, M., Wei, J., *Kelley, B., *Li, X., *Schaal, E., Meyer, K., Montgomery, P., *Goers, A., *Wood, T., *Copley, L., in press, Triassic Tank: Platform margin and slope architecture in space and time, Nanpanjiang Basin, south China, in Playton, T., Harris, M., and Verwer, K., eds. Deposits, Architecture and Controls of Carbonate Margin, Slope, and Basinal Settings: SEPM special publication.

Lehrmann, D., J., Minzoni, M., Payne, J., *Li, X., and Yu, M., 2012, Lower Triassic Oolites of the Nanpanjiang Basin: controls on facies architecture, giant ooids, marine cements and implications for hydrocarbon reservoirs: American Association of Petroleum Geologists, Bulletin, v. 96, n. 8, p. 1389-1414.

Lehrmann, D. J., *Pei, D., Enos, p., Ellwood, B. B., Zhang, J., Wei, J., *Dillett, P., *Koenig, *J., Steffen, K., *Druke, D., *Gross, J., *Kessel, B., *Newkirk, T., 2007, Impact of differential tectonic subsidence on isolated carbonate platform evolution: Triassic of the Nanpanjiang basin, south China: American Association of Petroleum Geologists Bulletin, v. 91, no. 3, p. 287-320.

Lehrmann, D. J., Ramezani, J., Bowring, S. A., Martin, M. W., Montgomery, P., Enos, Paul, Payne, J. L., Orchard, M. J., Wang, H., Wei, J., 2006, Timing of recovery from the end-Permian extinction: Geochronologic and biostratigraphic constraints from south China: Geology, V. 34, P. 1053-1056.

Payne, J. L., Lehrmann, D. J., Wei, Jiayong, Orchard, M. P., Schrag, D. P., Knoll, A. H., 2004, Large Perturbations of the Carbon Cycle During Recovery from the End-Permian Extinction, Science, v. 23, p. 506-509.

Lehrmann, D. L., Payne, J. L., *Felix, S. V., *Dillett, P. M., Wang Hongmei, Yu Youyi, and Wei Jiayong, 2003, Permian-Triassic boundary sections from shallow-marine carbonate platforms of the Nanpanjiang Basin, south China: Implications for oceanic conditions associated with the end-Permian extinction and its aftermath: Palaios, v. 18, n. 2, p. 138-152.

(*denotes student co-authors)

Susie P. Gonzalez is assistant director of University Communications and can be reached at susie.gonzalez@trinity.edu.