Dr. Thomas Olszewski Dr. Thomas OlszewskiAssociate Professor, Geology & Geophysics
Texas A&M University
Grant 46096-G8
Refining Sequence Stratigraphic Interpretations Using Benthic Fossil Communities from the Permian Basin of West Texas

Dr. Thomas Olszewski is a storyteller of sorts. His inspirations are the ancient rocks and fossils of the Permian Basin in West Texas, one of the most prolific onshore hydrocarbon provinces in the United States.

Approximately 260 – 265 million years ago, West Texas was a marine coastline in the tropics. Today, those ancient reef deposits—similar in scale and nature to the Great Barrier Reef in Australia—are exposed along the face of the Guadalupe Mountains. Dr. Olszewski’s ACS PRF grant research focuses on the fossil marine ecological communities associated with that ancient reef.

Dr. Olszewski’s team examines deposits below this mountain ridge, where ancient reef slope deposits are exposed. The reef slope was steep, starting near sea level and going to the floor of the Permian Basin over 1,000 feet below sea level. The rocks at the foot of the mountain front preserve sediment that was moved down the ancient slope from shallower water, and they record natural environmental perturbations caused by changes in sea level and climate that occurred as the deposits accumulated.

Dr. Olszewski and a colleague in the field.Dr. Olszewski and a colleague in the field.

Living organisms are very sensitive to changes in their environment. By examining the basin’s fossil ecosystem, Dr. Olszewski’s team can piece together the story of how various organisms changed over millions of years, and how complex ecological systems have evolved in response to past environmental changes. They can also try to predict how such systems will respond in the future.

Advancing understanding of the ancient ecology of the Permian Basin facilitates development of its petroleum and gas reservoirs. Petroleum and other natural gas reservoirs exist in pockets determined by what kind of sediment was being deposited at any given location in a basin, which in turn was determined by subtle environmental changes. Some sedimentary material makes for better reservoirs than others, so understanding how ancient changes in sea level influenced sedimentation can help predict the location of reservoirs in the rock record. Ultimately, this allows for more efficient development of hydrocarbon resources.

The bulk of ACS PRF funding for this project supported field work and a research assistantship for Dr. Olszewski’s student, Leigh Fall. (Dr. Fall’s dissertation is based on this research, and she received her Ph.D. in 2010.) Moving forward, Dr. Olszewski intends to expand his research to other areas within the Permian Basin. With his colleague Dr. Michael Tice, he has begun to investigate not just fossils and reef organisms, but also basinal sandstones deposited by turbidity currents, which commonly host petroleum reservoirs.

Dr. Thomas Olszewski is an Associate Professor and has been at Texas A&M University in the Department of Geology and Geophysics since 2003. He received his Ph.D. from Pennsylvania State University in 2000 and was a post-doctoral fellow at Indiana University – Bloomington from 2000-2001. Dr. Olszewski was awarded the 2009 Schuchert Medal by the Paleontological Society. The Charles Schuchert Award is presented to a person under 40 whose work reflects excellence and promise in the science of paleontology.

Moving Mountains; Dr. Surpless
Desert Sea Fossils; Dr. Olszewski
Lighting Up Metals; Dr. Assefa
Ecological Polymers; Dr. Miller