A geologist from The University of Texas at Arlington is investigating the origin of loess, a sediment formed by the accumulation of wind-blown dust, in the western United States.
The National Science Foundation awarded Majie Fan, associate professor of earth and environmental sciences, a three-year, $323,787 grant to investigate the nature, causes and climate importance of loess’ appearance in Montana, Wyoming and northeast Colorado. Her research will identify the sediment’s source, when it appeared and the climate changes that caused it to form.
Fan and collaborator Ran Feng, assistant professor of geosciences at the University of Connecticut, theorize that global climate cooling and/or elevation change of the earth’s surface in the western U.S. 34 million years ago worked together to produce the climate circumstances for the loess accumulation.
Feng, a specialist in computational climate change, will develop a climate simulation model to alternate the height of the western U.S. and climate parameters to see if it’s feasible to produce a climate dry enough to generate winds that could transport loess.
“We know that the region was under ocean water about 80 million years ago,” Fan said. “How could loess, which is transported by wind and signals a very dry climate, form there?”
Fan was born on the Loess Plateau in northern China, a dry highland named for its loose, fine-grained, yellowish topsoil. As a young girl living in a rural province, Fan owned few toys and occupied much of her time by playing in the dirt that defined her home.
Years later, during a research excursion in Wyoming, a group of familiar rocks caught Fan’s eye. They were loess.
Fan said her motivation for the project is to understand the sudden, regional climate change that caused continental aridification to accumulate loess. Discovering the reason for the rapid shift could inform geologists’ forecasting of subsequent environmental changes.
“We don’t know what will happen in the future, but we can always learn from the past,” Fan said. “Using that knowledge, we can better predict how the climate will change in the future.”
Arne Winguth, professor and chair of the Department of Earth and Environmental Sciences, said Fan’s investigation will shed light on important climate events in earth’s history.
“The multidisciplinary research focus in the western United States is of great interest to understand the rapid climate change during the Eocene/Oligocene cooling,” Winguth said. “Dr. Fan’s findings will not only improve understanding of the Earth’s climate history during the Early Cenozoic era, but it also will help us to understand processes that lead to climate change in the future.”
