Monday, September 16, 2013

UNO Doctoral Student Presents Research to Geological Society of America

A University of New Orleans doctoral student has received an award from the Geological Society of America and will present his research at the group's annual meeting next month.

Prabhat Neupane, who is pursuing his doctorate in the UNO Department of Earth and Environmental Sciences, received financial support from the Geological Society of America to attend the GSA annual meeting next month in Denver and present his research.

GSA is a leading organization dedicated to advancing the geosciences and promoting the geosciences in the service to humankind. This year, the organization celebrates its 125-year anniversary and to celebrate, GSA has selected 125 students from across the U.S., including Neupane and his colleagues, to participate in the organization's annual conference, which runs Oct. 27-30 in Denver. The financial scholarship awards are offered through a program called "On to the Future." Neupane and his peers will present their work in a series of poster presentations sponsored by the program.

At the meeting, Neupane, together with colleagues from the Western Kentucky University Department of Geology and Geography and Brown University Department of Geological Sciences, will present exciting research on a vegetation change in the foothills of the Himalayas during late Neogene, a 20-million-year geologic period predating the Cenozoic Era, said M. Royhan Gani, UNO assistant professor of earth and environmental science.

The Neogene period and timescale started more than 23 million years ago and ended more than 2.6 million years ago, according to online news sources. During this time, mammals and birds evolved into roughly modern forms and early hominids, the ancestors of humans, appeared. Continental shifting also occurred, causing changes including the connection of North and South America, changing the flow of ocean currents around the world and cooling the global climate.

Neupane and his colleagues researched vegetation near the Nepal Himalaya and found that during Neogene, the Nepal foothills experienced a change of vegetation from forest to grasslands. The researchers also discovered that the vegetation shift stemmed from changes in precipitation pattern, season temperature and fire frequency—not a drop in atmospheric pCO2 levels, as some scientists previously believed.

To gain a deeper understanding of this vegetation shift in the Siwalik succession of Nepal, Neupane and his colleagues deployed a compound-specific isotope analysis of biomarkers preserved in floodplain shale and paleosols, researchers said in an abstract for their poster presentation.

Using elements of leaf wax and approximations of precipitation, vegetation and an annual air temperature derived from soil bacteria, researchers compared organic-rich shale and paleosol samples from the Siwalik strata in the Surai Khola and Karnali River sections of the Nepal Himalaya—and compared their findings with strata from established paleomagnetic age data of the region.

The researchers' exploration showed that during Neogene, the Nepal Himalaya began to be dominated by grasses and then plants, according to the abstract. The timing of the vegetation shift broadly matches with previous vegetation change studies of the Siwalik rocks.