GSA Annual Meeting in Denver, Colorado, USA - 2016

Paper No. 237-30
Presentation Time: 9:00 AM-6:30 PM


JORDAN, Miranda M., Geology, Sam Houston State University, 1905 University Ave, Huntsville, TX 77340 and SUMRALL, Jeanne Lambert, Geology, Blinn College, 902 College Avenue, Brenham, TX 77833, MMJ021@SHSU.EDU

Denudation rates were calculated for three eolian dunes on Eleuthera, Bahamas through field measurements and lab analysis. One set of samples were gathered from North Twin Coves dune on the Eastern side of the island, and two sets of samples were gathered from two separate dunes located on the Southernmost tip of Eleuthera, collectively known as South Point and South Point Dune. One portion of the set of samples were chiseled above a truncation surface, and the second portion of the set of samples were chiseled from below the truncation surface. Five portions of the above gathered samples were carbon dated; the age of the oldest dune was 7,004 years old and the youngest portion of the youngest dune was 4,581 years old. It was determined that all three dunes fall within the Holocene, with a gap of 2,400 years. The carbon dates were then compared with field measurements to determine the rate of active denudation on the dunes present on Eleuthera. South Point Dune was utilized for this calculation due to the active denudation surface observed in the field. The calculated denudation rate for South Point Dune was found to be 76 centimeters every thousand years. Portions of the samples were then analyzed for pore space, grain size, grain shapes, and dominant allochems to determine if there were any biological differences. Lastly, using field measurements, it was determined that the dominant paleo-wind direction matches the Easterly Trade Winds present today. This data, along with all other observed and calculated data collected in this study, will expand research into how paleoclimate altered the carbonate topography within The Bahamas.