The plant life kept a hold on the sandy soils because groundwater and rainfall were adequate to maintain some vegetation, even as elsewhere much of Nebraska's topsoil blew away. However, new evidence suggests that sometime in the last 1,000 years, major droughts occurred in Nebraska's sand sea that significantly reduced the sand-stabilizing vegetation and lowered water tables. First is understanding the mechanics of how the sand gets out there, and then, second, determining the age of those sand sheets. Swinehart and Loope will be searching for conclusive evidence in the first 5-6 feet of thick peat deposits located in at least 27 different interdune regions. Their previous work, also partially funded by NSF, determined that the base of the peat is about 12,000 years old and was most likely deposited when dunes dams blocked drainage in the area.
Vegetation stabilizes the sand and keeps it from blowing around.
The bulk of the grant money will fund student help and radiocarbon dating over two years. Most of the samples will be collected from three sites in Cherry County by coring and by excavating trenches. It's like changing the temperature of the ocean or a huge lake. We think the dune-peatland system will record drought that might be missed in other environments. Convex-up sand ridges, present at the edges of the sand sheet in the center of some interdune valleys, also indicate the place where the bouncing sand hit the remaining plant life and came to rest.