Pore Space and Concretion Distribution In a Prairie Mound Fragipan.

Prairie mounds are unique soil landscape features distributed across the Arkansas River Valley in eastern Oklahoma and western Arkansas.  Mounds in this area can be as large as one-meter in height and fifteen- to thirty- meters in diameter.  They commonly have a fragipan below an overthickened A horizon and above a lithologic discontinuity between loess and fine-textured alluvium or residuum.  A study of the characteristics of these fragipans could lend interesting insights into prairie mound genesis. A mound was bisected and the exposed mound-center profile was described and sampled according to standard methods.   Intact peds from the Bx1 (D­­_b­ = 1.79 g cm^-3) and Bx2 (D­­_b­ = 1.77 g cm^-3) were analyzed for bulk density using a 3D laser scanner.  Concretion content as well as abundance of vesicular, vugh and interconnected pore space as evaluated using X-ray computed tomography (CT) will be discussed.