Guest post by Mike Salisbury, Grad Student at Auburn University and the Auburn Geomorphology Lab
What comes to mind when you think of hot summer weather and being done with your spring classes? Digging trenches and augering old river terraces in the Ozarks, of course! On my recent trip to the Buffalo National Scenic River, AR with the AU Geomorphology Crew (Dr. Stephanie Shepherd, Mark Simon, and Samantha Eckes) and Kathleen Rodrigues from the Desert Research Institute (DRI), I did just that.
Fluvial terraces are remnants of former river floodplains. Over the course of a week, our crew augered, dug, analyzed soils, laughed, cried, and collected samples at a handful of Buffalo River terrace sites. Some of the soil samples will be dated via optically-stimulated luminescence (OSL) techniques at DRI by Kathleen. Dating these terraces can contribute to the overall understanding of local fluvial activity, among other things.
Having taken soil morphology last semester, I was able to put my new pedology skills to good use. With each auger, the soil was placed on a tarp (creating a soil profile of sorts), the auger hole depth was measured, and soil characteristics—color, texture, and consistence—were recorded. During this analysis, it was fascinating to observe the changes in sand and clay as we progressed; typically, there was very little change in soil color. OSL requires a soil that is a bit sandy, so if Kathleen felt the texture was appropriate, a sample for OSL was taken. This included attaching a black PVC pipe to the end of the auger to sample the soil and doing the, as I like to call it, “auger dance” without cursing too much. We also collected samples for the AU Geomorphology Lab--using a machine called the Mastersizer (great name, right?), which assesses particle size using laser diffraction, the samples will be examined in the lab and these results will be compared to field data.
Overall, the trip was a success. I am grateful for the experience and appreciate the new knowledge gained.