Tree Stump, Sunday

August 19, 2012

A crew of approximately 27 volunteers met at the site at 9 AM.   Sarah, Holmes and Dave were joined by Andrew Blodgett (MNH student staff), faculty and students from ISU, William Penn University, Indian Hills Community College and Oskaloosa High School along with staff from the Mahaska and Story County Conservation Boards. Once again Titan Machinery supplied the vital backhoe. 

Volunteers used probes to explore the bench John had previously cut overlooking the west side of the discovery pit, but encountered only gravel and iron deposits until early afternoon when the stump of a buried tree was uncovered. It was resting 5-6 feet below the modern ground level and is in excellent condition.  Further excavation disclosed the tree was growing on a layer of silt approximately 1 ft. thick on the downhill (east) side and only inches thick on the uphill (west) side, overlying a large sloping mass of smurfic blue clay.  The tree roots mostly follow the silt/clay boundary but a few penetrate deeply into the clay.  The team resolved to collect the stump for analysis but late in the afternoon the excavators encountered a bone concentration downhill and NE of the stump. Time ran out and the team resolved to return with a small group of volunteers the next day to continue digging. The team departed at approximately 5:30 PM.