Initial Site Visit

December 16, 2011

Tiffany Adrain, Art Bettis, Holmes Semken, all of the Department of Geoscience and David Brenzel of the Indian Creek Nature Center, Marion met the landowner at 3:00 PM on a clear Friday afternoon to examine the mammoth specimens that the landowner had collected, visit the locality and discuss the feasibility of the University of Iowa excavating the Mahaska County Mammoth Site. The meeting went well and all parties agreed that the site potentially is an outstanding scientific resource. We agreed to help excavate the mammoth and preserve all of the scientific information that could be extracted from the bone-bearing matrix (plant macrofossils, mollusks, chemistry) at the University of Iowa. At least one bone is to be donated to serve as a voucher specimen and to provide samples for geochemical analysis. We also agreed that the first step to careful excavation was to core the site to get a complete stratigraphic section. Art collected a grab sample of the matrix to test for plant macrofossils and other paleoecological indicators that may be present. A tree branch was collected as a potential source for a radiocarbon date. We looked at the landowner’s artifact collection as well as about 20 skeletal elements that he had excavated to date. The bones ranged in size from a femur to terminal phalanges. Thus, it is clear that the skeleton has not been sorted by fluvial processes. Gnawing by a carnivore on the tibia documented that the mammoth decayed on the surface before burial. Also, the landowner noted that the five cervical vertebrae were the only elements that were articulated.

Holmes A. Semken and David G. Brenzel, April 28, 2012