Saturday, November 21, 2009

Rehydroxylation Dating-- 10-21-09 update

Our collaborating student researchers are making steady progress in their efforts to replicate the ceramic rehydroxylation dating technique published by Moira Wilson and her colleagues over the summer. If you wish to read all my posts about rehydroxylation, click here.

Helen Ranck, Patrick Bowen, and Jessica Beck have been working on different parts of the problem and they've learned a great deal so far.

Here is one of Helen's graphs that describes the mass gain of one of her test samples:
She and Patrick have been trying to find out the best way to keep the sherds at a constant temperature and atmosphere while the fragment absorbs water. Patrick has discovered some key changes in practice that have really helped reduce the variation in calculated dates, bringing the projections closer to our expectations. Jarek Drelich, associate professor in Michigan Tech's Materials Science and Engineering department, has been very helpful working with them both.

Jessica Beck has finished some of her testing. She calculated the porosity of a group of the sherds using a methodology outlined by the National Institute of Standards and Technology (NIST). Jessica discovered that the Davenports' earthenware ranges from 10%-15% porous, and that both the median and the mode will be around 13% or 14%. I'm looking forward to her final conclusions and her estimates on firing temperature as revealed through her other testing!

1 comment:

  1. Hey Tim, we're trying to do the same thing out here at Long Beach. It would be HUGE if it paid off. Good luck!

    Hector Neff