Thanks for the explanation, Chris. It makes a bit more sense now. That sediment must be extremely tough stuff to fight pressure like that. It seems that risking an expensive piece of equipment would necessitate extra precautions, but then again, this is not funded like it should be funded, I'm sure.
Too bad about the Oak Ridge fault though; I once knew someone who told me quite a bit about it and I've been fascinated ever since.
Hope tomorrow is easier for you all.
Beth