You must have, getting two similar replies in 10 seconds. ;)
I reall had multiple points in mind by suggesting geology. One obvious point is that creationists have just as many problems with hard science as they do with biology. In fact there isn't any branch of science that can be understood by a young earth creationist.
But that would be embarrassing to admit in front of the school board, so let's pick on a branch of science that hasn't done anything for us.
Except for possibly medicine, agriculture, and one or two other things.