For five years, Luckenbach and his colleagues have carefully worked to put the pieces back together. The top layer is called plowed soil because it's been mixed up over generations by farmers' plows. There we shake out any grasses and paw through the rest, looking for pieces of the past. I hold up a dark, smooth something about an inch long. Though few of us volunteers have been on a dig before, we quickly pick up the basics.
Coal ash is worthless, but bits of brick are good.
Even an oyster-shell hinge can suggest who was eating oysters. Assistant director Jim Gibb squats beside the girl and brushes the bit clean. It goes into the plastic bag hanging near her screen. Sierra's grandmother, Kay Pfeifer, likes the fact that getting messy can be educational. When they learn about this period in social studies, it'll make more sense.