Waterscreening!

Hand and trowel screening of soil through a shaker screen does not recover all artifacts, particularly ones smaller than 1/4 inch. In special circumstances, in feature fill situations or other places where the recovery of small items is needed, water screening is an alternative process. This water screening device is used in the laboratory or in the field to clean and examine soil samples taken from archaeological features and sites. It was developed to retrieve small organic materials, such as seeds and bone fragments, as well as tiny flint chips, from archaeological deposits.

(Anne and Kelley waterscreening)

A mesh screen is put atop a larger screen with the soil put into the screen. It is then carefully hosed down with water and sorted. It is then set out to dry on a separate screen. After drying, the same material will then be 'floated' in a flotation tank to pull out any organic material. After that, it is cataloged and bagged like any other artifact.

*NB* This is very messy work!