Ageologist finds siltstone in a canyon. what does this mean?

If siltstone is found in a canyon, it could mean that the area can be once a sea, delta or a shore. Siltstone is a sedimentary rock that is formed through compression and suspension from substance deposits. The canyon can be a part of the sea that has dried and formed in a million years.

After an artifact's position has been mapped and recorded in field notes, the artifact is taken to the site laboratory to be cleaned and labeled. Artifacts are then sorted according to type of material, e.g., stone, ceramic, metal, glass, or bone, and after that into subgroups based on similarities in shape, manner of decoration, or method of manufacture.  

The objects are finally wrapped for transfer to an off-site laboratory. That any off-site processing be performed quickly is desirable so that the documentation of all artifacts found at the site may proceed without delay.