After further study and identification of this area as a quarry, it appears that this is one of a series of cuts into the bedrock associated with quarry machinery. This one, specifically, may have accommodated one of the posts to which cranes’ tie-rods were tied

Possible cut in tufo used to hold a vessel upright. The presence of a vessel's base and part of the side wall (SU77) within the layer in the cut may attest to such a use. Because of a lack of human bone, it is not believed to be associated with a jar burial, but may be a cut used to hold a storage vessel upright.