After study this SU is tentatively interpreted as an abandoned quarry assay pit.

Quarry cut. This cut preserves an unfinished quarry section with one block (SU110) preserved in situ. The deepest portion of the cut was probably a space for the quarry workers to move freely around block SU110, but may have been the location where other blocks of tufo had already been removed. The cut preserves the narrow trenches cut into the tufo to separate the block (SU110) from the geologic strata of tufo. The smaller and shallower portion of the cut in the northwest corner may have been created to facilitate entry into the quarry cut, but it may also have been an area where the quarry workers were testing to see if the underlying tufo was suitable for quarrying.