Combining residue analysis of floors and ceramics for the study of activity areas at the Garum Shop at Pompeii

In this paper, we propose the application-for the first time in the Mediterranean area-of the combination of the study of chemical residues in floors and ceramics, with the aim of providing information about the activities carried out in archeological buildings. We chose the Garum Shop at Pompeii to test the method. In fact, due to the peculiarity of this archeological context, it provided an ideal case in which the activities performed are in part known, and the ceramic vessels recovered are still in situ. Floor samples were studied by means of spot tests developed in Mexico aimed at identifying the presence of phosphates, fatty acids, and protein residues, while the organic residues preserved in the ceramic matrix of amphorae, dolia, and other ceramic vessels were studied by gas chromatography coupled with mass spectrometry. Moreover, we integrated the data obtained with specific studies directed at better identifying the solid residues found inside two of the amphorae studied: botanical studies of fruit stones recovered in a Dressel 20 amphora and the characterization of the lime preserved in an African amphora. The research allowed for the identification of the traces of some of the activities performed, such as cooking and producing garum in the floors of the building, and the use and re-use of amphorae and dolia before the Vesuvian eruption.