In this work we present the geophysical prospection done in Florida Blanca archaeological Site, in San Julián Bay, Santa Cruz province, Argentina. Ground Penetrating Radar and the resistivity method were applied to find very shallow clay-brick archaeological structures. An optimization in the resolution of both methods was necessary to detect the low contrasts in the electrical response of the soil and the clay-brick walls. Profiles were carried out in the zone of interest and outside it to compare results. A periodic distribution of low contrast shallow anomalies was found with both methods indicating the presence of the walls of the houses.