During the Intermediate Tardo period, the communities of San Pedro de Atacama and Loa Superior produced similar ceramic types. Ceramics, together with other materials, suggest an intensification of a shared regional identity during this period. The analysis of X-ray fluorescence using portable equipment of 251 ceramic fragments (Dupont, Ayquina and Turi variants) from various sites of the Intermediate Tardo indicated that these ceramic types form two separate chemical groups linked to the two regions. Few fragments with chemical values for the Loa Superior were identified in San Pedro’s sample, and none with San Pedro values were found in the ‘Loa Superior’ sample. The above suggests that in both areas own and local raw materials were used to co-produce the main styles, pointing to the existence of a supra-regional identity. These results discuss the model of differential power during the Tardo period to explain these patterns.