Palynological analysis of an archaeological chinampa in Xochimilco (Basin of Mexico). Construction technology and agricultural production

Abstract

In order to better understand the construction techniques used in archaeological chinampas excavated at San Gregorio Atlapulco, Xochimilco (located in the southern Basin of Mexico), modified standard techniques for the extraction of palynomorphs were applied. The palynological assemblage recovered from the archaeological chinampa and adjacent canal profiles suggests that the local and regional vegetation present in the Basin of Mexico consisted of halophilic and aquatic vegetation, grassland, pine-oak forest and Abies forest. The abundant Amaranthaceae pollen observed could come from different species and have diverse origins, however, it may indicate the cultivation of Suaeda sp., a highly prized food plant in Mexican cuisine. The analyses suggest that the construction technique in the archaeological chinampa is similar to the models previously proposed, but this particular variant incorporates some modifications described in other examples. According to radiocarbon determinations, it is suggested that the chinampa was constructed following the Classic period, after around 1640 BP (340–540 cal CE), and was probably utilized initially during the Aztec I-II periods. Therefore, we conclude that the elaboration and maintenance techniques of the SGAX-CH02 chinampa at Xochimilco were more diverse than previous research on archaeological chinampas suggests.