Geoarchaeological approach to agricultural terraces at Carrizal and Asampay (Department of Belén, Catamarca, Argentina)

• First geoarchaeological characterization of Asampay and Carrizal (Catamarca, Argentina) agricultural terraces. • Integrated chemical, mineralogical, and textural analyses applied to terrace soils. • Geochemical enrichment demonstrates deliberate soil management within terrace systems. • Terrace soils show P, TOC, OM and N signatures consistent with broader Andean fertilization practices. • Results indicate shared pre-Columbian knowledge of terrace construction and soil enhancement across the Andes. This paper aims to characterize the pre-Columbian agricultural terraces of the Asampay and Carrizal ravines (Department of Belén, Catamarca, Argentina) through a geoarchaeological approach. These terraces are associated with archaeological sites dating to the late 15th and early 16th centuries AD. To this end, we identify the agricultural practices employed in two cultivation structures through chemical, mineralogical, and compositional analyses. These results are compared with those obtained from a control test pit to assess the impact of these practices on the crop fields. Although the textural analyses did not reveal clear differences, the geochemical results show enrichment in phosphorus, organic carbon, organic matter, and nitrogen in the terrace soils (As.Laz.T1 and Caz.Cpi.T1) compared with the control sample (As.Las.Tg1). These variations suggest a range of soil management practices, potentially involving the application of fertilizers and organic amendments. The elevated concentrations of phosphorus and organic matter suggest that the soils were deliberately fertilized, while the increase in nitrogen indicates heightened plant activity within the cultivation structures. This study demonstrates the potential of geoarchaeological approaches for identifying soil management practices in pre-Columbian agricultural terraces of the Hualfín Valley.