Submerged Archaeoanthrosols of the estearias (stilt villages) in Maranhão: A new frontier in Pedoarchaeology in Brazil

ABSTRACT The submersed anthrosols of the estearias in Maranhão exhibit unique characteristics that expand our understanding of anthropogenic soils in complex hydromorphic and fluviolacustrine environments. This study aimed to characterize these soils morphologically, physically, and chemically, and to compare them with other Amazonian Archaeological Dark Earths (ADEs) from upland and floodplain environments. A database of 160 anthropic horizons from 71 profiles in eight studies was compiled from theses and dissertations, allowing detailed comparative analyses. Principal Component Analysis and Pearson correlation were applied to identify the main soil properties associated with each environment. The results indicate that, beyond anthropogenic additions, prolonged flooding and redox-affected conditions play a crucial role in soil formation. When combined with horizons containing ceramic artifacts, charcoal, and organic sediments, these features suggest that the estearias soils formed under distinct dynamics compared to typical ADEs. The novel association of anthropogenic and organic horizons in submerged estuarine soils highlights the complexity of environmental and human interactions in the region. These findings support the need for revising ADE classification criteria, particularly regarding the exclusive use of available phosphorus as a diagnostic parameter. Complementary studies, including micromorphology, mineralogy, and spatial and temporal analyses, are essential to understand the genesis and dynamics of these soils. Despite their limited agricultural potential, these soils represent a valuable scientific and cultural heritage.