Spatial Dependence of Organic Carbon and Granulometry in Archaeological Soils of Lagoa Grande das Queimadas, Northeastern Brazil

The objective of this work was to evaluate the spatial dependence of the total organic carbon (TOC) and granulometric attributes of the archeological Site Lagoa Grande das Queimadas located at Piauí State, Northeastern Brazil. For this purpose, soil samples were collected up to 200 cm deep, totaling 38 samples, and the TOC and granulometry was analyzed in the laboratory. The data obtained were analyzed using descriptive statistics and geostatistical. The results showed that there is spatial dependence. The kriging showed that the TOC up to 85 cm decays in depth and from 85 cm to 110 cm there is an increase and decaying again after 110 cm. The different semivariogram shows models are great tools for understanding the spatial distribution of granulometric data, emphasizing the need for adjustment and choice of appropriate models according to the specificity of the data. The use of geostatistical techniques proved to be efficient to understand the spatial dependence of the data. The results indicate lithological discontinuity and contribute to the understanding of the formation processes of archaeological sites.