Banca de DEFESA: LEONIS JÚNIOR SANTOS DA SILVA

Uma banca de DEFESA de MESTRADO foi cadastrada pelo programa.
STUDENT : LEONIS JÚNIOR SANTOS DA SILVA
DATE: 26/02/2026
TIME: 09:00
LOCAL: Sala 13
TITLE:

Sambaquis on the Rio de Janeiro Coast: Soil study at the Fazenda Campos Novos - Cabo Frio / RJ.

KEY WORDS:

Anthropogenic soils. Pedogenesis. Magnetic Susceptibility

PAGES: 156
BIG AREA: Ciências Agrárias
AREA: Agronomia
SUBÁREA: Ciência do Solo
SPECIALTY: Gênese, Morfologia e Classificação dos Solos
SUMMARY:

Sambaqui soils are examples of the socio-environmental function of cultural heritage, since studies on them elucidate not only paleontological issues, but also archaeological ones, due to the practices of the societies that occupied and built them. This study aims to spatialize of the occurrence of sambaquis in Rio de Janeiro State and contribute with theoretical elements for their study, including criteria for classification and mapping of the soils. To this end, in the first chapter, a non-exhaustive systematic review of research on sambaqui soils and their occurrence in the state of Rio de Janeiro was conducted. A geographic information database was constructed with the data found in the literature, a digital map was created with estimated location of sambaquis and, by using digital soil mapping, prediction of soil classes in two areas of Rio de Janeiro state. In the second chapter, attributes of soil samples from previous work at the Fazenda Campos Novos sambaqui, in the district of Tamoios in Cabo Frio (RJ) were characterized. The samples were provided by researchers from Embrapa Solos and UFRJ, as well as data from analyses already conducted and published. Chemical analysis of the soil samples indicated high concentrations of organic carbon, calcium, and high pH values. Very dark colors, 10YR 4/4 and darker, were observed in the soil samples of the sambaqui. The shell content at each depth was quantified using a 2 mm sieve, also revealing high amounts in the sambaqui. The magnetic susceptibility (MS) analysis was performed on samples placed in an equidistant grid of 53 points and the values were interpolated by kriging, allowing to identify a strong and positive spatial dependence of this attribute. The samples from soil sections of a depth of 60 cm, at the 10 points, had the greatest anomalies in the SM. Sequential phosphorus fractionation analysis was also performed on the samples to assess the bioavailability of this element in sambaqui soils. The P contents found were high, especially in the fraction extracted with 1 mol. L-1 HCl. The legacy samples were analyzed by X-ray fluorescence and spectroradiometry. A correlation was observed between the attributes: magnetic susceptibility, P bioavailability fractions, Munsell color, Ca, and organic carbon, which were identified as relevant parameters in sambaqui soils, both for understanding the dynamics of specific pedogenic processes and for digital mapping of these soils. The attributes soil color, base saturation and thickness of the superficial sections fit the definition of Black Soils (FAO / INBS). In addition to that, the P and shells contents allow for the identification of anthropic horizons, which is relevant to the inclusion of the studied sambaquis as soils with strong human influence in taxonomic systems. It should also be noted that the sambaquis of Rio de Janeiro urgently requires public policies and environmental education initiatives to ensure the preservation of these archaeological sites.

COMMITTEE MEMBERS:
Presidente - 387335 - LUCIA HELENA CUNHA DOS ANJOS
Externo ao Programa - ***.043.937-** - LUIZ ALBERTO DA SILVA RODRIGUES PINTO - UFRRJ
Externo à Instituição - WENCESLAU GERALDES TEIXEIRA - EMBRAPA