Navegando por Assunto "Soil"

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Acesso aberto (Open Access)
The ceramic artifacts in archaeological black earth (terra preta) from Lower Amazon Region, Brazil: chemistry and geochemical evolution
(Instituto Nacional de Pesquisas da Amazônia, 2004-09) COSTA, Marcondes Lima da; KERN, Dirse Clara; PINTO, Alice Helena Eleotério; SOUZA, Jorge Raimundo da Trindade
This paper carried out a chemical investigation of archaeological ceramic artifacts found in archaeological sites with Black Earth (ABE) in the Lower Amazon Region at Cachoeira-Porteira, State of Pará, Brazil. The ceramic artifacts, mostly of daily use, belong to Konduri culture (from 900 to 400 years BP). They are constituted of SiO2, Al2O3, Fe2O,3, Na2O and P2O5; SiO2 and Al2O3 together add up to 80 % and indicate influence of acid rocks, transformed into clay minerals basically kaolinite. The relative high contents of P2O5 (2.37 % in average) come out as (Al,Fe)-phosphate, an uncommon fact in primitive red ceramics, but found in some roman and egyptian archaeological sites. The contents of the trace elements are similar or below the Earth's crust average. This chemical composition (except P2O5) detaches saprolite material derived acid igneous rocks or sedimentary ones as the main raw material of the ceramics. The contents of K, Na and Ca represent the feldspars and rock fragments possibly introduced into saprolitic groundmass, indicated by mineralogical studies. The presence of cauixi and cariapé as well as quartz sand was confirmed by optical microscope, SEM analyses and by the high silica contents of ceramic fragments. Phosphorus was possibly incorporated into groundmass during cooking of foods, and ABE soil profile formation developed on yellow Latosols. The raw materials and its tempers (cauixi, or cariapé, feldspar, crushed rocks, old ceramic artifacts and quartz fragments) are found close to the sites and therefore and certainly came from them.
Acesso aberto (Open Access)
A transformação na paisagem do reassentamento rural coletivo, Travessão km 27, Vitória do Xingu/PA
(Universidade Federal do Pará, 2019-12) ALVAREZ, Wellington de Pinho; COSTA, Danyelly Feitosa da; HERRERA, Raírys Cravo
The present work seeks to make an analysis of the landscape change of the Collective Rural Resettlement (RRC) located at Travissão km 27 of Vitória do Xingu / PA, which was built as a way to reward the riverside families affected by the Belo Monte HPP. To make this analysis will be used satellite images from the years 1991, 1997, 2007, 2011 and 2018, and classified land use and land cover in these years so that we can understand the current dynamics at the site and show that families currently use resettlement land for agriculture and livestock, thus being the main landscape shapers in the RRC.