• en
  • pt-br
20 results

Pedogenesis in an Archaeological Dark Earth – Mulatto Earth Catena over Volcanic Rocks in Western Amazonia, Brazil

Luís Antônio Coutrim dos Santos, Jane Kelly Silva Araujo, Valdomiro Severino de Souza Júnior, Milton César Costa Campos, Marcelo Metri Corrêa, Regilene Angélica da Silva Souza

31/Jul/2018

ABSTRACT Archaeological Dark Earth (ADE) pedogenesis and pre-Columbian history are fundamental for understanding the biodiversity and pedodiversity of the Neotropical rainforest in the Amazon region. This study aimed to evaluate the morphological, physical, chemical, and mineralogical properties as well as NaOH-extractable organic matter [OM(NaOH)] in ADE and Mulatto Earth (ME) overlying volcanic rocks along a toposequence (four soil profiles) in western Amazonia, Brazil. The soil profiles show anthropic A horizons over an argic horizon (Bt) in the ADE (Humic, Pretic […]

Mineralogy, Micromorphology, and Genesis of Soils with Varying Drainage Along a Hillslope on Granitic Rocks of the Atlantic Forest Biome, Brazil

Anderson Almeida Pacheco, João Carlos Ker, Carlos Ernesto Gonçalves Reynaud Schaefer, Mauricio Paulo Ferreira Fontes, Felipe Vaz Andrade, Eder de Souza Martins, [...]

06/Jul/2018

ABSTRACT Although the physical environment of the Atlantic Forest realm is well known, studies on the soil-landform relationships are fundamental to improve the management of soil resources to facilitate sustainable development. The purpose of this study was to evaluate a representative topossequence on the “Mares de Morros” landscape of deeply weathered regolith on leucocratic granite rocks and demi-orange convex slopes. The soils varied along the topossequence according to drainage and were classified as Acrudox, Pseudogleysol, and Epiaquent. The clay fraction […]

Reversibility of the Hardening Process of Plinthite and Petroplinthite in Soils of the Araguaia River Floodplain under Different Treatments

Angélica Pires Batista Martins, Glenio Guimarães Santos, Virlei Álvaro de Oliveira, Deyvid Diego Carvalho Maranhão, Leonardo Santos Collier

18/Jun/2018

ABSTRACT Although ferruginous materials occur frequently in soils of tropical regions, information about the reversal of the hardening process of these materials is scarce. This study assessed the influence of different chemical treatments and periods of immersion on the reversibility of the hardening process of plinthite and petroplinthite in soils of the Araguaia River plain. Soil samples were collected from the plinthic horizons in 0.10 m high and 0.15 m diameter PVC cylinders and divided into subsamples with a rock […]

Hardening and Stability of Plinthic Materials of the Araguaia River Floodplain under Different Drying Treatments

Angélica Pires Batista Martins, Glenio Guimarães Santos, Virlei Álvaro de Oliveira, Deyvid Diego Carvalho Maranhão, Leonardo Santos Collier

20/Apr/2018

ABSTRACT Plinthite and petroplinthite occur frequently in Brazilian soils, but there is little information on the behavior of these materials. The aim of the present study was to assess the effect of different drying periods on the hardening and stability of plinthic materials of soils in the floodplain of the Araguaia River and the João Leite stream in Goiás. Soil samples were collected, with the aid of 0.10 m high and 0.15 m diameter PVC cylinders, directly from the plinthic […]

Pedological Studies of Subaqueous Soils as a Contribution to the Protection of Seagrass Meadows in Brazil

Gabriel Nuto Nóbrega, Danilo Jefferson Romero, Xosé Luis Otero, Tiago Osório Ferreira

05/Feb/2018

ABSTRACT: Seagrass meadows are considered one of the most important and valuable ecosystems on the planet, but also one of the most threatened. Missing knowledge about their existence and their subtidal nature are the main reasons for the lack of information about seagrass soils, especially in Brazil and other tropical areas. This study discussed the paradoxical lack of information about subaqueous soils, with a view to stimulate research on soil properties of seagrass meadows. This short communication provides information about […]

Soils Developed on Geomorphic Surfaces in the Mountain Region of the State of Rio de Janeiro

Ademir Fontana, Cesar da Silva Chagas, Guilherme Kangussu Donagemma, Andressa Rosas de Menezes, Braz Calderano

05/Dec/2017

ABSTRACT: The evaluation of soils in representative landscapes constitutes an opportunity to evaluate spatial distribution, discuss formation processes, and apply this knowledge to land use and management. In this sense, from the perspective of an environmentally diversified region, the aim of the present study is to evaluate the occurrence and understand the formation of soils in different geomorphic surfaces of a landscape from a mountain region in the state of Rio de Janeiro. The study was developed in the Pito […]

Genesis of Soils from Bauxite in Southeastern Brazil: Resilication as a Soil-Forming Process

Ana Carolina Campos Mateus, Fábio Soares de Oliveira, Angélica Fortes Drummond Chicarino Varajão, Caroline Cibele Vieira Soares

30/Oct/2017

ABSTRACT Pedological studies using X-ray diffraction (XRD), X-ray fluorescence (XRF), optical microscopy, and scanning electron microscopy (SEM-EDS) showed a Xanthic Ferralsol formed from the degradation of bauxite on a slope in the Caparaó region, in southeastern Brazil. We found a decrease in the number and size of bauxite fragments toward the top of the profiles, bauxite fragments that were more degraded at the top of the profiles, transformation of gibbsite into kaolinite, and absolute enrichment in silicon in the mass […]

Weathering of Rhyolites and Soil Formation in an Atlantic Forest Fragment in Northeastern Brazil

Stephany Alves Brilhante, Jean Cheyson Barros dos Santos, Valdomiro Severino de Souza, Jane Kelly Silva Araújo, Mateus Rosas Ribeiro, Marcelo Metri Corrêa

27/Sep/2017

ABSTRACT Weathering and pedogenesis have been studied for a wide range of rocks and climates around the world. However, the eruption of rhyolitic magmas is a rare geological event, which leads to few studies associated with the rhyolite-soil-landscape relationship. In this context, this study evaluated the influence of rhyolite weathering on the properties of soils along a slope in an Atlantic Forest environment in the state of Pernambuco, northeastern Brazil. Four weathering profiles derived from rhyolites were classified and sampled […]

Micromorphology of Paleosols of the Marília Formation and their Significance in the Paleoenvironmental Evolution of the Bauru Basin, Upper Cretaceous, Southeastern Brazil

Márcio Luiz da Silva, Alessandro Batezelli, Francisco Sérgio Bernardes Ladeira

29/Mar/2017

ABSTRACT Deduction of associated paleoenvironments and paleoclimate, definition of the chronosequence of paleosols, and paleogeographic reconstruction have become possible through the application of micromorphology in paleopedology. Micromorphology has also been useful in recognition of weathering processes and definition of minerals formed in succession. In this respect, the objective of this study was to identify the development of pedogenic processes and discuss their significance in the paleoclimate evolution of the Marília Formation (Maastrichtian) of Bauru Basin. Three sections of the Marília […]

Chemical-Mineralogical Characterization of Magnetic Materials from Magnetic Soils of the Southern Espinhaço Mountain Chain and of the Upper Jequitinhonha Valley, State of Minas Gerais, Brazil

Alexandre Christófaro Silva, Solange de Souza, José Domingos Fabris, Maurício Soares Barbosa, Uidemar Morais Barral, Roberto Vial Costa

09/Mar/2017

ABSTRACT In the Southern Espinhaço Mountain Chain and in the Upper Jequitinhonha Valley, magnetic soils, in different pedogenetic stages, are found to be forming over intrusions of basic lithology. The essential chemical and mineralogical properties of samples from magnetic soil profiles from those two physiographic environments in the state of Minas Gerais, Brazil, are reported. Three of the pedons (Rhodic Kandiustox – RKox, Rhodic Haplustox – RHox, and Typic Argiustoll – TAoll) were identified as being indeed developed over basic […]

1 2