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 […]

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 […]

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 […]

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 […]

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 […]

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 […]

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 […]

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 […]

ABSTRACT Horizons with varying degrees of cementation are a common feature of the soils from the coastal tablelands of Northeastern Brazil. In most cases, these horizons are represented by the following subsurface horizons: fragipan, duripan, ortstein, and placic. The aims of this study were to analyze differences regarding the development and the degree of expression of cementation in soils from the coastal tablelands of Northeastern Brazil: Planossolo Háplico (p-SX), Espodossolo Humilúvico (p-EK), Espodossolo Ferrihumilúvico (p-ESK), and Argissolo Acinzentado (p-PAC) pedons. […]

ABSTRACT The influence of post-burial geological processes on preserving pedogenic properties has great importance in identifying ancient paleosols both in the field and in a laboratory. However there are not many publications that focus on characterizing paleosol diagenesis. As temperature and pressure progressively increase, evidence of pedogenesis is modified and destroyed, hindering paleoenvironment characterization and interpretation. This paper discusses diagenetic evidence and its relation to strictly pedogenic features, like structure, cements, nodules, and neoformation of clay minerals using the carbonate […]