DEGEO - Departamento de Geologia
URI permanente desta comunidadehttp://www.hml.repositorio.ufop.br/handle/123456789/8
Navegar
18 resultados
Filtros
Configurações
Resultados da Pesquisa
Item Metabarcoding of soil fungal communities in rupestrian grassland areas preserved and degraded by mining : implications for restoration.(2023) Figueiredo, Maurílio Assis; Silva, Thamar Holanda da; Pinto, Otavio Henrique Bezerra; Leite, Mariangela Garcia Praça; Oliveira, Fábio Soares de; Messias, Maria Cristina Teixeira Braga; Rosa, Luiz Henrique; Câmara, Eduardo Aguiar Saraiva; Lopes, Fabyano Alvares Cardoso; Kozovits, Alessandra RodriguesRupestrian grasslands are vegetation complexes of the Cerrado biome (Brazilian savanna), exhibiting simultaneously great biodiversity and important open-pit mining areas. There is a strong demand for the conservation of remaining areas and restoration of degraded. This study evaluated, using next-generation sequencing, the diversity and ecological aspects of soil fungal communities in ferruginous rupestrian grassland areas preserved and degraded by bauxite mining in Brazil. In the preserved and degraded area, respectively, 565 and 478 amplicon sequence variants (ASVs) were detected. Basidiomycota and Ascomycota comprised nearly 72% of the DNA, but Ascomycota showed greater abundance than Basidiomycota in the degraded area (64% and 10%, respectively). In the preserved area, taxa of different hierarchical levels (Agaromycetes, Agaricales, Mortierelaceae, and Mortierella) associated with symbiosis and decomposition were predominant. However, taxa that colonize environments under extreme conditions and pathogens (Dothideomycetes, Pleoporales, Pleosporaceae, and Curvularia) prevailed in the degraded area. The degradation reduced the diversity, and modified the composition of taxa and predominant ecological functions in the community. The lack of fungi that facilitate plant establishment and development in the degraded area suggests the importance of seeking the restoration of this community to ensure the success of the ecological restoration of the environment. The topsoil of preserved area can be a source of inocula of several groups of fungi important for the restoration process but which occur in low abundance or are absent in the degraded area.Item Ferruginous duricrusts associated with diamond occurrences in the Diamantina Plateau, south Espinhaço Range, Brazil.(2021) Milagres, Alcione Rodrigues; Oliveira, Fábio Soares de; Varajão, Angélica Fortes Drummond Chicarino; Varajão, César Augusto ChicarinoMacromorphological and micromorphological characterization of the alteration facies associated with geomorphological studies are of great importance for understanding the genesis and evolution of ferruginous duricrusts. The study of the ferruginous duricrusts in the Diamantina Plateau (Southern Espinhaço Range, Minas Gerais), a region known worldwide for hosting important diamond deposits, was based on the characterization of the faciological variations of representative alteration profiles. The morphometric indexes of the area, macromorphological description of the profiles, and sampling for micromorphological and mineralogical analyzes were carried out to assist in the understanding of the landforms. The results show that the ferruginous duricrusts occur preferentially in the plateaus and high slopes, with the Sopa-Brumadinho Formation as substrate. Two types of ferruginous duricrust have been identified. Type 1 is characterized as a platy duricrust developed from a saprolite of hematitic phyllite with a ferruginous banded structure. Type 2 is characterized by a massive duricrust typically lateritic that overlaps a nodular and mottled facies, originated from a saprolite of hematitic phyllite with a diffuse distribution of opaque minerals. This phyllite is one of the rocks that occur with the diamond host rocks in the old mines of the region. Both types of ferruginous duricrusts formed by relative accumulation evolve into fragmentary facies and the soil. Locally, in discordant contact, occurs a concretionary duricrust, characterized by an absolute iron accumulation mechanism.Item Geochemical evolution of soils developed from pyroclastic rocks of Trindade Island, South Atlantic.(2021) Mateus, Ana Carolina Campos; Varajão, Angélica Fortes Drummond Chicarino; Oliveira, Fábio Soares de; Petit, Sabine; Schaefer, Carlos Ernesto Gonçalves ReynaudThe geochemical behavior of the major, minor, trace and rare earths elements (REEs) in soil profiles from ultramafic volcanoclastic rocks of the Vulcão do Paredão and Morro Vermelho Formation from Trindade Island (TI) was analyzed in this study. Losses and gains of chemical elements were calculated through the mass balance for two profiles along the slope: one located at higher altitude (460 m) and the other at lower altitude (258 m). In all profiles, Al, Fe and Ti accumulate due to their low mobility, whereas Ca, Na, K and Mg are the most intensely leached. Soils located at lower altitude show higher K and Mg values in the surface due to the contribution of saline sprays. Leaching of the REEs from higher to the lower slope led to the enrichment of these elements, especially the light REEs, in the soil at the lowest altitude (258 m). The high altitude profile showed Ce positive anomaly due to longer exposure to weathering. The geochemical balance shows a relative enrichment of Ti, Mn, Fe, Co, Cr, Ni, V, Zr, S related to the loss of mobile elements during the soil formation process, despite the youthful nature of these volcanic rocks.Item Non-allophanic Andosols of Trindade Island, south Atlantic : a new soil order in Brazil.(2020) Mateus, Ana Carolina Campos; Varajão, Angélica Fortes Drummond Chicarino; Oliveira, Fábio Soares de; Petit, Sabine; Schaefer, Carlos Ernesto Gonçalves ReynaudThe pedological studies carried out so far in Trindade Island (TI) have obtained patchy evidences of allophane, without detailed mineralogical and micromorphological studies to confirm the occurrence of Andosols in TI. Therefore, in this study, the mineralogical, micromorphological, physical and chemical characterization of four soil profiles from Vulcão do Paredão (P1) and Morro Vermelho formations (P2, P3, and P4) were carried on the latest volcanic events in Brazil from Trindade Island (TI) with the aim of to evaluate the presence of Andosols in this oceanic island. Profiles P1 and P2 are developed on pyroclastic bombs, and show, respectively, A-Bi- C and decapitated A-C horizons, whereas P3 and P4 are developed on lapillitic and bomb pyroclasts, show A-C horizons. The soil profiles have a reddish and brownish clayey matrix, are highly friable and show a plastic consistency. Their microstructures are granular, single grain and intergrain microaggregate, in which aggregates display an undifferentiated b-fabric. The mineralogical constituents of the bulk fraction are biotite, hematite, magnetite, ilmenite, pyroxene, olivine, halloysite, goethite, anatase, and rutile. The clay fraction is marked by the presence of halloysite, ferrihydrite, and little amounts of allophane. All soils presented andic properties and can be classified as non-allophanic Andosols. In addition, micromorphological features closely resemble those reported in Andosols from other volcanic islands from elsewhere. The predominance of halloysite in the clay fraction formed by alteration of sideromelane, suggests that allophane would be an intermediate phase of this rapid transformation favored by the wet climate conditions of the highest parts of TI.Item Soil-chronosequence and quaternary landscape evolution at the marine terraces of Harmony Point, Nelson Island, Maritime Antarctica.(2022) Rodrigues, William Fortes; Machado, Mariana de Resende; Oliveira, Fábio Soares de; Schaefer, Carlos Ernesto Gonçalves Reynaud; Leite, Mariangela Garcia Praça; Michel, Roberto Ferreira Machado; Araújo, Teodoro Gauzzi Rodrigues deThis study characterized the physical, chemical, macro- and micromorphological soil properties from three successive marine terrace levels from Harmony Point (Nelson Island, Maritime Antarctica) in order to understand the pedological signatures of Quaternary coastal landscape evolution of Maritime Antarctica. Soils were sampled on the Late Holocene beach (current beach) and Mid Holocene marine terraces higher up, at 3, 8, and 12 m a.s.l. At the lower levels, the predominant soils were Gelorthents, whereas Haplogelepts dominate the higher terraces. Soil properties are mostly influenced by parent material and faunal activity, in which cryoclastic (thermal weathering) and phosphatization are the main soil-forming processes. Soils from the upper levels are more developed, deeper with reddish colors, granular structures and incipient formation B horizon. These horizonation features highlight that soils vary according with age of glacier-isostatic terrace uplift, representing a Quaternary soil chronosequence. All marine terrace levels are Ornithogenic soils, at varying degrees. However, the presence of old bird nesting sites for long periods led to formation of phosphatic horizons, stable Fe-phosphate minerals and abundant vegetation in the highest terraces of this part of Maritime Antarctica.Item Phosphatization under birds’ activity : ornithogenesis at different scales on Antarctic Soilscapes.(2021) Rodrigues, William Fortes; Oliveira, Fábio Soares de; Schaefer, Carlos Ernesto Gonçalves Reynaud; Leite, Mariangela Garcia Praça; Pavinato, Paulo SérgioExtensive areas of penguins’ nesting (Pygoscelis sp.), on ice-free areas, account for vast deposits of organic matter- rich guano in maritime Antarctica. One such area, at Harmony Point, currently houses different penguin colonies with extensive and unique ornithogenic soils, where phosphatization is the key soil-forming process. We sought to enhance the knowledge of phosphatization process, products, cycles, and phosphorus (P) forms in these un- usual soils. We compared ornithogenic and non-ornithogenic soils, based on advanced chemical, micromor- phological and mineralogical analyses of samples of guano and phosphate biocrusts, complete with P and OM fractionation. Ornithogenic soils have the organic P-pool as the largest phosphorous compartment, followed by varying P-Ca forms. In contrast, soils unaffected by phosphatization showed a high inorganic P-pool. Penguin guano is enriched with P, Ca, K, Cu, Zn, C and N. The phosphatic biocrusts are composed of struvite and hy- droxyapatite, forming a gradient of phosphate forms. We recognized three different phosphatization environ- ments, namely (i) present-day marine birds’ rookeries, (ii) adjacent zone of rookeries and (iii) abandoned rookeries. Geomorphological evolution of the coastal areas, by Holocene glacier retreat, resulted in the changing location of penguin colonies, resulting in a larger area and varying ages of phosphatization, forming ornithogenic soils with contrasting evolution degrees. Abandoned areas have greater vegetation growth, with higher diversity.Item Geochemistry of Antarctic periglacial soils from Harmony Point, Nelson Island.(2021) Rodrigues, William Fortes; Oliveira, Fábio Soares de; Schaefer, Carlos Ernesto Gonçalves Reynaud; Araújo, Teodoro Gauzzi Rodrigues de; Leite, Mariangela Garcia PraçaLittle is known about the geochemical baseline of Antarctic soils in diferent environments. We investigated the soil geo- chemistry of the two main landscape units of Harmony Point (Nelson Island, Maritime Antarctica): the coastal domain and the upper platform. Fourteen soil samples (seven in each landscape unit) were divided according to depth (hA for surface and hC for subsurface horizons) and characterized by their major, trace elements and REE concentrations. The concentration of major elements (SiO2, TiO2, Al2O3, Fe2O3, MgO, CaO, MnO, and K2O) were determined by X-ray fuorescence, whereas trace elements were quantifed by inductively coupled plasma-optical emission spectrometry (Co, Ni, As, Cd, Pb, Ba, Cr, Cu, V, Zn, and Zr) and REE by inductively coupled plasma mass spectrometry. The results showed geochemical variation with depth, either related to pedological processes (phosphatization, humifcation, podzolization, and cryoturbation), and parent material constitution (andesitic basalt in upper platform and mixed volcanic sediments in coastal domain). The main chemical aspects distinguishing Harmony Point soils from other Maritime Antarctic soils from the vicinity are: (i) higher CIA index; (ii) P2O5 enrichment due to bird guano and enhanced pedogenesis; (iii) REE retention; (iv) enrichment in Fe2O3 and S concentrations. The REE concentration was infuenced by weathering processes combined with allochthonous inputs, such as volcanic ashes and iceberg-transported granitic boulders at the coastal domain. The Harmony Point soils are little subjected to anthropic impacts, so they can be used as a basis for environmental monitoring programs in the Maritime Antarctica region.Item Solos e superfícies de erosão : uma contextualização da evolução da paisagem na Serra do Espinhaço Meridional (SdEM), Minas Gerais.(2020) Varajão, César Augusto Chicarino; Varajão, Angélica Fortes Drummond Chicarino; Oliveira, Fábio Soares de; Barreto, Helen Nébias; Salgado, André Augusto RodriguesO estudo investigou a evolução da paisagem da Serra do Espinhaço Meridional (SdEM), MG, através da caracterização macromorfológica, mineralógica, micromorfológica e química de solos desenvolvidos nas principais unidades lito-estratigráficas da região. Ocorrem principalmente Neossolos e Cambissolos, decapeados e cobertos discordantemente por um paleopavimento. Considerando as variações climáticas, as superfícies de erosão e as recentes datações dos solos, entendemos que após um longo período sob condições desérticas no Cretáceo (Superfície Pós-Gondwana) até o Paleoceno (Superfície Sul-Americana), ocorreu uma abrupta variação climática no Eoceno, em que condições quentes e úmidas formaram os mantos de alteração e o desmantelamento dos veios de quartzo presentes nas unidades subjacentes (Supergrupo Espinhaço). Estas condições também estiveram presentes durante o Mioceno, desaparecendo no Plioceno, onde a instalação de um novo clima desértico promoveu o desaparecimento da vegetação e a consequente erosão-decapitação dos perfis de solo. Neste contexto se formou o paleopavimento regional supracitado, interpretado como contemporâneo à Superfície Velhas. Sobre ele, durante o Quaternário, formaram-se inúmeras turfeiras, que sugerem condições climáticas regionais amenas.Item Chemical and microstructural behaviour of ferruginous rocky outcrops topsoils applied to degraded mining areas.(2020) Rocha, Fernanda Carolina Gomes; Oliveira, Fábio Soares de; Leite, Mariangela Garcia Praça; Dias, Diego Dayvison; Messias, Maria Cristina Teixeira Braga; Kozovits, Alessandra RodriguesTopsoil transposition is an efficient technique for recovering miningdegraded areas. However, storage time may reduce its functionality. To evaluate the effect of storage and litter addition, physical (microstructure) and chemical (fertility) properties were assessed in stored (3-months) and non-stored topsoils. Twelve months after transposition, regardless of the storage time, soil fertility and microstructure were improved, due to the mechanical work of plant roots recruited from topsoil seed bank or rain, and decomposition of pre-existing plant fragments. Litter addition did not affect chemical attributes but influenced microstructure transformations. Paedogenetic evolution was clearly fed by revegetation establishing a sustainable feedback system.Item Soil-landscape interplays at Harmony Point, Nelson Island, Maritime Antarctica : chemistry, mineralogy and classification.(2019) Rodrigues, William Fortes; Oliveira, Fábio Soares de; Schaefer, Carlos Ernesto Gonçalves Reynaud; Leite, Mariangela Garcia Praça; Araújo, Teodoro Gauzzi Rodrigues de; Bockheim, James G.; Putzke, JairSoils and landforms of Nelson Island remain one of the least studied in the South Shetlands Archipelago, despite that it is one of the oldest ice-free areas and is strongly vegetated. In this paper, we examine the main processes and factors of soil formation at Harmony Point and the relation of soils to landforms, vegetation and lithology. To achieve the goals, 26 pedons were collected and studied from a 4 km2 ice-free area at Harmony Point (S62°18′; W059°10′) on the southern area of Nelson Island (Maritime Antarctica). The soils were sampled on all representative local landforms, including three levels of uplifted marine terraces up to cryoplanated plateau, waterlogged depressions, rock felsenmeer, debris slopes and patterned ground, and a paraglacial border of the ice cap (270 m a.s.l). Sampling along the cryoplanated plateau was carried out along a gradient extending inland from the margins of the Ice Cap; and sampling of the marine terraces was performed along a chronosequence under varying bird-nesting influence and age. The main pedogenetic processes observed in this area are marked phosphatization, melanization from the accumulation of organic matter, and cryoturbation. Soil development varies from weakly developed, shallow, stony and cryoturbated to well-developed and organic-rich, phosphate soils with colors ranging from grayish to brown. The mineralogical composition of the clay fraction contains secondary minerals, indicating the active role of chemical weathering. Ornithogenic soils have mature phosphate minerals such as vivianite and taranakite, as well as poorly crystalline leucophosphite. Intensively cryoturbated soils are underlain by permafrost and are classified as Typic Haploturbels; polygonal soils are widespread on the cryoplanated plateau. Areas without permafrost were classified as Typic Gelorthents. Phosphatization is a dominant soil-forming process in this area and is associated with past and present-day guano accumulation by bird nesting and has led to the the development of deeper Ornithogenic Haplorthels. The ornithogenic soils occur at different topographic levels on the cryplanated platform and marine terraces. High P concentrations can be used as a proxy of the past nesting birds' activities, with far-reaching implications, especially with regards to vegetation growth and microbial activity and diversity.