Soil quality indicator of oxisols grown with sugarcane and native forest in northeastern São Paulo state,Brazil     

Ludmila de Freitas  Marcílio Vieira Martins Filho  José Carlos Casagrande  Ivanildo Amorim de Oliveira  Luiz Gabriel da Silva 《Environmental Earth Sciences》2018,77(18):642

The evaluation of soil quality is an important tool for degradation monitoring and sustainable management implementation. The objective of this study was to measure physical and chemical soil properties to set soil quality and validate a model of soil quality indicator in latosols (oxisols) under sugarcane cropping and native forest. The study was carried out in the cities of Araras, Santa Ernestina, and Guariba in São Paulo State, Brazil. We collected 24 samples of disturbed and undisturbed soil at 0.0–0.10 m layer from three areas grown with sugarcane and neighboring locations under native woodland. We assessed the following soil properties: (a) chemical—pH in CaCl₂, organic matter (OM), phosphorus (P), potassium (K⁺), calcium (Ca²⁺), magnesium (Mg²⁺), potential acidity (H?+?Al), aluminum (Al³⁺), and sulfur (S); (b) physical—macro- and microporosity, soil bulk density (Ds), aggregate stability, mean weight diameter (MWD), rill (K_r) and interrill (K_i) global erodibility, shear stress (τc), and magnetic susceptibility (MS). Data underwent multivariate statistics to identify the properties that denote soil quality and to set their weights within the functions of soil quality indicator (SQI). This study showed that the multivariate analysis was efficient in determining which physical and chemical properties were most sensitive, of which we can mention total sand, MS, clay, microporosity, Mg, Ca, pH, and OM. We can therefore conclude that the quality indicators of soils grown with sugarcane were lower than those under forest were, showing the need for adoption of conservation management practices.  相似文献   

Anomalous heat flow belt along the continental margin of Brazil     

Hamza  Valiya M.  Vieira  Fabio P.  Silva  Raquel T. A. 《International Journal of Earth Sciences》2018,107(1):19-33

International Journal of Earth Sciences - A comprehensive analysis of thermal gradient and heat flow data was carried out for sedimentary basins situated in the continental margin of Brazil (CMB)....  相似文献   

Petrological,geochemical, isotopic,and geochronological constraints for the Late Devonian–Early Carboniferous magmatism in SW Gondwana (27–32°LS): an example of geodynamic switching     

Dahlquist  Juan A.  Alasino  Pablo H.  Basei  Miguel A. S.  Morales Cámera  Matías M.  Macchioli Grande  Marcos  da Costa Campos Neto  Mario 《International Journal of Earth Sciences》2018,107(7):2575-2603

International Journal of Earth Sciences - We report a study integrating 13 new U–Pb LA-MC-ICP-MS zircon ages and Hf-isotope data from dated magmatic zircons together with complete...  相似文献   

Cyclic and Dynamic Behavior of Sand–Rubber and Clay–Rubber Mixtures     

Rios  Sara  Kowalska  Magdalena  Viana da Fonseca  António 《Geotechnical and Geological Engineering》2021,39(5):3449-3467

Geotechnical and Geological Engineering - In this paper, the possibility of using fine scrap tyre rubber to improve the mechanical properties of soil subjected to cyclic loading is...  相似文献   

Characterization of a landslide-triggered debris flow at a rainforest-covered mountain region in Brazil     

Cabral  Victor Carvalho  Reis  Fábio Augusto Gomes Vieira  D’Affonseca  Fernando Mazo  Lucía  Ana  dos Santos Corrêa  Claudia Vanessa  Veloso  Vinicius  Gramani  Marcelo Fischer  Ogura  Agostinho Tadashi  Lazaretti  Andrea Fregolente  Vemado  Felipe  Pereira Filho  Augusto José  dos Santos  Claudia Cristina  Lopes  Eymar Silva Sampaio  Rabaco  Lis Maria Reoni  do Carmo Giordano  Lucilia  Zarfl  Christiane 《Natural Hazards》2021,108(3):3021-3043

Natural Hazards - Debris flows represent great hazard to humans due to their high destructive power. Understanding their hydrogeomorphic dynamics is fundamental in hazard assessment studies,...  相似文献   

A combined structural and seasonal approach to assess wildfire susceptibility and hazard in summertime     

Bergonse  Rafaello  Oliveira  Sandra  Gonçalves  Ana  Nunes  Sílvia  da Câmara  Carlos  Zêzere  José Luis 《Natural Hazards》2021,106(3):2545-2573

Natural Hazards - Wildfire susceptibility and hazard models based on drivers that change only on a multiyear timescale are considered of a structural nature. They ignore specific short-term...  相似文献   

Holocene environmental change on the Atlantic coast of NW Iberia as inferred from the Ponzos wetland sequence     

Luis Gómez-Orellana  Pablo Ramil-Rego  Javier Ferreiro da Costa  Castor Muñoz Sobrino 《Boreas: An International Journal of Quaternary Research》2021,50(4):1131-1145

The intertidal environment of the Ponzos beach (NW Iberian Peninsula) hosts a sedimentary sequence (including large wood fragments) deposited during the first half of the Holocene in a hygrophilous continental wetland. Pollen and macrofossil data alongside radiocarbon dating allow reconstruction of the changes that occurred during the Early and Middle Holocene in the landscape of the NW Iberia coastal lowlands, as well as the local wetland plant communities, in response to the climate variations and the eustatic sea-level oscillations. The sequence represents the evolution of a coastal wetland from its initial phases as a hygrophilous wetland towards the subsequent installation of a freshwater lagoon. Pollen data show the dominant role of Atlantic (mainly deciduous) woody taxa, the scarcity of conifers and the lack of Mediterranean elements in the coastal landscapes around the Ponzos site. The presence and abundance of some taxa such as deciduous Quercus, Castanea, Fagus, Tilia and Ulmus during the Early Holocene provides further support for the occurrence of glacial refuges in the Cantabrian-Atlantic area during the Last Glaciation. The diverse vegetation that characterizes the modern landscapes in this territory established later, spreading from these glacial reservoirs of biodiversity. In this sense, the notable and early presence of Fagus at the beginning of the Holocene, a tree also previously recorded during several phases of the Last Glacial Cycle on the NW Iberia coasts, is noteworthy. In addition, during the Early and Middle Holocene are recorded other trees that are currently extirpated as natural taxa in the area, such as Pinus, Tilia and Carpinus.  相似文献   

Nanomineralogy of evaporative precipitation of efflorescent compounds from coal mine drainage     

Luis F.O.Silva  Diana Pinto  Guilherme L.Dotto  James C.Hower 《地学前缘(英文版)》2021,12(6):404-410

Efflorescent nanophases(NPs)are found as a transitory accumulation of potentially hazardous elements(PHEs),particularly in tropical climates.The central objective of this study was to investigate the distribution of PHEs with NPs through the evaporative formation structures(EFS)of enormously PHEs-rich coal-mine drainages(CMD).The EFS were studied in natural coal mine drainage for five months in order to determine their geochemical and ecological structures and to assess their position in the reduction of PHEs in nature.The largest coal-fired power plant in South America,located in south Brazil,is used as an example of such a problem.In this work,a novel methodology for the analysis of PHEs in CMD precipitates is proposed for this affected coal area.The analytical method,combining X-Ray Diffraction(XRD)and advanced electron microscopies,shows the importance of nanomineralogy in understanding different circumstances of coal contamination.Several ultrafine-nanoparticles(UNPs)were identified in the sampled soils and river sediments together with the PHEs.A decrease in PHEs was identified in association with UNPs.However,further investigations are required with regard to the mobility of PHEs in water,atmosphere,soils,and sediments.The EPS was thoroughly studied,acquiring suitable understanding with investigational facts for Ca and Fe-sulphates,pickeringite,and several amorphous phases.  相似文献   

Style Transfer applied to CT image downscaling: a study case from Brazilian Coquinas     

Souza  João Paulo da Ponte  Avansi  Michelle Chaves Kuroda  Belila  Aline Maria Poças  Vidal  Alexandre Campane 《Computational Geosciences》2021,25(5):1457-1471

Computational Geosciences - The identification of micropore systems in carbonate rocks is an important task of image processing because of the high impact these systems cause on fluid flow....  相似文献   

Advances in SHRIMP geochronology and their impact on understanding the tectonic and metallogenic evolution of southern Brazil     

L. A. Hartmann  J. A. D. Leite  L. C. Da Silva  M. V. D. Remus  N. J. McNaughton  D. I. Groves 《Australian Journal of Earth Sciences》2013,60(5):829-844

Significant improvements, both in understanding the evolution of zircons and in understanding the geotectonic and metallogenetic evolution of the complex terrain of southern Brazil, are obtained from a SHRIMP geochronology study and reviewed in this paper. The use of backscattered electron and cathodoluminescence images, prior to SHRIMP isotopic determinations, proved of enormous fundamental value for this technique. Zircon is a domainal open‐system mineral in many geological conditions; very old domains may be preserved, but the same crystal may show ages of younger tectonic events. Zircons may recrystallise inwards from the rims or outwards from the cores, and also along euhedral high‐U or metamict thin zones. Zircons also may be recrystallised during gold‐related hydrothermalism, phyllic alteration of granitic rocks. The precise dating of amphibolite dykes can be achieved by the identification and dating of magmatic zircons. Precambrian orogenies are identified along with the intervening intracratonic tectonic cycles of supercontinents in southern Brazil from 3300 to 470 Ma. Granulite protoliths were formed during the Jequié Orogeny (ca 2600 Ma), but extensive arc accretion occurred in the Palaeoproterozoic (ca 2250 Ma) Encantadas Orogeny. Late in the Transamazonian Cycle, granites were formed by crustal melting at about 2000 Ma in the Camboriú Orogeny. Both accretionary and collisional orogenies are also identified in the Neoproterozoic Brasiliano Cycle. These are the accretionary Passinho Orogeny (ca 900 Ma) and São Gabriel Orogeny (ca 700 Ma), that were succeeded by the collisional Dom Feliciano Orogeny (ca 600 Ma). Base‐metal and gold deposition occurred in juvenile island arcs and in late orogenic porphyry‐copper‐type magmatic‐hydrothermal settings during the Neoproterozoic.  相似文献