Article
Geochemistry & Geophysics
Camila Santos Silveira, Leonardo Lagoeiro, Carolina Cavalcante, Rhander Taufner, Paola Ferreira Barbosa, Marcos Tadeu de Freitas Suita, Thailli Conte
Summary: This study measured and analyzed the crystallographic preferred orientation (CPO) and seismic anisotropy of naturally deformed gabbronorites and mafic mylonites. The results revealed the influence of different deformation mechanisms on deformation processes and seismic anisotropy.
Article
Engineering, Chemical
Hong Peng, Ngoc Quy Vu, James Vaughan, Sicheng Wang, Shuai Gao
Summary: In this study, bauxite residue samples were treated with aqueous HCl solutions to investigate the dissolution kinetics, ion exchange, and adsorption performance. XRD, XPS, and SEM measurements were used to determine the reaction mechanisms. The results showed that the adsorption performance decreased with increasing acid concentrations, mainly due to the structural changes of the sodalite phase. Other mineral phases had a minor contribution to the adsorption. Furthermore, different adsorption mechanisms were revealed for Pb2+ and Cu2+, which were related to surface disruption.
INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
(2023)
Article
Geosciences, Multidisciplinary
William Smith, Wolfgang Maier, Stephen Barnes, Gareth Moorhead, David Reid, Bartosz Karykowski
Summary: This study investigated the diverse processes involved in the formation of the Merensky Reef in the western Bushveld Complex. The results suggest that the reef formation was a combination of magmatic, hydrodynamic and hydromagmatic processes.
GEOSCIENCE FRONTIERS
(2021)
Article
Geosciences, Multidisciplinary
Priyanka Negi, Ashima Saikia, Mansoor Ahmad, Dewashis Upadhyay, Salim Akhtar
Summary: This study reports new major and trace element data for anorthosite enclaves hosted within granites in the Central Indian Tectonic Zone, providing modern insights into the petrogenesis of anorthosites. The findings suggest that anorthosites may have formed from plagioclase-saturated basaltic melt.
FRONTIERS IN EARTH SCIENCE
(2022)
Review
Metallurgy & Metallurgical Engineering
Yanxiu Wang, Ting-an Zhang, Guozhi Lv, Yan Liu, Weiguang Zhang, Qiuyue Zhao
Summary: The calcification-carbonation method is a novel technology for recovering Na2O and Al2O3 from bauxite residue through mineral transformation, achieving the harmless treatment of the residue. Research on the mineral transformation law of the key calcification and carbonation steps has been conducted, providing important references for reducing costs and promoting the application of this new technology.
Article
Engineering, Chemical
Yu Li, Xiaolin Pan, Zhongyang Lv, Hongfei Wu, Haiyan Yu
Summary: In this paper, a novel zero-waste process was proposed to comprehensively utilize high-silicon bauxite, and the phase transition mechanism and leaching properties were studied. The optimal roasting conditions for atmospheric-pressure leaching and high-pressure leaching were determined.
MINERALS ENGINEERING
(2022)
Article
Environmental Sciences
Xueqian Ren, Xi Zhang, Pinpeng Tuo, Bin Yang, Juan Chen, Wei Guo, Jie Ren
Summary: The study investigated the dose-response relationship in alkaline reduction induced by ferrous sulfate (FS) neutralization in combined bauxite residue, finding that FS could effectively improve the characteristics of the combined bauxite residue, and guide its disposal.
ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH
(2022)
Article
Chemistry, Multidisciplinary
Guotao Zhou, Yilin Wang, Tiangui Qi, Qiusheng Zhou, Guihua Liu, Zhihong Peng, Xiaobin Li
Summary: The conversion of Al-substituted goethite to hematite in gibbsitic bauxite was investigated in this study. The results showed that the synthetic Al-goethite started converting to hematite at around 280 degrees C, while the natural Al-goethite started converting at around 320 degrees C. The addition of NaOH accelerated the conversion process. The converted hematite inherited the needle-like appearance of the original Al-goethite and had a porous structure. Digestion experiments confirmed that low-temperature roasting-Bayer digestion significantly improved alumina recovery and resulted in iron-rich red mud that can be easily co-processed in the steel industry, which could lead to significant emission reduction.
Article
Geochemistry & Geophysics
Reza Maghdour-Mashhour, Ben Hayes, Robert Bolhar, Henriette Ueckermann
Summary: Layered mafic-ultramafic intrusions, such as the Rustenburg Layered Suite in South Africa, provide valuable insights into magma differentiation and solidification processes. The detailed study of the MG3F anorthosite within this suite challenges the traditional paradigm of a melt-dominated chamber and reveals distinct compositional variations within the anorthosite layer. The relationships between the anorthosite, surrounding pyroxenite, and chromitite in the Lower-Upper Critical Zone boundary are crucial for understanding the magmatic evolution of this complex.
JOURNAL OF PETROLOGY
(2021)
Article
Engineering, Environmental
Luis Alberto Macias-Perez, Clement Levard, Mohamed Barakat, Bernard Angeletti, Daniel Borschneck, Laurent Poizat, Wafa Achouak, Melanie Auffan
Summary: The study analyzed the geochemical composition of different bauxite residues produced in southern France and explored the development of bacterial and fungal communities using high-throughput sequencing technology. Results showed that microbial richness, diversity, and network complexity increased significantly with the deposit age, eventually reaching an equilibrium community composition similar to typical soils.
JOURNAL OF HAZARDOUS MATERIALS
(2022)
Article
Geochemistry & Geophysics
J. E. Bourdeau, B. Hayes, S. E. Zhang, A. Logue, G. M. Bybee
Summary: This study investigates the field and petrological relationships, as well as the chemistry of blocks hosted in a layered sequence of poikilitic anorthosites in the Rustenburg Layered Suite. The blocks have distinct compositions compared to their hosts, suggesting a different petrogenesis and transport mechanism. The study also develops a numerical model to understand the crystallinity and magma flow rate of the plagioclase slurries that carried these blocks.
CONTRIBUTIONS TO MINERALOGY AND PETROLOGY
(2022)
Article
Geosciences, Multidisciplinary
Jeremie Lehmann, Alan M. Brower, Trishya M. Owen-Smith, Grant M. Bybee, Ben Hayes
Summary: This study characterizes the architecture of the Mesoproterozoic Kunene Complex anorthosite suite in Angola and Namibia using remote sensing and field observations, and reveals that the reflectance signature of the rocks is primarily influenced by the degree of metasomatism. This method can be applied to other anorthositic terrains.
GEOSCIENCE FRONTIERS
(2023)
Article
Geology
Eduardo T. Mansur, Trond Slagstad, Sarah A. S. Dare, Jan Sverre Sandstad
Summary: This study provides a systematic characterization of different Ni-Cu-Co mineralizations in the Espedalen Complex in Norway. It distinguishes between primary sulphides and deformed sulphides, which exhibit variations in Ni and Cu tenors as well as platinum group element concentrations. The assessment of other geological domains' correlation with the Espedalen Complex is crucial for further exploration of potential Ni-Cu-Co deposits in the area.
ORE GEOLOGY REVIEWS
(2023)
Article
Geosciences, Multidisciplinary
Qian Yuan, Chao Zhang, Feng Cheng, Xiaofeng Cao, Eamonn Needham, Han Zheng, Xinbiao Lu
Summary: In this study, the origin and formation time of the Daxigou Anorthosite Complex (DAC) were investigated through geochronological and geochemical analyses. The closure time of the DAC was determined through in-situ petrographic thin section U-Pb dating of zircon coronas. The results suggest that the formation of this rock body may be related to Paleoproterozoic tectono-thermal events.
Article
Multidisciplinary Sciences
Yiming Zhang, Nicholas L. Swanson-Hysell, Margaret S. Avery, Roger R. Fu
Summary: This study obtained estimates of Earth's magnetic field strength in deep time by analyzing anorthosite xenoliths. The results indicate the existence of a strongly powered geodynamo in the past, challenging the hypothesis of a young inner core and the progressive decay of Earth's dynamo strength. These findings provide new insights into the evolution of Earth and the mechanisms behind the formation of the magnetic field.
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
(2022)
Article
Geosciences, Multidisciplinary
Ivan Carlos Carreiro Almeida, Carlos Ernesto Goncalves Reynaud Schaefer, Raphael Braganca Alves Fernandes, Fabio Soares Oliveira, Thiago Torres Costa Pereira
Summary: Microscopic studies of soil in polar regions using scanning electron microscopy and microprobe analysis combined with field description and laboratory analyses provide valuable information on soil genesis. A study conducted in Maritime Antarctica revealed the presence of phosphate-rich ornithogenic soils with distinct acidic and neutral pH types, suggesting different forming processes.
JOURNAL OF SOUTH AMERICAN EARTH SCIENCES
(2021)
Article
Environmental Sciences
Fernanda C. G. Rocha, Fabio S. de Oliveira, Mariangela G. P. Leite, Diego D. Dias, Maria Cristina T. B. Messias, Alessandra R. Kozovits
Summary: Topsoil transposition is an efficient technique for recovering mining-degraded areas, with improvements in soil fertility and microstructure attributed to the mechanical work of plant roots and decomposition of plant fragments. Litter addition does not impact chemical attributes but can influence microstructure transformations, while revegetation helps establish a sustainable feedback system for soil improvement.
INTERNATIONAL JOURNAL OF MINING RECLAMATION AND ENVIRONMENT
(2021)
Article
Ecology
Thamar Holanda da Silva, Paulo E. A. S. Camara, Otavio Henrique Bezerra Pinto, Micheline Carvalho-Silva, Fabio Soares Oliveira, Peter Convey, Carlos Augusto Rosa, Luiz Henrique Rosa
Summary: The study utilizing next-generation sequencing technology found a complex fungal community in the permafrost of the South Shetland Islands, including various animal, human, and plant pathogenic fungi.
Article
Multidisciplinary Sciences
Rafael G. Siqueira, Davi Lopes, Jose Joao L. L. De Souza, Carlos Ernesto G. R. Schaefer, Caroline D. Souza, Fabio S. De Oliveira, Elpidio Inacio Fernandes Filho
Summary: Sulfurization is a pedogenic process that varies according to climate gradient in Antarctica. Warmer and wetter regions exhibit higher weathering degree, acidity, phosphorus adsorption capacity, and well-crystallized iron oxides and kaolinite formation in acid sulfate soils, while drier regions show lower acidity, higher base contents, and presence of weatherable minerals.
ANAIS DA ACADEMIA BRASILEIRA DE CIENCIAS
(2022)
Article
Multidisciplinary Sciences
Davi Do Vale Lopes, Fabio S. De Oliveira, Jose Joao L. L. De Souza, Mariana De Resende Machado, Carlos Ernesto G. R. Schaefer
Summary: This study focuses on the influence of flying birds on soil genesis in ornithogenic soils of Antarctica. The results show that sites influenced by flying birds undergo active chemical weathering processes and phosphatization accelerates mineralogical and micromorphological transformations in soils. However, under the current global warming trend and expected sea-level rise, these ornithogenic environments are vulnerable to accelerated erosion rates.
ANAIS DA ACADEMIA BRASILEIRA DE CIENCIAS
(2022)
Article
Biodiversity Conservation
Paulo E. A. S. Camara, Graciele C. A. de Menezes, Fabio S. Oliveira, Caroline Delpupo Souza, Eduardo T. Amorim, Carlos E. G. R. Schaefer, Peter Convey, Otavio H. B. Pinto, Micheline Carvalho-Silva, Luiz H. Rosa
Summary: The study on microbial diversity in the Ellsworth Mountains found DNA from 48 taxa, mostly originating from South America. The results indicated that rock type, exposure age, or sampling location did not affect the diversity of DNA.
Article
Environmental Sciences
Renata Jordan Henriques, Fabio Soares de Oliveira, Carlos Ernesto Goncalves Reynaud Schaefer, Marcio Rocha Francelino, Paulo Roberto Canto Lopes, Eduardo Osorio Senra, Valeria Ramos Lourenco
Summary: Brazil has a vast coastline and the largest and most complex fluvio-marine archipelago on the planet. Marajo Island in the Amazon River mouth is a key area for long-term sustainable management of coastal resources and an important sentinel of global marine ecosystem changes. A detailed geoenvironmental stratification analysis revealed the complex social and environmental features of the area, as well as signs of indigenous occupation and impacts of sea-level rise.
ENVIRONMENTAL EARTH SCIENCES
(2022)
Article
Geosciences, Multidisciplinary
Larissa Paraguassu, Fabio Soares Oliveira, Caroline Delpupo, Pedro Henrique Almeida, Carlos Ernesto Gonsalves Reynaud Schaefer, Mariana de Resende Machado, Marcos Gervasio Pereira
Summary: This study investigates the pedogenic evolution of carbonate-rich soils on Fernando de Noronha and Trindade volcanic islands in the South Atlantic. The results show that the parent material and local climate are the main factors driving soil genesis, and the differences in landscape and climate evolution between the islands explain the variations in soil characteristics. The study suggests the inclusion of new sub-groups in the Brazilian Soil Classification System.
JOURNAL OF SOUTH AMERICAN EARTH SCIENCES
(2022)
Article
Ecology
Paulo E. A. S. Camara, Fabio Leal Viana Bones, Fabyano Alvares Cardoso Lopes, Fabio S. Oliveira, Cristine Chaves Barreto, Diego Knop Henriques, Larissa Paraguassu Campos, Micheline Carvalho-Silva, Peter Convey, Luiz Henrique Rosa
Summary: Trindade Island, the most recent volcanic component of Brazilian territory, has experienced severe damage to its native vegetation due to human influence. However, after the eradication of goats and other feral animals, the island's vegetation has been recovering, and even rediscovery of endemic species previously considered extinct has been made. Using high throughput sequencing, this study reveals a rich and complex diversity of microorganisms, invertebrates, and plants in the recovering native forest of Trindade Island.
Article
Zoology
Rodolfo Assis Magalhaes, Rodrigo Lima Massara, Fabio Soares de Oliveira, Flavio Henrique Guimaraes Rodrigues
Summary: This study conducted the first quantitative investigation of the species-habitat relationships for the Brazilian three-banded armadillo. The results showed that the occupancy probability of this threatened species was high in human-modified landscapes, and its detection probability was influenced by active searches and camera traps.
Article
Ecology
Daniel M. Arruda, Carlos E. G. R. Schaefer, Rubia S. Fonseca, Elpidio I. Fernandes-Filho, Gustavo V. Veloso, Lucas C. Gomes, Fabio S. Oliveira, Guilherme R. Correa, Mario M. Espirito-Santo, Guilherme C. Oliveira, Ricardo R. C. Solar
Summary: Changes in vegetation cover due to climate events and human activity are occurring in Brazil, leading to the loss of suitable habitat surface and the need for mitigation strategies. A future scenario predicts that the Amazon basin will experience major vegetation changes, with dryer vegetation replacing rainforest in some areas. The Brazilian semiarid region will also see an expansion of caatinga cover, resulting in the loss of suitable habitat for current deciduous forests. Protected areas will be significantly impacted, with indigenous lands facing greater damage. Urgent creation of protected areas in less affected regions is proposed to preserve biodiversity and cultural heritage.
Article
Ecology
Daniel M. Arruda, Carlos E. G. R. Schaefer, Rubia S. Fonseca, Elpidio I. Fernandes-Filho, Gustavo V. Veloso, Lucas C. Gomes, Fabio S. Oliveira, Guilherme R. Correa, Mario M. Espirito-Santo, Guilherme C. Oliveira, Ricardo R. C. Solar
Summary: Changes in vegetation cover due to climate events and human activities are already happening. Predicting the impacts of future climate is crucial for developing strategies to mitigate these changes. This study models the responses of Brazilian biomes to future CO2 levels and assesses the effects on protected areas. The results show significant changes in vegetation, with potential losses of habitat and increased threat to biodiversity.
Article
Multidisciplinary Sciences
Carlos Ernesto G. R. Schaefer, Eduardo O. Senra, Daniela Schmitz, Rafael G. Siqueira, Mayara D. De Paula, Jair Putzke, Fabio S. De Oliveira, Lara G. Maia, Anifo S. M. Ibraimo, Marcio R. Francelino
Summary: Areas of high concentration of seal carcasses have been observed in localized areas of James Ross Island, Antarctica, which play an important role in the establishment and succession of vegetation due to physical and chemical effects throughout the decomposition process.
ANAIS DA ACADEMIA BRASILEIRA DE CIENCIAS
(2023)
Article
Soil Science
Marcos Gervasio Pereira, Rafael Cipriano da Silva, Miguel Cooper, Lucia Helena Cunha dos Anjos, Deyvid Diego Carvalho Maranhao, Fabio Soares de Oliveira
Summary: This study investigates the pedogenetic changes and transformation between different horizons in basic rock-derived profiles in a toposequence in Pinheiral, Rio de Janeiro State, Brazil, providing insights into the evolution of soil properties under tropical conditions.
REVISTA BRASILEIRA DE CIENCIA DO SOLO
(2022)
Article
Multidisciplinary Sciences
William F. Rodrigues, Mariana R. Machado, Fabio S. de Oliveira, Carlos Ernesto G. R. Schaefer, Mariangela G. P. Leite, Roberto F. M. Michel, Teodoro Gauzzi
Summary: This study characterized the physical, chemical, macro-and micromorphological soil properties from three successive marine terrace levels from Harmony Point (Nelson Island, Maritime Antarctica) and found that soil properties are mainly influenced by parent material and faunal activity. The presence of old bird nesting sites also affects soil properties, resulting in the formation of phosphatic horizons and abundant vegetation on the highest terraces.
ANAIS DA ACADEMIA BRASILEIRA DE CIENCIAS
(2022)
