José Carlos Sícoli Seoane | Universidade Federal do Rio de Janeiro (UFRJ) (original) (raw)

Papers by José Carlos Sícoli Seoane

Geosciences = Geociências

As trilhas são caminhos que conectam paisagens e pessoas. Neste trabalho apresentamos uma propost... more As trilhas são caminhos que conectam paisagens e pessoas. Neste trabalho apresentamos uma proposta de sistematização metodológica para uma abordagem geossistêmica da geodiversidade em trilhas da Mata Atlântica, articulando suas bases com os princípios da geoética e da interpretação ambiental visando contribuir para o atingimento dos Objetivos de Desenvolvimento Sustentável da Agenda 2030. Estudos sobre a geodiversidade, em uma perspectiva geoética, apontam para a necessidade de uma mudança de comportamento e de atitudes responsáveis dos geocientistas para com o Sistema Terra. Neste contexto, a interpretação ambiental constitui estratégia fundamental para a comunicação com a sociedade. A proposta é apresentada com base em três estudos de caso no Estado do Rio de Janeiro (Brasil): Caminho Darwin na Serra da Tiririca, Travessia Petrópolis-Teresópolis e Transcarioca. A partir de vivências e pesquisas científicas desenvolvidas, em sintonia com demandas dos gestores e usuários de trilhas ...

Geosciences = Geociências

O uso público de unidades de conservação através da promoção das trilhas tem se configurado em um... more O uso público de unidades de conservação através da promoção das trilhas tem se configurado em uma importante ferramenta de conservação da natureza. Em uma abordagem geossistêmica, a parte abiótica da natureza é conhecida como Geodiversidade que juntamente com a Bio e a Sociodiversidade compõem o Sistema Terra. Na conservação da natureza, a Biodiversidade ocupa papel de destaque. Dessa maneira, esta pesquisa tem por objetivo analisar a percepção da geodiversidade por usuários da Trilha Transcarioca no Rio de Janeiro visando contribuir para a sensibilização e consequente valorização da Geodiversidade. Para tal, foi aplicado questionário online com 16 perguntas no Google Forms e os dados processados e disponibilizados no Power BI. Os resultados indicam que a frequência diminuiu durante a pandemia, que poucos usuários foram guiados, que o trecho 25 é o mais realizado e o PNT é a UC mais visitada. O conceito Geodiversidade é conhecido por 86,7%, os mirantes são as paisagens mais represe...

Frontiers in Marine Science

Thermal stress is now considered the major recent cause of coral reef degradation; yet few studie... more Thermal stress is now considered the major recent cause of coral reef degradation; yet few studies have been conducted describing those effects on Southwestern Atlantic (SWA) reefs. The SWA represents a coral endemism hotspot with low-functional redundancy and therefore high extinction risk. Recent research has suggested a “thermal refuge” potential for SWA; however, evidence could suggest a different trend. We report herein an unprecedented coral mortality on the largest coastal Brazilian Marine Protected Area (MPA) following the worst thermal stress event since 1985. Degree Heating Week (DHW) values over 4.0 were observed for 107 days, averaging 8.70 for the period, with a maximum of 12.1. Average live coral cover was reduced by 18.1% while average turf algae cover increase by 19.3%. Mortality was highest for three coral species, with a mean mortality of 50.8% per transect for Millepora braziliensis, 32.6% for Mussismilia harttii and 16.6% for Millepora alcicornis. Our unique data...

Diversity

Mesophotic reefs are poorly known worldwide despite their great ecological relevance and manageme... more Mesophotic reefs are poorly known worldwide despite their great ecological relevance and management importance for coral reef conservation strategies. To aid in filling this gap, we conducted a pioneering, large-scale survey, covering a total of around 315 miles in length, in the largest Brazilian coastal Marine Protected Area (MPA) Costa dos Corais. From the digital bathymetry model (30 to 50 m depth) generated by a multibeam echo sounder, we selected areas of greater geomorphological diversity for a detailed investigative expedition of mesophotic ecosystems. Various sampling techniques were used: single-beam echo sounders for detailing the relief, a remotely operated underwater vehicle (ROV) for habitat type investigation, baited remote underwater video (BRUV) for collecting images of the fish community, and scuba diving to perform transects describing the benthic and fish community. We analyzed reef environments from 20 to 68 m deep. As a result, we present the mapping and geomor...

Science of The Total Environment, 2021

The Abrolhos bank is home of the richest coral reef system of the Southwestern Atlantic, where en... more The Abrolhos bank is home of the richest coral reef system of the Southwestern Atlantic, where endemic coral species are found. It has been reported that Abrolhos' corals are under intense stress due to increasing of Marine Heat Waves during the last decades. Additionally, anthropic interventions along the adjacent coastal regions are a factor of concern since they contribute to the increase in the sediment load and to organic debris input in the reef domain. In November 2015, the collapse of the Fundão mining tailings dam resulted in the release of approximately 50 million m3 of iron oxide and quartz-rich slurry into the Doce River. Aiming at using a fingerprint of the tailings and to assess the presence of traces of the Fundão dam material from this event on the Abrolhos bank, this work presents new 87Sr/86Sr and 143Nd/144Nd isotope ratios of marine suspended sediment samples collected between 2016 and 2020 from a network of sediment traps throughout the reef and complementary suspended material at sea . In parallel, we monitored meteo-oceanographic parameters and modeled surface marine currents as an attempt to identify the sediment transport between the Doce River mouth and Abrolhos bank. The r isotopes were used as provenance proxies based on the fact that minerals and rocks tend to have specific isotopic signatures reflecting their own geological derivation. In this context, the isotopic ratios of various potential regional sources for the sedimentation in Abrolhos bank were evaluated. Our monitoring and isotopic measurements indicate that Doce River signatures are detected at Abrolhos bank, following the seasonal Doce River discharge at sea. Isotopic signature of Doce River at Abrolhos bank was also observed during the austral winter (July-August) when cold fronts migrate at the Brazilian coast with higher frequency and energy.

Revista Brasileira de Geomorfologia, 2021

As variações do nível relativo do mar (VNRM) tiveram um papel importante na formação das planície... more As variações do nível relativo do mar (VNRM) tiveram um papel importante na formação das planícies costeiras fluminenses durante o Holoceno, sendo responsáveis pela construção de extensas feições deposicionais costeiras na Região dos Lagos. Modelos de reconstituição paleoambiental tridimensionais de VNRM são importantes para entender a evolução sedimentar costeira em ambientes formados por cordões litorâneos, lagunas, deltas, estuários, pântanos e ilhas barreiras, que são feições geomorfológicas comuns no litoral brasileiro. Objetiva-se desenvolver um modelo tridimensional de reconstituição paleoambiental na região da planície costeira de Cabo Frio, Rio de Janeiro. Como procedimento metodológico, realizou-se levantamento faciológico e análise sedimentológica em seis locais, em conjunto com análises de sensoriamento remoto. Os ambientes de sedimentação foram interpretados através de imagens de satélite e diante da correlação encontrada entre as análises sedimentológicas e geomorfológ...

Environmental Management, 2020

E. (2020). Methodological proposal for the inventory and assessment of geomorphosites: An integra... more E. (2020). Methodological proposal for the inventory and assessment of geomorphosites: An integrated approach focused on territorial management and geoconservation. Environmental Management.

Anais da Academia Brasileira de Ciencias

Interpretation of sea-level indicators is essential when studying paleo sea-level fluctuations du... more Interpretation of sea-level indicators is essential when studying paleo sea-level fluctuations during the Holocene. Sea-level indicators may have different origins, such as geological (beachrocks) and biological (vermetids and barnacles). In order to reconstruct paleo sea-level, it is necessary to attribute an indicative meaning to each sea-level indicator. This paper aims to discuss issues raised by Angulo et al. (2016) regarding to the sea-level fluctuations curve proposed by Castro et al. (2014) to the Rio de Janeiro State coast, Brazilian southeast. The key issue that deserves posing is that local or regional curves cannot be built based on large scale (global) RSL geophysical models even in places of steady crust like Brazil. Here, we put into question the relative sea-level fluctuation curve model proposed by Angulo et al. (2006, 2016) to the coast of Rio de Janeiro State and Pernambuco State. It is strengthened the proposal of using different origins indicators on RSL vertica...

Anais da Academia Brasileira de Ciências, 2014

The present paper aims to investigate the relative sea-level and the coastal evolution during the... more The present paper aims to investigate the relative sea-level and the coastal evolution during the Holocene in the Rio de Janeiro coastline, based on geological and biological indicators. Using topographic survey, excavation and coring, and 14C dating of these coastal deposits and beachrocks outcrops, we have reconstructed a sea-level curve for the Holocene. For the first time on the Brazilian coast it was identified a negative record of relative sea-level during Late Pleistocene and Early Holocene transition. After the transition, a relatively rapid increase of sea-level began. At approximately at 8500 cal yr BP, the sea-level was 0.5 m below the current level, was overtaken for the first time in the Holocene, at approximately 7500 cal yr BP. The maximum level of +2.5 m was reached between 4770 and 4490 cal yr BP. At the point of maximum transgression, the sea-level began a general behavior of lowering until the present. These results confirm other data already obtained elsewhere al...

Environmental Earth Sciences, 2015

A three-step sequential extraction procedure, which was based on the BCR method, was used to anal... more A three-step sequential extraction procedure, which was based on the BCR method, was used to analyse Guanabara Bay sediment samples to evaluate the potential mobility of some metals and metalloids. Zn and Cd were found to be the most labile metals because these were recovered in the first extraction stage and were associated with the non-residual fraction of the sediment. In contrast, Cr, Cu, Ni, and Hg were the least labile metals, and 62 to 84 % of the concentrations of these metals were found in the organic residual fraction of the sediment samples. The spatial distribution of the metal concentrations in Guanabara Bay led to the identification of various sources of contamination. The continental sources, which were related to Fe and Al, were distributed in the northern and central sectors, although lower concentrations were found in the mouths of the rivers that flow into the estuarine system of Guanabara Bay. The urban emission sources are related to the discharges of the São João de Merití River, which exhibit significant levels of Ba, Cd, Ni, Zn, and Hg. The São João de Merití River and harbour activities also show a predominance of Pb and Cu. The system formed by the Iguaçu River and the Sarapuí River is mainly characterised by V and Cr. The metals associated with biogeochemical processes, such as As and Mn, were found in the central sector of Guanabara Bay.

Continental Shelf Research, 2013

This study assesses the 3Ͳkyr paleoecology and sedimentary evolution of the Abrolhos carbonate sh... more This study assesses the 3Ͳkyr paleoecology and sedimentary evolution of the Abrolhos carbonate shelf, Bahia, Brazil, using a twoͲmeterͲlong core collected in a carbonate muddy sediment. The paleoecology was based on the distribution of benthic foraminifer functional groups associated with grain size, total organic carbon (TOC) and total nitrogen (TN), organic C/N and 13 C/ 12 C ratios. The results identified three biosedimentary units showing that symbiontͲbearing foraminifers (Peneroplis and Archaias) decrease in abundance. However, other small taxa (Miliolinella and Cornuspira) and stressͲtolerant genera (Bolivina, Elphidium and Ammonia) increase in abundance toward the core top. Grain size decreases toward the top of the core, suggesting a weakening of hydrodynamic winnowing toward recent time. The TOC and TN concentrations increase, and the C/N ratios decrease, suggesting an increase of marine productivity from nearby gobletͲshaped structures called "chapeirões". Changes in the benthic foraminifer community can be linked to the sedimentological and organic matter input, which are the result of climatic and oceanographic variations at different spatial and time scales, thus illustrating reduced potential to support symbiontͲbearing foraminifer communities to the end of the Holocene. A high Spearman correlation coefficient (0.74; p < 0.05) was noted for Peneroplis and Archaias (Group A). At the top of the sedimentary succession (Unit III), other small taxa dominated, of which Miliolinella

Several studies have shown that the Amazonia region has recorded intense and prolonged drought ev... more Several studies have shown that the Amazonia region has recorded intense and prolonged drought events during the middle Holocene and less intense and shorter during the upper Holocene when lake levels and forest biomass increased. Records of these events have been observed at various locations in soils and lake sediments. In this lapse time from 8000 cal BP, Taylor Dome ice core record (Antartica) showed an increase around 25 ppm of CO2 concentration. In this study, paleofires records were obtained through the charcoal particle fluxes analysis and the interpretation of the lake level were obtained trough the organic and mineralogical indicators in lacustrine sediments and soils from amazonian ecosystens. Analyses in lacustrine sediments cores were made at the following locations in Brazilian Amazon: Lagoa da Pata (AM), Humaitá (AM), Lago do Saci (PA), Carajás N4 (PA), Lago Comprido (PA) and Caracarana (RO), reservoirs sediments in an intense land use change region (Alta Floresta, MT...

Revista Brasileira de Cartografia

Esse trabalho ilustra as vantagens do uso de geotecnologias portáteis (notebook, GPS, SIG) e insu... more Esse trabalho ilustra as vantagens do uso de geotecnologias portáteis (notebook, GPS, SIG) e insumos distribuídos gratuitamente ou com baixo custo (Carta Geológica da CPRM, MDE SRTM, imagens orbitais ASTER e LANDSAT-7) no mapeamento em sentido amplo, e ao Mapeamento Geológico em particular. A área de estudo corresponde à carta geológica folha Volta Redonda, na escala 1:100.000, incluindo parte dos estados do Rio de Janeiro e São Paulo, Brasil. A área possui cobertura de mapeamento geológico consistente (SILVA et al., 2007) e de vários produtos de Sensoriamento Remoto. Um sistema com um receptor GPS integrado a um notebook foi montado e através das ferramentas de GIS disponíveis no ArcGis 9.2, da ESRI, otimizou-se a navegação, locação, visita e coleta de feições geológicas em campo, bem como a identificação de anomalias espectrais obtidas por técnicas de Processamento Digital de Imagens, especialmente pela Análise por Principais Componentes (APC), aplicadas às imagens de satélite. Es...

Radiocarbon, 2021

The vermetidae fossils of Petaloconchus varians, formed by calcium carbonate, associated with the... more The vermetidae fossils of Petaloconchus varians, formed by calcium carbonate, associated with their radiocarbon ages, are the most accurate indicators of paleo sea level due to their restricted occupation in the intertidal zone in the rocky shore. However, the recrystallization of minerals can affect these age calculations and, consequently, the interpretation of the data. The aim of this study is to present new indicators of paleo sea-level changes in Southeast Brazil for the last 6000 years contributing to fill the data gap for the late Holocene. The influence of the recrystallization process was successfully resolved using the CarDS protocol, enabling the separation of the original aragonite fraction by density, prior to radiocarbon dating. This avoids the rejuvenation of ages and ensures greater efficiency for data interpretation. Paleo sea-level indicators were able to show a progressive increase in sea level up to the transgressive maximum of 4.15 m in 3700 BP years, followed ...

Revista Brasileira de Cartografia, 2018

Revista Brasileira de Cartografia, 2016

Realidade Virtual e uma tecnologia de interface avancada entre o usuario e o sistema computaciona... more Realidade Virtual e uma tecnologia de interface avancada entre o usuario e o sistema computacional, com o objetivo de simular a realidade com imersao em 3D, atraves de tecnicas e equipamentos. Com base nestes conceitos foi desenvolvida a Metodologia SIGMA Vale, fruto de uma parceria entre Vale, Servico Geologico Britânico (BGS) e Coffey, para integracao de dados geologicos, geoquimicos, geofisicos, geotenicos e geograficos em uma interface de visualizacao avancada de Realidade Virtual (RV), com subsidios de geotecnologia (VRGIS), permitindo uma navegacao intuitiva, com interacao em tempo real, e possibilitando a imersao do usuario do sistema no modelo gerado atraves do uso de equipamentos de RV. O modelo gerado, quando visualizado em modo Desktop RV (computador ou notebook) ou em uma Sala de Realidade Virtual, permite a geovisualizacao integrada de dados de superficie (ortofotos, imagens de satelite, modelos digitais de terreno, mapas geologicos, estruturas geologicas, localizacao de...

Geosciences = Geociências

As trilhas são caminhos que conectam paisagens e pessoas. Neste trabalho apresentamos uma propost... more As trilhas são caminhos que conectam paisagens e pessoas. Neste trabalho apresentamos uma proposta de sistematização metodológica para uma abordagem geossistêmica da geodiversidade em trilhas da Mata Atlântica, articulando suas bases com os princípios da geoética e da interpretação ambiental visando contribuir para o atingimento dos Objetivos de Desenvolvimento Sustentável da Agenda 2030. Estudos sobre a geodiversidade, em uma perspectiva geoética, apontam para a necessidade de uma mudança de comportamento e de atitudes responsáveis dos geocientistas para com o Sistema Terra. Neste contexto, a interpretação ambiental constitui estratégia fundamental para a comunicação com a sociedade. A proposta é apresentada com base em três estudos de caso no Estado do Rio de Janeiro (Brasil): Caminho Darwin na Serra da Tiririca, Travessia Petrópolis-Teresópolis e Transcarioca. A partir de vivências e pesquisas científicas desenvolvidas, em sintonia com demandas dos gestores e usuários de trilhas ...

Geosciences = Geociências

O uso público de unidades de conservação através da promoção das trilhas tem se configurado em um... more O uso público de unidades de conservação através da promoção das trilhas tem se configurado em uma importante ferramenta de conservação da natureza. Em uma abordagem geossistêmica, a parte abiótica da natureza é conhecida como Geodiversidade que juntamente com a Bio e a Sociodiversidade compõem o Sistema Terra. Na conservação da natureza, a Biodiversidade ocupa papel de destaque. Dessa maneira, esta pesquisa tem por objetivo analisar a percepção da geodiversidade por usuários da Trilha Transcarioca no Rio de Janeiro visando contribuir para a sensibilização e consequente valorização da Geodiversidade. Para tal, foi aplicado questionário online com 16 perguntas no Google Forms e os dados processados e disponibilizados no Power BI. Os resultados indicam que a frequência diminuiu durante a pandemia, que poucos usuários foram guiados, que o trecho 25 é o mais realizado e o PNT é a UC mais visitada. O conceito Geodiversidade é conhecido por 86,7%, os mirantes são as paisagens mais represe...

Frontiers in Marine Science

Thermal stress is now considered the major recent cause of coral reef degradation; yet few studie... more Thermal stress is now considered the major recent cause of coral reef degradation; yet few studies have been conducted describing those effects on Southwestern Atlantic (SWA) reefs. The SWA represents a coral endemism hotspot with low-functional redundancy and therefore high extinction risk. Recent research has suggested a “thermal refuge” potential for SWA; however, evidence could suggest a different trend. We report herein an unprecedented coral mortality on the largest coastal Brazilian Marine Protected Area (MPA) following the worst thermal stress event since 1985. Degree Heating Week (DHW) values over 4.0 were observed for 107 days, averaging 8.70 for the period, with a maximum of 12.1. Average live coral cover was reduced by 18.1% while average turf algae cover increase by 19.3%. Mortality was highest for three coral species, with a mean mortality of 50.8% per transect for Millepora braziliensis, 32.6% for Mussismilia harttii and 16.6% for Millepora alcicornis. Our unique data...

Diversity

Mesophotic reefs are poorly known worldwide despite their great ecological relevance and manageme... more Mesophotic reefs are poorly known worldwide despite their great ecological relevance and management importance for coral reef conservation strategies. To aid in filling this gap, we conducted a pioneering, large-scale survey, covering a total of around 315 miles in length, in the largest Brazilian coastal Marine Protected Area (MPA) Costa dos Corais. From the digital bathymetry model (30 to 50 m depth) generated by a multibeam echo sounder, we selected areas of greater geomorphological diversity for a detailed investigative expedition of mesophotic ecosystems. Various sampling techniques were used: single-beam echo sounders for detailing the relief, a remotely operated underwater vehicle (ROV) for habitat type investigation, baited remote underwater video (BRUV) for collecting images of the fish community, and scuba diving to perform transects describing the benthic and fish community. We analyzed reef environments from 20 to 68 m deep. As a result, we present the mapping and geomor...

Science of The Total Environment, 2021

The Abrolhos bank is home of the richest coral reef system of the Southwestern Atlantic, where en... more The Abrolhos bank is home of the richest coral reef system of the Southwestern Atlantic, where endemic coral species are found. It has been reported that Abrolhos' corals are under intense stress due to increasing of Marine Heat Waves during the last decades. Additionally, anthropic interventions along the adjacent coastal regions are a factor of concern since they contribute to the increase in the sediment load and to organic debris input in the reef domain. In November 2015, the collapse of the Fundão mining tailings dam resulted in the release of approximately 50 million m3 of iron oxide and quartz-rich slurry into the Doce River. Aiming at using a fingerprint of the tailings and to assess the presence of traces of the Fundão dam material from this event on the Abrolhos bank, this work presents new 87Sr/86Sr and 143Nd/144Nd isotope ratios of marine suspended sediment samples collected between 2016 and 2020 from a network of sediment traps throughout the reef and complementary suspended material at sea . In parallel, we monitored meteo-oceanographic parameters and modeled surface marine currents as an attempt to identify the sediment transport between the Doce River mouth and Abrolhos bank. The r isotopes were used as provenance proxies based on the fact that minerals and rocks tend to have specific isotopic signatures reflecting their own geological derivation. In this context, the isotopic ratios of various potential regional sources for the sedimentation in Abrolhos bank were evaluated. Our monitoring and isotopic measurements indicate that Doce River signatures are detected at Abrolhos bank, following the seasonal Doce River discharge at sea. Isotopic signature of Doce River at Abrolhos bank was also observed during the austral winter (July-August) when cold fronts migrate at the Brazilian coast with higher frequency and energy.

Revista Brasileira de Geomorfologia, 2021

As variações do nível relativo do mar (VNRM) tiveram um papel importante na formação das planície... more As variações do nível relativo do mar (VNRM) tiveram um papel importante na formação das planícies costeiras fluminenses durante o Holoceno, sendo responsáveis pela construção de extensas feições deposicionais costeiras na Região dos Lagos. Modelos de reconstituição paleoambiental tridimensionais de VNRM são importantes para entender a evolução sedimentar costeira em ambientes formados por cordões litorâneos, lagunas, deltas, estuários, pântanos e ilhas barreiras, que são feições geomorfológicas comuns no litoral brasileiro. Objetiva-se desenvolver um modelo tridimensional de reconstituição paleoambiental na região da planície costeira de Cabo Frio, Rio de Janeiro. Como procedimento metodológico, realizou-se levantamento faciológico e análise sedimentológica em seis locais, em conjunto com análises de sensoriamento remoto. Os ambientes de sedimentação foram interpretados através de imagens de satélite e diante da correlação encontrada entre as análises sedimentológicas e geomorfológ...

Environmental Management, 2020

E. (2020). Methodological proposal for the inventory and assessment of geomorphosites: An integra... more E. (2020). Methodological proposal for the inventory and assessment of geomorphosites: An integrated approach focused on territorial management and geoconservation. Environmental Management.

Anais da Academia Brasileira de Ciencias

Interpretation of sea-level indicators is essential when studying paleo sea-level fluctuations du... more Interpretation of sea-level indicators is essential when studying paleo sea-level fluctuations during the Holocene. Sea-level indicators may have different origins, such as geological (beachrocks) and biological (vermetids and barnacles). In order to reconstruct paleo sea-level, it is necessary to attribute an indicative meaning to each sea-level indicator. This paper aims to discuss issues raised by Angulo et al. (2016) regarding to the sea-level fluctuations curve proposed by Castro et al. (2014) to the Rio de Janeiro State coast, Brazilian southeast. The key issue that deserves posing is that local or regional curves cannot be built based on large scale (global) RSL geophysical models even in places of steady crust like Brazil. Here, we put into question the relative sea-level fluctuation curve model proposed by Angulo et al. (2006, 2016) to the coast of Rio de Janeiro State and Pernambuco State. It is strengthened the proposal of using different origins indicators on RSL vertica...

Anais da Academia Brasileira de Ciências, 2014

The present paper aims to investigate the relative sea-level and the coastal evolution during the... more The present paper aims to investigate the relative sea-level and the coastal evolution during the Holocene in the Rio de Janeiro coastline, based on geological and biological indicators. Using topographic survey, excavation and coring, and 14C dating of these coastal deposits and beachrocks outcrops, we have reconstructed a sea-level curve for the Holocene. For the first time on the Brazilian coast it was identified a negative record of relative sea-level during Late Pleistocene and Early Holocene transition. After the transition, a relatively rapid increase of sea-level began. At approximately at 8500 cal yr BP, the sea-level was 0.5 m below the current level, was overtaken for the first time in the Holocene, at approximately 7500 cal yr BP. The maximum level of +2.5 m was reached between 4770 and 4490 cal yr BP. At the point of maximum transgression, the sea-level began a general behavior of lowering until the present. These results confirm other data already obtained elsewhere al...

Environmental Earth Sciences, 2015

A three-step sequential extraction procedure, which was based on the BCR method, was used to anal... more A three-step sequential extraction procedure, which was based on the BCR method, was used to analyse Guanabara Bay sediment samples to evaluate the potential mobility of some metals and metalloids. Zn and Cd were found to be the most labile metals because these were recovered in the first extraction stage and were associated with the non-residual fraction of the sediment. In contrast, Cr, Cu, Ni, and Hg were the least labile metals, and 62 to 84 % of the concentrations of these metals were found in the organic residual fraction of the sediment samples. The spatial distribution of the metal concentrations in Guanabara Bay led to the identification of various sources of contamination. The continental sources, which were related to Fe and Al, were distributed in the northern and central sectors, although lower concentrations were found in the mouths of the rivers that flow into the estuarine system of Guanabara Bay. The urban emission sources are related to the discharges of the São João de Merití River, which exhibit significant levels of Ba, Cd, Ni, Zn, and Hg. The São João de Merití River and harbour activities also show a predominance of Pb and Cu. The system formed by the Iguaçu River and the Sarapuí River is mainly characterised by V and Cr. The metals associated with biogeochemical processes, such as As and Mn, were found in the central sector of Guanabara Bay.

Continental Shelf Research, 2013

This study assesses the 3Ͳkyr paleoecology and sedimentary evolution of the Abrolhos carbonate sh... more This study assesses the 3Ͳkyr paleoecology and sedimentary evolution of the Abrolhos carbonate shelf, Bahia, Brazil, using a twoͲmeterͲlong core collected in a carbonate muddy sediment. The paleoecology was based on the distribution of benthic foraminifer functional groups associated with grain size, total organic carbon (TOC) and total nitrogen (TN), organic C/N and 13 C/ 12 C ratios. The results identified three biosedimentary units showing that symbiontͲbearing foraminifers (Peneroplis and Archaias) decrease in abundance. However, other small taxa (Miliolinella and Cornuspira) and stressͲtolerant genera (Bolivina, Elphidium and Ammonia) increase in abundance toward the core top. Grain size decreases toward the top of the core, suggesting a weakening of hydrodynamic winnowing toward recent time. The TOC and TN concentrations increase, and the C/N ratios decrease, suggesting an increase of marine productivity from nearby gobletͲshaped structures called "chapeirões". Changes in the benthic foraminifer community can be linked to the sedimentological and organic matter input, which are the result of climatic and oceanographic variations at different spatial and time scales, thus illustrating reduced potential to support symbiontͲbearing foraminifer communities to the end of the Holocene. A high Spearman correlation coefficient (0.74; p < 0.05) was noted for Peneroplis and Archaias (Group A). At the top of the sedimentary succession (Unit III), other small taxa dominated, of which Miliolinella

Several studies have shown that the Amazonia region has recorded intense and prolonged drought ev... more Several studies have shown that the Amazonia region has recorded intense and prolonged drought events during the middle Holocene and less intense and shorter during the upper Holocene when lake levels and forest biomass increased. Records of these events have been observed at various locations in soils and lake sediments. In this lapse time from 8000 cal BP, Taylor Dome ice core record (Antartica) showed an increase around 25 ppm of CO2 concentration. In this study, paleofires records were obtained through the charcoal particle fluxes analysis and the interpretation of the lake level were obtained trough the organic and mineralogical indicators in lacustrine sediments and soils from amazonian ecosystens. Analyses in lacustrine sediments cores were made at the following locations in Brazilian Amazon: Lagoa da Pata (AM), Humaitá (AM), Lago do Saci (PA), Carajás N4 (PA), Lago Comprido (PA) and Caracarana (RO), reservoirs sediments in an intense land use change region (Alta Floresta, MT...

Revista Brasileira de Cartografia

Esse trabalho ilustra as vantagens do uso de geotecnologias portáteis (notebook, GPS, SIG) e insu... more Esse trabalho ilustra as vantagens do uso de geotecnologias portáteis (notebook, GPS, SIG) e insumos distribuídos gratuitamente ou com baixo custo (Carta Geológica da CPRM, MDE SRTM, imagens orbitais ASTER e LANDSAT-7) no mapeamento em sentido amplo, e ao Mapeamento Geológico em particular. A área de estudo corresponde à carta geológica folha Volta Redonda, na escala 1:100.000, incluindo parte dos estados do Rio de Janeiro e São Paulo, Brasil. A área possui cobertura de mapeamento geológico consistente (SILVA et al., 2007) e de vários produtos de Sensoriamento Remoto. Um sistema com um receptor GPS integrado a um notebook foi montado e através das ferramentas de GIS disponíveis no ArcGis 9.2, da ESRI, otimizou-se a navegação, locação, visita e coleta de feições geológicas em campo, bem como a identificação de anomalias espectrais obtidas por técnicas de Processamento Digital de Imagens, especialmente pela Análise por Principais Componentes (APC), aplicadas às imagens de satélite. Es...

Radiocarbon, 2021

The vermetidae fossils of Petaloconchus varians, formed by calcium carbonate, associated with the... more The vermetidae fossils of Petaloconchus varians, formed by calcium carbonate, associated with their radiocarbon ages, are the most accurate indicators of paleo sea level due to their restricted occupation in the intertidal zone in the rocky shore. However, the recrystallization of minerals can affect these age calculations and, consequently, the interpretation of the data. The aim of this study is to present new indicators of paleo sea-level changes in Southeast Brazil for the last 6000 years contributing to fill the data gap for the late Holocene. The influence of the recrystallization process was successfully resolved using the CarDS protocol, enabling the separation of the original aragonite fraction by density, prior to radiocarbon dating. This avoids the rejuvenation of ages and ensures greater efficiency for data interpretation. Paleo sea-level indicators were able to show a progressive increase in sea level up to the transgressive maximum of 4.15 m in 3700 BP years, followed ...

Revista Brasileira de Cartografia, 2018

Revista Brasileira de Cartografia, 2016

Realidade Virtual e uma tecnologia de interface avancada entre o usuario e o sistema computaciona... more Realidade Virtual e uma tecnologia de interface avancada entre o usuario e o sistema computacional, com o objetivo de simular a realidade com imersao em 3D, atraves de tecnicas e equipamentos. Com base nestes conceitos foi desenvolvida a Metodologia SIGMA Vale, fruto de uma parceria entre Vale, Servico Geologico Britânico (BGS) e Coffey, para integracao de dados geologicos, geoquimicos, geofisicos, geotenicos e geograficos em uma interface de visualizacao avancada de Realidade Virtual (RV), com subsidios de geotecnologia (VRGIS), permitindo uma navegacao intuitiva, com interacao em tempo real, e possibilitando a imersao do usuario do sistema no modelo gerado atraves do uso de equipamentos de RV. O modelo gerado, quando visualizado em modo Desktop RV (computador ou notebook) ou em uma Sala de Realidade Virtual, permite a geovisualizacao integrada de dados de superficie (ortofotos, imagens de satelite, modelos digitais de terreno, mapas geologicos, estruturas geologicas, localizacao de...