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In this study, we examined the epiplastic microalgal community that developed on low-density polyethylene (LD-PE) plastic debris found in two distinct regions of the Monastir Bay (Tunisia): the coast exposed to anthropogenic discharges and the open sea in front of the Kuriat Islands. The analysis of trace elements accumulated in the plastisphere was also carried out. The collected plastispheres were predominantly composed of cyanobacteria. Chlorophytes and diatoms were also found. Euglenophyceae was also recorded but with comparatively low relative abundance (RA), whereas dinoflagellates were almost absent. The diatom showed a high diversity of species (25 species). Potentially harmful microalgae (PHM) were more abundant in the plastisphere than in seawater at all stations. For all coastal area stations, most of the PHM colonizing the plastisphere are potentially harmful cyanobacteria. For S1 (offshore station), the PHM community profile was characterized by the dominance of potentially harmful diatoms. The main potentially harmful cyanobacterium identified on the plastisphere was Phormidium sp. Pseudo-nitzschia spp. was the only potentially harmful diatom observed on the plastisphere. Accumulation of trace elements in plastisphere was higher than that in sediments. Trace elements in plastisphere are ranked with a very high contamination factor at all sites, according to the sequence Pb > Cu > Cd > Ni > Zn. The accumulation of trace elements in the plastisphere is highest near areas with harbor and industrial activities and the urban rejects zone.

portuguesO Complexo Pedra Branca (CPB) esta localizado na zona oeste da cidade do Rio de Janeiro (SE Brasil) e esta inserido tectonicamente no Dominio Costeiro, pertencente ao Terreno Oriental da Faixa Ribeira Central. Os litotipos que formam o CPB foram gerados em eventos relacionados a Orogenese Brasiliana (~600 Ma), abrigando assim rochas pre- a pos-colisionais. Estudos anteriores de corpos graniticos pos-tectonicos na Faixa Ribeira revelaram que o magmatismo ocorreu em dois pulsos distintos, com intervalo de aproximadamente 30 Ma entre eles. O presente estudo analisou 9 amostras do CPB, atraves dos metodos geocronologicos U-Pb e Lu-Hf via LA-ICP-MC-MS, referentes as litologias granito Pedra Branca e granito Favela, possiveis representantes do pulso mais antigo e mais jovem, respectivamente, buscando melhorar a compreensao do magmatismo pos-tectonico na regiao. As medias das idades encontradas para o granito Pedra Branca (509 ± 5 Ma) e granito Favela (489 ± 6 Ma) corroboraram com os valores descritos na literatura e indicaram que o magmatismo ocorrido no CPB teve origem na forma de pulsos progressivos, porem num intervalo de tempo menor (~20 Ma) do que foi anteriormente determinado. O indicador petrogenetico eHf indicou participacao de fontes crustais e mantelicas, dando carater bimodal ao magmatismo registrado no CPB EnglishThe Pedra Branca Complex is located at the western region of the Rio de Janeiro city (SE Brazil). Tectonically it is inserted in the Coastal Domain, which is part of the central segment of the Ribeira Belt. The lithologies that formed this rocky complex were generated in events related to the Brasiliano Orogeny (~ 600 Ma), thus contains pre- to- post-collisional rocks. Previous studies on post-tectonic granite bodies belonging to Ribeira belt revealed that the magmatism occurred in two distinct pulses, with an interval of approximately ~ 30 Ma between them. The present study analyzed 9 CPB samples, using the U-Pb and Lu-Hf through LA-ICP-MC-MS geochronological methods, with focus on the Pedra Branca granite and Favela granite, which may represent the older and the younger pulses respectively, in order to improve the understanding of the post-tectonic magmatism in the area. The average ages found for the Pedra Branca (509 ± 5 Ma) and Favela (489 ± 6 Ma) granites confirm the previously described ages in the literature. However, they indicate that the magmatism in CPB occurred in the form of progressive pulses, with an interval between both events of ~ 20 Ma, that is, less than what was previously estimated (of ~ 30 Ma). In addition, the petrogenetic indicator eHf indicated the participation of crustal and mantle sources, which gives a bimodal character to the magmatism registered in the CPB

A Baía de Guanabara, um dos mais importantes sistemas costeiros do sudeste brasileiro, com os seus primeiros rasgos estruturais durante o pré-cambriano e instalação definitiva durante o Cenozoico, tem vindo a ser modelada por processos relacionados com alterações climáticas e mais recentemente pela forte atividade antrópica, na região. Este trabalho pretende efetuar uma síntese de registros sedimentares históricos relacionados com a ação antrópica no entrono da Baía de Guanabara e definir o início do Antropoceno neste sistema costeiro.Em adição, os resultados desta investigação permitem a divisão do Antropoceno em quatro periodos de sedimentação na Bia da Guanabara.A documentação e os dados analisados permitem considerar que a camada sedimentar que marca o início do Antropoceno, na Baía de Guanabara foi depositada em 1502 (Ano Domine), no decurso da “Pequena Idade do Gelo”, ano a partir do qual teve início o processo de ocupação colonialista dos Portugueses. Esforços de ocupação e defesa local após o descobrimento, em 1502, culminou com a criação da cidade do Rio de Janeiro, em 1565.A partir de então observam-se no registro sedimentar a redução granulométrica dos sedimento, em plena Pequena Idade do Gelo, aumento progressivo dos teores de matéria orgânica mudanças polínicas resultantes do desmatamento para extração do pau-brasil, para a cultura da cana-de-açúcar, que se estendeu dos séculos XVI ao XIX, e do café nos séculos XVIII e XIX. De meados do séc. XVIII ao início do séc. XX inicia o ciclo da mineração, seguida do começo do ciclo da industrialização e principia de forma incipiente a poluição danosa na Baía de Guanabara. O desenvolvimento industrial, a partir da invenção da máquina a vapor, associado à necessidade de matéria-prima, conseguida a baixo custo nos países colonizados à época, marcou a segunda fase do Antropoceno na Baía de Guanabara, a partir de meados do século XVIII e que terá durado até ao início do século XX. Esta fase é identificada em registros sedimentares onde ocorre aumento expressivo de metais.Início do séc. XX ao início dos anos 50 a alteração de mais de 10 Km da orla ocidental da baía próxima a desembocadura causa a alteração do padrão hidrodinâmico dando lugar a um aumento acentuado da acumulação de sedimentos finos em vastas áreas da Baía de GuanabaraA quarta fase do Antropoceno, após meados do século XX, teve lugar num cenário de grande crescimento demográfico e industrial. A Baía de Guanabara passou a recolher o excedente sedimentar provocado pelas intervenções antrópicas acrescido do aumento dos resíduos domésticos (lixo em geral e esgoto) e industriais (óleo, metais pesados, substâncias tóxicas e carga orgânica) oriundos da expansão das atividades no seu entorno, acarretando a aceleração da perda de sua área de superfície e de profundidade.

This work studies the Buracica Stage (Barremian, Early Cretaceous) in the Reconcavo Basin, Bahia State (N.E. Brazil), comprising the Sao Sebastiao and Pojuca formations, from the analysis of 143 well logs and outcrop records. The Reconcavo Basin is a rift basin associated with the beginning of the South Atlantic Ocean. The basin started with very slow subsidence rates, leading to the formation of shallow lakes and the deposition of shales and sandstones, which compose the Brotas Group; later, subsidence accelerated and gave rise to the formation of a deep lake. Then the deep lake basin was filled throughout six depositional episodes making up the so-called Reconcavo tectonic sequence. Previous studies divided the last depositional event of Reconcavo Basin into seven fourth-order sequences concerning the Marker Bed “1” to the Marker Bed “F” stratigraphic interval. Sequence boundaries were marked by sharp flooding surfaces related to the transgression of lacustrine system due to rapid tectonic subsidence and generation of accommodation. In turn, the sequences are divided into three systems tracts: the lake lowstand systems tract, the transgressive systems tract and the lake highstand systems tract. The maximum flood surface of the sequences generally coincides with the stratigraphic marker “B” to “F”. Depositional systems like braided-fluvial plus eolian dunes, meandering-fluvial, deltaic, or moving-lake and near-shore deposits were identified in this work. Isopach, isolith and sand percentage maps indicate depocentre and source area distribution like the previous Aratu Stage. The primary sources of the sediments are located in the west and north areas; only from the third sequence, an eastern source could be described conspicuously. The fourth-order cyclicity is controlled by lake level changes, related to climatic factors (Milankovitch cycles). The results from the studies of cyclicity confirm the proposed stratigraphic model. They indicate 43,000 years for each fourth-order sequence and 150,000 years for the third-order sequences, which provide an accumulation rate of 1200 mm per 1000 years for the studied interval.

This work analyzes the results of the SP2 core (50.30 m length) collected in the coastal plain of Sepetiba Bay (SB; SE Brazil), 2 km away from the Guandu River mouth (latitude 22° 55′S, longitude 43° 46′W). It aims to study the influence of the Holocene relative sea level (RSL) on the coastal plain of SB. After description, the SP2 core was sampled at every 5 cm for grain size, geochemical, mineralogical and foraminiferal analyses. Four radiocarbon dates obtained in the first 18 m were modulated with Bayesian statistics. The SP2 core is composed of basement rocks, gneisses (50.30–43.80 m); river sediments (43.80–21.00 m) up to about ≈ 5.0 kyr BP; a sediment package marked by sudden textural and compositional changes, accumulated between ≈ 5.0 and 4.7 kyr BP; muddy sediments deposited between 4.7 and 0.8 kyr BP (18.80–3.35 m) with intercalations of sandy levels; an upper part of disturbed embankment sediments used for the implantation of Santa Cruz Thermoelectric Power Plant. The fluvial sands accumulated before ≈ 5.0 kyr BP were deposited before the maximum Mid-Holocene relative sea level. They were probably eroded and transported by the drainage network of the N region of SB, namely by the Guandu River. Between ≈ 4.5 and 3.5 kyr BP, the foraminiferal abundance and assemblage composition indicate that the study site was a shallow marine environment, due to the Mid-Holocene relative sea-level highstands (MHSLH). Between ≈ 3.5 and 3.0 kyr BP, the sediment accumulation rate (SAR) was the lowest of the last ≈ 5 kyr BP and the study site was exposed to subaerial weathering processes, in a scenario of the relative sea-level drop. A new phase of marine influence was recorded between ≈ 3.0 and 1.9 kyr BP, associated with the highest SAR of this record, up to ≈ 27.4 m/kyr BP. Between ≈ 1.9 and 1.8 kyr BP, the study site was under subaerial weathering processes. Since then the SAR reduced significantly to a mean value of ≈ 4.5 m/kyr and, between ≈ 1.8 and 0.8 kyr BP, the study site was again under the marine influence. Foraminifera were not found, after ≈ 0.8 kyr BP, in the SP2 core. However, the occurrence of a shallow marine environment was identified in another core, between ≈ 1.4 and 0.35 kyr BP, in the Guaratiba Mangrove, NE of SB. The results of the SP2 core suggest that MHSLH left a striking record in the study area, although some of the identified environmental changes are probably related to adjustments of the lower course of Guandu River and tidal channels and variations in the configuration of sandy littoral strands. The growth of a barrier–island system, the Marambaia barrier island, since the last ≈ 8–7.5 kyr BP may also have induced changes in the study area.

Living (stained) benthic foraminifera from the continental shelf of Santos Basin, southeastern Brazilian continental margin, were investigated to understand their distribution patterns and their relationship with chlorophyll-a and particulate organic matter contents. Sediments were collected from 44 to 203 m of water depth. This study analysis benthic foraminifera and abiotic data, including grain size, total organic matter, distributions of ocean chlorophyll-a and particulate organic matter. Foraminiferal diversity and richness were positively correlated to the chlorophyll-a and particulate organic carbon contents. Stations located on the southern portion of the study area and sampled during austral winter are probably under the seasonal influence of the Brazilian Coastal Current intrusion, and Rio de la Plata and Lagoa dos Patos plumes. Ammonia rolshauseni, Textularia? sp. and Gyroidina umbonata are present within the foraminifera assemblages at these stations. On the other hand, stations in the north, are characterized by the presence of Uvigerina peregrina, Quinqueloculina atlantica, Hanzawaia concentrica and Bulimina marginata, and they are influence of Cabo Frio’s southward-moving plume.

The Araçuaí and Ribeira orogens have been studied for decades, and recently, these two orogens were described as the Araçuaí–Ribeira Orogen System. Despite much work investigating this orogenic system, some issues, such as the connection between the two orogens, are still not fully understood. This work aimed to present unpublished Lu-Hf data for the Santa Angélica Intrusive Complex (SAIC) and for the host rocks that are part of the Rio Negro magmatic arc, as well as to present U-Pb ages for these rocks, thus contributing to the understanding of the geological processes that acted in the transition zone between the Araçuaí and Ribeira orogens. Two samples were collected corresponding to the magmatic arc and six samples from the Santa Angélica Intrusive Complex. The zircon grains were separated from the samples and subjected to geochronological (U-Pb) and isotopic (Lu-Hf) analysis by laser ablation-induced coupled plasma mass spectrometry (LA-ICP-MS). The geochronological data for the host rocks indicate a crystallization age of ca. 595 Ma. In contrast, the Hf isotopic data point to at least two magmatic sources, one crust, and one mantle. The geochronological data obtained for the SAIC rocks show three age peaks. The first peak (537 ± 5 Ma) coincides with the process of crustal anatexis and possibly marks the beginning of the generation of magmas associated with post-collisional magmatism. The second peak (510 ± 5 Ma) registers the apex of crystallization of the SAIC, and the third peak of ages (488 ± 7 Ma) marks the upper limit of the magmatism in the SAIC. The SAIC isotopic data point to at least two crustal components and a mantle component (juvenile).

The main objective of this work is to analyze the consequences of eutrophication in benthic meiofaunal organisms (foraminifera) in an internal area of Sepetiba Bay (State of Rio de Janeiro, SE, Brazil). This study is interesting because, at the studied site, the sediments corresponding to the period of greatest accumulation of organic matter were not contaminated by metals, although Sepetiba Bay has areas known to be polluted by this type of contaminants. Thus, in this study, it was possible to consider only the impact caused by eutrophication. In the SP6 core, collected in the Sepetiba Bay internal area and studied in this work, textural, geochemical (concentration of chemical elements; 210 Pb and 137 Cs; radiocarbon data) and foraminifera were analyzed in a muddy section, with a few intercalations of sandy layers. The sediments of the analyzed section were deposited in the last ≈2,350 BP years. The concentrations of Al, Cd, Co, Fe, Mn, Ni, Pb, Sn, Ti, V and Zn are higher at the base of the core and decrease towards the top. The contents of TOC, P and Zr have inverse paterns. The ratios of these elements to their background value have similar patterns. However, previous studies have recognized that during the twentieth century Cd, Zn, Cr and Pb concentrations increased in several areas of Sepetiba Bay, mainly due to industrial activity. The area where this core was collected may have been dredged. Radiocarbon ages suggest a loss of ≈2000 years of sedimentary registration, marked by an unconformity at a depth of 126 cm, probably caused by dredging. A new sedimentary sequence unpolluted by metals but highly enriched in organic matter was deposited on the surface of that discontinuity. Foraminifera were quite abundants in the lower section (240-126 cm; between ≈2,400-2,090 years BP, execept in the sandy layers), corresponding to sediment deposition before dredging. After dredging, the accumulation of very fine-grained sediments rich in organic matter generated eutrophication phenomena, which caused a drastic reduction in the abundance and diversity of these organisms. This work testifies the effect of eutrophication on meiofaunal organisms. Although some coastal foraminifer species tolerate harmful effects caused by eutrophication, it is recognized that the impact has been so negative that even these species occur with reduced abundance in the study area. IMPACTO DA EUTROFICACAO EM FORAMINIFEROS BENTONICOS NA BAIA DE SEPETIBA (ESTADO DO RIO DE JANEIRO, SE BRASIL) Resumo O principal objetivo deste trabalho e analisar as consequencias da eutrofizacao em organismos meiofaunais bentonicos (foraminiferos) em uma area interna da Baia de Sepetiba (Estado do Rio de Janeiro, SE, Brasil). Este estudo e interessante porque, no local estudado, os sedimentos correspondentes ao periodo de maior acumulacao de materia orgânica, nao estavam contaminados por metais, apesar da Baia de Sepetiba ter areas reconhecidamente poluidas por este tipo de contaminantes. Assim neste estudo foi possivel considerar apenas o impacto causado pela eutrofizacao. No testemunho SP6, coletado na area interna da Baia de Sepetiba e estudado neste trabalho, foram analisados dados texturais, geoquimicos (concentracao de elementos quimicos; 210 Pb e 137 Cs; dados de radiocarbono) e foraminiferos numa seccao lamosa, com intercalacoes de camadas arenosas. Os sedimentos da secao analisada foram depositados nos ultimos 2.350 anos BP. As concentracoes de Al, Cd, Co, Fe, Mn, Ni, Pb, Sn, Ti, V e Zn sao mais elevadas na base do testemunho e diminuem em direcao ao topo. O conteudo de TOC, P e Zr possui padroes inversos. As razoes destes elementos com o respectivo valor de fundo possuem padroes semelhantes. Porem, estudos anteriores reconheceram em varias areas da Baia de Sepetiba um aumento das concentracoes de Cd, Zn, Cr e Pb durante o seculo XX, principalmente devido a atividade industrial. A area onde foi coletado este testemunho podera ter sido dragada. As idades de radiocarbono sugerem uma perda de aproximadamente 2000 anos de registro sedimentar, marcada por uma inconformidade a 126 cm de profundidade, causada provavelmente por dragagem. Uma nova sequencia sedimentar nao poluida por metais, mas bastante enriquecida em materia orgânica foi depositada sobre a superficie da descontinuidade. Os foraminiferos eram relativamente abundantes na secao inferior (240-126 cm; entre ≈2.400-2.090 anos BP), correspondente a deposicao de sedimentos antes da dragagem. Apos a dragagem, a acumulacao de sedimentos muito finos e ricos em materia orgânica, gerou fenomenos de eutrofizacao, que terao causado uma reducao drastica da abundância e diversidade destes organismos. Este trabalho testemunha o efeito da eutrofizacao em organismos meiofaunais. Apesar de algumas especies de foraminiferos costeiros tolerarem efeitos nefastos causados pela eutrofizacao, reconhece-se que o impacto foi tao negativo que mesmo estas especies ocorrem com abundância reduzida na area estudada. Palavras-chave: Area Costeira. Registro Paleoambiental. Impacto Antropico. Meiofauna, Abordagem Multiproxy.

The present research was developed aiming to study macroscopically the effects of karstification that, over the time, affected significantly the carbonated massif in Khózuè, Cheringoma Plateau (Mozambique). The research was carried out from a field study (collecting samples and photos) for a period of one week, in May of 2017, in Khózuè. During the field work, evidences found in nature were recorded as well as, the mode of occurrence of several structures (caves, dolines and speleothems). The karstification in the study area that occurs in the Cheringoma Formation (from Middle Eocene) was greatly conditioned by fractures which influenced the process and formation of caves and dolines. These structures tended to follow morphological patterns depending on guide fractures orientation allied to their genesis and creating, in certain cases, dolines with a cross morphology. In addition to caves and dolines, karstic activity in the Cheringoma Formation massif also created other structures, especially speleothems, which are not widespread, and also preservation/fossilization of plant remains by mineralization. Chemical weathering chemical weathering, but especially internal geodynamic phenomena transformed the Khózuè massif one karst region with peculiar characteristics. ResumoEste trabalho foi desenvolvido com o objetivo de estudar macroscopicamente os efeitos da carstificação que, com o tempo, afetaram significativamente o maciço carbonatado de Khózuè, no platô de Cheringoma (Moçambique). A pesquisa foi realizada a partir de um estudo de campo (coleta de amostras e fotografias), em 2017, em Khózuè. Durante as atividades de campo, foram analisadas as estruturas encontradas na área de estudo, tal como a ocorrência de falhas, cavernas, dolinas e espeleotemas. A carstificação na área de estudo, associada á Formação Cheringoma (do Eoceno Médio), foi muito influenciada por falhas. Estas favoreceram a formação de cavernas e dolinas. Essas estruturas tenderam a assumir padrões morfológicos condicionados pela orientação de falhas. Em certos casos, as falhas deram origem por exemplo a dolinas em forma de cruz. Além de cavernas e dolinas, a atividade cárstica no maciço da Formação Cheringoma deu lugar também a outras estruturas, como por exemplo, espeleotemas encontrados em apenas alguns locais e a processos de preservação/fossilização por mineralização de restos vegetais. A meteorização química, mas sobretudo fenómenos de geodinâmica interna transformaram o maciço calcário de Khózuè uma região cárstica com características peculiares. Palavras-chave: Karstificação. Cavernas. Dolinas. Espeleotemas. Fossilização. Fraturas.

The Petroleum Terminal Pipeline “Dutos e Terminais do Centro Sul (DTCS)” is one of the largest petroleum terminals in Brazil. To assess wastewater treatment efficiency of the DTCS and to evaluate the contamination by potentially toxic elements (PTE) of sediments, ten sampling points were studied near the riser output of the submarine outfall in the summer of 2005, 2006 and 2007, and ten sampling points were studied along the São Sebastião Channel (CSS). All data were above the standards required by the Brazilian salt water/brackish Water Directives (CONAMA Resolution 454/2012). However, the sediments near the submarine outfall were enriched by As and Cu, with concentrations exceeding the threshold effect level (TEL). In 2005 and 2006, the concentrations of Ba, Sr, Ni and Pb exceeded the values established by TEL in some places. Concentrations of As were 69 times higher than that measured in the background station. In 2007, all the analyzed metals almost doubled the concentrations of that found in 2005. High concentrations of PTE in the sediments, namely Ba and As, are a source of contamination that should be considered for the water quality management planning of the DTCS system. Avaliação da Contaminação por Elementos Químicos Potencialmente Tóxicos (PTE) dos Sedimentos da Região do Terminal Petrolífero “Dutos e Terminais do Centro Sul (DTCS)”, SP, Brasil ResumoO Terminal Petrolífero “Dutos e Terminais do Centro Sul (DTCS)”, SP, Brasil é um dos maiores terminais de petróleo do Brasil. Para avaliar a eficiência do tratamento de águas residuais do DTCS e estimar a contaminação por elementos potencialmente tóxicos (PTE) dos sedimentos, foram estudados dez pontos de amostragem perto da saída do ducto submarino no verão de 2005, 2006 e 2007 e dez pontos de amostragem ao longo do Canal de São Sebastião (CSS). Todos os dados estavam acima dos padrões exigidos pelas Diretrizes Brasileiras para Águas Salgadas/Salobras (Resolução CONAMA 454/2012). No entanto, os sedimentos perto do exutor submarino estavam enriquecidos por As e Cu, tendo as concentrações excedido o nível limiar de efeito (TEL; the threshold effect level). Em 2005 e 2006, as concentrações de Ba, Sr, Ni e Pb ultrapassaram os valores estabelecidos para o TEL. As concentrações de As foram 69 vezes superiores às medidas na estação de fundo. Em 2007, todos os PTE tinham quase duplicado as concentrações de 2005. As altas concentrações de PTE nos sedimentos, nomeadamente Ba e As, são uma fonte de contaminação que deve ser considerada no planejamento da gestão da qualidade da água do sistema DTCS. Palavras-chaves: Elementos Químicos Potencialmente Tóxicos. Sedimentos. Emissários Submarinos. Efluentes Petroquímicos.

The coastal areas, the most populated regions in the world, are those which have undergone the greatest human influence. In Brazilian southeastern coast, the region around Guanabara Bay (GB) is one of the most densely populated, with large cities, such as Rio de Janeiro and Niteroi, and is highly industrialized. Due to anthropic activities tones of effluents, waste and sewage is daily released in GB. Despite, several works have been performed aiming to study the current and past human influence in GB, the sources of pollutants that have impacted this bay since the late nineteenth century. This work is a new contribution aiming to identify the main sources of pollution in the northern/northeast region of GB using stable isotopes of lead (Pb) and metal concentrations during the last decades. It analyses results obtained along the core T3 collected in the northeast region of Guanabara Bay, near the Guapimirim Environmental Protected Area (known as Apa de Guapimirim), a mangrove fringe. Twenty-two sediment samples collected along this core were submitted to grain size, total organic carbon content (TOC), elemental concentrations (Ag, Ca, Cu, P, Pb, S and Zn) and stable isotopes of lead (Pb) analyses. The sediment accumulation rate was estimated by 210 Pb. Results of core T3 were compared with similar data acquired in core T8, collected in Guanabara Bay, at north of Paqueta island. The comparison of the geochemical results allowed to verify that both cores recorded the same reality. Previous works have shown that the northern/northeast region of Guanabara Bay is low polluted by metals, however, since the ≈1950 a marked increase in eutrophication and metal contamination and another noticeable pulse after ≈1970, were recorded in both cores studied in this work. The 206 Pb/ 207 Pb values suggest that the main source of pollutants to northern/northeast region of GB since the second half of the 20 th century have been related to deforestation and landfill and embankment engineering works preformed around the GB, in addition to mineral products applied in industrial goods, as well as oil, agricultural and organic loads. FONTES DE POLUENTES NA AREA NORTE / NORDESTE DA BAIA DE GUANABARA (SE, BRASIL), DESDE O SECULO XIX, COM BASE EM ISOTOPOS DE CHUMBO E CONCENTRACOES DE METAIS Resumo As areas costeiras, as mais populosas do mundo, sao as que tem recebido a maior influencia humana. No litoral sudeste brasileiro, a regiao em torno da Baia de Guanabara (GB), uma das mais densamente povoadas, com grandes cidades, como Rio de Janeiro e Niteroi, e altamente industrializada. Devido as atividades antropicas toneladas de efluentes, residuos e esgoto sao liberados diariamente na GB. Apesar de varios trabalhos terem sido realizados com o objetivo de estudar a influencia humana atual e passada na GB, nao se sabe quais tem sido as fontes de poluentes mais impactantes nesta baia desde o final do seculo XIX. Assim, este trabalho tem como principal objetivo identificar as principais fontes de poluicao na regiao norte / nordeste da GB usando isotopos estaveis de chumbo (Pb) e concentracoes de metais nas ultimas decadas. Analisa os resultados obtidos ao longo do testemunho T3, coletado na regiao nordeste da Baia de Guanabara, proximo a Area Ambiental Protegida de Guapimirim (conhecida como Apa de Guapimirim), uma orla de mangue. Vinte e duas amostras de sedimentos coletadas ao longo deste testemunho foram submetidas a analises granulometricas, teor de carbono orgânico total (COT), concentracoes elementares (Ag, Ca, Cu, P, Pb, S e Zn) e isotopos estaveis de chumbo (Pb). A taxa de acumulacao de sedimentos foi estimada com Pb 210 . Os resultados do testemunho T3 foram comparados com dados semelhantes adquiridos no testemunho T8, coletado na Baia de Guanabara, a norte da ilha de Paqueta. A comparacao dos resultados geoquimicos permitiu verificar que os dois testemunhos registram a mesma realidade. Trabalhos anteriores mostraram que a regiao norte / nordeste da Baia de Guanabara e pouco poluida por metais, no entanto, observou-se nos dois testemunhos que desde 1950 aumentou acentuadamente a eutrofizacao e a concentracao de metais tendo ocorrido um outro pulso de contaminacao depois de 1970. Os valores de 206 Pb / 207 Pb sugerem que as principais fontes de poluentes na regiao norte / nordeste da GB, desde a segunda metade do seculo 20, estiveram relacionadas com o desmatamento e aterros em torno da GB, alem de minerais aplicados em produtos industrias, e ainda petroleo, produtos aplicados na agricultura e materia orgânica. Palavras-chave: Concentracao de metais. Isotopos de Pb. Contaminacao. Fontes de poluicao. Litoral. Registro antropogenico.

This work analyses lead concentrations and isotope ratios 204 Pb, 206 Pb, 207 Pb, 208 Pb, determined by leaching and total dissolution techniques from surface bottom sediment samples collected in the western sector of Sepetiba Bay, Rio de Janeiro (SE Brazil). The main aim of this work was to identify possible sources of Pb, particularly those related to anthropogenic activities for the study area located in the external region of this bay. Isotope ratios of 206 Pb, 207 Pb ranged from 1.160 to 1.259 for the total dissolution technique and from 1.175 to 1.188 for the leaching technique. The Pb isotope signature of the surface sediments of the western sector of Sepetiba Bay were compared with that obtained in other studies performed in Sepetiba Bay, including records of pre- and pos-industrial activity, and in other Brazilian regions. The isotope signature of the analyzed sediments in the western sector of Sepetiba Bay is similar to that obtained in previous works realized in the eastern and northeastern internal region of this bay which is under strong urbanization and industrial pressure. The results of Pb isotope signature obtained by the integrated use of total dissolution and leaching techniques allowed to trace the presence of sediments dredged from highly contaminated areas located in the eastern and north-eastern internal region of Sepetiba Bay probably as a consequence of dredging activities and natural processes of sediment dispersion. IMPACTOS ANTROPOGENICOS NO SETOR OESTE DA BAIA DE SEPETIBA (SE DO BRASIL) ACESSADOS PELA COMPOSICAO ISOTOPICA DE PB DE SEDIMENTOS SUPERFICIAIS Resumo Este trabalho analisa as concentracoes de chumbo (Pb) e isotopos de Pb ( 204 Pb, 206Pb, 207 Pb, 208 Pb) determinados por tecnicas de lixiviacao e dissolucao total de amostras de sedimentos de fundo, coletadas no setor oeste (regiao externa) da Baia de Sepetiba, no Rio de Janeiro (SE Brasil). O principal objetivo deste trabalho foi identificar possiveis fontes de Pb, principalmente aquelas relacionadas a atividades antropogenicas na area de estudo. A assinatura do isotopo Pb dos sedimentos analisados foi comparada com os dados obtidos em outros estudos realizados na Baia de Sepetiba e em outras regioes brasileiras, incluindo registros de atividade pre e pos-industrial. Na regiao externa da Baia de Sepetiba, os valores de 206 Pb/ 207 Pb variaram de 1.160 a 1.259 para a tecnica de dissolucao total e de 1.175 a 1.188 para a tecnica de lixiviacao. A assinatura isotopica dos sedimentos analisados e semelhante a obtida em trabalhos anteriores realizados na regiao interna leste e nordeste desta baia, que esta sob forte influencia da urbanizacao e pressao industrial. Os resultados da assinatura dos isotopos de Pb obtidos pelo uso integrado das tecnicas de dissolucao total e lixiviacao permitiram rastrear, no setor oeste (regiao externa) da Baia de Sepetiba, a presenca de sedimentos provinientes de areas altamente contaminadas localizadas na regiao interna leste e nordeste da baia de Sepetiba, provavelmente como consequencia das atividades de dragagem e processos naturais de dispersao de sedimentos. Palavras-chave: Isotopos de Pb. Geoquimica. Atividades antropogenicas. Fonte de sedimentos. Impacto de dragagem. Litoral.

Guanabara Bay (southeastern Brazil) is located in the metropolitan region of the Rio de Janeiro State and is being affected by high levels of anthropization. This work analyzes not only the concentrations of potentially toxic elements (PTEs), but also Pb stable isotopes to trace possible anthropogenic and natural sources of pollutants in the northern region of Guanabara Bay and the Suruí and Magé rivers. The Governador Island Channel, the regions to the north of Governador Island, north and west of Paquetá Island, and the Magé coast are most affected by PTEs. In the study area, high PTE concentrations result from both natural and anthropogenic sources. The main sources of metals include municipal solid waste incineration, atmospheric aerosols, and ore lead tailings, as indicated by Pb isotopes. This work shows that Pb stable isotopes, associated with metal contamination, can improve the assessment of estuarine environment quality.

The section between the 7 and 11 electric markers in the Aratu Stage of the Reconcavo Basin (Lower Cretaceous) has been studied in order to perform a stratigraphic analysis. This section bear reservoir rocks known as Imbe, Cambuqui and Miranga sandstones. It produces petroleum in fields like Miranga, Aracas, Taquipe, Miranga Norte and Imbe. The isopach map showed a general trend of increased subsidence for south and southeast. A series of structural lows surround the platform region known as Quirico High. Southwestward, the Taquipe Canyon is an indication of the lake deepening in that region. In terms of depositional systems, it was interpreted that the Aratu Stage presented a river-dominated deltaic system all over its depositional history. In the proximal regions, located to the north and northwest, the main facies belong to the fluvial and delta plain associations and to the delta front and prodelta in the most distal system. The isolithic map and the sand percentage map indicates a main axial sand distribution. The main sedimentary inflow comes from north and northwest. Near the southeastern faulted border there is a slight contribution from the alluvial fans attached to the Salvador fault. As a natural consequence, the stratigraphic sections showed a decrease of sand south and southeastward as well as the Spontaneous Potential (SP) logs indicate a progressive change from fluvial (normal bell shapes) to deltaic patterns (inverted bell shapes). The sedimentary cyclicity is strongly depicted in the Aratu section. Part of it can be observed in resistivity and SP logs, where auto-correlation can be obtained. Peaks in the resistivity logs indicate lag deposits due to periodic lake flooding. The resistivity value, as a function of the thickness of ostracodal and fish remains calciferous sandstones and shales, allows to separate several orders of peaks (four to six orders). Conventional cyclicity analyses indicate clearly an orbital control due to precession and axial obliquity. The calculated sedimentation ratio is 60 cm/1000 years, and the time interval of 1.44 Ma for deposition of the entire section. ANALISE ESTRATIGRAFICA DO ANDAR ARATU (CRETACIO INFERIOR), BACIA RECONCAVO (BRASIL), COM ROCHAS RESERVATORIO DE HIDROCARBONETOS Este trabalho efetua uma analise estratigrafica da secao entre os marcos eletricos 7 e 11, no Andar Aratu, da Bacia do Reconcavo (Cretaceo Inferior). Esta secao possui rochas reservatorio conhecidas como arenitos de Imbe, Cambuqui e Miranga. Produz petroleo em campos como Miranga, Aracas, Taquipe, Miranga Norte e Imbe. O mapa de isopacas mostrou uma tendencia geral de aumento da subsidencia para o sul e sudeste. Uma serie de baixos estruturais cercam a regiao da plataforma conhecida como a elevacao Quirico. A sudoeste, o canyon de Taquipe constitui uma indicacao do aprofundamento do lago naquela regiao. Os dados obtidos indicam que o Andar Aratu apresentou um sistema deltaico dominado por rio em toda a sua historia deposicional. Nas regioes proximais, localizadas a norte e noroeste, as principais facies pertencem as associacoes fluvial e planicie deltaica, marcando a area mais distal do sistema deposicional, a frente deltaica e o prodelta. O mapas de isolinhas e de percentagem de areia indicam que a distribuicao de areia e sobretudo axial. O principal influxo sedimentar vem do norte e do noroeste. Perto da fronteira com a falha do sudeste ha uma pequena contribuicao de leques aluviais associados a falha de Salvador. Como consequencia natural, as secoes estratigraficas mostraram um decrescimo de areia para sul e sudeste. Os registros geofisicos de Potencial Espontâneo indicam uma mudanca progressiva dos padroes fluviais (em forma de sino) para padroes deltaicos (em forma de sino invertido). A ciclicidade sedimentar e fortemente representada no Andar Aratu. Parte dela pode ser observada nos registros geofisicos de resistividade e de Potencial Espontâneo. Picos nos registros de resistividade indicam inundacoes periodicas do ambiente lacustre. O valor da resistividade, dependente da espessura de arenitos calcarios e xistos com vestigions de ostracodes e peixes, permite separar varias ordens de picos (quatro a seis ordens). Analises de ciclicidade convencionais indicam claramente um controle orbital devido a precessao e obliquidade axial. A taxa de sedimentacao calculada e de 60 cm / 1000 anos, correspondente ao intervalo de tempo de deposicao de toda a secao (andar Aratu) de 1,44 Ma. Palavras-chave: Exploracao de Petroleo. Mapas de Isopacas. Mapas de Isolinhas. Resistividade. Analises de Ciclicidade. Controle Orbital. Sistemas Deposicionais. Sistema Deltaico Dominado por Rio.

The Lu-Hf method has been used in the investigation of geological samples in order to understand processes and sources of magmatic rocks. This paper discusses the reference materials GJ-01, 91.500 and Mud Tank isotopic composition by LA-ICP-MS to investigate how suitable they are for the zircon analysis through this technique. The results show that the three zircons have homogeneous compositions for the proposed objectives. Considering that relatively high Yb contents produce isobaric interference, the results of this work have shown that the Mud Tank is the best reference material, since it has lower values of this element. Thus, the Mud Tank allows to obtain more reliable results due to lower correction requirements. In addition, it should be emphasized that the presented data corroborate the application of Hf isotopes for geological evolution and characterization of magmatic sources. The high abundances of Hf in the zircon grains allow to preserve the isotopic signatures of its crystallization from magmatic sources, allowing to characterize the isotopic signatures of the reservoir (s) that gave origin to that rocks, and in case studies of paleoclimate and paleoceanographic records and/or of sedimentary basins evolution, it allows to identify the origin of the sediments or temporal and spatial changes of the source of sedimentary particles. COMPOSIÇÃO ISOTÓPICA DE Lu, Hf e Yb ANALISADA POR LA-ICP-MS DOS MATERIAIS DE REFERÊNCIA “GJ-01”, “91.500” e “MUD TANK”: APLICAÇÃO DA GEOCRONOLOGIA Lu-Hf EM ZIRCÃO ResumoO método Lu-Hf tem sido utilizado para entender processos de formação e fontes de rochas magmáticas. Este artigo analisa a composição isotópica por LA-ICP-MS dos materiais de referência GJ-01, 91.500 e Mud Tank para investigar quão adequados eles são para a análise de zircônio através desta técnica. Os resultados mostram que os três zircões possuem composições homogêneas podendo ser usados com materiais de referência para as pesquizas referidas. Considerando que teores relativamente altos de Yb produzem interferência isobárica, os resultados deste trabalho mostraram que o Mud Tank é o melhor material de referência, uma vez que possui os menores valores deste elemento. O Mud Tank permite obter resultados mais confiáveis por requerer menor correção dos valores obtidos. Além disso, deve-se ressaltar que os dados apresentados corroboram a aplicação de isótopos de Hf para a evolução geológica e caracterização de fontes magmáticas. As altas abundâncias de Hf nos grãos de zircão permitem preservar as assinaturas isotópicas de sua cristalização a partir de fontes magmáticas, permitindo caracterizar as assinaturas isotópicas do (s) reservatório (s) que deram origem a essas rochas. Têm também utilidade em estudos de paleoclima e paleoceanográficos e/ou da evolução das bacias sedimentares, permitindo identificar a origem dos sedimentos ou mudanças temporais e espaciais da fonte das partículas sedimentares. Palavras-chave: Método Isotópico Lu-Hf. Interferência isobárica. Análise de Alta Resolução Espacial. Zircão. Calibração de materiais de georeferenciamento. Pesquisa analítica.

Paleoenvironmental reconstructions in coastal environments have been carried out using indicators of relative sea level oscillation (RSL), among them, mollusk shells, beachrocks and sedimentary records. Data from eleven geological-geotechnical drilling cores (from 15 m to 30 m long) distributed along the Ipanema - Leblon coastline and on the edge of the Rodrigo de Freitas Lagoon and respective stratigraphic profiles were analyzed in this work. Eleven radiocarbon ages obtained from shell samples calibrated to eliminate the effect of reservoir were used to perform the time evolution of the study area. The obtained results allowed to identify five distinct stages on the sedimentary evolution of the Southern Zone of the Rio de Janeiro City related to the Holocene RSL variations: the first stage under continental environmental conditions, with sea level approximately 4.5 m below the current; the second stage corresponding to a paleo-cove formed due to the sea level rising; the third stage associated with the mid-Holocene maximum transgression, in which the entire study area was flooded; the fourth stage following the gradual lowering of the RSL and marked by the formation of a paleo-bay; the fifth stage corresponding to the current configuration of the coastline. EVOLUCAO E RECONSTITUICAO PALEO-AMBIENTAL DA ZONA SUL DA CIDADE DO RIO DE JANEIRO (SE BRASIL) Resumo As reconstrucoes paleoambientais em ambientes costeiros tem sido realizadas utilizando indicadores de oscilacao relativa do nivel do mar (NRM), entre eles, conchas de moluscos, beachrocks e registros sedimentares. Foram analisados neste trabalho, dados de onze testemunhos de perfuracao geologico-geotecnica (de 15 m a 30 m de comprimento) distribuidos ao longo do litoral de Ipanema - Leblon e a beira da Lagoa Rodrigo de Freitas e respectivos perfis estratigraficos. Onze idades de radiocarbono calibradas obtidas em amostras de conchas foram utilizadas no estudo da evolucao temporal da area de estudo. Os resultados obtidos permitiram identificar cinco etapas distintas da evolucao sedimentar da Zona Sul da cidade do Rio de Janeiro, relacionadas com variacoes do NRM durante o Holoceno: a primeira etapa, sob a influencia de condicoes ambientais continentais, esta relacionada com um nivel do mar aproximadamente 4,5 m abaixo do atual; a segunda etapa corresponde a uma paleo-enseada formada devido a elevacao do nivel do mar; o terceiro estagio associado a transgressao maxima do Holoceno medio, em que toda a area de estudo foi inundada; o quarto estagio, apos o abaixamento gradual do NRM, e marcado pela formacao de uma paleo-baia; a quinta etapa corresponde a configuracao atual do litoral. Palavras-chave: Mudanca relativa do nivel do mar. Quaternario. Sedimentacao Marinha. Evolucao litoral. Modelo 2D.

Scarce knowledge is available concerning the diatom ecology of hypersaline environments and their potential to use as bioindicators. The aim of this study was to characterize and quantify diatom assemblages from Vermelha Lagoon associated with environmental parameters in order to establish environmental quality bioindicators for hypersaline environments. Species distribution displayed a weak relationship with environmental parameters analyzed in DCA analyses. The cluster analyses evidenced the presence of four diatom groups in the lagoon: Group I - located on the south margin of the lagoon, represented by N. arenaria; Group II - located in the north, the central sector and near the communication channel with Araruama Lagoon, dominated by F. interposita. The Group III - distributed in the shallowest regions, where primary productivity is high. Species H. acutiuscula and C. placentula in this group reached high relative abundance values. Group IV is characterized by increased salinity and lipids values, characterizing hypertrophic sediment conditions. These stations were located in the Saltpan water catchment and were characterized by a decreased number of species and the dominance of A. robusta.

This work is based on a compilation of benthic foraminiferal data collected in the Aveiro Lagoon and in the adjacent continental shelf and upper slope (center of Portugal). It intends to provide an overall analysis from transitional to the outer continental shelf of the occurrence and distribution of species in living and to present updated taxonomic data and illustrations of most of the species found in the in the Aveiro Lagoon and in the adjacent continental shelf including in total assemblages. Cluster analysis (CA) and Principal Components Analysis (PCA) interpreted as depth functions allow us to identify the main species in different ecoenvironments and sectors of the study area. The most unusual living assemblage was documented in the lagoon inlet under very strong tidal currents activity, composed mostly by the following species (both in living and total assemblages): Rotaliammina concava, Lepidodeuterammina ochracea, Quinqueloculina seminula , Gavelinopsis praegeri , Paratrochammina haynesi, Remaneica helgolandica and Remaneicella gonzalezi. The distribution patterns of some Trochamminidae and Remaneicidae species whose ecology and distribution pattern are poorly known, have proved to be a marker of more or less hydrodynamic and stable/unstable environments in coastal and transitional marine environments. OCORRENCIA DE FORAMINIFEROS E DISTRIBUICAO DAS PRINCIPAIS ESPECIES NA LAGOA DE AVEIRO E NA PLATAFORMA CONTINENTAL ADJACENTE (PORTUGAL) Resumo Este trabalho baseia-se numa compilacao de dados foraminiferos bentonicos recolhidos na Laguna de Aveiro e na plataforma continental adjacente (centro de Portugal). Pretende efetuar uma analise geral da distribuicao de especies nas associacoes vivas e totais (vivas e mortas) na area de estudo, em funcao da profundidade. Pretende ainda apresentar dados taxonomicos e ilustracoes da maioria das especies encontradas na Laguna de Aveiro e na plataforma continental adjacente. A analise de agrupamento (CA) e a analise de componentes principais (PCA), em funcao da profundidade, permitem identificar as principais especies em diferentes ecossistemas e setores da area de estudo. A associacao viva mais invulgar foi encontrada na embocadura da Laguna de Aveiro, um ambiente sujeito a forte corrente de mare. Essa associacao era composta principalmente pelas seguintes especies (na associacao viva e total): Rotaliammina concava, Lepidodeuterammina ochracea, Quinqueloculina seminula , Gavelinopsis praegeri , Paratrochammina haynesi, Remaneica helgolandica and Remaneicella gonzalezi . Os padroes de distribuicao de algumas especies de Trochamminidae e Remaneicidae, cuja ecologia e padrao de distribuicao sao pouco conhecidos, mostraram ser um marcador de ambientes mais ou menos hidrodinâmicos e de estabilidade/instabilidade do substrato em ambientes marinhos costeiros e de transicao. Palavras-chave: Ecologia. Taxonomia. Imagens digitais. Analise Estatistica. Ambientes Transicionais e Costeiros Marinhos.

The postcollisional magmatism in the Ribeira Belt, a collisional Orogen developed through several episodes during the convergence of the Pan-African/Brasiliano Orogeny, was marked in the Eastern Terrane (Rio de Janeiro, SE Brazil) by intense granitic magmatism of Cambro-Ordovician age. This magmatism was previously divided into the Surui and Nova Friburgo suites, both interpreted as I-type granites generated by the interactions of magmas with crustal and mantle origins. This paper presents a new contribution to the understanding of the Sana Granite. It is based on the analysis of field work, mineralogical and geochemical (elemental concentrations by Inductively Coupled Plasma Emission Spectrometer, ICP-ES, and Inductively Coupled Plasma Mass Spectrometry, ICP-MS) data, and U–Pb dating and Lu–Hf isotope analyses, by Laser Ablation Inductively Coupled Plasma Mass Spectrometry (LA-ICP-MS) from the main body and one satellite of the Sana Granite. The results of this work show that the Sana Granite, previously grouped with the Nova Friburgo suite, presents petrographic, geochemical, and isotopic characteristics that do not match its initial petrogenetic interpretation. Data from this work show that the Sana Granite is composed of alkali feldspar granites, syenogranites and monzogranites. All these rocks are hololeucocratic to leucocratic, with small grains ranging from fine to coarse. They are silica-supersaturated, peraluminous, and mostly alkali-calcic rocks and plot at the limit between the ferrous and magnesian fields. Crystallization ages of 480 ± 6 million years (Ma) and 495 ± 4 Ma are obtained in the main body of the Sana Granite, while the ages obtained in the satellite body are 506 ± 10 Ma and 508 ± 5 Ma. The Hf isotope data indicate crustal sources, with depleted mantle model ages (TDM) varying between 2.22 and 1.69 Ga and eHf values ranging between −15.54 and − 6.54. The data set from this work suggests that Sana is an S-type granite formed by the partial melting of metasedimentary rocks from the dehydration of hydrous minerals, such as biotite and muscovite. This massif is composed of muscovite-bearing peraluminous granitoids (MPGs) associated with high-pressure collisional Orogens. Considering that the characteristics of the Sana Granite are incompatible with those of the Nova Friburgo suite, it is proposed to use the Sana suite to characterize S-type granites generated in the postcollisional stage of the Ribeira Belt.

We gathered total organic carbon (%) and relative abundances of benthic foraminifera in intertidal areas and transitional waters from the English Channel/European Atlantic Coast (587 samples) and the Mediterranean Sea (301 samples) regions from published and unpublished datasets. This database allowed to calculate total organic carbon optimum and tolerance range of benthic foraminifera in order to assign them to ecological groups of sensitivity. Optima and tolerance range were obtained by mean of the weighted-averaging method. The data are related to the research article titled "Indicative value of benthic foraminifera for biomonitoring: assignment to ecological groups of sensitivity to total organic carbon of species from European intertidal areas and transitional waters The authors are grateful to the Swiss National Science Foundation, the Agence de l'Eau Artois-Picardie, the Communauté d'Agglomération du Boulonnais, the Université de Lille, the Université du Littoral Côte d'Opale, the Laboratoire d'Océanologie et de Géosciences for their financial support to FOBIMO workshops in Fribourg (Switzerland), Wimereux (France) and Texel (The Netherlands); Additional funding was provided by Spanish MINECO (RTI2018-095678-B-C21, MCIU/AEI/FEDER, UE)

This work sheds light on the recent evolution (≈1915–2015 AD) of Sepetiba Bay (SB; SE Brazil), a subtropical coastal lagoon on the southwestern Brazilian coast, based on a multiproxy approach. Variations in geochemical proxies as well as textural, mineralogical and geochronological data allow us to reconstruct temporally constrained changes in the depositional environments along the SP3 sediment core collected from the central area of SB. At the beginning of the twentieth century, the substrate of the study site was composed of coarse-grained sediments, largely sourced from felsic rocks of proximal areas and deposited under moderate to strong shallow marine hydrodynamics. Since the 1930s, the study area has undergone silting and received high contributions of materials from mafic rocks sourced by river basins. The SP3 core reveals a shallowing-upward sequence due to human-induced silting with significant eutrophication since the middle of 1970, which was caused by significant enrichment of organic matter that was provided by not only marine productivity but also continental and human waste. In addition, the sediments deposited after 1980 exhibit significant enrichment and are moderately to strongly polluted by Cd and Zn. Metals were dispersed by hydrodynamics from the source areas, but diagenetic processes promoted their retention in the sediments. The potential ecological risk index (PERI) indicates that the level of high (considerable) ecological risk is in sediments deposited in ≈1995 (30–32 cm; subsurface). The applied methodology allowed us to understand the thickness of the bottom sediment affected by eutrophication processes and contaminants. Identical methodologies can be applied in other coastal zones, and can provide useful information to decision makers and stakeholders that manage those areas.

International audience; This work contributes to the ongoing work aiming at confirming benthic foraminifera as a biological quality element. In this study, benthic foraminifera from intertidal and transitional waters from the English Channel/European Atlantic coast and the Mediterranean Sea were assigned to five ecological groups using the weighted-averaging optimum with respect to TOC of each species. It was however not possible to assign typical salt marsh species due to the presence of labile and refractory organic matter that hampers TOC characterization. Tests of this study species’ lists with Foram-AMBI on two independent datasets showed a significant correlation between Foram-AMBI and TOC, confirming the strong relation between foraminifera and TOC. For one of the validation datasets, associated macrofaunal data were available and a significant correlation was found between the foraminiferal Foram-AMBI and the macrofaunal AMBI. The here proposed lists should be further tested withsensitivity-based indices in different European regional settings.

Microbial communities in marine deep-sea sediments represent highly productive and bioactive living organism potential despite the extremely oligotrophic feature of the Mediterranean Sea. Else, the characterization of natural microbial communities from deep-sea sediments is still important for marine microbial ecological studies in relation with environmental conditions. Therefore, we assessed the microbial communities (bacteria and diatoms) in sediments obtained from three deep Mediterranean sites (an oceanic Atlantic site and two Western and Eastern sites), using Scanning Electronic Microscopy (SEM), culturing viable forms of bacteria and their biochemical characterization besides hydrobiological and chemical characteristics of the three sites

Multiproxy approach based on textural, mineralogical, geochemical, and microfaunal analyses on a 176-cm-long core (SP8) has been applied to reconstruct the Holocene paleoenvironmental changes and disentangling natural vs. anthropogenic variability in Marambaia Cove of the Sepetiba Bay (SE Brazil). Sepetiba Bay became a lagoonal system due to the evolution and development of the Marambaia barrier island during the Holocene and the presence of an extensive river basin. Elemental concentrations from pre-anthropogenic layers from the nearby SP7 core have been used to estimate the baseline elemental concentrations for this region and to determine metals enrichment factors (EF), pollution load index (PLI), and sediment pollution index (SPI). Record of the core SP8 provides compelling evidence of the lagoon evolution differentiating the effects of potentially toxic elements (PTEs) under natural vs. anthropic forcing in the last ~ 9.5 ka BP. The study area was probably part of coastal sand ridges between ≈ 9.5 and 7.8 ka BP (radiocarbon date). Events of wash over deposited allochthonous material and organic matter between ≈ 8.6 and 7.8 ka. Climatic event 8.2 ka BP, in which the South American Summer Monsoon was intensified in Brazil causing higher rainfall and moisture was scored by an anoxic event. Accumulation of organic matter resulted in oxygen depletion and even anoxia in the sediment activating biogeochemical processes that resulted in the retention of potentially toxic elements (PTEs). After ≈ 7.8 ka BP at the onset of the Holocene sea-level rise, a marine incursion flooded the Marambaia Cove area (previously exposed to subaerial conditions). Environmental conditions became favorable for the colonization of benthic foraminifera. The Foram Stress Index (FSI) and Exp(H’bc) indicate that the environmental conditions turned from bad to more favorable since ≈ 7.8 ka BP, with maximum health reached at ≈ 5 ka BP, during the mid-Holocene relative sea-level highstand. Since then, the sedimentological and ecological proxies suggest that the system evolved to an increasing degree of confinement. Since ≈ 1975 AD, a sharp increase of silting, Cd, Zn, and organic matter also induced by anthropic activities caused major changes in foraminiferal assemblages with a significant increase of Ammonia/Elphidium Index (AEI), EF, and SPI values and decreasing of FSI and Exp(H’bc) (ecological indicators) demonstrating an evolution from “moderately polluted” to “heavily polluted” environment (bad ecological conditions), under variable suboxic conditions. Thus, core SP8 illustrates the most remarkable event of anthropogenic forcing on the geochemistry of the sediments and associated pollution loads and its negative effect on benthic organisms.

Since the 1960 s, there has been a rapid expansion of drilling activities in the central and northern Adriatic Sea to meet the increasing global energy demand. The discharges of organic and inorganic pollutants, as well as the alteration of the sediment substrate, are among the main impacts associated with these activities. In the present study, we evaluate the response of benthic foraminifera to the activities of three gas platforms in the northwestern Adriatic Sea, with a special focus on the Armida A platform for which extensive geochemical data (organic matter, trace elements, polycyclic aromatic hydrocarbons, other hydrocarbons, and volatile organic compounds) are available. The response to disturbance is assessed by analyzing the foraminiferal diversity using the traditional morphology-based approach and by 18S rDNA-based metabarcoding. The two methods give congruent results, showing relatively lower foraminiferal diversity and higher dominance values at stations closer to the platforms (

This work aims to propose new standards to assess the degree of sediment contamination in saline and brackish environments, since the legislation currently used in Brazil is based on Canadian/American regulations, which do not comply with the conditions in Brazil. This study is based on geochemical analyses of 340 surface sediment samples collected in the Green Coast region (Rio de Janeiro, Brazil), including Mangaratiba, Angra dos Reis and Ribeira coves and Ilha Grande and Sepetiba bays. This region is influenced by industrial, harbor, urban and tourist activities and was affected by a dam rupture episode that released contaminated material. The results show heterogeneity in the distribution and range of metal concentrations in the study area depending on the supply of metals from natural and anthropogenic sources. Environmental characteristics such as coastal and tidal currents, water temperature and salinity, local depth, sediment grain size, sedimentary dynamics and biogeochemical processes influence the dispersion or retention of metals. The pollution load index (PLI) suggests that Sepetiba Bay is the region with the most environmental degradation due to anthropogenic contamination. In this context, we propose the establishment of new levels of contamination according to the Cd, Cr, Cu, Mn, Ni, Pb, V and Zn concentrations in sediments of salt and brackish waters, considering I) background level; II) level 1 - with anthropogenic influence; and III) level 2 - contaminated. The results of this work also suggest that, except for zinc, the range of metal concentrations admitted by Brazilian legislation are quite permissive and not adequate for Brazilian coastal environments.

Multiproxy approach based on textural, mineralogical, geochemical, and microfaunal analyses on a 176-cm-long core (SP8) has been applied to reconstruct the Holocene paleoenvironmental changes and disentangling natural vs. anthropogenic variability in Marambaia Cove of the Sepetiba Bay (SE Brazil). Sepetiba Bay became a lagoonal system due to the evolution and development of the Marambaia barrier island during the Holocene and the presence of an extensive river basin. Elemental concentrations from pre-anthropogenic layers from the nearby SP7 core have been used to estimate the baseline elemental concentrations for this region and to determine metals enrichment factors (EF), pollution load index (PLI), and sediment pollution index (SPI). Record of the core SP8 provides compelling evidence of the lagoon evolution differentiating the effects of potentially toxic elements (PTEs) under natural vs. anthropic forcing in the last ~ 9.5 ka BP. The study area was probably part of coastal sand ridges between ≈ 9.5 and 7.8 ka BP (radiocarbon date). Events of wash over deposited allochthonous material and organic matter between ≈ 8.6 and 7.8 ka. Climatic event 8.2 ka BP, in which the South American Summer Monsoon was intensified in Brazil causing higher rainfall and moisture was scored by an anoxic event. Accumulation of organic matter resulted in oxygen depletion and even anoxia in the sediment activating biogeochemical processes that resulted in the retention of potentially toxic elements (PTEs). After ≈ 7.8 ka BP at the onset of the Holocene sea-level rise, a marine incursion flooded the Marambaia Cove area (previously exposed to subaerial conditions). Environmental conditions became favorable for the colonization of benthic foraminifera. The Foram Stress Index (FSI) and Exp(H'bc) indicate that the environmental conditions turned from bad to more favorable since ≈ 7.8 ka BP, with maximum health reached at ≈ 5 ka BP, during the mid-Holocene relative sea-level highstand. Since then, the sedimentological and ecological proxies suggest that the system evolved to an increasing degree of confinement. Since ≈ 1975 AD, a sharp increase of silting, Cd, Zn, and organic matter also induced by anthropic activities caused major changes in foraminiferal assemblages with a significant increase of Ammonia/Elphidium Index (AEI), EF, and SPI values and decreasing of FSI and Exp(H'bc) (ecological indicators) demonstrating an evolution from "moderately polluted" to "heavily polluted" environment (bad ecological conditions), under variable suboxic conditions. Thus, core SP8 illustrates the most remarkable event of anthropogenic forcing on the geochemistry of the sediments and associated pollution loads and its negative effect on benthic organisms.

This work sheds light on the recent evolution (≈1915-2015 AD) of Sepetiba Bay (SB; SE Brazil), a subtropical coastal lagoon on the southwestern Brazilian coast, based on a multiproxy approach. Variations in geochemical proxies as well as textural, mineralogical and geochronological data allow us to reconstruct temporally constrained changes in the depositional environments along the SP3 sediment core collected from the central area of SB. At the beginning of the twentieth century, the substrate of the study site was composed of coarse-grained sediments, largely sourced from felsic rocks of proximal areas and deposited under moderate to strong shallow marine hydrodynamics. Since the 1930s, the study area has undergone silting and received high contributions of materials from mafic rocks sourced by river basins. The SP3 core reveals a shallowing-upward sequence due to human-induced silting with significant eutrophication since the middle of 1970, which was caused by significant enrichment of organic matter that was provided by not only marine productivity but also continental and human waste. In addition, the sediments deposited after 1980 exhibit significant enrichment and are moderately to strongly polluted by Cd and Zn. Metals were dispersed by hydrodynamics from the source areas, but diagenetic processes promoted their retention in the sediments. The potential ecological risk index (PERI) indicates that the level of high (considerable) ecological risk is in sediments deposited in ≈1995 (30-32 cm; subsurface). The applied methodology allowed us to understand the thickness of the bottom sediment affected by eutrophication processes and contaminants. Identical methodologies can be applied in other coastal zones, and can provide useful information to decision makers and stakeholders that manage those areas.

Heavy metals are one of the most hazardous pollutants in marine environments because of their bioaccumulation and biomagnification capabilities. Among them, cadmium (Cd) has been considered as one of the most dangerous for marine organisms. Here we incubated Ammonia cf. parkinsoniana specimens, a benthic foraminiferal taxon used in previous experiments, for up to 48 h in natural seawater with different concentrations of Cd to unravel the physiological change. We document a reduced pseudopodial activity of the Cd-treated specimens at concentrations &gt, 10&ndash, 100 ppb in comparison with the control specimens. Moreover, confocal images of Cd-treated specimens using Nile Red as a fluorescent probe reveal an enhanced intracellular neutral lipid accumulation in the form of lipid droplets at 6 h and 12 h. This bioassay experiment allows for the direct evaluation of Cd-dose to A. cf. parkinsoniana-response relationships under laboratory controlled conditions and provides complementary information to field observations as well as to water quality guidelines and thresholds.

This study provides a comparison between living (LAs) and dead (DAs) assemblages of benthic foraminifera in 137 sites located at the mouth region of the Aveiro Lagoon (N Portugal). This coastal lagoon, commonly named Ria de Aveiro, is under strong anthropogenic influence due to changes in natural hydrodynamics through engineering structures and by the input of contaminants. The sedimentary environments of the mouth area are characterized by biotic (benthic foraminifera) and sedimentological (grain size, trace metals and total organic carbon concentrations) data. The pollution load index (PLI) identifies areas of increased concentrations of potentially toxic trace metals. An innovative combination of several statistical methods and extremely detailed data analyses allowed to verify that the dead associations (DAs) and the living assemblages (LAs) are absent or reduced in the deep and most hydrodynamically active zones along the navigable waterways of the channels. Breakwaters reducing the bottom currents allow the development of larger and more diversified LAs. The most suitable areas for LAs are located close to the South Jetty and in Mira Channel excluding the navigable channel and the eastern margin. LAs have in general little similarity with the DAs. Confined zones and areas with high organic matter flux and trace metals concentrations, where the sediments are being accumulated, are particularly unfavourable environments for living foraminifera. The obtained results evidenced that marked differences in hydrodynamics determine large dissimilarities between LAs and DAs. In some environments the taphonomic effects caused by the removal and high accumulation of foraminiferal tests can significantly misrepresent the faunal composition in the fossil registry, and lead to misinterpretations about the paleoenvironmental evolution.

This study characterizes the quantity and quality of organic matter present in surface sediments of the NE sector of Guanabara Bay (SE, Brazil), based on geochemical and statistical analysis. The geochemical analyses included stable isotopes in sedimentary bulk organic matter (orgδ13C), total organic carbon (TOC), total sulfur (TS) and Rock Eval pyrolysis parameters, such as free hydrocarbons (S1), generating source potential (S2), production index (PI), oxygen and hydrogen indices (OI, HI) and the maturation index of organic matter (Tmax). The analyzed data were statistically treated to find main factors that are influencing the sedimentary composition. The low activity of the bottom currents favors the deposition of fine-grained sediments, rich in organic matter, in most of the studied area. The organic matter present in the sediments is being supplied by local and allochthonous sources and can be considered a good source of type III kerogen, and therefore has the potential to generate gas, if the geological context is adequate. Considering the quantity, type of organic matter and potential of hydrocarbon generation four main groups of stations were identified. Stations in which the sediments: i) encompass a relatively high component of OM sourced mainly from the adjacent continental areas close to the Apa de Guapimirim (less contaminated by oil) and S. Gonçalo (Roncador River) regions; ii) contain some autochthonous contribution, located between the Paquetá and Governador Islands, where biogenic gas seeping should be predicted hereafter; iii) have higher contamination by oil, situated near Mauá and REDUC Oil Refinery, of Duque de Caxias; iv) present intermediate characteristics, located in the remaining study area. ResumoEste estudo efetua a caracterização da quantidade e qualidade da matéria orgânica presente em sedimentos superficiais do setor NE da Baía de Guanabara (SE, Brasil), com base em análises geoquímicas e estatísticas. Os dados geoquímicos incluíram isótopos estáveis em matéria orgânica (ORGδ13C), carbono orgânico total (TOC), enxofre total (TS) e parâmetros de pirólise Rock Eval, como por exemplo, teores se hidrocarbonetos livres (S1), potencial de geração hidrocarbonetos (S2), índice de produção (PI), índices de oxigênio e hidrogênio (OI, HI) e índice de maturação da matéria orgânica (Tmax). Os dados analisados foram tratados estatisticamente a fim de serem identificados os principais fatores que influenciam a composição sedimentar. A fraca atividade das correntes de fundo, favorece a deposição de sedimentos finos ricos em matéria orgânica, na maior parte da área estudada. A matéria orgânica presente nos sedimentos está sendo fornecida por fontes locais e alóctones e pode ser considerada uma boa a excelente fonte de querogênio do tipo III, tendo, pois, potencial para a geração de gás, desde que o contexto geológico seja adequado. Considerando-se a quantidade, o tipo de matéria orgânica e o potencial de geração de hidrocarbonetos podem ser identificados quatro grupos principais de estações. Estações em que os sedimentos: i) possuem teores relativamente elevados de matéria orgânica oriunda principalmente das áreas continentais, localizadas próximo da Apa de Guapimirim (menos contaminadas por petróleo) e S. Gonçalo (Rio Roncador); ii) contêm alguma contribuição autóctone, situadas entre a Ilha de Paquetá e a Ilha do Governador, onde se poderá prever a ocorrência de libertação de gás biogênico num futuro próximo; iii) possuem maior contaminação por petróleo, localizadas próximo de Mauá e da refinaria Reduc, de Duque de Caxias; iv) apresentam características intermédias, situadas na restante área de estudo.

Lead (Pb) has been regarded as a very toxic element that poses a serious threat to biota. A mesocosm experiment is performed to assess the influence of Pb on meiofaunal (metazoans within 45-500 µm) and benthic foraminiferal (protozoans) communities. To this end, sediments bearing such communities are incubated in mesocosms, exposed to different levels of Pb in seawater, and monitored for up to eight weeks. Concentrations of Pb below 1 ppm in water do not promote a significant increase of this metal in sediments. Relatively high concentrations of Pb seem to affect meiofaunal and benthic foraminiferal communities by reducing their richness or diversity, and the abundance of the most sensitive taxa. The mesocosm approach can be considered an effective method to document the responses of meiofaunal and benthic foraminiferal communities to various kinds and concentrations of pollutants over time. This approach allows the evaluation of dose-response relationships, validates the outcomes of field studies, and possibly confirms the sediment quality guidelines and thresholds. This article is protected by copyright. All rights reserved.

This study characterizes the quantity and quality of organic matter present in surface sediments of the NE sector of Guanabara Bay (SE, Brazil), based on geochemical and statistical analysis. The geochemical analyses included stable isotopes in sedimentary bulk organic matter (orgδ13C), total organic carbon (TOC), total sulfur (TS) and Rock Eval pyrolysis parameters, such as free hydrocarbons (S1), generating source potential (S2), production index (PI), oxygen and hydrogen indices (OI, HI) and the maturation index of organic matter (Tmax). The analyzed data were statistically treated to find main factors that are influencing the sedimentary composition. The low activity of the bottom currents favors the deposition of fine-grained sediments, rich in organic matter, in most of the studied area. The organic matter present in the sediments is being supplied by local and allochthonous sources and can be considered a good source of type III kerogen, and therefore has the potential to generate gas, if the geological context is adequate. Considering the quantity, type of organic matter and potential of hydrocarbon generation four main groups of stations were identified. Stations in which the sediments: i) encompass a relatively high component of OM sourced mainly from the adjacent continental areas close to the Apa de Guapimirim (less contaminated by oil) and S. Gonçalo (Roncador River) regions; ii) contain some autochthonous contribution, located between the Paquetá and Governador Islands, where biogenic gas seeping should be predicted hereafter; iii) have higher contamination by oil, situated near Mauá and REDUC Oil Refinery, of Duque de Caxias; iv) present intermediate characteristics, located in the remaining study area.

The use of geochemical normalizers has been applied in sedimentological studies in several study contexts, such as pollution, diagenetic and provenance assessment. Selected textural and mineralogical data of 137 surface sediment samples were compared by statistical analyses with geogenic elements concentrations normalized by the Al, Be, Ce, Fe, Fe+Al, Li, Rb and Sc aiming to identify the best normalizer to trace different sources of bottom sediments for the Aveiro Lagoon entrance (NW of Portugal). The study area is heterogenous in terms of hydrodynamics and sedimentary processes.The most commonly applied geochemical normalizer for the sediments elemental concentrations has been the aluminum. However, the statistical analyses evidenced that the best normalizer was the scandium, since Principal Components Analysis results have evidenced that the element/Sc values are largely independent of sediment granulometry and thus have allowed the identification of compositional differences not related to grain size. Statistical analyses have also allowed to discriminate groups of stations that: i) trace the entry and exit of mixed sources sediments of the lagoon due to the action of tidal currents; ii) contain materials provided from the erosion of granitoids present mainly along the Douro River basin, located to the north, and transported southward by coastal drift; iii) encompasse sediments provided from the erosion of the Schist–Greywacke Complex crossed by the Vouga River that drains into the inner central zone of the lagoon and; iv) represent an area of sediment accumulation located near the entrance of Mira Channel, where lithogenic materials, provided by mixed lithologies in addition to organic matter, are being deposited. The results of this work contribute to the knowledge of the sedimentary dynamics of the Aveiro Lagoon, a coastal system which is part of a littoral stretch that is being strongly eroded, due to natural and anthropic causes and should be applicable to other coastal systems with similar characteristics. ResumoO uso de normalizadores geoquímicos tem sido aplicado em estudos sedimentológicos em diversos contextos, como por exemplo, de poluição, avaliação diagenética e de proveniência de sediments. Dados texturais e mineralógicos selecionados de 137 amostras de sedimentos superficiais foram comparados através de análises estatísticas com concentrações de elementos geogênicos normalizadas por Al, Be, Ce, Fe, Fe + Al, Li, Rb e Sc. O estudo visou identificar o melhor normalizador para traçar diferentes fontes de sedimentos de fundo para a entrada da Lagoa de Aveiro (NW de Portugal), uma área heterogênea em termos de processos hidrodinâmicos e sedimentares.O normalizador geoquímico mais comumente aplicado em sedimentos tem sido o alumínio. No entanto, as análises estatísticas evidenciaram que o melhor normalizador foi o escândio, uma vez que os resultados da análise de componentes principal evidenciaram que os valores das razões elemento/Sc são amplamente independentes da granulometria sedimentar e permitiram a identificação de diferenças composicionais não relacionadas com o tamanho do grão. Análises estatísticas também permitiram discriminar grupos de estações que: i) traçam a entrada e saída de fontes mistas de sedimentos da laguna, devido à ação das correntes de maré; ii) contêm materiais provenientes da erosão de granitóides presentes principalmente ao longo da bacia do Rio Douro, localizada a norte, e transportados para sul por deriva litoral; iii) contêm sedimentos provenientes da erosão do Complexo Xisto-grauvaquico atravessado pelo Rio Vouga, que desagua na zona central interna da laguna e; iv) representam uma área de acumulação de sedimentos localizada perto da entrada do Canal Mira, onde materiais litogênicos, fornecidos por litologias diversificadas, além de matéria orgânica, estão sendo depositados.Os resultados deste trabalho contribuem para o conhecimento da dinâmica sedimentar da Laguna de Aveiro, um sistema costeiro que faz parte de um trecho litorâneo fortemente erodido, devido a causas naturais e antrópicas and may be applicable to other coastal systems with similar characteristics.

The use of geochemical normalizers has been applied in sedimentological studies in several study contexts, such as pollution, diagenetic and provenance assessment. Selected textural and mineralogical data of 137 surface sediment samples were compared by statistical analyses with geogenic elements concentrations normalized by the Al, Be, Ce, Fe, Fe+Al, Li, Rb and Sc aiming to identify the best normalizer to trace different sources of bottom sediments for the Aveiro Lagoon entrance (NW of Portugal). The study area is heterogenous in terms of hydrodynamics and sedimentary processes. The most commonly applied geochemical normalizer for the sediments elemental concentrations has been the aluminum. However, the statistical analyses evidenced that the best normalizer was the scandium, since Principal Components Analysis results have evidenced that the element/Sc values are largely independent of sediment granulometry and thus have allowed the identification of compositional differences not related to grain size. Statistical analyses have also allowed to discriminate groups of stations that: i) trace the entry and exit of mixed sources sediments of the lagoon due to the action of tidal currents; ii) contain materials provided from the erosion of granitoids present mainly along the Douro River basin, located to the north, and transported southward by coastal drift; iii) encompasse sediments provided from the erosion of the Schist–Greywacke Complex crossed by the Vouga River that drains into the inner central zone of the lagoon and; iv) represent an area of sediment accumulation located near the entrance of Mira Channel, where lithogenic materials, provided by mixed lithologies in addition to organic matter, are being deposited. The results of this work contribute to the knowledge of the sedimentary dynamics of the Aveiro Lagoon, a coastal system which is part of a littoral stretch that is being strongly eroded, due to natural and anthropic causes and should be applicable to other coastal systems with similar characteristics.