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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.

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).

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 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.

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.

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 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.

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.

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.

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.

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.

Nine crab species samples, males and females, were collected after homogeneously prospection of sediment surface of Bizerte Lagoon. Crabs were caught by dip net from Bizerte Lagoon during spring 2012. Concentrations of metals (Zn, As, Cd, Cr, Cu, Fe, Ni, Pb and Zn) were evaluated in the carapace and muscle tissue of crabs and in surface sediment samples. Concentrations of metals accumulated in the benthic crabs tissues were compared to the reactive metals content that constitute the bioavailable fraction of the sediments. Total organic carbon and carbonate contents were also determined, since they are principal requirements associated with crab development. Results of this work indicate that, in the study area, the metals that reach the highest concentrations in the sediments-water interface are by decreasing order Zn, Cr and Pb. The reactive concentrations of these metals are also the highest. However, the trace elements that are being accumulated in the carapace and muscle of crabs are mainly As and Cu. Continental waters flowing into the Bizerte Lagoon are the main source and the principal cause of the enrichment of trace elements in sediment. Results highlight that the reactive concentrations of metals in sediments were the principal cause of their bioaccumulation in the crabs tissues. The important results of this work highlight that cabs can be very useful on studies of monitoring and evaluation of environmental quality in addition to data obtained from the sediment as they also give information about the bioaccumulation of metals through the oceanic food webs. Resumo Nove amostras de especies de caranguejos, machos e femeas, foram coletadas na superficie do sedimento da Laguna de Bizerte. Os caranguejos foram capturados com uma rede na Laguna de Bizerte, na primavera de 2012. Foram avaliadas nas carapacas e no tecido muscular dos caranguejos e em amostras de sedimentos superficiais, concentracoes de metais (Zn, As, Cd, Cr, Cu, Fe, Ni, Pb e Zn). As concentracoes de metais acumuladas nos tecidos de caranguejos benticos foram comparadas com o teor de metais reativos que constituem a fracao biodisponivel dos sedimentos. Os teores totais de carbono orgânico e carbonato tambem foram determinados, uma vez que sao requisitos principais associados ao desenvolvimento dos caranguejos. Os resultados deste trabalho indicam que, na area de estudo, os metais que atingem as maiores concentracoes na interface sedimentos-agua sao, por ordem decrescente, Zn, Cr e Pb. As concentracoes reativas desses metais tambem sao as mais elevadas. No entanto, os metais que estao sendo acumulados nas carapacas e nos musculos dos caranguejos sao principalmente As e Cu. As aguas continentais que desembocam na Laguna Bizerte sao a principal fonte e a principal causa do enriquecimento de metais nos sedimentos. Os resultados sugerem que as concentracoes reativas de metais nos sedimentos foram a principal causa de sua bioacumulacao nos tecidos dos caranguejos. Os resultados deste trabalho revelam que para alem dos dados sedimentologicos, os caranguejos podem ser muito uteis em estudos de monitoramento e avaliacao da qualidade ambiental, pois fornecem informacoes sobre a bioacumulacao de metais atraves das cadeias alimentares oceânicas.

The main environmental variables controlling benthic foraminiferal distributions were identified and used to assess their influence on ecological indices developed as predictors of Ecological Quality Status (EcoQS) in marine ecosystems. Gradient forest and random forest models were applied to assess the predictive value of a selection of abiotic (environmental) and biotic (foraminifera) variables in a costal marine area in the central Adriatic Sea (Italy). This approach yields evidence that the predictor variables sand, silt, Pollution Load Index, and TN have the greatest influence on the distribution of benthic foraminifera in this area. In addition, we identify thresholds for the most important environmental variables that influence ecological indices. These findings contribute to efforts to determine how to best improve sediment quality and environmental stability for marine conservation. Further application of these approaches represents a useful tool for policymakers to survey the diversity of marine organisms and to improve the ability to protect and restore marine ecosystems by identifying predictors of diversity and identifying key thresholds in these predictors.

In the Godineau River Estuary, located in Trinidad Island (off the northeast coast of Venezuela), were found 114 taxa of foraminifera and 17 of thecamoebians in the dead fauna. Most of the identified foraminiferal species were rare because they were transported from the Gulf of Paria to this estuary. The autochthonous foraminiferal assemblage was represented by several tropical estuarine species such as Ammonia tepida, Ammotium salsum, Arenoparrella mexicana, Cribroelphidium excavatum, Ammonia parkinsoniana, Haplophragmoides wilberti, Miliammina fusca and Ammotium cassis. The thecamoebians assemblages, found in the inner part of this estuary, were dominated by Cyclopyxis spp., Centropyxis spp., Difflugia corona and Difflugia urceolata. The relative abundance of the main species of foraminifera and thecamoebians were analyzed through Q-mode and R-mode cluster analyses. Statistical results revealed the presence of three different environments in the Godineau River Estuary related to different hydrodynamic conditions and more or less oceanic or fluvial influence. The first sector represents the most confined region of the estuary and was mainly composed by agglutinated foraminifera together with thecamoebians. The second sector was located in the middle part of the estuary and was associated with the presence of brackish waters. The third sector denotes the outermost part of the estuary characterized by the greatest hydrodynamic activity and highest oceanic influence within the estuary. This sector was marked by the occurrence of a large number typical-marine foraminifera species.

Two species, Spirobolivina papillosa n. sp. and Spirobolivina retorta n. sp., are described from the Bizerte Lagoon (Tunisia), a Mediterranean transitional ecosystem. Two additional species, S. curta (Cushman, 1933) and S. minuta McCulloch, 1977, are also recorded from this lagoon. The identification and documentation of the new species are followed by a comparison with all the species belonging to the genus Spirobolivina and with selected species assigned to the genera Bolivinopsis and Spiroplectoides. Spirobolivina spp. are uncommon in Mediterranean modern environments and their ecology and paleoecology are poorly understood.

This work provides a comparison between living (LAs) and dead (DAs) benthic foraminiferal assemblages in 53 sampled sites located in intertidal and subtidal areas of Ria de Aveiro (Portugal). The results of multivariate statistical analysis provide evidence for the main factors that control the distribution of DAs and LAs, which seems to correspond to different gradients of marine/continental influence, conditioned by differences in the hydrodynamics of tidal currents. In addition to these factors, the LAs are clearly influenced by the total organic carbon, biopolymers and pollutants. The main factor that however drives the high level of agreement or the degree of disorder between the DAs and the LAs seems to be the hydrodynamics. The highest level of agreement between the DAs and the LAs is found in sheltered inner lagoon areas, out of the tidal currents strongest influence. This study shows an interesting application of advanced statistical analysis to study the similarity between LAs and DAs aiming to identify the zones or conditions of a coastal system in which the DAs can potentially be a better record of Las. Through similar studies conducted in coastal systems it is possible to select the most suitable sites to collect cores in view of the development of paleoenvironmental studies. (c) 2016 Elsevier B.V. All rights reserved.

International audience; This study analyzes the benthic trophic state of Bizerte Lagoon (Tunisia) based on the total organic matter and the bioavailability of biopolymeric carbon including proteins (PTN), carbohydrates (CHO), lipids (LIP), chlorophyll a, as well as bacteria counts. The overall simultaneously extracted metals (SEM), and acid volatile sulfides (AVS) as well as the SEM/AVS ratio indicative of the toxicity of the sediments also were analyzed aiming to study their impact in the dimension, composition and structure of both dead and living benthic foraminiferal assemblages.In the studied sites TOC content is relatively high and the PTN/CHO values indicate that they can be considered as meso-eutrophic environments. The CHO/TOC and C/N values suggest that the OM which accumulated on the sediments surface has mainly natural origin despite the introduction of municipal and industrial effluents in the lagoon and the large bacterial pool.The living assemblages of benthic foraminifera of Bizerte Lagoon are quite different to other Mediterranean transitional systems studied until now. They are composed of typical lagoonal species but also include several marine and opportunistic species including significant numbers of bolivinids, buliminids, Nonionella/Nonionoides spp. and Cassidulina/Globocassidulina spp. These assemblages seem to benefitfrom the physicochemical parameters and the sediment stability. They may however face environmental stress in the lagoon related to the AVS production as a result of the organic matter degradation and toxicity in some areas due to the available concentrations of metals. Nonetheless statistical results evidence that the structure and dimension of assemblages are being controlled mostly by OM quantity and quality related mainly to the availability of PTN, CHO and chlorophyll a. Results of this work support the importance of considering OM quantity and quality in studies of environmental impact in coastal systems.

The ecological quality status of the NE region of the Guanabara Bay (SE Brazil), one of the most important Brazilian embayments, is evaluated. For this purpose, sediment samples from in the inner of the Guanabara Bay (GB) were collected and analyzed (grain-size, mineralogy, geochemistry and living foraminifera). In this study, it is hypothesized that the potentially toxic elements (PTEs) concentrations, in solution and associated with organic matter (OMPTEs, potential nutrient source), may represent two potential pathways to impact benthic foraminifers. A multiproxy approach applied to complex statistical analyses and ecological indexes shows that the study area is, in general, eutrophic (with high organic matter and low oxygen content), polluted by PTEs and oil. As a consequence, foraminifera are not abundant and their assemblages are poorly diversified and dominated by some stress-tolerant species (i.e., Ammonia tepida, Quinqueloculina seminula, Cribroelphidium excavatum). The results allow us to identify a set of species sensitive to eutrophication and OMPTEs. Factors such as the increase of organic matter contents and OMPTEs and, in particular of Zn, Cd and Pb, the oxygen depletion and the presence of oil, altogether contribute to a marked reduction in the abundance and diversity of foraminifera. Ammonia-Elphidium Index and the Foram Stress Index confirm that the NE zone of GB is, in general, “heavily polluted”, with “poor ecological quality status” and experiences suboxic to anoxic conditions. In light of it, special attention from public authorities and policymakers is required in order to take immediate actions to enable its environmental recovery.

Outcrops of Neogene carbonates of the North Brazilian platform occur exclusively along the equatorial coast and represent some of the few existing examples of Neogene carbonate systems of the Atlantic coast of South America. The Pirabas Formation (early-middle Miocene) is the northernmost part of this platform. Although onshore mainly consists of small and scattered outcrops, it considerably extends in the subsurface keeping record of relevant geological and paleontological episodes of tropical South American history. Intending to improve the knowledge of South American carbonate and providing a solid basis for future comparisons between the Pirabas Basin and other, largely subsurface, Cenozoic basins, this research investigates the Aricuru outcrops by combining a standard petrographical and paleontological approach with advanced microCT analyses. The Aricuru area is characterized by mixed siliciclastic-carbonate sand-sized deposits, which probably deposited after the early Miocene according to the palynological assemblage. The bioclastic fraction of the rock is dominated by benthic foraminifera (mostly soritids, amphisteginids, small rotaliids, and small miliolids, typical of marginal marine environments), bryozoans, calcareous algae (Halimeda), echinoderms and mollusks. The abundant siliciclastic fraction together with the taxonomic composition of the foraminiferal, echinodermal, crustacean, ichnofossil and fish assemblages indicates deposition in a tropical coastal environment featuring both protected and more exposed sectors. The carbonate system probably developed under abundant nutrient supply, which fostered heterotroph suspension feeders over hermatypic corals. The demise of this system was most likely caused by a growth in siliciclastic input due to increased rainfall in the coastal area. The sedimentary evolution of the Pirabas Formation is similar to the one of the Foz do Amazonas Basin, and fits well with the general evolutionary trend of Cenozoic carbonate factories of the region, indicating the potential of the Pirabas subsurface record for understanding other Cenozoic basins, their paleoenvironmental significance, and their potential as oil, gas and water reservoirs.

The distribution of living (rose Bengal stained) Reophax pyriformis Yamashita, Sousa and Kaminski, n. sp., an agglutinated benthic foraminiferal species, was analyzed in the area of the Campos Basin (southeastern Brazilian continental margin). The study is based on 34 oceanographic stations (54 samples), located between 400 m and 3000 m water depth. The distribution of living R. pyriformis n.sp. density is compared to sedimentological parameters, such as total organic carbon, total nitrogen, calcium carbonate, phytopigment, lipids biomarkers (sterols, fatty acids and n-alcohols), total lipids, and bacterial biomass, as well as the particulate organic matter flux to the seafloor. This species was found in the range of 1000–1200 m water depth, with an average living depth of 1.52 cm in the sediment. The distribution of this species seems to be related to lipid biomarkers (allochthone and/or continental derivative, zooplankton and/or fauna, phytoplankton or primary producers) and total organic carbon under the influence of Intermediate Western Boundary Current conditions.

Sea surface temperatures (SSTs) were reconstructed from planktonic foraminiferal assemblages in two sediment cores off the NW Iberian Continental Margin for the last 40 kyr. Results of this work were compared with published SSTs estimated in six cores from the Iberian Margin and the δ 18 O data from NGRIP ice core of Greenland. Longitudinal and latitudinal SST changes were identified in several intervals related to alterations in the hydrographic conditions off the Iberian Peninsula, namely the influence of the upwelling system, the intensity of Paleo-Portugal and Paleo-Azores Currents, and the positions of the Polar and Arctic Fronts. During the Holocene, the SSTs were quite stable along the west Iberian Margin when compared with the last glaciation. However, during the Last Glacial Maximum (LGM) SSTs were not much lower than during the Holocene. The Portugal Current, as an eastward descending branch of the North Atlantic Drift, should have been quite vigorous in transporting warm water to the west Iberian Margin, which could have moderated the SSTs during the LGM. However, our results suggest a much higher instability during the LGM than previously reported and much lower SSTs at 42°N. The lowest SSTs during the last 40 ka were recorded during the Heinrich Stadials (HS) and the Younger Dryas (YD). During the HS, SSTs at the northwest Iberian Margin were lower than today by about 10 to 16 °C as a result of the invasion of cool and low-salinity water masses and the increased transport of icebergs from the northern seas. The Polar Front was persistently situated at 42°N for ~ 3 ka during the HS1, and a comparable present-day Arctic Front should have been present up to the latitude of 40°N during the HS2, HS3, and HS4 off the west Iberian Peninsula. The HS were recorded all along the west Iberian Margin. However, an overall trend of increasing of mean SSTs from north to south of ~ 8 °C during the HS1, of ~ 10 °C during the HS2b and HS3, of ~ 11 °C during the HS2a, and of ~ 4 °C during the HS4 was recorded. These gradients also were present during the YD of ~ 9 °C and the LGM of ~ 4 °C and may be related to the strong influence of the Paleo-Azores Current in southern areas.

This work aims to define the factors driving the accumulation of metals in the sediment of the lagoon of Aveiro (Portugal). The role of initial diagenetic processes in controlling trace metal retention in surface sediment is traced by mineralogy, magnetic susceptibility and geochemical analyses. Although several studies have focused on the metal distribution in this polihaline and anthropized coastal lagoon, most of them have been solely focused on the total metal concentrations. This study instead represents the first attempt to evaluate in a vast area of the Aveiro Lagoon the role of biogeochemical processes in metal availability and distribution in three extracted phases: exchangeable cations adsorbed by clay and elements co-precipitated with carbonates (S1), organic matter (S2) and amorphous Mn hydroxides (S3). According to the sediment guideline values, the sediment is polluted by, for instance, As and Hg in the inner area of the Murtosa Channel, Pb in the Espinheiro Channel, Aveiro City canals and Aveiro Harbour, and Zn in the northern area of the Ovar Channel. These sites are located near the source areas of pollutants and have the highest total available concentrations in each extracted phase. The total available concentrations of all toxic metals are however associated, firstly, with the production of amorphous Mn hydroxides in most of the areas and, secondly, with adsorption by organic compounds. The interplay of the different processes implies that not all of the sites near pollution sources have polluted surface sediment. The accumulation of metals depends on not only the pollution source but also the changing in the redox state of the sediments that may cause alterations in the sediment retention or releasing of redox-sensitive metals. Results of this work suggest that the biogeochemical processes may play a significant role in the increase of the pollutants in the sediment of the Aveiro Lagoon.

This work aims to compare the dimensions and composition of benthic foraminiferal biocenoses (living specimens) during two summer sampling events. Forty-four sediment samples were collected on the Aveiro Continental Shelf (Center of Portugal) (latitude of 40o30'N-40o50'N, longitude of 8o46'W-9o20'W) for granulometry, total organic matter (TOM) and living foraminiferal analyses. The sediment samples were collected during summers of 1994 and 1995, on stations located along transects (east-west direction) and between the bathymetries of 10-200 m. During the sampling campaigns, measurements of salinity, temperature and density data were recorded in the water column. The results showed that the living assemblages were mainly found in stations located between 20-80 m depth. The abundance of living foraminifera was generally reduced at depths

The Pirabas Formation (early to middle Miocene) from the equatorial margin of North Brazil is characterized by a shallow-marine carbonate platform with high fossil diversity and abundant micro- and macrofossil remains. The Pirabas Formation represents a unique carbonate system along the Atlantic margin of South America that developed before the onset of the Amazon delta. We studied the palaeontology and lithofacies of outcrops of the uppermost Pirabas Formation and found that was deposited in a coastal marine environment with marginal lagoons under the influence of a tidal regime and tropical storms. The remains of calcareous algae, molluscs, crustaceans, echinoiderms, bryozoans, solitary corals, fish and marine mammals, together with foraminifera, ostracods and other marine microfossils, shaped a biogenic framework, that together with the post-depositional processes of dissolution of skeletal grains, is responsible for the mean packstone-floatstone porosity of 14.9%. The palaeontological framework and the petrophysical characterization of the carbonate rocks from the uppermost Pirabas Formation outcrop represent a baseline to interpret the entire Pirabas Formation in the subsurface stratigraphic sections (cores) of this important Neogene unit. Considering that carbonate rocks account for ~50% of oil and gas reservoirs around the world, this research provides a model for Neogene tropical carbonate deposits useful for carbonate petroliferous reservoirs in the Brazilian equatorial basins.

The vertical distribution (0 to 100 m) of planktonic foraminifera was investigated based on 40 tow samples that were collected in eight stations, during the austral summer of 2002, in a geographically restricted area (23°S–25°S and 40°W–44°W) on the southeastern Brazilian continental margin. Species' abundances are low (less than 10 specimens/m3), which is typical of an oligotrophic area. The foraminifera assemblage is mainly composed of warm water species (Globigerinoides ruber white and pink forms), with a predominance of spinose and symbiont-bearing species. Temperature and inorganic nutrient enrichment of the surface are the main factors that control foraminiferal abundance and diversity; nevertheless salinity can also influence the ecological descriptors. The role of the deep chlorophyll maximum (DCM) in the distribution of foraminifera is not always clear, but the increase in the abundance of G. ruber (white and pink) seems to be related to a deeper DCM, and high salinities (S>36.5). The ecological habitat of these species is affected by the depth of the mixed layer, with a predominance of the white form in deeper layers. Increases in the foraminiferal diversity are related to the dynamics of the Brazil Current system, which displaces the area of high productivity in the euphotic zone off the coast. The abundances of Globigerina bulloides, Globigerina falconensis, Globigerinella calida and Globigerinella siphonifera follow the nutrient enrichment of the surface water mass, corroborating the usefulness of these species as paleoproductivity proxies in the study area. These data confirm the use of diversity measurements and assemblages composition for reconstructing past water column structures in subtropical oceans.

This study aims to explore the hydrodynamic factors that influence the depositional processes on the upper continental margin of southeastern South America. Mineralogy and the activities of natural ( 40 K) and artificial ( 137 Cs) radionuclides from surface sediment samples were used to evaluate the provenance and oceanographic controls on depositional processes. High values of the smectite/illite (S/I) ratio indicate that the Rio de la Plata (RdlP) is a major source of terrigenous sediments to the continental shelf between 38°S and 27°S and that its importance decreases towards lower latitudes. This is also corroborated by the high radionuclide 40-K activity found in muddy sediments. The kaolinite/illite (K/I) ratio highlights the interplay between two hydrodynamic controls in the sediment distribution of the study area: (i) the Brazil Current, which supplies the shelf mostly in the northern portion of the study area with kaolinite-enriched clay minerals from tropical regions, and (ii) the Brazil Coastal Current, which transports the clay minerals, mainly illite and smectite, from the RdlP to the southern portion of the study area (up to 27°S). This is also corroborated by high 137-Cs activities. In the deeper parts (>300 m) of the study area, high calcite content indicates the progressive decrease in terrigenous input towards the outer shelf and upper slope.

The main aims of this work are: to evaluate by laser-ablation inductively-coupled plasma mass spectrometry (LA-ICP-MS) the Pb isotopic composition of the reference material NIST 612 (a calcium-sodium aluminosilicate glass); to verify the potentialities of using the NIST SRM 612 as calibration standard for environmental studies on (carbonatic) bivalves and; to apply this standard in for quantifying the ontogenic (temporal) variations of Pb isotopes in two species of bivalve shells, Glycymeris undata Linnaeus 1758 and Pitar fulminatus (Menke, 1828) from Ilha Grande Bay (Rio de Janeiro, SE Brazil), in order to identify the Pb isotopic signatures and; propose a new tool to be applied in biological and environmental characterization studies. In these analyses a Neptune sector multicoletors mass spectrometer and 193 nm Excimer Laser Ablation device also were used. The averages for isotope ratios,206Pb/204Pb = 16.9027 ± 0.0011, 207Pb/204Pb = 15.4446 ± 0014, 208Pb/204Pb = 36.5544 ± 0.0044, 208Pb/207Pb = 0.91374 ± 0.00002 and 207Pb/206Pb = 0.9134 ± 0.0001, the calculated mass fractionation averages, of 0.07%, and the quantification procedures based on the external calibration, are in agreement with the true values obtained in the literature. The results of this work, obtained with the LA-MC-ICP-MS system, strongly support the hypothesis that abundance of Pb isotopes in carbonates can be determined on the basis of external calibration using the NIST 612 standard, despite the large difference between the CaCO3 composition and the glass silicate that compose this reference material. This fact suggests that NIST glass standards can be applied to several types of materials, whose geochemical composition of the matrix is not necessarily equivalent to that of the standards, by means of a careful setup of the LA-ICP-MS system. The obtained results confirm the hypothesis that it is possible to perform isotope analyzes of lead in bivalve shells using the LA-ICP-MS technique. The Pb isotope results obtained in layers of bivalve P. fulminatus allowed to identify the biological and environmental factors that influence the Pb isotopic ratios in the shell.

In the original article, Joao Marcelo Ballalai was inadvertently omitted as an author of this article. The author list is correct as reflected here.

Neste capitulo e apresentado um estudo ecologico de foraminiferos bentonicos vivos, coletados em estacoes localizadas no talude continental, Plato de Sao Paulo e cânions da Bacia de Campos, no ano de 2008 (periodo seco) e de 2009 (periodo chuvoso). As estacoes seguem nove transectos de 400 a 3.000 m de profundidade. O estudo teve como objetivo investigar mudancas na densidade, diversidade e composicao de foraminiferos bentonicos, ao longo desses transectos, em resposta a fatores ambientais. As mudancas na comunidade seguem o gradiente batimetrico e sao controladas pela disponibilidade e, provavelmente, qualidade do alimento. Os maiores valores medios de densidade, diversidade e riqueza, assim como o predominio de foraminiferos calcarios hialinos e especies infaunais refletem maior aporte de alimento recebido de forma continuada, nas estacoes mais rasas (400 m). Nas estacoes entre 700 e 1.000 m de profundidade, a densidade de individuos diminui e a presenca de especies oportunistas, que se reproduzem rapidamente na sequencia de pulsos de fitodetritos, e o reflexo de um aporte alimentar possivelmente sazonal. O aumento consideravel dos foraminiferos textulariideos, o decrescimo continuo na densidade de individuos e tambem nos valores do Indice de Produtividade de Foraminiferos Bentonicos (BFHP), a medida que aumenta a profundidade e valores extremamente baixos nas estacoes mais profundas (3.000 m), indicam condicoes tipicamente oligotroficas nesse setor da Bacia de Campos. A comparacao de dados de densidade e de composicao de especies nos periodos seco e chuvoso permite-nos inferir que no periodo chuvoso o aporte de alimento foi maior. Os valores de densidade e biomassa de foraminiferos bentonicos vivos permitem-nos deduzir que o Cânion Almirante Câmara constitui um local de maior aprisionamento de materia orgânica entre as isobatas de 400 a 1.000 m, em comparacao ao talude aberto para os mesmos limites de profundidades. A natureza do substrato e provavelmente os teores de oxigenio nas aguas do fundo oceânico revelaram-se fatores condicionantes secundarios na distribuicao desses organismos.