Biogeochemistry of a hypersaline lagoon east of Rio de Janeiro, Brazil

Höhn, Axel; Tobschall, H. J.; Maddock, John Edmund Lewis

doi:10.1016/0048-9697(86)90086-0

Cited by 29 publications

(26 citation statements)

References 5 publications

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“…In Coorong Lagoon, Australia (Botz and Borch 1984), the occurrence of aragonite was related to periods of lower salinity. The hypothesis of dolomite dilution by groundwater inflow into the Lagoa Vermelha has already been addressed by Höhn et al (1986) and Moreira et al (1987) interpreting pore-water chemistry and mineral occurrence. However, such hypotheses are not exclusive, they are complementary.…”

Section: Discussionmentioning

confidence: 99%

Stromatolite Growth in Lagoa Vermelha, Southeastern Coast of Brazil: Evidence of Environmental Changes

et al. 2017

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Among the oldest remains of living beings to have inhabited the Earth’s surface, there are the stromatolites—laminated sedimentary rocks associated with lithified mats of layered phototrophic microbial communities—which grow in specific environmental conditions. In the present work, we study a recent carbonatic stromatolite from Lagoa Vermelha (Rio de Janeiro, Brazil), a shallow coastal hypersaline lagoon. X-ray diffraction was associated to a depth chronological model defining three different sections based on changes in mineral composition of the stromatolite with increased dolomite content. Although a mean growth rate of 0.19±0.03 mm/yr is observed, the model discloses decreasing growth rates among the sections. Since dolomite formation can be related to high availability of Mg+2, confirmed by an expressive presence of (Ca, Mg)CO3, the lower growth rates were associated to a more arid environment, until approximately 1440 cal AD, with higher temperatures and consequently promoting water evaporation and salinity enhancement.

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Section: Discussionmentioning

confidence: 99%

Stromatolite Growth in Lagoa Vermelha, Southeastern Coast of Brazil: Evidence of Environmental Changes

et al. 2017

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“…The main elevations are the mountains of Sapiatiba, Sapiatiba Mirim and Palmital band and the hills of Cabo Frio, such as Miranda, Forno, Atalaia, Cabo and Farol [ 24 ] The local geology is composed by Quaternary sandbar deposits and recent dune fields (aeolian deposits) [ 25 ]. Radiocarbon analyses of shells from different sediment cores recovered from Vermelha Lagoon provided an age between 3,800 and 4,200 years BP, corresponding probably to the beginning of its formation [ 26 ]. The region presents relatively low rainfall (854 mm/year), high annual evaporation rates (between 1,200 and 1,400 mm), average temperature of 23°C, insolation between 200 and 220h/month, summer with the predominance of NE winds and winter marked by discontinuous S-SW winds periods [ 27 ].…”

Section: Methodsmentioning

confidence: 99%

“…In 1981, a fresh water channel about 3 m deep was constructed around the lagoon ( Fig 1 ) to prevent sub-superficial water inflow [ 26 ]. Thus, nowadays Vermelha Lagoon is not receiving freshwater directly from rivers and streams.…”

Section: Methodsmentioning

confidence: 99%

Assessment of the trophic state of a hypersaline-carbonatic environment: Vermelha Lagoon (Brazil)

et al. 2017

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Vermelha Lagoon is a hypersaline shallow transitional ecosystem in the state of Rio de Janeiro (Brazil). This lagoon is located in the protected area of Massambaba, between the cities of Araruama and Saquarema (Brazil), and displays two quite uncommon particularities: it exhibits carbonate sedimentation and displays the development of Holocene stromatolites. Due to both particularities, the salt industry and property speculation have been, increasingly, generating anthropic pressures on this ecosystem. This study aims to apply a multiproxy approach to evaluate the trophic state of Vermelha Lagoon based on physicochemical parameters and geochemical data for the quantification and qualification of organic matter (OM), namely total organic carbon (TOC), total sulfur (TS), total phosphorus (TP) and biopolymeric carbon (BPC), including carbohydrates (CHO), lipids (LIP) and proteins (PTN). The CHO/TOC ratio values suggest that OM supplied to the sediment is of autochthonous origin and results, essentially, from microbial activity. The cluster analyses allowed the identification of four regions in Vermelha Lagoon. The Region I included stations located in shallow areas of the eastern sector of Vermelha lagoon affected by the impact of the artificial channel of connection with Araruama Lagoon. The Region II, under the influence of salt pans, is characterized by the highest values of BPC, namely CHO promoted by microbiological activity. The Region III include stations spread through the lagoon with high values of dissolved oxygen and lower values of TP. Stromatolites and microbial mattes growth was observed in some stations of this sector. Region IV, where the highest values of TOC and TS were found, represents depocenters of organic matter, located in general in depressed areas. Results of this work evidences that the Vermelha Lagoon is an eutrophic but alkaline and well oxygenated environment (at both water column and surface sediment) where the autotrophic activity is greater than heterotrophic one. These particular conditions make this a special and rare ecosystem.

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“…Trabalhos realizados em esteiras microbianas recentes apontam que a parte superior do estrato verde é composta de diatomáceas e carbonatos seguida por cianobactérias (Höhn, Tobschall, Maddock, 1986). Abaixo do estrato verde observa-se mais comumente um estrato vermelho composto por bactérias aeróbicas e bactérias fotossintetizantes anaeróbicas.…”

Section: Composição Biológica Das Estruturasunclassified

Composição cianobacteriana e química dos estromatólitos da lagoa Salgada, Neógeno do estado do Rio de Janeiro, Brasil

Silva

Alves

Magina

et al. 2013

Geol. USP, Sér. cient.

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Disponível on-line no endereço www.igc.usp.br/geologiausp -95 -Resumo A lagoa Salgada é um corpo aquático costeiro, situada no norte do estado do Rio de Janeiro. A evolução geológica da lagoa está associada às oscilações do nível do mar durante o Neógeno e apresenta esteiras microbianas, estromatólitos estratiformes e estromatólitos individuais e contínuos. Estromatólitos são estruturas carbonáticas laminadas formadas pela atividade metabólica de esteiras microbianas. O estudo permitiu a identificação de 31 espécies de cianobactérias nos estromatólitos e nas esteiras microbianas. A família de maior frequência é a Synechococcaceae. Nove espécies ocorrem nos estágios de desenvolvimento dos estromatólitos. Os tipos de esteiras são lisa, tufada, poligonal e em bolha, tendo como seus principais agentes produtores as cianobactérias filamentosas. Os restos esqueletais incluem bivalves, gastrópodes, ostracódios, foraminíferos e outros táxons. A alta frequência de cianobactérias ocorre pela adaptação à salinidade aliada à baixa competição na área. Os resultados possibilitam inferir os paleoambientes e eventos de sedimentação ocorridos na lagoa e podem ser aplicados na interpretação dos estromatólitos pretéritos.Palavras-chave: Cianobactérias; Esteiras microbianas; Estromatólitos recentes; Lagoa Salgada; Brasil. AbstractSalgada lagoon is a coastal aquatic body in northern Rio de Janeiro state. The geological evolution of the lagoon is associated with the oscillation of sea level during the Late Neogene. The lagoon presents microbial mats, stratiform stromatolites, individual and continuous stromatolites. Stromatolites are laminated carbonate build-ups formed by the metabolic activity of microbial mats. This study identified 31 species of cyanobacteria in stromatolites and microbial mats. The Family Synechococcaceae is the most frequent. Nine species are usual throughout the evolution of the calcareous stromatolites. Microbial mat types include flat, tufted, polygonal and blister forms, all produced mainly by filamentous cyanobacteria. Skeletal remains include bivalves, gastropods, ostracods, foraminifers and other taxons. The high frequency of cyanobacteria in the area occurs because of their adaptation to hypersalinity allied to low competition. The results indicate that a variety of paleoenvironmental and sedimentary events occurred in the lagoon and may be applied to the interpretation of ancient stromatolites.

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Biogeochemistry of a hypersaline lagoon east of Rio de Janeiro, Brazil

Cited by 29 publications

References 5 publications

Stromatolite Growth in Lagoa Vermelha, Southeastern Coast of Brazil: Evidence of Environmental Changes

Stromatolite Growth in Lagoa Vermelha, Southeastern Coast of Brazil: Evidence of Environmental Changes

Assessment of the trophic state of a hypersaline-carbonatic environment: Vermelha Lagoon (Brazil)

Composição cianobacteriana e química dos estromatólitos da lagoa Salgada, Neógeno do estado do Rio de Janeiro, Brasil

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