WorldWideScience

Sample records for basin northern brazil

  1. Visan miospore biostratigraphy and correlation of the Poti Formation (Parnaba Basin, northern Brazil).

    Science.gov (United States)

    Melo; Loboziak

    2000-10-01

    The Poti Formation, which consists mainly of sandstones with minor proportions of carbonaceous shales and other siliciclastic lithologies, represents all the Viséan strata thus far recorded in the Parnaíba Basin, northern Brazil.Well-preserved miospores featuring species with both Southern Euramerican and Gondwanan affinities have been recovered from this formation in four well sections. The most characteristic species are listed in this paper, and brief systematic descriptions are presented for the most significant species, along with comments on their biostratigraphy. A new generic combination is proposed: Cordylosporites magnidictyus (Playford and Helby) Loboziak and Melo comb. nov. Comparisons with miospores illustrated from the Grand Erg Occidental, Algerian Sahara, are tentatively proposed.In terms of the Western European Carboniferous palynozonation, miospore assemblages from the Poti Formation are assignable to the Perotrilites tessellatus-Schulzospora campyloptera (TC)-Raistrickia nigra-Triquitrites marginatus (NM) zonal range. This corresponds to the upper part of the Holkerian and the whole Asbian, which are British regional stages for the lower to middle parts of the upper Viséan. The Viséan age formerly attributed to biostratigraphic interval XII of Petrobras' regional palynostratigraphic scheme is therefore confirmed. As already noted in our recent investigations of the Faro Formation in the Amazon Basin and equivalent strata of the Solimões Basin, latest Tournaisian and early to middle Viséan sections are either absent or barren of characteristic miospores in the Parnaíba Basin as well.

  2. A new species of Bryconops (Teleostei: Characidae from the rio Madeira basin, Northern Brazil

    Directory of Open Access Journals (Sweden)

    Juliana M. Wingert

    Full Text Available A new species of Bryconops is described from a tributary to the rio Madeira in the Amazon basin, State of Rondônia, Brazil. Bryconops piracolina belongs to the subgenus Bryconops by having no teeth or rarely one tooth in the maxilla, and a naked area on cheek between the second and third infraorbitals. The new species is distinguished from all species of this subgenus by the presence of a large black blotch on dorsal-fin base. Furthermore, it is distinguished from all congeners, except B. inpai, by possessing the adipose fin entirely black. It differs from B. inpai by the lack of humeral spots. It further differs from all species of the subgenus Bryconops, except B. caudomaculatus, by having the last scales of the longitudinal series of scales that bears the lateral line series not pored beyond the end of the hypural plate, and differs from B. caudomaculatus by the smaller number of pored lateral line scales (31-36, mean 34.6, vs. 37-43, mean = 40.6, respectively.

  3. Lower Permian stems as fluvial paleocurrent indicators of the Parnaíba Basin, northern Brazil

    Science.gov (United States)

    Capretz, Robson Louiz; Rohn, Rosemarie

    2013-08-01

    A comprehensive biostratinomic study was carried out with abundant stems from the Lower Permian Motuca Formation of the intracratonic Parnaíba Basin, central-north Brazil. The fossils represent a rare tropical to subtropical paleofloristic record in north Gondwana. Tree ferns dominate the assemblages (mainly Tietea, secondarily Psaronius), followed by gymnosperms, sphenophytes, other ferns and rare lycophytes. They are silica-permineralized, commonly reach 4 m length (exceptionally more than 10 m), lie loosely on the ground or are embedded in the original sandstone or siltstone matrix, and attract particular attention because of their frequent parallel attitudes. Many tree fern stems present the original straight cylindrical to slightly conical forms, other are somewhat flattened, and the gymnosperm stems are usually more irregular. Measurements of stem orientations and dimensions were made in three sites approximately aligned in a W-E direction in a distance of 27.3 km at the conservation unit "Tocantins Fossil Trees Natural Monument". In the eastern site, rose diagrams for 54 stems indicate a relatively narrow azimuthal range to SE. These stems commonly present attached basal bulbous root mantles and thin cylindrical sandstone envelopes, which sometimes hold, almost adjacent to the lateral stem surface, permineralized fern pinnae and other small plant fragments. In the more central site, 82 measured stems are preferentially oriented in the SW-NE direction, the proportion of gymnosperms is higher and cross-stratification sets of sandstones indicate paleocurrents mainly to NE and secondarily to SE. In the western site, most of the 42 measured stems lie in E-W positions. The predominantly sandy succession, where the fossil stems are best represented, evidences a braided fluvial system under semiarid conditions. The low plant diversity, some xeromorphic features and the supposedly almost syndepositional silica impregnation of the plants are coherent with marked dry

  4. Tectonics and paleogeography of the Marajó Basin, northern Brazil

    Directory of Open Access Journals (Sweden)

    JOÃO B. S. COSTA

    2002-09-01

    Full Text Available The Marajó Basin area presents geologic and geomorphologic features chiefly due to the Mesozoic extension and post-Miocene neotectonics. The extension event with an Early and a Late Cretaceous phases originated four sub-basins that constitutes the Marajó Basin, with a thick continental clastic sequence showing marine influence. NW and NNW normal faults and NE and ENE strike-slip faults controlled the basin geometry. The extension, related to the Equatorial Atlantic opening, propagated into the continent along crustal weakness zones of the Precambrian Tumucumaque, Amapá and Araguaia orogenic belts. The neotectonic event is a strike-slip regime which developed transtensional basins filled in by Upper Tertiary shallow marine (Pirabas Formation and transitional sequences (Barreiras Group, followed by Quaternary fluvial deposits and transitional sequences derived from the Amazon and Tocantins rivers and the Marajoara estuary. The current landscape has a typical estuarine morphology. The coast morphology presents sea-cliffs on transitional Upper Tertiary sequences, while inwards dominate hills sustained by Mid-Pleistocene lateritic crust, with a flat erosive surface at 70 m. In the eastern Marajó Island several generations of paleochannels associated with fluvial-estuarine sequences are recognized, while a fluvial-marine plain is widespread on its western side.A área da Bacia do Marajó apresenta feições geológicas e geomorfológicas devidas principamente à distensão Mesozóica e à neotectônica pós-miocênica. O evento de distensão, com fases do Cretáceo Inferior e Superior, originou quatro sub-bacias que contituem a Bacia do Marajó, com uma espessa seqüência clástica continental mostrando influência marinha. Falhas normais NW e NNW e direcionais NE e ENE controlaram a geometria da bacia. A distensão, relacionada com a abertura do Atlântico Equatorial, propagou-se continente adentro ao longo de zonas de fraqueza crustal dos

  5. Two new species of Pseudancistrus (Siluriformes, Loricariidae from the Amazon basin, northern Brazil

    Directory of Open Access Journals (Sweden)

    Gabriel da Costa e Silva

    2015-02-01

    Full Text Available Two new species of Pseudancistrus, a genus diagnosed by non-evertible cheek plates and hypertrophied odontodes along the snout margin, are described from two drainages of the Brazilian Shield: P. kayabi from the rio Teles Pires (rio Tapajós basin and P. asurini from the rio Xingu. The new species are distinguished from congeners (P. barbatus, P. corantijniensis, P. depressus, P. nigrescens, P. reus, and P. zawadzkii by the coloration pattern. Pseudancistrus kayabi has dark bars on the dorsal and caudal fins which are similar to that of P. reus from the Caroní River, Venezuela. Pseudancistrus asurini is unique among Pseudancistrus in having whitish tips of the dorsal and caudal fins in juveniles to medium-sized adults.

  6. Megafans of the Northern Kalahari Basin

    Science.gov (United States)

    Wilkinson, M. J.; Miller, R. McG.; Eckardt, F.; Kreslavsky, M. A.

    2016-01-01

    We identify eleven megafans (partial cones of fluvial sediment, >80 km radius) in the northern Kalahari Basin, using several criteria based on VIS and IR remotely sensed data and SRTM-based surface morphology reconstructions. Two other features meet fewer criteria of the form which we class as possible megafans. The northern Kalahari megafans are located in a 1700 km arc around the southern and eastern flanks of the Angola's Bié Plateau, from northern Namibia through northwest Botswana to western Zambia. Three lie in the Owambo subbasin centered on the Etosha Pan, three in the relatively small Okavango rift depression, and five in the Upper Zambezi basin. The population includes the well-known Okavango megafan (150 km), Namibia's Cubango megafan, the largest megafan in the region (350 km long), and the largest nested group (the five major contiguous megafans on the west slopes of the upper Zambezi Valley). We use new, SRTM-based topographic roughness data to discriminate various depositional surfaces within the flat N. Kalahari landscapes. We introduce the concepts of divide megafans, derived megafans, and fan-margin rivers. Conclusions. (i) Eleven megafan cones total an area of 190,000 sq km. (ii) Different controls on megafan size operate in the three component basins: in the Okavango rift structural controls become the prime constraint on megafan length by controlling basin dimensions. Megafans in the other les constricted basins appear to conform to classic relationships fan area, slope, and feeder-basin area. (iii) Active fans occupy the Okavango rift depression with one in the Owambo basin. The rest of the population are relict but recently active fans (surfaces are relict with respect to activity by the feeder river). (iv) Avulsive behavior of the formative river-axiomatic for the evolution of megafans-has resulted in repeated rearrangements of regional drainage, with likely effects in the study area well back into the Neogene. Divide megafans comprise the

  7. Evolution and palaeoenvironment of the Bauru Basin (Upper Cretaceous, Brazil)

    Science.gov (United States)

    Fernandes, Luiz Alberto; Magalhães Ribeiro, Claudia Maria

    2015-08-01

    The Bauru Basin was one of the great Cretaceous desert basins of the world, evolved in arid zone called Southern Hot Arid Belt. Its paleobiological record consists mainly of dinosaurs, crocodiles and turtles. The Bauru Basin is an extensive region of the South American continent that includes parts of the southeast and south of Brazil, covering an area of 370,000 km2. It is an interior continental basin that developed as a result of subsidence of the central-southern part of the South-American Platform during the Late Cretaceous (Coniacian-Maastrichtian). This sag basin is filled by a sandy siliciclastic sequence with a preserved maximum thickness of 480 m, deposited in semiarid to desert conditions. Its basement consists of volcanic rocks (mainly basalts) of the Lower Cretaceous (Hauterivian) Serra Geral basalt flows, of the Paraná-Etendeka Continental Flood Basalt Province. The sag basin was filled by an essentially siliciclastic psammitic sequence. In lithostratigraphic terms the sequence consists of the Caiuá and Bauru groups. The northern and northeastern edges of the basin provide a record of more proximal original deposits, such as associations of conglomeratic sand facies from alluvial fans, lakes, and intertwined distributary river systems. The progressive basin filling led to the burial of the basaltic substrate by extensive blanket sand sheets, associated with deposits of small dunes and small shallow lakes that retained mud (such as loess). Also in this intermediate context between the edges (more humid) and the interior (dry), wide sand sheet areas crossed by unconfined desert rivers (wadis) occurred. In the central axis of the elliptical basin a regional drainage system formed, flowing from northeast to southwest between the edges of the basin and the hot and dry inner periphery of the Caiuá desert (southwest). Life in the Bauru Basin flourished most in the areas with the greatest water availability, in which dinosaurs, crocodiles, turtles, fish

  8. Aquatic life protection index of an urban river Bacanga basin in northern Brazil, São Luís - MA

    Directory of Open Access Journals (Sweden)

    A. K. Duarte-dos-Santos

    Full Text Available Abstract Bacanga River Basin faces environmental problems related to urbanization and discharge of untreated domestic sewage, which compromise its ecosystem health. Due to the small number of studies that assessed its water quality, the present study aimed to assess the current status of this ecosystem based on the aquatic life protection index. Samples were carried out every two months, in a total of six events, in six sites along the basin, where the water samples were collected to assess physicochemical parameters and calculate the trophic state index and the index of minimum parameters for the protection of aquatic communities. The data were also compared with values determined by the resolution National Environment Council - CONAMA 357/05. Our results reveal significant changes in the water quality of Bacanga River Basin. An increase in nutrients and chlorophyll-a concentration led it to eutrophication. The surfactant values were high and put in danger the aquatic biota. Dissolved oxygen rates were below the values allowed by the resolution in most sites sampled. The current water quality is terrible for the protection of aquatic life in 61.92% of the sites sampled.

  9. Groundwater quality in the Northern Coast Ranges Basins, California

    Science.gov (United States)

    Mathany, Timothy M.; Belitz, Kenneth

    2015-01-01

    The Northern Coast Ranges (NOCO) study unit is 633 square miles and consists of 35 groundwater basins and subbasins (California Department of Water Resources, 2003; Mathany and Belitz, 2015). These basins and subbasins were grouped into two study areas based primarily on locality. The groundwater basins and subbasins located inland, not adjacent to the Pacific Ocean, were aggregated into the Interior Basins (NOCO-IN) study area. The groundwater basins and subbasins adjacent to the Pacific Ocean were aggregated into the Coastal Basins (NOCO-CO) study area (Mathany and others, 2011).

  10. Backwater effects in the Amazon River basin of Brazil

    Science.gov (United States)

    Meade, R.H.; Rayol, J.M.; Da Conceicao, S.C.; Natividade, J.R.G.

    1991-01-01

    The Amazon River mainstem of Brazil is so regulated by differences in the timing of tributary inputs and by seasonal storage of water on floodplains that maximum discharges exceed minimum discharges by a factor of only 3. Large tributaries that drain the southern Amazon River basin reach their peak discharges two months earlier than does the mainstem. The resulting backwater in the lowermost 800 km of two large southern tributaries, the Madeira and Puru??s rivers, causes falling river stages to be as much as 2-3 m higher than rising stages at any given discharge. Large tributaries that drain the northernmost Amazon River basin reach their annual minimum discharges three to four months later than does the mainstem. In the lowermost 300-400 km of the Negro River, the largest northern tributary and the fifth largest river in the world, the lowest stages of the year correspond to those of the Amazon River mainstem rather than to those in the upstream reaches of the Negro River. ?? 1991 Springer-Verlag New York Inc.

  11. Complete Genome Sequence of Streptococcus iniae UEL-Si1, Isolated in Diseased Nile Tilapia (Oreochromis niloticus) from Northern Paraná, Southern Brazil.

    Science.gov (United States)

    Vilas-Boas, Laurival A; Headley, Selwyn A; Gonçalves, Kátia B; Scarpassa, Josiane A; Pretto-Giordano, Lucienne G

    2017-01-12

    The Streptococcus iniae UEL-Si1 strain was isolated from diseased Nile tilapia within the Paranapanema River Basin, Northern Paraná, Brazil. This is an emerging infectious disease agent of fish from Brazil, and sequencing of the complete genome is fundamental to understanding aspects relative to pathogenesis, infection, epidemiology, and immunity. Copyright © 2017 Vilas-Boas et al.

  12. The Northeastern Brazil and Gabon Basins: a Double Rifting System Associated with Multiple Crustal Detachment Surfaces

    Science.gov (United States)

    Castro, Augusto Canellas M., Jr.

    1987-12-01

    Analysis of structural, stratigraphic, and gravimetric data from the Reconcavo, Tucano, and Sergipe-Alagoas basins in northeastern Brazil and the Gabon basin in Africa shows that these basins originated in a double rifting system associated with multiple crustal detachment surfaces and that the direction of dip of the detachment surfaces was reversed at the Vaza-Barris fault system. This geometry is in agreement with models and data from modern rifts, but it requires the existence of a predominantly extensional stress regime in the northern part of the South Atlantic during the early stages of oceanic evolution. Evidence for the existence of such a stress regime is given by application of kinematic constraints to Early Cretaceous reconstructions of the South Atlantic Ocean. Interpretation of the regional geologic setting suggests that the double rifting system and the point of final continental rupture were controlled by the preexisting structural orientation of the tectonic provinces in the Precambrian basement.

  13. A new species of Sipapoantha (Genianaceae: Heliae) from northern Brazil

    NARCIS (Netherlands)

    Lepis, K.B.; Maas, P.J.M.; Struwe, L.

    2011-01-01

    A new species from Gentianaceae (tribe Helieae) is described from northern Brazil. Sipapoantha obtusisepala sp. nov. is distinct from the previously single member of the genus, Sipapoantha ostrina, by having a woody and branched habit, sessile and ovate leaves with an acute apex, and a smaller calyx

  14. A new species of Sipapoantha (Gentianaceae: Helieae) from northern Brazil

    NARCIS (Netherlands)

    Lepis, K.B.; Maas, P.J.M.; Struwe, L.

    2011-01-01

    A new species from Gentianaceae (tribe Helieae) is described from northern Brazil. Sipapoantha obtusisepala sp. nov. is distinct from the previously single member of the genus, Sipapoantha ostrina, by having a woody and branched habit, sessile and ovate leaves with an acute apex, and a smaller calyx

  15. Northern Rivers Basins human health monitoring program : report

    Energy Technology Data Exchange (ETDEWEB)

    Gabos, S. [Alberta Health, Edmonton, AB (Canada). Health Surveillance

    1999-04-01

    The Northern River Basins Human Health Monitoring Program was established in 1994 to investigate the possible relationships between various environmental risk factors and the health of northern residents in the province. This report presents the initial analysis of the health program and examines the differences in health outcomes across the province and compares the Northern Rivers Basin Study (NRBS) area with the other areas of the province. A series of maps and graphs showed the prevalence of certain diseases and disorders within the Peace and Athabasca river basins. The focus of the report was on reproductive health, congenital anomalies, respiratory ailments, circulatory diseases, gastrointestinal disorders, endocrine and metabolic disorders, and neurocognitive disorders. The study showed that compared to other areas of the province, the NRBS area had higher incidences of endometriosis, selected congenital anomalies, bronchitis, pneumonia, peptic ulcers and epilepsy. There were three potential exposure pathways to environmental contaminants. These were through ingestion of water or food, inhalation of air and through dermal exposure. refs., tabs., figs.

  16. Northern Rivers Basins human health monitoring program : report

    International Nuclear Information System (INIS)

    Gabos, S.

    1999-04-01

    The Northern River Basins Human Health Monitoring Program was established in 1994 to investigate the possible relationships between various environmental risk factors and the health of northern residents in the province. This report presents the initial analysis of the health program and examines the differences in health outcomes across the province and compares the Northern Rivers Basin Study (NRBS) area with the other areas of the province. A series of maps and graphs showed the prevalence of certain diseases and disorders within the Peace and Athabasca river basins. The focus of the report was on reproductive health, congenital anomalies, respiratory ailments, circulatory diseases, gastrointestinal disorders, endocrine and metabolic disorders, and neurocognitive disorders. The study showed that compared to other areas of the province, the NRBS area had higher incidences of endometriosis, selected congenital anomalies, bronchitis, pneumonia, peptic ulcers and epilepsy. There were three potential exposure pathways to environmental contaminants. These were through ingestion of water or food, inhalation of air and through dermal exposure. refs., tabs., figs

  17. First isolation of enterovirus 71 (EV-71 from Northern Brazil

    Directory of Open Access Journals (Sweden)

    Leticia Martins Lamarão

    Full Text Available Enterovirus 71 (EV-71 has been associated to cases of neurological disease in many countries including Brazil. This virus has now been reported from three of the five Brazilian regions. Our study relates the findings concerning to the first isolate of this virus in Northern region of Brazil. A 15-month old female patient, from the rural zone of the municipality of Santana do Araguaia in southern Pará state was admitted at the hospital with acute, flaccid, asymmetric and ascending motor deficiency, located in the right lower limb. Stools samples from this child were inoculated in RD cells and was isolated an EV-71. We plan to sequence our strain and compare it to other isolates in Brazil. Differences at the molecular level can explain why EV-71 strains circulating in other continents, such as Asia, appear to be more virulent.

  18. First isolation of enterovirus 71 (EV-71 from Northern Brazil

    Directory of Open Access Journals (Sweden)

    Lamarão Leticia Martins

    2003-01-01

    Full Text Available Enterovirus 71 (EV-71 has been associated to cases of neurological disease in many countries including Brazil. This virus has now been reported from three of the five Brazilian regions. Our study relates the findings concerning to the first isolate of this virus in Northern region of Brazil. A 15-month old female patient, from the rural zone of the municipality of Santana do Araguaia in southern Pará state was admitted at the hospital with acute, flaccid, asymmetric and ascending motor deficiency, located in the right lower limb. Stools samples from this child were inoculated in RD cells and was isolated an EV-71. We plan to sequence our strain and compare it to other isolates in Brazil. Differences at the molecular level can explain why EV-71 strains circulating in other continents, such as Asia, appear to be more virulent.

  19. Contribution to the stratigraphy of the onshore Paraiba Basin, Brazil

    Energy Technology Data Exchange (ETDEWEB)

    Rossetti, Dilce F.; Valeriano, Marcio M., E-mail: rossetti@dsr.inpe.br [Instituto Nacional de Pesquisas Espaciais (INPE), Sao Jose dos Campos, SP (Brazil). Divisao de Sensoriamento Remoto; Goes, Ana M.; Brito-Neves, Benjamim B. [Universidade de Sao Paulo (USP), Sao Paulo, SP (Brazil). Inst. de Geociencias; Bezerra, Francisco H.R.; Ochoa, Felipe L. [Universidade Federal do Rio Grande do Norte (UFRN), Natal, RN (Brazil). Centro de Ciencias Exatas e da Terra. Departamento de Geologia

    2012-06-15

    Several publications have contributed to improve the stratigraphy of the Paraiba Basin in northeastern Brazil. However, the characterization and distribution of sedimentary units in onshore areas of this basin are still incomplete, despite their significance for reconstructing the tectono- sedimentary evolution of the South American passive margin. This work provides new information to differentiate among lithologically similar strata, otherwise entirely unrelated in time. This approach included morphological, sedimentological and stratigraphic descriptions based on surface and sub-surface data integrated with remote sensing, optically stimulated luminescence dating, U+Th/He dating of weathered goethite, and heavy mineral analysis. Based on this study, it was possible to show that Cretaceous units are constrained to the eastern part of the onshore Paraiba Basin. Except for a few outcrops of carbonatic-rocks nearby the modern coastline, deposits of this age are not exposed to the surface in the study area. Instead, the sedimentary cover throughout the basin is constituted by mineralogically and chronologically distinctive deposits, inserted in the Barreiras Formation and mostly in the Post-Barreiras Sediments, of early/middle Miocene and Late Pleistocene-Holocene ages, respectively. The data presented in this work support tectonic deformation as a factor of great relevance to the distribution of the sedimentary units of the Paraiba Basin. (author)

  20. Late Pleistocene echimyid rodents (Rodentia, Hystricognathi) from northern Brazil.

    Science.gov (United States)

    Ferreira, Thais M F; Olivares, Adriana Itati; Kerber, Leonardo; Dutra, Rodrigo P; Avilla, Leonardo S

    2016-06-07

    Echimyidae (spiny rats, tree rats and the coypu) is the most diverse family of extant South American hystricognath rodents (caviomorphs). Today, they live in tropical forests (Amazonian, coastal and Andean forests), occasionally in more open xeric habitats in the Cerrado and Caatinga of northern South America, and open areas across the southern portion of the continent (Myocastor). The Quaternary fossil record of this family remains poorly studied. Here, we describe the fossil echimyids found in karst deposits from southern Tocantins, northern Brazil. The analyzed specimens are assigned to Thrichomys sp., Makalata cf. didelphoides and Proechimys sp. This is the first time that a fossil of Makalata is reported. The Pleistocene record of echimyids from this area is represented by fragmentary remains, which hinders their determination at specific levels. The data reported here contributes to the understanding of the ancient diversity of rodents of this region, evidenced until now in other groups, such as the artiodactyls, cingulates, carnivores, marsupials, and squamate reptiles.

  1. Fishes of the Taquari-Antas river basin (Patos Lagoon basin, southern Brazil

    Directory of Open Access Journals (Sweden)

    FG. Becker

    Full Text Available The aquatic habitats of the Taquari-Antas river basin (in the Patos Lagoon basin, southern Brazil are under marked environmental transformation because of river damming for hydropower production. In order to provide an information baseline on the fish fauna of the Taquari-Antas basin, we provide a comprehensive survey of fish species based on primary and secondary data. We found 5,299 valid records of fish species in the basin, representing 119 species and 519 sampling sites. There are 13 non-native species, six of which are native to other Neotropical river basins. About 24% of the total native species are still lacking a taxonomic description at the species level. Three native long-distance migratory species were recorded (Leporinus obtusidens, Prochilodus lineatus, Salminus brasiliensis, as well as two potential mid-distance migrators (Parapimelodus nigribarbis and Pimelodus pintado. Although there is only one officially endangered species in the basin (S. brasiliensis, restricted range species (21.7% of total species should be considered in conservation efforts.

  2. The Quaternary alluvial systems tract of the Pantanal Basin, Brazil

    Directory of Open Access Journals (Sweden)

    Mario Luis Assine

    Full Text Available ABSTRACT The Pantanal Basin is an active sedimentary basin in central-west Brazil that consists of a complex alluvial systems tract characterized by the interaction between different river systems developed in one of the largest wetlands in the world. The Paraguay River is the trunk river system that drains the water and part of the sediment load received from areas outside of the basin. Depositional styles vary considerably along the river profiles throughout the basin, with the development of entrenched meandering belts, anastomosing reaches, and floodplain ponds. Paleodrainage patterns are preserved on the surface of abandoned lobes of fluvial fans, which also exhibit many degradational channels. Here, we propose a novel classification scheme according to which the geomorphology, hydrological regime and sedimentary dynamics of these fluvial systems are determined by the geology and geomorphology of the source areas. In this way, the following systems are recognized and described: (I the Paraguay trunk-river plains; (II fluvial fans sourced by the tablelands catchment area; (III fluvial fans sourced by lowlands; and (IV fluvial interfans. We highlight the importance of considering the influences of source areas when interpreting contrasting styles of fluvial architectures in the rock record.

  3. Three-dimensional seismo-tectonics in the Po Valley basin, Northern Italy

    NARCIS (Netherlands)

    Turrini, Claudio; Angeloni, Pamela; Lacombe, Olivier; Ponton, Maurizio; Roure, François

    2015-01-01

    The Po Valley (Northern Italy) is a composite foreland-foredeep basin caught in between the Southern Alps and Northern Apennine mountain belts. By integrating the 3D structural model of the region with the public earthquake dataset, the seismo-tectonics of the basin is shown at different scales of

  4. Northern Great Basin Seasonal Lakes: Vulnerability to Climate Change.

    Science.gov (United States)

    Russell, M.; Eitel, J.

    2017-12-01

    Seasonal alkaline lakes in southeast Oregon, northeast California, and northwest Nevada serve as important habitat for migrating birds utilizing the Pacific Flyway, as well as local plant and animal communities. Despite their ecological importance, and anecdotal suggestions that these lakes are becoming less reliable, little is known about the vulnerability of these lakes to climate change. Our research seeks to understand the vulnerability of Northern Great Basin seasonal lakes to climate change. For this, we will be using historical information from the European Space Agency's Global Surface Water Explorer and the University of Idaho's gridMET climate product, to build a model that allows estimating surface water extent and timing based on climate variables. We will then utilize downscaled future climate projections to model surface water extent and timing in the coming decades. In addition, an unmanned aerial system (UAS) will be utilized at a subset of dried basins to obtain precise 3D bathymetry and calculate water volume hypsographs, a critical factor in understanding the likelihood of water persistence and biogeochemical habitat suitability. These results will be incorporated into decision support tools that land managers can utilize in water conservation, wildlife management, and climate mitigation actions. Future research may pair these forecasts with animal movement data to examine fragmentation of migratory corridors and species-specific impacts.

  5. Relationship between sandstone-type uranium deposits and hydrocarbon in the northern ordos basin

    Science.gov (United States)

    Wang, Feifei; Wang, Jianqiang; Guo, Pei; Cheng, Xianghu; Li, Bei; Song, Zisheng; Wei, Anjun

    2017-05-01

    The Ordos Basin is one of the largest proliferous basins and also one of the most important uranium-bearing basins in China. It is characterized by the coexistence of petroleum and uranium in the northern part of the basin. To understand the coexistence mechanism, more studies are called for on the genesis of sandstone-type uranium deposits in the northern part of the basin, especially on the role of hydrocarbon in uranium mineralization. In this study, we investigated the relationship between uranium and hydrocarbon in the northern Ordos Basin using the methods of petrology, mineralogy and geochemistry. Our results show that the hydrocarbon seepage plays an important role in the mineralization of sandstone-type uranium deposits. It greatly affects the reduction in mineralization and the environmental rehabilitation to protect the ore body from being destroyed by the groundwater after mineralization.

  6. Fish, Marmelos Conservation Area (BX044), Madeira River basin, states of Amazonas and Rondônia, Brazil

    OpenAIRE

    Camargo, Mauricio; Giarrizzo, Tommaso

    2007-01-01

    The present study provides a species list of fish from the Marmelos River Area – BX044 in the states of Amazonas and Rondônia in northern Brazil. During a Rapid Ecological Assessment (REA) performed in October and November of 2003, 133 fish species from six orders and 24 families were recorded. The most diverse families were Characidae (47 species), Cichlidae (15 species), Loricariidae (12 species) and Pimelodidae (7 species). 23 fish species were common to the entire river basin and 4 were e...

  7. Fish, Marmelos Conservation Area (BX044, Madeira River basin, states of Amazonas and Rondônia, Brazil.

    Directory of Open Access Journals (Sweden)

    Camargo, M.

    2007-01-01

    Full Text Available The present study provides a species list of fish from the Marmelos River Area – BX044 in the states ofAmazonas and Rondônia in northern Brazil. During a Rapid Ecological Assessment (REA performed in October andNovember of 2003, 133 fish species from six orders and 24 families were recorded. The most diverse families wereCharacidae (47 species, Cichlidae (15 species, Loricariidae (12 species and Pimelodidae (7 species. 23 fish specieswere common to the entire river basin and 4 were endemic to the aquatic system studied.

  8. Late Pleistocene echimyid rodents (Rodentia, Hystricognathi from northern Brazil

    Directory of Open Access Journals (Sweden)

    THAIS M.F. FERREIRA

    2016-06-01

    Full Text Available ABSTRACT Echimyidae (spiny rats, tree rats and the coypu is the most diverse family of extant South American hystricognath rodents (caviomorphs. Today, they live in tropical forests (Amazonian, coastal and Andean forests, occasionally in more open xeric habitats in the Cerrado and Caatinga of northern South America, and open areas across the southern portion of the continent (Myocastor. The Quaternary fossil record of this family remains poorly studied. Here, we describe the fossil echimyids found in karst deposits from southern Tocantins, northern Brazil. The analyzed specimens are assigned to Thrichomys sp., Makalata cf. didelphoides and Proechimys sp. This is the first time that a fossil of Makalata is reported. The Pleistocene record of echimyids from this area is represented by fragmentary remains, which hinders their determination at specific levels. The data reported here contributes to the understanding of the ancient diversity of rodents of this region, evidenced until now in other groups, such as the artiodactyls, cingulates, carnivores, marsupials, and squamate reptiles.

  9. Comparison of the rift and post-rift architecture of conjugated salt and salt-free basins offshore Brazil and Angola/Namibia, South Atlantic

    Science.gov (United States)

    Strozyk, Frank; Back, Stefan; Kukla, Peter A.

    2017-10-01

    This study presents a regional comparison between selected 2D seismic transects from large, conjugated salt and salt-free basins offshore southern Brazil (Campos Basin, Santos Basin, Pelotas Basin) and southwest Africa (Kwanza Basin, northern and southern Namibe Basin, Walvis Basin). Tectonic-stratigraphic interpretation of the main rift and post-rift units, free-air gravity data and flexural isostatic backstripping were used for a comprehensive basin-to-basin documentation of key mechanisms controlling the present-day differences in conjugated and neighbouring South Atlantic basins. A significant variation in the tectonic-sedimentary architecture along-strike at each margin and between the conjugated basins across the South Atlantic reflects major differences in (1) the structural configuration of each margin segment at transitional phase between rifting and breakup, as emphasized in the highly asymmetric settings of the large Santos salt basin and the conjugated, salt-free southern Namibe Basin, (2) the post-breakup subsidence and uplift history of the respective margin segment, which caused major differences for example between the Campos and Espirito Santo basins and the conjugated northern Namibe and Kwanza basins, (3) variations in the quantity and distribution of post-breakup margin sediments, which led to major differences in the subsidence history and the related present-day basin architecture, for example in the initially rather symmetric, siliciclastic Pelotas and Walvis basins, and (4) the deposition of Aptian evaporites in the large rift and sag basin provinces north of the Rio Grande Rise and Walvis Ridge, highly contrasting the siliciclastic basins along the margin segments south of the ridges. The resulting present-day architecture of the basins can be generally classified as (i) moderately symmetric, salt-free, and magma-rich in the northern part of the southern segment, (i) highly asymmetric, salt-bearing and magma-poor vs. salt-free and magma

  10. The central and northern Appalachian Basin-a frontier region for coalbed methane development

    Science.gov (United States)

    Lyons, P.C.

    1998-01-01

    The Appalachian basin is the world's second largest coalbed-methane (CBM) producing basin. It has nearly 4000 wells with 1996 annual production at 147.8 billion cubic feet (Bcf). Cumulative CBM production is close to 0.9 trillion cubic feet (Tcf). The Black Warrior Basin of Alabama in the southern Appalachian basin (including a very minor amount from the Cahaba coal field) accounts for about 75% of this annual production and about 75% of the wells, and the remainder comes from the central and northern Appalachian basin. The Southwest Virginia coal field accounts for about 95% of the production from the central and northern parts of the Appalachian basin. Production data and trends imply that several of the Appalachian basin states, except for Alabama and Virginia, are in their infancy with respect to CBM development. Total in-place CBM resources in the central and northern Appalachian basin have been variously estimated at 66 to 76 trillion cubic feet (Tcf), of which an estimated 14.55 Tcf (~ 20%) is technically recoverable according to a 1995 U.S. Geological Survey assessment. For comparison in the Black Warrior basin of the 20 Tcf in-place CBM resources, 2.30 Tcf (~ 12%) is technically recoverable. Because close to 0.9 Tcf of CBM has already been produced from the Black Warrior basin and the proved reserves are about 0.8 Tcf for 1996 [Energy Information Administration (EIA), 1997]. U.S. Crude Oil, Natural Gas, and Natural Gas Liquids Reserves, 1996 Annual Report. U.S. Department of Energy DOE/EIA-0216(96), 145 pp.], these data imply that the central and northern Appalachian basin could become increasingly important in the Appalachian basin CBM picture as CBM resources are depleted in the southern Appalachian basin (Black Warrior Basin and Cahaba Coal Field). CBM development in the Appalachian states could decrease the eastern U.S.A.'s dependence on coal for electricity. CBM is expected to provide over the next few decades a virtually untapped source of

  11. LBA-ECO CD-06 Physical, Political, and Hydrologic Maps, Ji-Parana River Basin, Brazil

    Data.gov (United States)

    National Aeronautics and Space Administration — This data set contains physical, hydrologic, political, demographic, and societal maps for the Ji-Parana River Basin, in the state of Rondonia, Brazil. These data...

  12. LBA-ECO CD-06 Soil Classification Map, Ji-Parana River Basin, Rondonia, Brazil

    Data.gov (United States)

    National Aeronautics and Space Administration — This data set provides a digital map of soil orders for the Ji-Parana River Basin, in the state of Rondonia, Brazil (Western Amazonia). Soil orders were manually...

  13. LBA-ECO CD-06 Soil Classification Map, Ji-Parana River Basin, Rondonia, Brazil

    Data.gov (United States)

    National Aeronautics and Space Administration — ABSTRACT: This data set provides a digital map of soil orders for the Ji-Parana River Basin, in the state of Rondonia, Brazil (Western Amazonia). Soil orders were...

  14. LBA-ECO CD-06 Physical, Political, and Hydrologic Maps, Ji-Parana River Basin, Brazil

    Data.gov (United States)

    National Aeronautics and Space Administration — ABSTRACT: This data set contains physical, hydrologic, political, demographic, and societal maps for the Ji-Parana River Basin, in the state of Rondonia, Brazil....

  15. A Blind Normal Fault beneath the Taipei Basin in Northern Taiwan

    Directory of Open Access Journals (Sweden)

    Kou-Cheng Chen

    2010-01-01

    Full Text Available The Taipei basin, historically low in seismicity, is located in northern Taiwan. A dense broadband seismic array was deployed in the basin in June 2004 to monitor seismic activity. During the period of operation, three felt earthquakes occurred near the eastern part of the Taipei basin, about 3 km to the south of Taipei 101 then the tallest building in the world. Relocated earthquakes show a southeast-dipping distribution of hypocenters beneath the Taipei basin. The seismicity pattern and focal mechanisms of the three felt events suggest the existence of a blind normal fault whose surface projection is along the river channel in the middle of the basin.

  16. Present-day 3D structural model of the Po Valley basin, Northern Italy

    NARCIS (Netherlands)

    Turrini, C.; Lacombe, O.; Roure, F.

    2014-01-01

    A 3D structural model of the Po Valley basin (Northern Italy) was built by integrating the dataset available from the public domain (DEM, wells, isobath-maps, cross-sections, outcrop-trends).The model shows the complex foredeep-foreland architecture across the basin, from the Moho level to the

  17. Arsenic mobility in sediments from Paracatu River Basin, MG, Brazil.

    Science.gov (United States)

    Rezende, Patrícia Sueli; Costa, Letícia Malta; Windmöller, Cláudia Carvalhinho

    2015-04-01

    Paracatu River Basin, Minas Gerais, Brazil, houses long areas of irrigated agriculture and gold-, lead-, and zinc-mining activities. This region has a prevalence of sulfide minerals and a natural occurrence of high levels of arsenopyrite. In this work, surface water, groundwater, sediments and local vegetable samples were collected in October 2010 and November 2011 and were analyzed to evaluate arsenic (As) distribution, mobility, and transport in these environmental compartments. All sediment samples (738-2,750 mg kg(-1)) and 37 % of the water samples [less than the limit of detection (LOD) to 110 µg L(-1)] from the rivers and streams of Paracatu had As concentrations greater than the quality standards established by national and international environmental organizations (5.9 mg kg(-1) for sediments and 10 µg L(-1) for water). Most vegetable samples had As concentrations within the normal range for plants (lower than the LOD to 120 mg kg(-1)). A correlation among As concentrations in water, sediment, and vegetable samples was verified.

  18. Interaction between trench retreat and Anatolian escape as recorded by neogene basins in the northern Aegean Sea

    NARCIS (Netherlands)

    Beniest, A.; Brun, J. P.; Gorini, C.; Crombez, V.; Deschamps, R.; Hamon, Y.; Smit, Jeroen

    2016-01-01

    The evolution of the North Aegean Sea is studied through the development of three deep basins: the North Aegean Trough, the North Skyros Basin and the Ikaria Basin. Bathymetric data, a 2D seismic dataset and the well-investigated stratigraphic records of the onshore deep basins of northern Greece

  19. Tectonic subsidence of the Zhu 1 Sub-basin in the Pearl River Mouth Basin, northern South China Sea

    Science.gov (United States)

    Tang, Xiaoyin; Yang, Shuchun; Zhu, Junzhang; Long, Zulie; Jiang, Guangzheng; Huang, Shaopeng; Hu, Shengbiao

    2017-12-01

    The Pearl River Mouth Basin, which is situated on the northern margin of the South China Sea, has attracted great attention not only because of its tectonic setting but also because of its abundant hydrocarbon resources. We have analyzed the Cenozoic tectonic subsidence history of 4 drilled wells and 43 artificial wells from the Zhu 1 Sub-basin of the Pearl River Mouth Basin by back-stripping, using newly interpreted seismic profiles. We also calculated the average tectonic subsidence rates of the four sags in the Zhu 1 Sub-basin. The rifting and post-rifting stages are separated by abrupt changes in the tectonic subsidence curves and average subsidence rates. In the eastern sags of the Zhu 1 Sub-basin, tectonic subsidence started to slow at ca. 30 Ma, compared with ca. 23.8 Ma in the western sags. This probably corresponds to the timing of break-up and suggests that rifting in the Pearl River Mouth Basin ended earlier in the eastern sags than in the western sags. Anomalously accelerated tectonic subsidence occurred at 17.5-16.4 Ma during the post-rifting stage, with average subsidence rates as high as 301.9 m/Myr. This distinguishes the Pearl River Mouth Basin from classical Atlantic passive continental marginal basins, which demonstrate exponentially decaying post-rift tectonic subsidence.

  20. Exploration potential of Paraiba and Natal platform basins, NE Brazil; Potencial exploratorio das bacias da Paraiba e da plataforma de Natal, NE do Brazil

    Energy Technology Data Exchange (ETDEWEB)

    Barbosa, Jose A. [Universidade Federal de Pernambuco (UFPE), Recife, PE (Brazil); Lima Filho, Mario; Neumann, Virginio H. [Universidade Federal de Pernambuco (UFPE), Recife, PE (Brazil). Dept. de Geologia; Maranhao Neto, Jose Carneiro; Araujo, Joao A.A. [Universidade Federal de Pernambuco (UFPE), Recife, PE (Brazil). Programa de Pos Graduacao em Geociencias

    2008-07-01

    The portion of Brazilian continental margin located between the Pernambuco Shear Zone (ZCPE) and Touros High, enclosing Natal Platform and Paraiba basin, NE Brazil, presents a thin sedimentary cover represented by Neo- Cretaceous deposits, over an elevated basement. In this zone the narrow platform ends abruptly against the ocean plate, forming a scarped slope. This area corresponds to the Transverse zone of Northeast Brazil (TZN) limited by two extensive transcurrent E-W shear zones that acted as accommodation zones for the strain produced by the advance of the southern and northern rift branches. During the Aptian, the rift suffered a NE deflection and contoured the Borborema Province and the TZN. The resistance of this block to the rift advance generated a prominent and elevated region into the Atlantic gulf which resulted in the absence of rift deposition over the Brazilian margin and its deviation to the African side. The model suggested by this paper denominates this area as the 'exception zone' of the Brazilian margin, which possess a poor petroliferous potential and need to be separated from the sector corresponding to the Pernambuco basin, located to south of ZCPE, representing the last piece of margin before the rift deflection and possessing an important petroliferous potential. (author)

  1. Petroleum potential of the northern Sinu-San Jacinto Basin, Colombia: an integrated petroleum system and basin modeling approach

    Energy Technology Data Exchange (ETDEWEB)

    Nino, Christian H.; Goncalves, Felix T.T.; Bedregal, Ricardo P. [Universidade Federal do Rio de Janeiro (UFRJ), RJ (Brazil). Coordenacao dos Programas de Pos-graduacao de Engenharia (COPPE). Lab. de Modelagem de Bacias (LAB2M); Azevedo, Debora A. [Universidade Federal do Rio de Janeiro (UFRJ), RJ (Brazil). Inst. de Quimica; Landau, Luis [Universidade Federal do Rio de Janeiro (UFRJ), RJ (Brazil). Coordenacao dos Programas de Pos-graduacao de Engenharia (COPPE). Lab. de Metodos Computacionais em Engenharia (LAMCE)

    2004-07-01

    The northern Sinu-San Jacinto basin, located in the northwestern corner of South America (Colombia), belongs to the accretionary prism that resulted from the collision and subduction of the Caribbean plate under the South America plate. Despite all the previous exploratory efforts, solely a few small sub-commercial oil and gas accumulation have been found up to now. The geological and geochemical information acquired by different companies during the lasts decades was integrated with new geochemical analysis and basin modeling to characterize the petroleum systems, to reconstruct the hydrocarbon charge history in the study area and to better assess the exploratory risk. (author)

  2. Deep seismic reflection profiling of sedimentary basins offshore Brazil: Geological objectives and preliminary results in the Sergipe Basin

    Science.gov (United States)

    Mohriak, Webster Ueipass; Lira Rabelo, JoséHenrique; De Matos, Renato Darros; De Barros, Mozart C.

    1995-12-01

    The first deep seismic reflection profiles offshore Brazil were acquired in Campos Basin and processed to 10 s TWT in 1984. Starting in 1989, Petrobrás acquired an extensive data set of deep seismic profiles using special acquisition equipment capable of effectively penetrating through the sedimentary layers and imaging the whole crustal architecture. These deep (18 s TWT) seismic reflection profiles extend across the Atlantic-type marginal basins, from the platform to the deepwater province, presently considered frontier regions for petroleum exploration. This work addresses the geological objectives of a deep seismic profile in the Sergipe Basin and discusses the results obtained by integrating regional seismic, gravity and magnetic data. When combined, these data provide evidence that deep seismic reflectors observed in the Sergipe Basin are related to intracrustal-upper mantle structures rather than sedimentary features. The deep seismic reflection profile in the Sergipe Basin also suggests that, rather than a non-volcanic passive margin, the deepwater extension of this basin is marked by several magmatic structures, including thick wedges of seaward-dipping reflectors and volcanic plugs. These magmatic features are associated with basinforming processes resulting from lithospheric extension during the breakup of Gondwana in the Early Cretaceous and subsequent emplacement of oceanic crust. These results are compared to the crustal scale structures observed in the Campos Basin, in the southeastern margin of Brazil. The interpretation of the deep structure of these basins indicates that final separation between the South American and African plates formed passive margins characterized by different patterns of crustal attenuation underlying the rift blocks.

  3. Tectonoestratigraphic and Thermal Models of the Tiburon and Wagner Basins, northern Gulf of California Rift System

    Science.gov (United States)

    Contreras, J.; Ramirez Zerpa, N. A.; Negrete-Aranda, R.

    2014-12-01

    The northern Gulf of California Rift System consist sofa series faults that accommodate both normal and strike-slip motion. The faults formed a series of half-greens filled with more than 7 km of siliciclastic suc­cessions. Here, we present tectonostratigraphic and heat flow models for the Tiburón basin, in the southern part of the system, and the Wag­ner basin in the north. The models are constrained by two-dimensional seis­mic lines and by two deep boreholes drilled by PEMEX­-PEP. Analysis of the seismic lines and models' results show that: (i) subsidence of the basins is controlled by high-angle normal faults and by flow of the lower crust, (ii) basins share a common history, and (iii) there are significant differences in the way brittle strain was partitioned in the basins, a feature frequently observed in rift basins. On one hand, the bounding faults of the Tiburón basin have a nested geometry and became active following a west-to-east sequence of activation. The Tiburon half-graben was formed by two pulses of fault activity. One took place during the protogulf extensional phase in the Miocene and the other during the opening of Gulf of California in the Pleistocene. On the other hand, the Wagner basin is the result of two fault generations. During the late-to middle Miocene, the west-dipping Cerro Prieto and San Felipe faults formed a domino array. Then, during the Pleistocene the Consag and Wagner faults dissected the hanging-wall of the Cerro Prieto fault forming the modern Wagner basin. Thermal modeling of the deep borehole temperatures suggests that the heat flow in these basins in the order of 110 mW/m2 which is in agreement with superficial heat flow measurements in the northern Gulf of California Rift System.

  4. Palynostratigraphy and sedimentary facies of Middle Miocene fluvial deposits of the Amazonas Basin, Brazil

    Science.gov (United States)

    Dino, Rodolfo; Soares, Emílio Alberto Amaral; Antonioli, Luzia; Riccomini, Claudio; Nogueira, Afonso César Rodrigues

    2012-03-01

    Palynostratigraphic and sedimentary facies analyses were made on sedimentary deposits from the left bank of the Solimões River, southwest of Manaus, State of Amazonas, Brazil. These provided the age-dating and subdivision of a post-Cretaceous stratigraphic succession in the Amazonas Basin. The Novo Remanso Formation is subdivided into upper and lower units, and delineated by discontinuous surfaces at its top and bottom. The formation consists primarily of sandstones and minor mudstones and conglomerates, reflecting fluvial channel, point bar and floodplain facies of a fluvial meandering paleosystem. Fairly well-preserved palynoflora was recovered from four palynologically productive samples collected in a local irregular concentration of gray clay deposits, rich in organic material and fossilized wood, at the top of the Novo Remanso Formation upper unit. The palynoflora is dominated by terrestrial spores and pollen grains, and is characterized by abundant angiosperm pollen grains ( Tricolpites, Grimsdalea, Perisyncolporites, Tricolporites and Malvacearumpollis). Trilete spores are almost as abundant as the angiosperm pollen, and are represented mainly by the genera Deltoidospora, Verrutriletes, and Hamulatisporis. Gymnosperm pollen is scarce. The presence of the index species Grimsdalea magnaclavata Germeraad et al. (1968) indicates that these deposits belong to the Middle Miocene homonymous palynozone (Lorente, 1986; Hoorn, 1993; Jaramillo et al., 2011). Sedimentological characteristics (poorly sorted, angular to sub-angular, fine to very-coarse quartz sands facies) are typical of the Novo Remanso Formation upper part. These are associated with a paleoflow to the NE-E and SE-E, and with an entirely lowland-derived palinofloristic content with no Andean ferns and gymnosperms representatives. All together, this suggests a cratonic origin for this Middle Miocene fluvial paleosystem, which was probably born in the Purus Arch eastern flank and areas surrounding the

  5. Fishes from the Itapecuru River basin, State of Maranhão, northeast Brazil

    Directory of Open Access Journals (Sweden)

    MC Barros

    Full Text Available The Itapecuru is a relatively large river in the northeastern Brazilian state of Maranhão. During several expeditions to this basin, we collected 69 fish species belonging to 65 genera, 29 families and 10 orders. Characiformes and Siluriformes were the orders with the largest number of species and Characidae, Loricariidae, Cichlidae, Auchenipteridae and Pimelodidae were the richest families. About 30% of the fish fauna of the Itapecuru basin is endemic or restricted to northeastern Brazil. Just over a fifth (22% of the species is also known to occur in the Amazon basin and only a few are more widely distributed in South American.

  6. Slump structures in quaternary slope sediments of the northern Derbent Basin (Caspian Sea)

    Science.gov (United States)

    Verzhbitskii, V. E.; Lobkovskii, L. I.; Roslyakov, A. G.; Merklin, L. R.; Polyakov, A. S.; Levchenko, O. V.; Kovachev, S. A.; Zverev, A. S.; Garagash, I. A.; Mar, G. N.; Mutovkin, A. D.; Putans, V. A.; Libina, N. V.; Soltanovskii, I. I.; Slobodyan, V. Yu.; Gontarev, S. V.

    2009-06-01

    During Cruise 20-3 of the R/V Rift (April, 2006), the area that includes the shelf and slope of the Derbent Basin in the northern Middle Caspian was studied using the continuous seismoacoustic profiling method. In accordance with the previous standpoint, two Pleistocene deltaic complexes formed in the Enotaevian and Mangyshlakian time are defined in this area. The seismoacoustic records obtained for the northern slope of the Derbent Basin demonstrate the development of specific rootless exogenic-gravitational fold structures in the upper (˜150-200 m) Quaternary part of the sedimentary sequence. The Quaternary section encloses angular unconformities indicating the pulsating mode of gravitational processes in the northern slope of the basin. South-dipping gravitational normal faults (and/or normal fault-related flexures) displacing the bottom surface and uppermost sedimentary layers (with vertical amplitudes up to 5-6 m) were defined in the southern part of the study area. Several impulses of the submarine slump structures predated and accompanied the deposition of the upper deltaic sequence (Mangyshlakian), although their most intense formation took place later during the Novocaspian (Holocene) time. Thus, the structural analysis of the seismoacoustic data revealed intense development of different-origin and different-age gravitational structures within the Quaternary sediments in the northern slope of the Derbent Basin. These results should be taken into consideration when designing, building, and operating submarine constructions in order to prevent potential natural hazards and reduce their consequences.

  7. Foraminiferal patterns in two trophically different regions: the northern Adriatic Sea and the southern Levantine Basin.

    NARCIS (Netherlands)

    Jannink, N.T.; Duijnstee, Ivo; van der Zwaan, Bert

    2001-01-01

    In spite of the fact that the northern Adriatic Sea and southern Levantine Basin are trophically quite different, the benthic foraminiferal standing stocks through the seasons were found to be in the same range. This suggests that the amount offood (organic matter) available at the sediment-water

  8. Adaptation tot changing water resources in the Ganges basin, northern India

    NARCIS (Netherlands)

    Moors, E.J.; Groot, A.M.E.; Biemans, H.; Terwisscha van Scheltinga, C.T.H.M.; Siderius, C.; Stoffel, M.

    2011-01-01

    An ensemble of regional climate model (RCM) runs from the EU HighNoon project are used to project future air temperatures and precipitation on a 25 km grid for the Ganges basin in northern India, with a view to assessing impact of climate change on water resources and determining what multi-sector

  9. Assessment of coal geology, resources, and reserves in the northern Wyoming Powder River Basin

    Science.gov (United States)

    Scott, David C.; Haacke, Jon E.; Osmonson, Lee M.; Luppens, James A.; Pierce, Paul E.; Rohrbacher, Timothy J.

    2010-01-01

    The abundance of new borehole data from recent coal bed natural gas development in the Powder River Basin was utilized by the U.S. Geological Survey for the most comprehensive evaluation to date of coal resources and reserves in the Northern Wyoming Powder River Basin assessment area. It is the second area within the Powder River Basin to be assessed as part of a regional coal assessment program; the first was an evaluation of coal resources and reserves in the Gillette coal field, adjacent to and south of the Northern Wyoming Powder River Basin assessment area. There are no active coal mines in the Northern Wyoming Powder River Basin assessment area at present. However, more than 100 million short tons of coal were produced from the Sheridan coal field between the years 1887 and 2000, which represents most of the coal production within the northwestern part of the Northern Wyoming Powder River Basin assessment area. A total of 33 coal beds were identified during the present study, 24 of which were modeled and evaluated to determine in-place coal resources. Given current technology, economic factors, and restrictions to mining, seven of the beds were evaluated for potential reserves. The restrictions included railroads, a Federal interstate highway, urban areas, and alluvial valley floors. Other restrictions, such as depth, thickness of coal beds, mined-out areas, and areas of burned coal, were also considered. The total original coal resource in the Northern Wyoming Powder River Basin assessment area for all 24 coal beds assessed, with no restrictions applied, was calculated to be 285 billion short tons. Available coal resources, which are part of the original coal resource that is accessible for potential mine development after subtracting all restrictions, are about 263 billion short tons (92.3 percent of the original coal resource). Recoverable coal, which is that portion of available coal remaining after subtracting mining and processing losses, was determined

  10. War and early state formation in the northern Titicaca Basin, Peru.

    Science.gov (United States)

    Stanish, Charles; Levine, Abigail

    2011-08-23

    Excavations at the site of Taraco in the northern Titicaca Basin of southern Peru indicate a 2,600-y sequence of human occupation beginning ca. 1100 B.C.E. Previous research has identified several political centers in the region in the latter part of the first millennium B.C.E. The two largest centers were Taraco, located near the northern lake edge, and Pukara, located 50 km to the northwest in the grassland pampas. Our data reveal that a high-status residential section of Taraco was burned in the first century A.D., after which economic activity in the area dramatically declined. Coincident with this massive fire at Taraco, Pukara adopted many of the characteristics of state societies and emerged as an expanding regional polity. We conclude that organized conflict, beginning approximately 500 B.C.E., is a significant factor in the evolution of the archaic state in the northern Titicaca Basin.

  11. The National Health Services of Brazil and Northern Europe

    DEFF Research Database (Denmark)

    Gurgel Jr., Garibaldi D.; Carvalho de Sousa, Islâandia M.; de Araujo Oliveira, Sydia Rosana

    2017-01-01

    In 1990 the national health services in the United Kingdom and Sweden started to split up in internal markets with purchasers and providers. It was also the year when Brazil started to implement a national health service (SUS) inspired by the British national health service that aimed at principles......, and inequities have increased. The health sector reform in Brazil, on the other hand, contributed to great improvements in population health but never succeeded in changing the fact that more than half of health care spending was private. Demographic and epidemiological changes, with more elderly people having...... chronic disorders and very unequal comorbidities, bring the issue of integrality in the forefront in all 3 countries, and neither the public purchaser provider markets nor the 2-tier system in Brazil delivers on that front. It will demand political leadership and strategic planning with population...

  12. Stratigraphic architecture of Devonian lacustrine basins of northern Scotland

    DEFF Research Database (Denmark)

    Kristiansen, Thorben; Moreau, Julien; Andrews, Steven D.

    interpretations. The studied deposits have been deeply buried then exhumed so that they are exposed widely onshore. Post Caledonian tectonism has faulted and folded the Devonian succession making it challenging to reconstruct the stratigraphy and the basin architecture from geological data only. The Devonian...... sediments were deposited in a continental environment and fluvial and alluvial deposits are interbedded with lacustrine units. These lacustrine facies contain fishbeds which are organic rich mudstones with moderate source potential. Variations in burial history have resulted in variations in the source rock...... profiles. Correlations made to deep borehole data (Tain-1 well) have allowed marker beds to be attributed to specific seismic reflections. Finally, gravimetric data are used to calculate the depth to basement. The main focus of this work is to fully interpret the seismic architecture of the Devonian basins...

  13. Evolution of Parnaíba Cratonic Basin, Northeast Brazil

    Science.gov (United States)

    Rodríguez Tribaldos, V.; White, N. J.; Coelho, D. L. O.; Julià, J.

    2017-12-01

    Cratonic sedimentary basins are underlain by thick (200-250 km) lithosphere. They are 2-3 km thick and subside continuously for hundreds of millions of years. The driving mechanism of these enigmatic basins is unclear, due to the paucity of crustal-scale constraints. To address this shortcoming, a multi-disciplinary study of the Parnaíba cratonic basin has been carried out. Here, we combine analysis of a 1400 km long deep seismic reflection profile that crosses the basin, teleseismic earthquakes recorded by 12 broadband and 10 short-period seismometers, 25 ancillary seismic reflection profiles, and 46 well logs. Our objective is to shed light on the subsidence history of this basin in the context of its stratigraphic architecture and crustal structure. Interpretation of the deep seismic profile and joint modeling of receiver functions and surface wave dispersion measurements show that the Moho occurs at depths of 35 and 38 km outside the basin at either end of the deep profile. Beneath the basin itself, Moho depths of 39 km and 40-42 km were obtained for the eastern and western parts, respectively. Given the uncertainties, these results suggest that the crust is slightly thinner beneath the basin compared with its edges. Lithologic descriptions and borehole analysis reveal a stratigraphic succession that comprises interbedded shallow marine and continental deposits bounded by basin-wide disconformities. On shallow profiles, this succession is manifest as packages of parallel-bedded reflections separated by rugose surfaces that correspond to significant disconformities that resemble buried landscapes. Graben structures of Proterozoic and Early Paleozoic age are imaged beneath the southwest and southeast regions of the basin, respectively. Water-loaded subsidence curves show an exponential decrease over 350 Ma. A thermal model suggests that unfaulted subsidence can be characterized with time constants of 70-100 Ma. The relationship between apparently prolonged

  14. A seismic hazard overview of the Mitidja Basin (Northern Algeria)

    Science.gov (United States)

    Fontiela, J. F.; Borges, J.; Ouyed, M.; Bezzeghoud, M.; Idres, M.; Caldeira, B.; Boughacha, M. S.; Carvalho, J.; Samai, S.; Aissa, S.; Benfadda, A.; Chimouni, R.; Yalaoui, R.; Dias, R.

    2017-12-01

    The Mitidja Basin (MB) is located in N Algeria and it is filled by quaternary sediments with a length of 100 km on the EW direction and around 20 km width. The S and N limites comprise the Boumerdes-Larbaa-Blida, and the Thenia-Sahel active fault system, respectively. Both fault systems are of the reverse type with opposed dips and accommodate a general slip rate of ˜4 mm/year. In the basin occurred earthquakes that caused severe damage and losses such as the ones of Algiers (1365, Io=X; 1716, Io=X) and the Bourmedes earthquake (Mw 6.9; May 2003) that affected the area of Zemmouri and caused 2.271 deaths. The event was caused by the reactivation of the MB boundary faults. The earthquake generated a max uplift of 0.8m along the coast and a horizontal max. slip of 0.24m.Recent studies show that the Boumerdes earthquake overloaded the adjacent faults system with a stress increase between 0.4 and 1.5 bar. The stress change recommends a detailed study of mentioned faults system due to the increase of the seismic hazard. The high seismogenic potential of the fault system bordering the MB, increases the vulnerability of densely populated areas of Algiers and the amplification effect caused by the basin are the motivation of this project that will focus on the evaluation of the seismic hazard of the region. To achieve seismic hazard assessment on the MB, through realistic predictions of strong ground motion, caused by moderate and large earthquakes, it is important 1) develop a detailed 3D velocity/structure model of the MB that includes geological constraints, seismic reflection data acquired on wells, refraction velocities and seismic noise data, and determination of the attenuation laws based on instrumental records; 2) evaluate the seismic potential and parameters of the main active faults of the MB; 3) develop numerical methods (deterministic and stochastic) to simulate strong ground motions produced by extended seismic sources. To acquire seismic noise were used

  15. Carbonate Buildups in the Pernambuco Basin, NE Brazil.

    Science.gov (United States)

    Buarque, Bruno V; Barbosa, José A; Oliveira, Jefferson T C; Magalhães, José R G; Correia, Osvaldo J

    2017-01-01

    The Pernambuco Basin represents one of the most prominent regions for deep water oil and gas exploration off the Brazilian coast. This study aims to identify and describe the occurrence of carbonate buildups in the offshore regions of the basin. The study was based on an analysis of a set of 143 2D time-migrated seismic sections that cover the offshore region of the Pernambuco Basin. An interpretation of the seismic dataset was used to define the main seismic sequences related to the main regional pulses of deposition and to identify three main groups of carbonate buildups: 1) shelf margin reefs, 2) patch reefs, and 3) isolated carbonate buildups. The carbonate buildups formed in two main intervals during post-rift sequences of the Santonian-Maastrichtian and Paleocene-Middle Miocene, which extend the known periods of carbonate deposit formation in the basin. The formation of carbonate buildups was controlled by the tectonic evolution of the Pernambuco Plateau, which created a series of paleotopographic highs that enabled the establishment of oceanographically and climatically favorable conditions for carbonate formation and deposition. These findings are important for understanding the evolution of the basin and for future evaluations of its petroleum potential.

  16. Carbonate Buildups in the Pernambuco Basin, NE Brazil

    Directory of Open Access Journals (Sweden)

    BRUNO V. BUARQUE

    Full Text Available ABSTRACT The Pernambuco Basin represents one of the most prominent regions for deep water oil and gas exploration off the Brazilian coast. This study aims to identify and describe the occurrence of carbonate buildups in the offshore regions of the basin. The study was based on an analysis of a set of 143 2D time-migrated seismic sections that cover the offshore region of the Pernambuco Basin. An interpretation of the seismic dataset was used to define the main seismic sequences related to the main regional pulses of deposition and to identify three main groups of carbonate buildups: 1 shelf margin reefs, 2 patch reefs, and 3 isolated carbonate buildups. The carbonate buildups formed in two main intervals during post-rift sequences of the Santonian-Maastrichtian and Paleocene-Middle Miocene, which extend the known periods of carbonate deposit formation in the basin. The formation of carbonate buildups was controlled by the tectonic evolution of the Pernambuco Plateau, which created a series of paleotopographic highs that enabled the establishment of oceanographically and climatically favorable conditions for carbonate formation and deposition. These findings are important for understanding the evolution of the basin and for future evaluations of its petroleum potential.

  17. Hydrological studies in experimental and representative basins in Pernambuco State, Brazil

    Science.gov (United States)

    Montenegro, S. M. G. L.; da Silva, B. B.; Antonino, A. C. D.; Lima, J. R. S.; de Souza, E. S.; de Oliveira, L. M. M.; de Moura, A. E. S. S.; Souza, R. M. S.

    2014-09-01

    Hydrological studies in experimental and representative basins are of fundamental importance for water resources management. This paper presents some activities of hydrological research in experimental and representative basins of the State of Pernambuco, Brazil. The study areas are located at Tapacurá and Mundaú representative basins and at the Gameleira experimental basin, and in experimental plots in Pajeú basin. In the Tapacurá basin, three studies were performed: (1) different monthly coefficients "k" of the Thornthwaite method were tested to calculate the effective temperature and, consequently, the reference evapotranspiration, giving rise to the method identified as Modified Thornthwaite; (2) the spatial variability of the retention curve and hydraulic conductivity parameters were analysed using the Beerkan method; (3) changes in vegetation cover were evaluated through the NDVI and NDWI indexes using TM-Landsat 5 images. In the Mundaú representative basin, the performance of different evapotranspiration methods was evaluated and compared to the FAO standard method, Penman-Monteith. In the Pajeú basin, the experimental plot is covered by pasture and sensors were installed to monitor the following variables: rainfall, air temperature, the energy balance components (net radiation, latent and sensible heat, and soil heat flux), wind velocity and CO2 flux into atmosphere, soil moisture and runoff.

  18. The transgressive-regressive cycle of the Romualdo Formation (Araripe Basin): Sedimentary archive of the Early Cretaceous marine ingression in the interior of Northeast Brazil

    Science.gov (United States)

    Custódio, Michele Andriolli; Quaglio, Fernanda; Warren, Lucas Veríssimo; Simões, Marcello Guimarães; Fürsich, Franz Theodor; Perinotto, José Alexandre J.; Assine, Mario Luis

    2017-08-01

    Geologic events related to the opening of the South Atlantic Ocean deeply influenced the sedimentary record of the Araripe Basin. As consequence, upper stratigraphic units of the basin record a marine ingression in northeastern Brazil during the late Aptian. The timing and stratigraphic architecture of these units are crucial to understand the paleogeography of Gondwana and how the proto-Atlantic Ocean reached interior NE Brazil during the early Cretaceous. This marine ingression is recorded in the Araripe Basin as the Romualdo Formation, characterized by a transgressive-regressive cycle bounded by two regional unconformities. In the eastern part of the basin, the Romualdo depositional sequence comprises coastal alluvial and tide-dominated deposits followed by marine transgressive facies characterized by two fossil-rich intervals: a lower interval of black shales with fossil-rich carbonate concretions (Konservat-Lagerstätten) and an upper level with mollusk-dominated shell beds and shelly limestones. Following the marine ingression, an incomplete regressive succession of marginal-marine facies records the return of continental environments to the basin. The stratigraphic framework based on the correlation of several sections defines a transgressive-regressive cycle with depositional dip towards southeast, decreasing in thickness towards northwest, and with source areas located at the northern side of the basin. The facies-cycle wedge-geometry, together with paleocurrent data, indicates a coastal onlap towards NNW. Therefore, contrary to several paleogeographic scenarios previously proposed, the marine ingression would have reached the western parts of the Araripe Basin from the SSE.

  19. Lacustrine basin evolution and coal accumulation of the Middle Jurassic in the Saishiteng coalfield, northern Qaidam Basin, China

    Directory of Open Access Journals (Sweden)

    Meng Li

    2016-07-01

    Full Text Available Based on an extensive borehole survey of the Middle Jurassic coal-bearing sequences in the Saishiteng coalfield, northern Qaidam Basin (NQB, a total of 20 rock types and 5 sedimentary facies were identified, including braided river, meandering river, braided delta, meandering river delta, and lacustrine facies. The distribution of rock types and sedimentary facies contributed to the reconstruction of three periods' sedimentary facies maps of the Middle Jurassic in the Saishiteng coalfield, namely, the Dameigou age, the early Shimengou age and the late Shimengou age. That also provided the basis for the development of a three-stage depositional model of the Middle Jurassic in the NQB, indicating the lacustrine basin of the NQB in the Dameigou age and early Shimengou age were corresponding to an overfill basin, and that in the late Shimengou age was related to a balanced-fill basin. The analysis of the stability and structure of coal seams based on sedimentary facies maps showed that the preferred coal-forming facies in the Saishiteng coalfield were inter-delta bay and interdistributary bay of lower delta plain in the Dameigou age. In particular, the swamps that developed on the subaqueous palaeohigh favored the development of thick coal seams. Thus, minable coal seams may also be found along the Pingtai palaeohigh in the western part of the Saishiteng coalfield.

  20. Neogene palaeogeography and basin evolution of the Western Carpathians, Northern Pannonian domain and adjoining areas

    Science.gov (United States)

    Kováč, Michal; Márton, Emő; Oszczypko, Nestor; Vojtko, Rastislav; Hók, Jozef; Králiková, Silvia; Plašienka, Dušan; Klučiar, Tomáš; Hudáčková, Natália; Oszczypko-Clowes, Marta

    2017-08-01

    The data on the Neogene geodynamics, palaeogeography, and basin evolution of the Western Carpathians, Northern Pannonian domain and adjoining areas (ALCAPA Mega-unit) are summarized, re-evaluated, supplemented, and newly interpreted. The proposed concept is illustrated by a series of palinspastic and palaeotopographic maps. The Miocene development of the Outer Carpathians reflects the vanishing subduction of the residual oceanic and/or thinned continental crust. A compression perpendicular to the front of the orogenic system led to the closing of residual flysch troughs and to accretionary wedge growth, as well as to the development of a foredeep on the margin of the European Platform. Docking of the Outer Western Carpathians accretionary wedge, together with the Central Western Carpathians and Northern Pannonian domain, was accompanied by stretching of the overriding microplate. An orogen parallel and perpendicular extension was associated with the opening and subsidence of the Early and Middle Miocene hinterland (back-arc) basin system that compensated counter-clockwise rotations of the individual crustal fragments of ALCAPA. The Late Miocene development relates to the opening of the Pannonian Basin System. This process was coupled with common stretching of both ALCAPA and Tisza-Dacia Mega-units due to the pull exerted by subduction rollback in front of the Eastern Carpathians. The filling up of the hinterland basin system was associated with thermal subsidence and was followed by the Pliocene tectonic inversion and consequent erosion of the basin system margins, as well as part of the interior.

  1. Geophysical evidence of crustal-heterogeneity control of fault growth in the Neocomian Iguatu basin, NE Brazil

    Science.gov (United States)

    de Castro, David L.; Bezerra, Francisco H. R.; Castelo Branco, Raimundo M. G.

    2008-11-01

    Models of fault growth propose that rift initiation starts with short fault segments. Knowledge of the growth of these segments and their interactions is important to understanding rift geometry and evolution. In the northern part of the Borborema Province, northeastern Brazil, a continental-scale, Cretaceous extensional system of faults has been observed to have reactivated ductile Precambrian shear zones. The faults form small grabens that represent the rift stage of the sedimentary basins. We integrated airborne radiometric and magnetic data with terrestrial gravity survey to investigate the influence of crustal heterogeneity on fault growth and the development of the extensional faults in one of these grabens, the Iguatu basin. Previous studies presented geophysical data, which provide evidence that the Iguatu basin contains a half-graben geometry. In our study, gravity and airborne geophysical data indicate that the basement of the Iguatu basin is part of a heterogeneous structural framework composed of two structural domains, is affected by several ductile shear zones and intruded by a few granite bodies. The gravity modeling reveals that this basin is composed of three right-bend en echelon fault segments. They form a sigmoid system of normal faults that accommodate the strong ˜90° bend of the Precambrian shear zones from E-W to roughly N-S. The growth of these segments led to the generation of two isolated depocenters. The overlapping fault segments link through relay ramps. Release faults that are nearly perpendicular or oblique to the three main fault segments form marginal strike ramps and horst structures in both depocenters. 3D-gravity modeling incorporates the presence of interfering sources of a heterogeneous structural framework. The modeling reveals a maximum sedimentary cover 1620 m thick, which occurs at the bend of the reactivated shear zones. The gravity signature of a possible granite body, after removal of the gravity effect of the basin

  2. Echovirus 30 associated with cases of aseptic meningitis in state of Pará, Northern Brazil

    Directory of Open Access Journals (Sweden)

    Ceyla Maria Oeiras de Castro

    2009-05-01

    Full Text Available Investigation of the aetiology of viral meningitis in Brazil is most often restricted to cases that occur in the Southern and Southeastern Regions; therefore, the purpose of this study is to describe the viral meningitis cases that occurred in state of Pará, Northern Brazil, from January 2005-December 2006. The detection of enterovirus (EV in cerebrospinal fluid was performed using cell culture techniques, RT-PCR, nested PCR and nucleotide sequencing. The ages of the 91 patients ranged from 60 years old (median age 15.90 years. Fever (87.1%, headache (77.0%, vomiting (61.5% and stiffness (61.5% were the most frequent symptoms. Of 91 samples analyzed, 18 (19.8% were positive for EV. Twelve were detected only by RT- PCR followed by nested PCR, whereas six were found by both cell culture and RT-PCR. From the last group, five were sequenced and classified as echovirus 30 (Echo 30. Phylogenetic analyses revealed that Echo 30 detected in Northern Brazil clustered within a unique group with a bootstrap value of 100% and could constitute a new subgroup (4c according to the phylogenetic tree described by Oberste et al. (1999. This study described the first molecular characterization of Echo 30 in Brazil and this will certainly contribute to future molecular analyses involving strains detected in other regions of Brazil.

  3. Geodynamic implications for zonal and meridional isotopic patterns across the northern Lau and North Fiji Basins

    Science.gov (United States)

    Price, Allison A.; Jackson, Matthew G.; Blichert-Toft, Janne; Kurz, Mark D.; Gill, Jim; Blusztajn, Jerzy; Jenner, Frances; Brens, Raul; Arculus, Richard

    2017-03-01

    We present new Sr-Nd-Pb-Hf-He isotopic data for 65 volcanic samples from the northern Lau and North Fiji Basins. This includes 47 lavas obtained from 40 dredge sites spanning an east-west transect across the Lau and North Fiji basins, 10 ocean island basalt (OIB)-type lavas collected from seven Fijian islands, and eight OIB lavas sampled on Rotuma. For the first time, we are able to map clear north-south and east-west geochemical gradients in 87Sr/86Sr across the northern Lau and North Fiji Basins: lavas with the most geochemically enriched radiogenic isotopic signatures are located in the northeast Lau Basin, while signatures of geochemical enrichment are diminished to the south and west away from the Samoan hot spot. Based on these geochemical patterns and plate reconstructions of the region, these observations are best explained by the addition of Samoa, Rurutu, and Rarotonga hot spot material over the past 4 Ma. We suggest that underplated Samoan material has been advected into the Lau Basin over the past ˜4 Ma. As the slab migrated west (and toward the Samoan plume) via rollback over time, younger and hotter (and therefore less viscous) underplated Samoan plume material was entrained. Thus, entrainment efficiency of underplated plume material was enhanced, and Samoan plume signatures in the Lau Basin became stronger as the trench approached the Samoan hot spot. The addition of subducted volcanoes from the Cook-Austral Volcanic Lineament first from the Rarotonga hot spot, then followed by the Rurutu hot spot, contributes to the extreme geochemical signatures observed in the northeast Lau Basin.

  4. LBA-ECO CD-06 Ji-Parana River Basin Land Use and Land Cover Map, Brazil: 1999

    Data.gov (United States)

    National Aeronautics and Space Administration — ABSTRACT: This data set provides a land use/land cover map of the Ji-Parana River Basin in the state of Rondonia, Brazil produced from the digital classification of...

  5. LBA-ECO CD-06 Ji-Parana River Basin Land Use and Land Cover Map, Brazil: 1999

    Data.gov (United States)

    National Aeronautics and Space Administration — This data set provides a land use/land cover map of the Ji-Parana River Basin in the state of Rondonia, Brazil produced from the digital classification of eight...

  6. Deep Structure and Subsidence of Parnaíba Cratonic Basin, NE Brazil

    Science.gov (United States)

    Rodríguez Tribaldos, V.; White, N. J.; Coelho, D. L. O.; Julià, J.

    2016-12-01

    Cratonic basins are typically underlain by thick lithosphere and slowly subside over hundreds of millions of years. Their stratigraphy consist of unconformity-bounded sequences of continental and shallow marine sedimentary rocks. The origin and evolution of these basins remain enigmatic. Here, we address this problem by carrying out an integrative study of the Parnaíba cratonic basin in NE Brazil. We analyse a 1400 km long deep seismic reflection profile crossing the basin, teleseismic earthquakes recorded by 9 broadband and 10 short-period, 3 component seismometers, 25 ancillary seismic reflection profiles, and 46 wells distributed throughout the basin. Our aim is to constrain subsidence histories in the context of crustal structure and basin architecture. Combined interpretation of the deep seismic profile and 1D velocity models calculated by joint inversion of receiver functions and surface wave dispersion curves locates the Moho at 39 km beneath the city of Teresina on the basin's eastern region. At the eastern edge of the basin, the Moho lies at 37 km beneath Precambrian basement. In the centre of the basin, the Moho lies at 37 km. Beneath Teresina, an increase in S wave velocity at 30 km coincides with mid-crustal reflections on the deep seismic profile. This feature is interpreted as the top of a high-velocity body within the crust. Ancillary seismic profiles show that the stratigraphy is divisible into packages of undisturbed reflections separated by bright, rugged reflections that resemble buried paleolandscapes. Correlation of seismic profiles with well logs shows that these surfaces are basin-wide erosional unconformities that are observable in outcrop. Backstripped and water-loaded subsidence curves show exponential decrease in subsidence over the last 400 Ma. This background subsidence is punctuated by departures from the long-term trend at times when unconformities occur, which we interpret as mild regional uplift events.

  7. REGIONAL MAGNETOTELLURIC SURVEYS IN HYDROCARBON EXPLORATION, PARANA BASIN, BRAZIL.

    Science.gov (United States)

    Stanley, William D.; Saad, Antonio; Ohofugi, Walter

    1985-01-01

    The mangetotelluric geophysical method has been used effectively as a hydrocarbon exploration tool in the intracratonic Parana basin of South America. The 1-2 km thick surface basalts and buried diabase sills pose no problem for the magnetotelluric method because the natural electromagnetic fields used as the energy source pass easily through the basalt. Data for the regional study were taken on six profiles with sounding spaced 8 to 15 km apart. The magnetotelluric sounding data outline a linear uplift known as the Ponta Grossa arch. This major structural feature cuts across the northeast-trending intracratonic basin almost perpendicularly, and is injected with numerous diabase dikes. Significant electrical contrasts occur between the Permian sediments and older units, so that magnetotelluric measurements can give an indication of the regional thickness of the Permian and younger sediments to aid in interpreting hydrocarbon migration patterns and possible trap areas. Refs.

  8. Paleozoic unconformities favorable for uranium concentration in northern Appalachian basin

    International Nuclear Information System (INIS)

    Dennison, J.M.

    1986-01-01

    Unconformities can redistribute uranium from protore rock as ground water moves through poorly consolidated strata beneath the erosion surface, or later moves along the unconformity. Groundwater could migrate farther than in present-day lithified Paleozoic strata in the Appalachian basin, now locally deformed by the Taconic and Allegheny orogenies. Several paleoaquifer systems could have developed uranium geochemical cells. Sandstone mineralogy, occurrences of fluvial strata, and reduzate facies are important factors. Other possibilities include silcrete developed during desert exposure, and uranium concentrated in paleokarst. Thirteen unconformities are evaluated to determine favorable areas for uranium concentration. Cambrian Potsdam sandstone (New York) contains arkoses and possible silcretes just above crystalline basement. Unconformities involving beveled sandstones and possible fluvial strata include Cambrian Hardyston sandstone (New Jersey), Cambrian Potsdam Sandstone (New York), Ordovician Oswego and Juniata formations (Pennsylvania and New York), Silurian Medina Group (New York), and Silurian Vernon, High Falls, and Longwood formations (New York and New Jersey). Devonian Catskill Formation is beveled by Pennsylvanian strata (New York and Pennsylvania). The pre-Pennsylvanian unconformity also bevels Lower Mississippian Pocono, Knapp, and Waverly strata (Pennsylvania, New York, and Ohio), truncates Upper Mississippian Mauch Chunk Formation (Pennsylvania), and forms paleokarst on Mississippian Loyalhanna Limestone (Pennsylvania) and Maxville Limestone (Ohio). Strata associated with these unconformities contain several reports of uranium. Unconformities unfavorable for uranium concentration occur beneath the Middle Ordovician (New York), Middle Devonian (Ohio and New York), and Upper Devonian (Ohio and New York); these involve marine strata overlying marine strata and probably much submarine erosion

  9. Geochemistry of Central Atlantic Magmatic Province (CAMP) sills from deep boreholes in the Amazonas and Solimões basins, Brazil

    Science.gov (United States)

    Hatlen Heimdal, Thea; Svensen, Henrik H.; Pereira, Egberto; Planke, Sverre

    2016-04-01

    The Central Atlantic Magmatic Province (CAMP) is one of the most extensive Large Igneous Provinces (LIPs), and is associated with the breakup of Pangea and the subsequent opening of the central Atlantic Ocean. A large part of the province, including > 1 M km2 basins containing sill intrusions, is located in Brazil but has received limited attention due to the lack of outcrops. We have studied CAMP sills from seven deep boreholes (up to 3100 m deep) in the Amazonas and Solimões basins, northern Brazil. The boreholes contain up to ~ 482 m of sills (18 % of the stratigraphy), with a maximum individual sill thickness of 140 m. The sills were partly emplaced into thick Carboniferous evaporites. The main mineral phases of the sills include plagioclase and pyroxene, with accessory apatite, biotite, ilmenite and quartz. The majority of the sills are low-Ti dolerites (TiO2 < 2 wt.%), with the exception of four samples (with 2.2 - 3.3 wt.% TiO2). The low-Ti rocks range from basalt to basaltic andesite and plot in the tholeiitic field defined within the total alkali versus silica (TAS) classification. C1 chondrite normalized Rare Earth Element (REE) patterns for both Ti-groups show increasing LREE compared to HREE (La/Lu = 2.2 - 4.1) with no major anomalies, and attest to a relatively evolved nature (La = 17-65 ppm). Primitive mantle normalized patterns for low-Ti rocks show negative anomalies for Nb, Ta, P and Ti and positive for K, whereas the high-Ti rocks show generally opposite anomalies. Late stage patches in the dolerites contain apatite, quartz and Cl-bearing biotite, suggesting the presence of halogens that may partly derive from the host sedimentary rocks.

  10. Considerations on fluorides anomalies in Botucatu-Piramboia aquifers system, Parana basin, Brazil

    International Nuclear Information System (INIS)

    Kimmelmann, A.A.; Reboucas, A.C.; Reboucas, A.M.; Heine, C.A.

    1991-01-01

    Groundwater of a great number of deep wells dug to exploit the Botucatu-Piramboia aquifer system in the Parana Basin, Brazil, have high fluoride concentrations, over 1 ppm, that turns groundwater useless for human supply. Investigations being carried out a the Center for Groundwater Research (CEPAS) of the Institute of Geosciences at USP, Sao Paulo, indicate a relationship between fluoride concentration and groundwater age, dated with radiocarbon. (author)

  11. The Frasnian-Famennian boundary (Upper Devonian) in black shale sequences: US Southern Midcontinent, Illinois Basin, and northern Appalachian Basin

    Energy Technology Data Exchange (ETDEWEB)

    Over, D.J. (State Univ. of New York, Geneseo, NY (United States). Dept. of Geological Sciences)

    1994-04-01

    The Frasnian-Famennian (F/F) boundary in the Woodford Shale of the US southern Midcontinent, Sweetland Creek Shale of the Illinois Basin, and the Hanover Shale of the northern Appalachian Basin is recognized to a discrete horizon. In each locality the boundary is marked by evidence of a disconformity: phosphate nodules, concentration of conodonts, or coated and corroded grains. The Woodford Shale consists of finely laminated pyritic organic-rich shale containing interbeds of greenish shale and chert. The F/F boundary horizon is marked by a concentration of conodonts and phosphatic nodules. The boundary lag horizon contains Pa. linguliformis, Pa. subperlobtata, Pa. delicatula delicatula, and Pa. triangularis. Underlying laminations contain Ancyrognathus ubiquitus and Pa. triangularis indicating that the disconformity is within the uppermost MN Zone 13 or Lower triangularis Zone. The upper portion of the Type Sweetland Creek Shale consists of dark organic-rich shales. The F/F boundary is located within an interval containing three green shale interbeds. Palmatolepis triangularis in the absence of Frasnian species first occurs in the middle green shale. In the thick Upper Devonian clastic sequence of the northern Appalachian Basin the F/F boundary is within an interval of interbedded pyritic green and organic-rich silty shales of the Hanover Shale. At Irish Gulf strata containing Pa. triangularis overlie finely laminated dark shales containing Pa. bogartensis, Pa. triangularis, Pa. winchell, Ancyrodella curvata, and Icriodus alternatus. The conodont fauna transition is below a conodont-rich laminae containing a Famennian fauna that marks the boundary horizon.

  12. Northern Rivers Basins ecological and human health studies : summary, relevance and recommendations

    International Nuclear Information System (INIS)

    1999-04-01

    Residents in northern Alberta expressed concerns that the original Northern River Basins Study (NRBS) only examined the impacts of contaminants on ecological health and did not include impacts on human health. In response to these concerns, Alberta Health established the Northern River Basins Human Health Monitoring Program in 1994 to investigate the possible relationships between various environmental risk factors and the health of northern residents in the province. This document links the ecological information collected by the original NRBS program with the information provided by the health program. Issues regarding health impacts from pulp mills and oil sand mining were also discussed. The findings of the health program were summarized and recommendations were made for future studies. The contaminants of potential concern (COPC) arising from the original NRBS were described in terms of their sources and any known connections between exposure and human health. The COPCs included arsenic, dioxins, chlorinated furans, polycyclic aromatic hydrocarbons (PAH) polychlorinated biphenyls (PCB) mercury, chlorinated phenolics, toxaphene, carbon monoxide, nitrogen oxides, ozone, sulphur dioxide, acid sulphates and particulate matter. Examples of Canadian regulatory criteria for these contaminants were also presented. 41 refs., 1 tab

  13. Oral health and feeding frequency of preschool children in a city in northern Brazil

    OpenAIRE

    Piero Maia Fernandes; Karine Cristina Souza da Silva; Rayane Cardoso de Souza; Andresa Fernanda Medeiros da Costa; Cláudia Danielle Tavares Dutra; Carla Andréa Avelar Pires

    2014-01-01

    http://dx.doi.org/10.4025/actascihealthsci.v36i1.13850   Oral health and healthy eating habits are related to socioeconomic and cultural conditions of the population and imply the biopsychosocial health of the individual. This study investigated the oral health and feeding frequency of children attending a daycare in the municipality of Ananindeua, Pará State, northern Brazil. This was a cross-sectional study, quantitative and qualitative, descriptive, involving the examination of the o...

  14. The Paleozoic ichthyofauna of the Amazonas and Parnaíba basins, Brazil

    Science.gov (United States)

    Figueroa, Rodrigo Tinoco; Machado, Deusana Maria da Costa

    2018-03-01

    The Brazilian Paleozoic ichthyofauna from the Parnaíba and Amazonas basins regard a sparsely known diversity, including chondrichthyans and acanthodians, besides some osteichthyan remains. This work proposes a revision of the fossil material from these two sedimentary basins and synthesizes the morphological aspect of such material trying to understand the influences of those fossils to the paleontology of the region, comparing the Brazilian fossils with other gondwanan faunas. The Brazilian Paleozoic fish fauna shows great resemblance to those of Bolivia, especially during the Devonian. Many of the Acanthodian spines from the Manacapuru Formation (Amazonas Basin), and the Pimenteira Formation (Parnaíba Basin), are comparable to the taxa found in Bolivia. The lack of more Placoderm remains in the Brazilian outcrops is similar to the low diversity of this group in Bolivia, when compared to other South American and Euramerican localities. The most diverse Brazilian ichthyofauna is encountered in the Permian Pedra de Fogo Formation where numerous chondrichthyans and 'paleopterygians' remains are found, together with dipnoans and actinistians. Despite the apparent lack of more representative Paleozoic ichthyofaunas in Brazil, the available material that ranges from Lower Devonian to early Permian from Brazil bears important taxa that could address valuable taxonomic and biogeographic informations.

  15. Status and understanding of groundwater quality in the Northern Coast Ranges study unit, 2009: California GAMA Priority Basin Project

    Science.gov (United States)

    Mathany, Timothy M.; Belitz, Kenneth

    2015-01-01

    Groundwater quality in the 633-square-mile (1,639-square-kilometer) Northern Coast Ranges (NOCO) study unit was investigated as part of the Priority Basin Project (PBP) of the Groundwater Ambient Monitoring and Assessment (GAMA) Program and the U.S. Geological Survey (USGS) National Water-Quality Assessment Program. The study unit is composed of two study areas (Interior Basins and Coastal Basins) and is located in northern California in Napa, Sonoma, Lake, Colusa, Mendocino, Glenn, Humboldt, and Del Norte Counties. The GAMA-PBP is being conducted by the California State Water Resources Control Board in collaboration with the USGS and the Lawrence Livermore National Laboratory.

  16. Organic geochemistry and petroleum geology, tectonics and basin analysis of southern Tarim and northern Qaidam basins, northwest China

    Science.gov (United States)

    Hanson, Andrew Dean

    Organic geochemistry of oils from the Tarim basin, NW China, distinguish at least seven genetic groups of oils. The largest group are derived from Middle-Upper Ordovician anoxic slope-facies marls coincident with the margins of structural uplifts. Other groups include non-marine derived oils in the Luntai uplift, from southwest Tarim, in the Kuqa depression, and west of the Bachu uplift. A seep sample from west of Kashi clusters with Luntai oils. These results suggest that numerous source-rock horizons occur, but they are really restricted. Organic geochemistry of oils from northern Qaidam defines a family of hypersaline, anoxic lacustrine derived oils. Cenozoic outcrop samples from northern Qaidam are too organic lean to be of source quality, but dark laminated upper Oligocene mudstones from the Shi 28 well are of fair to good quality. Biomarkers provide a good correlation between the oils and the core samples. Organic matter is from algae and bacteria and lacks terrestrial material. Hydrocarbons are contained in upper Oligocene, Miocene, and Pliocene reservoirs. Eight oils are from NW Qaidam, but one sample comes from NE Qaidam, an area previously believed to only produce oils derived from Jurassic source rocks. Thus an unidentified Cenozoic source rock occurs in NE Qaidam. Thermal modeling indicates generation occurred in northwestern Qaidam within the last 3 million years, agreeing with observed low maturity biomarker parameters. Cenozoic stratigraphy in northern Qaidam and southern Tarim basins record the tectonic history of the surrounding structural/topographic elements. Paleocurrents record flow away from adjacent ranges from the Miocene to the present. Provenance data tie sediments to adjacent structural elements. Petrography indicates increasingly immature sandstones in Miocene and younger sediments relative to pre-Miocene samples. Apatite fission-track results from southeastern Tarim yield a cooling age of 17 +/- 1 Ma indicative of unroofing since at

  17. Prospecting for Natural Gas Gydrate in the Orca & Choctaw Basins in the Northern Gulf of Mexico

    Science.gov (United States)

    Cook, A.; Hillman, J. I. T.; Sawyer, D.; Frye, M.; Palmes, S.; Shedd, W. W.

    2016-12-01

    The Orca and Choctaw salt bounded mini-basins, which occur in 1.5 to 2.5 km water depth on the northern Gulf of Mexico slope, are currently under consideration as an IODP scientific drilling location for coarse-grained natural gas hydrate systems. We use a 3D seismic dataset for gas hydrate prospecting that covers parts of eleven lease blocks ( 200 km2) in the Walker Ridge protraction area. The study area includes the southern section of the Orca Basin and a smaller section of the northern Choctaw Basin. We have mapped a discontinuous bottom-simulating reflection (BSR) over nearly 30% of our seismic dataset, which varies significantly in both amplitude and depth throughout the area. The southeastern section of our dataset contains three positive impedance amplitude horizons with possible phase reversals at the BSR. Detailed mapping in the area also reveals at the base of gas hydrate stability, a complicated intercalation of an east-west trending fault system and an amalgamated deepwater depositional system comprising channel levee deposits and turbidite sheet sands. Three industry wells drilled in the southwestern section of our study area indicate that the sedimentary sequence infilling the basins consists of predominantly mud rich units with interbedded turbidite sands, forming a 2 km thick supra-salt sequence of late Miocene to Pleistocene sediments. Two of the industry wells have strong evidence for natural gas hydrate in clay-rich sediment, with moderate resistivity (between 2-10 Ωm) increases above background resistivity in zones that exceed 60 m thick. Additionally, the electromagnetic resistivity curves in these wells separate suggesting that the gas hydrate occurs in high-angle fractures. We will present our seismic dataset, our continuing analysis and selected drill sites in the Orca and Choctaw basins. Furthermore, our analysis in the southeastern section of the study area underscores the importance of interpreting faults when considering phase

  18. Application of a technique for scenario prediction of climate change impact on the water balance components of northern river basins

    Directory of Open Access Journals (Sweden)

    Gusev Yeugeniy M.

    2014-09-01

    Full Text Available The scenario forecasting technique for assessing changes of water balance components of the northern river basins due to possible climate change was developed. Three IPCC global emission scenarios corresponding to different possible scenarios for economic, technological, political and demographic development of the human civilization in the 21st century were chosen for generating climate change projections by an ensemble of 16 General Circulation Models with a high spatial resolution. The projections representing increments of monthly values of meteorological characteristics were used for creating 3-hour meteorological time series up to 2063 for the Northern Dvina River basin, which belongs to the pan-Arctic basin and locates at the north of the European part of Russia. The obtained time series were applied as forcing data to drive the land surface model SWAP to simulate possible changes in the water balance components due to different scenarios of climate change for the Northern Dvina River basin

  19. Miocene woods from the Qaidam Basin on northern Qinghai-Tibet Plateau with implications for paleoenvironmental change

    Science.gov (United States)

    Cheng, Ye-Ming; Yang, Xiao-Nan

    2016-02-01

    The Qaidam Basin with the most complete Cenozoic sedimentary preservation in northern Qinghai-Tibet Plateau is a key area for studying uplift and environmental change of the plateau. Three types of woods, Ulmus (Ulmaceae), Leguminosae (?) (angiosperm) and Cupressaceae (gymnosperm) were recognized from the large-scale preservation of fossil woods in late Miocene Shang Youshashan Formation in northern Qaidam Basin on the Qinghai-Tibet Plateau. Both investigations of their Nearest Living Relatives (NLRs) and previous grassland mammal evidences suggest that there have been temperate deciduous broad-leaved forest and needle-leaved forest with grass in northern Qaidam Basin during the late Miocene in contrast to the desert vegetation found there nowadays. The presence of the ancient forest steppe further implies that the southern part of the plateau used to be adequately low, so that the Indian and East Asian monsoons could approach the northern area and to accommodate the vegetation in late Miocene.

  20. Prospect analysis for sandstone-type uranium mineralization in the northern margin of Qaidam basin

    International Nuclear Information System (INIS)

    Liu Lin; Song Xiansheng; Feng Wei; Song Zhe; Li Wei

    2010-01-01

    Affected by the regional geological structural evolution, a set of sedimentary structure, i.e. the construction of coal-bearing classic rocks which is in favor of the sandstone-type uranium mineralization has deposited in the northern margin of Qaidam Basin since Meso-Cenozoic. A NWW thrust nappe tectonic belt, i.e. the ancient tectonic belt which is the basis for the development of ancient interlayer oxidation zone formed by the tectonic reverse in late Jurassic and Cretaceous. The Mid and late Jurassic layer was buried by the weak extension in Paleogene and the depression in early Neogene. The extrusion reversal from late Neogene to Quaternary made the basin into the development era of the modern interlayer oxidation zone. It can be concluded that the layer of the northern margin of Qaidam Basin has the premise for the formation of sandstone-type uranium ore. Based on the analysis of the characteristics of the thrust belt, the structure of the purpose layer, the sand body, the hydrogeology, the interlayer oxidation zone and uranium mineralization, the results indicated that the ancient interlayer oxidation zone is the prospecting type of sandstone-type uranium ore. Beidatan and the east of Yuqia are the favorable prospective area of sandstone-type uranium mineralization. (authors)

  1. Silviculture of eucaliptus plantations in the Paraiba do Sul basin, Brazil, and its potential implication on the basin ecohydrology.

    Science.gov (United States)

    Carriello, Felix; Andres Rodriguez, Daniel; Marques Neves, Otto; Vicens, Raul

    2014-05-01

    Silviculture of eucaliptus plantations is an important driver of the Mata Atlântica biome conversion into another land use in the Paraíba do Sul basin, in the southeastern of Brazil. This region is located in one of the most developed areas in Brazil, between Rio de Janeiro and São Paulo, the most important cities in Brazil, linked by Presidente Dutra highway. Between both cities there are another cities that produce a variety of goods - from meat to planes, cars and mobile phones. This area is, at the same time, one the most important hot spot for the Mata Atlântica biome. Here we have a large Mata Atlântica fragment protected by law and others fragments being conversed to pasture, agriculture, silviculture and urban areas. Paraiba do Sul river drains the region and runs into Rio de Janeiro State. The basin is highly anthropized, with multiple approaches of its waters resources. Its waters also serve Rio de Janeiro metropolitan area. Because land use and land cover changes impact the water yield in a basin, the study of its dynamic its of great importance for water resources management. We study the land use and land cover change in the region between 1986 and 2010, focusing in the development of silviculture of eucaliptus plantations. We used the HAND (Height Above Nearest Drainage) approach that uses the height above the nearest water body, acquired from SRTM Data and transformed into a Terrain Numeric Mode, to classify the landscape into three different ecohydrological environments: floodplain, mountain top and hillslope. This classes were intersected with 1986 and 2010 land use and cover change classification obtained from Landsat imagery. Results show that silviculture has increased in the region from 1986 to 2010. In both years, silviculture areas are mainly located at the hillslope (47%), while floodplain and mountain top share 28 % and 23 % respectively. Available census data from the Brazilian Institute of Geography and Statistics, IBGE, for 1995 and

  2. Coastal rocky reef fishes of Santa Catarina's northern islands, Brazil

    Directory of Open Access Journals (Sweden)

    Johnatas Adelir Alves

    2015-11-01

    Full Text Available The coast of the state of Santa Catarina only has non-biogenic reefs, i.e. rocky and artificial reefs, and is considered the geographic south limit for many reef fish species. At present the diversity of organisms associated with reef environments is threatened. This study aimed to record the number of families and species of reef fish fauna of the north coast of the state of Santa Catarina. The data were collected through underwater visual census performed on Graças archipelago (26°12'S /48º29'W, Tamboretes archipelago (26°22'S/48°31'W and Barra do Sul islands (26°27'S/48º35'W. A total of 166 species was observed (6 elasmobranchii and 160 actinopterygii belonging to 66 families. The families with more species richness were Carangidae (16, Epinephelidae (9, Blenidae (8, Serranidae (7, Haemulidae (6, Sparidae (6 Tetraodontidae (6, Labridae-Scarini (5, Labrisomidae (5 Pomacentridae (5, Lutjanidae (5 and Muraenidae (5. This study add to the current published list, new 115 species, including new occurrences (e.g. Chromis limbata, and some endemic (e.g. Sparisoma amplum, exotic (e.g. Omobranchus punctatus, endangered (e.g. Hippocampus erectus and overexploited (e.g. Lutjanus analis species. Twenty one species are present in the IUCN’s list, twelve in the IBAMA’s list and four in the local list. All elasmobranchii recorded here are considered threatened species, like the brazilian guitarfish (Rhinobatos horkelii, which appears in three red lists, and it is considered critically endangered. All species of Epinephelidae are mentioned in the list of risk categories of the IUCN and five are cited as overexploited or threatened with overexploitation by IBAMA. Among Epinephelidae, the goliath grouper (Epinephelus itajara, is present in all red lists and has specific protection rules in Brazil. The gathered information will allow to take appropriate conservation measures, such as the establishment of marine protected areas, monitoring of fishing

  3. Systematic heat flow measurements across the Wagner Basin, northern Gulf of California

    Science.gov (United States)

    Neumann, Florian; Negrete-Aranda, Raquel; Harris, Robert N.; Contreras, Juan; Sclater, John G.; González-Fernández, Antonio

    2017-12-01

    A primary control on the geodynamics of rifting is the thermal regime. To better understand the geodynamics of rifting in the northern Gulf of California we systematically measured heat-flow across the Wagner Basin, a tectonically active basin that lies near the southern terminus of the Cerro Prieto fault. The heat flow profile is 40 km long, has a nominal measurement spacing of ∼1 km, and is collocated with a seismic reflection profile. Heat flow measurements were made with a 6.5-m violin-bow probe. Although heat flow data were collected in shallow water, where there are significant temporal variations in bottom water temperature, we use CTD data collected over many years to correct our measurements to yield accurate values of heat flow. After correction for bottom water temperature, the mean and standard deviation of heat flow across the western, central, and eastern parts of the basin are 220 ± 60, 99 ± 14, 889 ± 419 mW m-2, respectively. Corrections for sedimentation would increase measured heat flow across the central part of basin by 40 to 60%. We interpret the relatively high heat flow and large variability on the western and eastern flanks in terms of upward fluid flow at depth below the seafloor, whereas the lower and more consistent values across the central part of the basin are suggestive of conductive heat transfer. Moreover, heat flow across the central basin is consistent with gabbroic underplating at a depth of 15 km and suggests that continental rupture here has not gone to completion.

  4. THE BRAZILIAN BIODIESEL PROGRAM AND REGIONAL DEVELOPMENT: CASES FROM NORTHERN BRAZIL

    Directory of Open Access Journals (Sweden)

    Marcus Vinicius Alves Finco

    2011-12-01

    Full Text Available Biofuel production has been greatly discussed in Brazil. In 2004, these debates led the country to develop new policies and implement a national program for biodiesel use and production (PNPB with the intent to increase the share of renewable energy and foster regional development. In this context, the present study aims to assess the impacts of PNPB on regional development in Tocantins State, northern Brazil. For this purpose, ranges of socio-economic indicators were collected among national and regional stakeholders, as well as specific literature. The preliminary results point out that distribution logistics appears to be a considerable constraint to the success of the PNPB. The concentration of biodiesel industries in the central-west region of the country, and the large distances to deliver biodiesel in the northern Brazil make biodiesel prices non-competitive when compared to fossil diesel. The results also suggest that the PNPB is not succeeding in promoting the integration of family agriculture in the Tocantins state, especially due to the structural difficulty of the agricultural sector, as well as the technical and political shortcomings presented by the mechanism of incentives.

  5. Deep Structure and Subsidence History of Parnaíba Cratonic Basin, NE Brazil

    Science.gov (United States)

    Rodríguez Tribaldos, Verónica; White, Nicky; Coelho, Diogo; Julià, Jordi

    2017-04-01

    Cratonic sedimentary basins constitute some of the largest sedimentary basins on Earth. They are typically underlain by thick (i.e. 200 km) lithosphere and are characterized by slow, punctuated subsidence that occurs over hundreds of millions of years. Their stratigraphic records mainly consist of sequences of continental and shallow marine sedimentary rocks bounded by basin-wide erosional unconformities. Despite the importance of these basins, their origin and evolution remain poorly understood, mainly due to scarcity of well-constrained geological and geophysical data. In order to address this problem, an integrative study of the Parnaíba Cratonic basin in NE Brazil has been carried out within the framework of a multidisciplinary investigation. Here, we combine the analysis of a 1400 km long deep seismic reflection profile that crosses the basin, teleseismic earthquakes recorded by 12 broadband and 10 short-period, 3 component seismometers, 25 ancillary seismic reflection profiles, and 46 wells distributed across the basin. Our main goal is to constrain the basin's subsidence history in the context of its deep crustal structure and sedimentary architecture. Joint inversion of receiver functions and Rayleigh wave group dispersion measurements has been used to calculate 1D shear wave velocity models for crust and upper mantle beneath each seismic station. Combined interpretation of these velocity profiles and the deep seismic reflection profile has been carried out. Our results suggest Moho depths of approximately 35 km and 38 km beneath Precambrian basement east and west of the Parnaíba basin, respectively. In contrast, the Moho occurs at approximately 39 km beneath the city of Teresina, located on the eastern region of the basin, and at depths between 40 km and 42 km beneath the central and western areas of the basin. These results are combined to construct a sub-surface model underneath Parnaíba, and gravity modeling is used to test its validity. Average

  6. Northern tamarisk beetle (Diorhabda carinulata) and tamarisk (Tamarix spp.) interactions in the Colorado River basin

    Science.gov (United States)

    Nagler, Pamela L.; Nguyen, Uyen; Bateman, Heather L.; Jarchow, Christopher; Glenn, Edward P.; Waugh, William J.; van Riper, Charles

    2018-01-01

    Northern tamarisk beetles (Diorhabda carinulata) were released in the Upper Colorado River Basin in the United States in 2004–2007 to defoliate introduced tamarisk shrubs (Tamarix spp.) in the region’s riparian zones. The primary purpose was to control the invasive shrub and reduce evapotranspiration (ET) by tamarisk in an attempt to increase stream flows. We evaluated beetle–tamarisk interactions with MODIS and Landsat imagery on 13 river systems, with vegetation indices used as indicators of the extent of defoliation and ET. Beetles are widespread and exhibit a pattern of colonize–defoliate–emigrate, so that riparian zones contain a mosaic of completely defoliated, partially defoliated, and refoliated tamarisk stands. Based on satellite data and ET algorithms, mean ET before beetle release (2000–2006) was 416 mm/year compared to postrelease (2007–2015) ET of 355 mm/year (pBasin has shown a steady decline since 2007 and equilibrium has not yet been reached. Defoliation is now proceeding from the Upper Basin into the Lower Basin at a rate of 40 km/year, much faster than initially projected.

  7. Estimating the remaining potential of the Reconcavo basin, Brazil: a basin modeling and material balance approach

    Energy Technology Data Exchange (ETDEWEB)

    Silva, Thamy C.S.D.; Goncalves, Felix T.T.; Bedregal, Ricardo P.; Cuinas Filho, Elio P. [Universidade Federal do Rio de Janeiro (UFRJ), RJ (Brazil). Coordenacao dos Programas de Pos-graduacao de Engenharia (COPPE). Lab. de Modelagem de Bacias (LAB2M); Landau, Luiz [Universidade Federal do Rio de Janeiro (UFRJ), RJ (Brazil). Coordenacao dos Programas de Pos-graduacao de Engenharia (COPPE). Lab. de Metodos Computacionais em Engenharia (LAMCE)

    2004-07-01

    The existence of a petroleum system requires a number of essential elements (traps and source, reservoir and seal rocks) and processes (HC generation and migration and trap formation) besides an adequate timing among the elements and processes and a positive balance between the HC generation and losses due to (re)migration. Due to the complexity of petroleum systems dynamics, the basin modeling technique is the only one that allows the integration of all geological, geophysical and geochemical data as well as the simulation of the involved phenomena in a physically consistent way, providing an integrated view of the geologic history of the processes and elements of the petroleum system. The main objectives of this work are to show a reconstruction of the thermal and maturity evolution of the sedimentary section of the Reconcavo Basin using a multi-1D (pseudo 3D) approach, to model petroleum generation and expulsion, and the evolution of the pod(s) of source rock through time and space using the pseudo 3D approach, simulate petroleum migration along the main carrier-beds, accumulation and remigration from the potential traps. The advanced exploratory stage (mature), the geologic context (an intracratonic rift that resembles a close system) and the availability of large amounts of public data, make the Reconcavo Basin an excellent place to perform a study that can provide basis to an estimate of the remaining petroleum potential in analogous petroleum systems. (author)

  8. Ground-water levels in intermontane basins of the northern Rocky Mountains, Montana and Idaho

    Science.gov (United States)

    Briar, David W.; Lawlor, S.M.; Stone, M.A.; Parliman, D.J.; Schaefer, J.L.; Kendy, Eloise

    1996-01-01

    The Regional Aquifer-System Analysis (RASA) program is a series of studies by the U.S. Geological Survey (USGS) to analyze regional ground-water systems that compose a major portion of the Nation's water supply (Sun, 1986). The Northern Rocky Mountains Intermontane Basins is one of the study regions in this national program. The main objectives of the RASA studies are to (1) describe the groundwater systems as they exist today, (2) analyze the known changes that have led to the systems present condition, (3) combine results of previous studies in a regional analysis, where possible, and (4) provide means by which effects of future ground-water development can be estimated.The purpose of this study, which began in 1990, was to increase understanding of the hydrogeology of the intermontane basins of the Northern Rocky Mountains area. This report is Chapter B of a three-part series and shows the general distribution of ground-water levels in basin-fill deposits in the study area. Chapter A (Tuck and others, 1996) describes the geologic history and generalized hydrogeologic units. Chapter C (Clark and Dutton, 1996) describes the quality of ground and surface waters in the study area.Ground-water levels shown in this report were measured primarily during summer 1991 and summer 1992; however, historical water levels were used for areas where more recent data could not be obtained. The information provided allows for the evaluation of general directions of ground-water flow, identification of recharge and discharge areas, and determination of hydraulic gradients within basin-fill deposits.

  9. Pollen grains in quaternary sediments from the Campos Basin, state of Rio de Janeiro, Brazil: Core BU-91-GL-05

    Directory of Open Access Journals (Sweden)

    Aline Gonçalves de Freitas

    2013-12-01

    Full Text Available Here, we describe pollen grains extracted from a Pleistocene-Holocene sediment core (BU-91-GL-05; 22°48'45"S; 41°54'13"W taken from the Albacora Slope (22°48'45"S; 41°54'13"W, located in the Campos Basin of the northern region of the state of Rio de Janeiro, Brazil. The analysis resulted in the identification and morphological description of 46 types of pollen: one of a gymnosperm genus (Podocarpus; and 45 of angiosperm taxa across 27 families-one family of monocotyledons (Poaceae and 26 families (30 types of dicotyledons. The most common angiosperm families were Amaranthaceae (Chenopodium, Amaranthus and Gomphrena; Fabaceae (Fabaceae type, Bauhinia, Inga and Canavalia; Malpighiaceae (Tetrapteris, Heteropteris and Peixotoa; Malvaceae (Sida, Abutilon, Hibiscus and Pseudobombax; Rubiaceae (Faramea, Borreria and Psychotria; Asteraceae (Eupatorium and tribe Vernonieae; Bignoniaceae (Bignoniaceae type, Adenocalymma and Tabebuia; and Onagraceae (Fuchsia and Ludwigia. The palynoflora in this study are associated with dense montane and submontane Atlantic Forest, semideciduous forest and restinga (coastal woodland, all of which are present in the state of Rio de Janeiro. Palynological analysis can provide important data about paleovegetation and paleoclimatic changes in the studied area during the Quaternary, specifically in the last 145,000 years.

  10. Geochemical characterization and miospore biochronostratigraphy of the Frasnian anoxic event in the Parnaiba basin, Northeast Brazil

    International Nuclear Information System (INIS)

    Rodrigues, R.; De Melo, J.H.G.; Alves, D.B.; Loboziak, S.

    1995-01-01

    Radioactive shales of Frasnian age in the Parnaiba Basin present high concentrations of organic matter. They correspond to a condensed section related to the Devonian maximum marine transgression. Combined geochemical, palynological and clay mineral data point out to a dominant algal contribution in the composition of the organic matter, as well as to anoxic depositional settings. This radioactive shale interval corresponds to the onset of a long-lasting, global anoxic event which was to be intensified in the Late Frasnian, and thus can be regarded as a marker for chronostratigraphic correlations. It includes the main source rocks of Devonian age in the Palaeozoic basins of north Brazil, and therefore represents a target of potential interest for hydrocarbon exploration. (authors). 16 refs., 10 figs., 1 tab., 17 photos

  11. Geochemical characterization and miospore biochronostratigraphy of the Frasnian anoxic event in the Parnaiba basin, Northeast Brazil

    Energy Technology Data Exchange (ETDEWEB)

    Rodrigues, R.; De Melo, J.H.G.; Alves, D.B. [Universidade Federal, Rio de Janeiro, RJ (Brazil); Loboziak, S. [Lille-1 Univ., 59 - Villeneuve-d`Ascq (France)

    1995-12-31

    Radioactive shales of Frasnian age in the Parnaiba Basin present high concentrations of organic matter. They correspond to a condensed section related to the Devonian maximum marine transgression. Combined geochemical, palynological and clay mineral data point out to a dominant algal contribution in the composition of the organic matter, as well as to anoxic depositional settings. This radioactive shale interval corresponds to the onset of a long-lasting, global anoxic event which was to be intensified in the Late Frasnian, and thus can be regarded as a marker for chronostratigraphic correlations. It includes the main source rocks of Devonian age in the Palaeozoic basins of north Brazil, and therefore represents a target of potential interest for hydrocarbon exploration. (authors). 16 refs., 10 figs., 1 tab., 17 photos.

  12. Cretaceous-Paleogene ostracods from the Paraíba Basin, northeastern Brazil

    Science.gov (United States)

    de Lima Barros, Cecília; Piovesan, Enelise Katia; Oliveira Agostinho, Sonia Maria

    2018-04-01

    This work presents a detailed taxonomic study on the marine ostracods from the Paraíba Basin, northeastern Brazil, in wells from the wells Itamaracá-1IT-03-PE and Poty-1PO-01-PE, which record the Maastrichtian-Danian boundary. Besides the taxonomic data, this paper contributes to the paleoenvironmental knowledge of Cretaceous-Paleogene ostracods from the Paraíba Basin. The analysis of 98 samples of the well Itamaracá-1IT-03-PE and 59 samples of the Poty-1PO-01-PE resulted in the record of 34 ostracode species, all representative of a marine environment with normal salinity. Seven new species are proposed: Cytherella centrocompressa sp. nov.; Cytherella paraibensis sp. nov.; Neonesidea potyensis sp. nov.; Bythoceratina spinosa sp. nov.; Eucytherura ventrotuberculata sp. nov.; Langiella fauthi sp. nov. and Protobuntonia punctatum sp. nov.

  13. A new species of Ituglanis (Siluriformes: Trichomycteridae from the rio Uruguai basin, southern Brazil

    Directory of Open Access Journals (Sweden)

    Juliano Ferrer

    2017-10-01

    Full Text Available ABSTRACT A new species of Ituglanis associated to the grasslands of the Pampa biome is described from the rio Uruguai basin, southern Brazil. The new species is distinguished from its congeners by the low number of ribs and by a unique color pattern composed of an outer layer with scattered round black blotches equivalent in size to the eye circumference over a reddish brown background on the lateral surface of the body. We provide the genetic sequences of the mitochondrial gene Cytochrome c Oxydase subunit I (COI for three of the paratypes and discuss aspects about the recent discovery of the new species.

  14. Roveacrinids in mid-Cretaceous biostratigraphy of the Sergipe Basin, northeastern Brazil

    Science.gov (United States)

    Ferré, Bruno; Walter, Simone; Bengtson, Peter

    2005-08-01

    As part of a study of the Cenomanian-Coniacian sedimentary succession in the Sergipe Basin in northeastern Brazil, microfacies analyses were tested for possible chronostratigraphic application. The common and widespread remains of roveacrinid echinoderms proved useful for intrabasinal biochronostratigraphy. Local dolomitization in the basin, which destroyed most other fossil remains, left the magnesian-calcitic roveacrinid skeletons largely unaffected. Thus, where diagnostic fossils are scarce or lacking, roveacrinids may provide an ancillary means of chronostratigraphic correlation. The forms recorded from Sergipe are described, and a stratigraphic range chart is presented for intrabasinal application, with the possibility of regional or even global correlation either qualitatively (presence/absence patterns) or quantitatively (eco-event patterns). Several roveacrinid abundance horizons have been reported worldwide in relation to sea level changes and associated hypoxic events, during which roveacrinids developed abundant opportunistic populations. The present study of the Sergipe Basin provides a basis for comparisons and correlations of roveacrinid occurrences in the mid-Cretaceous succession of the South Atlantic continental margin basins and ODP/DSDP drill cores.

  15. Cassiopidae gastropods, influence of Tethys Sea of the Romualdo Formation (Aptian-Albian), Araripe Basin, Brazil

    Science.gov (United States)

    Pereira, Priscilla Albuquerque; Cassab, Rita de Cassia Tardin; Barreto, Alcina Magnólia Franca

    2016-10-01

    The Cassiopidae family belongs to a group of gastropods of the Tethyan Realm, whose origin and dispersion are related a transgression of the Tethys Sea during the Early Cretaceous. The Romualdo Formation in the Araripe Basin, located in Northeast Brazil, presents fossil assemblages with echinoids, bivalves and cassiopid gastropods, indicating a marine sedimentation at the top of the formation. This research reveals three new species of this fauna: Gymnentome (Craginia) beurleni sp. nov., 'Pseudomesalia' ('Pseudomesalia') mennessieri sp. nov and 'Pseudomesalia' ('Pseudomesalia') santanensis sp. nov. We also review two other species: Craginia araripensisBeurlen, 1964 and Gymnentome romualdoiBeurlen, 1964, which we reclassify taxonomically as Paraglauconia (Diglauconia) araripensis and Gymnentome (Gymnentome) romualdoi, respectively; Paraglauconia (Diglauconia) lyrica Maury, 1936 and Gymnentome (Gymnentome) carregozica Maury, 1936 were the first recorded species in the Araripe Basin. The occurrence of these cassiopid gastropod fauna in other basins, such as Sergipe, Potiguar and Parnaíba, indicate the influence of waters coming from the north through the Tethys Sea in the Aptian-Albian and in the marginal continental basins of the Brazilian Northeast.

  16. Temporal evaluation of soil use conflicts in the Formoso river basin, state of Tocantins, Brazil

    Directory of Open Access Journals (Sweden)

    Kaio Cesar Cardoso de Lima Fonseca Alves

    2015-09-01

    Full Text Available The importance of permanent preservation areas (PPA is mainly associated to their environmental role to maintain, preserve, and conserve water resources and ecosystems within a basin. The objective of this study was to delimitate and quantify the areas of PPA along watercourses as well as anthropized areas within PPAs boundaries, in the Formoso river basin, state of Tocantins, Brazil. PPAs area was delimited considering boundaries according to the Brazilian Forest Law. We sampled areas within the watercourses classified up to hierarchical Level 4. Watercourses handling draw, automatic delimitation of PPA, and visual classification of the soil use conflicts based on LANDSAT 5 TM of 1985, 1998 and 2011 were carried out on Geographical Information System ArcGIS. PPA of the watercourses sampled in this study represent 1.14% (24,491.35 ha of the drainage area of the Formoso river basin. For 1985, an area of about 3,616.48 ha was quantified, which is characterized by conflicts related to soil use. However, these conflict areas were reduced to 3,341.25 ha and 3,345.37 ha, respectively, for 1998 and 2011. Due to the intense agricultural land expansion observed in the basin in the last decades, the mentioned reductions in soil use conflicts between 1985 and 1998 and subsequent maintenance can be linked to changes on Brazilian environmental legislation.

  17. Taxonomic revision of the fossil pulmonate mollusks of Itaboraí Basin (Paleocene, Brazil

    Directory of Open Access Journals (Sweden)

    Rodrigo Brincalepe Salvador

    2013-01-01

    Full Text Available The limestones of Itaboraí Basin (Middle Paleocene, Rio de Janeiro, Brazil, harbor a rich fossil molluscan fauna consisting exclusively of pulmonate snails, both terrestrial and freshwater. An extensive taxonomic revision of this paleofauna is conducted here. A new genus, Cortana, is described as well as two new species, Eoborus fusiforme and Gastrocopta itaboraiensis. The revised classification is as follows: Austrodiscus lopesi (Charopidae; Biomphalaria itaboraiensis (Planorbidae; "Brachypodella" britoi (Urocoptidae; Brasilennea arethusae, Brasilennea guttula, Brasilennea minor (Cerionidae; Bulimulus fazendicus, Bulimulus trindadeae, Cortana carvalhoi, Cyclodontina coelhoi, Itaborahia lamegoi, Leiostracus ferreirai, Plagiodontes aff. dentatus (Orthalicidae; Cecilioides sommeri (Ferussaciidae; Eoborus rotundus, Eoborus sanctijosephi, Eoborus fusiforme (Strophocheilidae; Gastrocopta mezzalirai, Gastrocopta itaboraiensis (Gastrocoptidae; Temesa magalhaesi (Clausiliidae. The species Strobilopsis mauryae was considered a synonym of Brasilennea arethusae; Bulimulus sommeri a synonym of Itaborahia lamegoi; and Vorticifex fluminensis a synonym of Eoborus sanctijosephi. Itaboraí Basin has the most ancient records of the families Orthalicidae, Gastrocoptidae, Ferussaciidae and Strophocheilidae. Moreover, the basin's records of Charopidae, Clausiliidae, Cerionidae, and Urocoptidae are among the most ancient in the world and, among these, those of Cerionidae, Clausiliidae and Urocoptidae deserve special attention since they are greatly removed from these families' current distribution. Additionally, Itaboraí has the most ancient records for the genera Austrodiscus, Brachypodella, Bulimulus, Cecilioides, Cyclodontina, Eoborus, Gastrocopta, Leiostracus, Plagiodontes and Temesa. There are three endemic genera in the basin: Brasilennea, Cortana and Itaborahia. Further discussion on paleobiogeography and evolution of this paleofauna is also provided.

  18. Modeling the tectonic development of the Tucano and Sergipe-Alagoas rift basins, Brazil

    Science.gov (United States)

    Karner, Garry D.; Egan, Stuart S.; Weissel, Jeffrey K.

    1992-12-01

    The Tucano and Sergipe-Alagoas basins of northeast Brazil form part of a regional extensional basin system that was operative during the Mesozoic breakup of South America and Africa with both basins developing on Precambrian crust. The synchronous development of the rift basins suggest that they are genetically linked in space and time. Whereas the offshore Sergipe-Alagoas basin is characterized by a substantial thickness of post-rift sediment, the Tucano basin either failed to develop or at least preserve a significant thickness of post-rift sediment. Observed primary porosities within both pre- and syn-rift Tucano basin sediment imply that significant post-rift sedimentation never occurred. Failure to develop significant post-rift subsidence has important thermal and mechanical implications for the reaction of the lithosphère to rifting and can be explained in terms of: (1) depth-dependent lithospheric extension in which intracrustal detachments allow the extension of the crust to be decoupled from the thinning of the lithospheric mantle, (2) small rates of extension that allow the lithosphere to cool during rifting, and/or (3) lithospheric rifting during which the flexural strength of the lithosphere remains high. With respect to points (2) and (3), forward modeling demonstrates that finite rifting rates over a 20-25 m.y. period are insufficient to cool the lithosphere to the point where post-rift subsidence fails to develop. An interesting complication arises when the flexural strength of the lithosphere remains large during rifting: it tends to suppress the vertical motions of the lithosphere, such as those engendered by the cooling of the lithosphere following rifting, thereby reducing significantly the amplitude of the post-rift subsidence. Thus, the lack of post-rift sedimentation within a basin does not necessarily imply that extension has been limited to the crust. From our kinematic modeling of the Tucano basin, the observed negative free-air and

  19. Three-dimensional seismo-tectonics in the Po Valley basin, Northern Italy

    Science.gov (United States)

    Turrini, Claudio; Angeloni, Pamela; Lacombe, Olivier; Ponton, Maurizio; Roure, François

    2015-10-01

    The Po Valley (Northern Italy) is a composite foreland-foredeep basin caught in between the Southern Alps and Northern Apennine mountain belts. By integrating the 3D structural model of the region with the public earthquake dataset, the seismo-tectonics of the basin is shown at different scales of observation. The three-dimensional geo-volume is used to review the seismicity around the region and validate the structure-earthquake association for such a complex tectonic framework. Despite the overall uncertainty due to the original data distribution-quality as well as the crustal scale model dimension, the direct correlation between structures and seismicity a) confirms the Po Valley region as an active tectonic system and b) allows the whole structural architecture to be revised by a unique three-dimensional perspective and approach. This study also indicates that 3D methodology is a powerful tool for better understanding of highly complex seismo-tectonic situations at both regional and local scales.

  20. A new species of Scinax Wagler, 1830 (Anura: Hylidae from the middle Amazon river basin, Brazil

    Directory of Open Access Journals (Sweden)

    Marcelo José Sturaro

    2014-01-01

    Full Text Available A new species of the hylid genus Scinax is described and illustrated. The new taxon was found in the Amazonian rainforest of northern Brazil, municipalities of Maués and Careiro da Várzea, state of Amazonas. The new species is characterized by its moderate size (male mean snout-vent length 36.3mm; body robust; large, orange, black-bordered axillary and inguinal spots; and bilobate vocal sac. This new species was found in primary and secondary forest on branches of shrubs or trees in, or next to, permanent ponds and flooded areas.

  1. Crinoids columnals (Echinodermata) of the Ererê Formation (late Eifelian-early Givetian, Amazon Basin), State of Pará, Brazil

    Science.gov (United States)

    Scheffler, S. M.; Fernandes, A. C. S. F.; da Fonseca, V. M. M.

    2014-01-01

    The faunal composition of stalked echinoderms in the Brazilian Devonian is still largely unknown despite the great abundance of crinoids in the shallow epicontinental seas of the Paleozoic. The first Devonian crinoids of Brazil, recorded in the literature in 1875 and 1903, were from the sedimentary rocks of the Ererê Formation in the Amazon Basin. Since then, the echinoderms of this formation have not been studied. This study, based on isolated pluricolumnals and columnals, described and identified Botryocrinus meloi n. sp., the first record for this genus in Brazil. In addition to this species, two other morphological patterns were identified: Tjeecrinus sp. and Morphotype AM/Er-01. The form of occurrence of the crinoid material and the paleoautoecology of B. meloi allow preliminary characterization of the habitat as a moderately deep water with weak to moderate currents and soft substrate. The similarity between B. meloi and Botryocrinus montguyonensis and of Tjeecrinus? sp. and T. crassijugatus, from the Devonian of the Armorican and Rhenan Massif, represents new evidence for the existence of contact between the faunas of the Amazon Basin with those of northern Gondwana and Armorica during the Middle Devonian.

  2. AMS-{sup 14}C measurements for the carbonate platform of the offshore Campos Basin, Rio de Janeiro State, Brazil

    Energy Technology Data Exchange (ETDEWEB)

    Coimbra, Melayne M. E-mail: melayne@onda.com.br; Barbosa, Catia F.; Soares-Gomes, Abilio; Silva, Cleverson G.; Rios-Netto, Aristoteles; Mueller, Ken A

    2000-10-01

    As part of our accelerator mass spectrometry (AMS) program in Brazil we prepared and measured some red algae carbonate crust samples from Campos Basin, Rio de Janeiro, Brazil. The measurements were performed at Purdue Rare Isotope Measurement Laboratory (PRIME Lab), Purdue University, IN, USA. This carbonate material is interlaminated with foraminiferal lime mud reflecting recurrent intervals of carbonate development, which might be linked to outer-shelf oceanographic circulation.

  3. Forming mechanism of the Ordovician karst carbonate reservoirs on the northern slope of central Tarim Basin

    Directory of Open Access Journals (Sweden)

    Heng Fu

    2017-07-01

    Full Text Available The Ordovician karst carbonate reservoirs on the northern slope of central Tarim Basin are important oil and gas exploration targets in the basin, but their dissolution mechanisms are in controversy. In this paper, based on the integrated study of sedimentation, sequence and reservoir, together with microscopic analysis and macroscopic seismic data analysis, the carbonate karst reservoirs in the study area were divided into three types: dissolved pore-cavity limestone reservoir, pore-cavity dolomite reservoir and fracture-cavity siliceous reservoir, and their forming mechanisms were discussed respectively. Some findings were obtained. First, dissolved pore-cavity limestone reservoirs are distributed in the upper Yingshan Fm and Yijianfang Fm of the Ordovician vertically, while pore-cavity dolomite reservoirs are mainly developed in the Penglai Fm and lower Yingshan Fm of the Ordovician with great thickness. Second, dissolved pore-cavity limestone reservoirs were formed by karstification on the third-order sequence boundary (lowstand tract, while pore-cavity dolomite reservoirs were formed by deep burial dolomitization controlled by karstification on the third-order sequence boundary, both of which are distributed in the highstand tract below the third-order sequence boundary. Third, siliceous reservoirs are developed under the control of faulting, as a result of reworking of deep hydrothermal fluids along faults to the limestone, and the siliceous reservoirs and their hydrothermal solution fracture-cavity systems are distributed near faults. It is further predicted that, in addition to the three types of reservoir above, platform-margin reef-flat reservoirs are developed in the Ordovician on the northern slope of central Tarim Basin.

  4. Hydrogeochemistry of high-fluoride groundwater at Yuncheng Basin, northern China

    Energy Technology Data Exchange (ETDEWEB)

    Li, Chengcheng [State Key Laboratory of Biogeology and Environmental Geology and School of Environmental Studies, China University of Geosciences, Wuhan 430074 (China); Gao, Xubo, E-mail: xubo.gao.cug@gmail.com [State Key Laboratory of Biogeology and Environmental Geology and School of Environmental Studies, China University of Geosciences, Wuhan 430074 (China); University of Texas at Austin, Austin, TX, 78705 (United States); Wang, Yanxin, E-mail: yx.wang@cug.edu.cn [State Key Laboratory of Biogeology and Environmental Geology and School of Environmental Studies, China University of Geosciences, Wuhan 430074 (China)

    2015-03-01

    Hydrogeochemical and environmental isotope methods were integrated to delineate the spatial distribution and enrichment of fluoride in groundwater at Yuncheng Basin in northern China. One hundred groundwater samples and 10 Quaternary sediment samples were collected from the Basin. Over 69% of the shallow groundwater (with a F{sup −} concentration of up to 14.1 mg/L), 44% of groundwater samples from the intermediate and 31% from the deep aquifers had F{sup −} concentrations above the WHO provisional drinking water guideline of 1.5 mg/L. Groundwater with high F{sup −} concentrations displayed a distinctive major ion chemistry: Na-rich and Ca-poor with a high pH value and high HCO{sub 3}{sup −} content. Hydrochemical diagrams and profiles and hydrogen and oxygen isotope compositions indicate that variations in the major ion chemistry and pH are controlled by mineral dissolution, cation exchange and evaporation in the aquifer systems, which are important for F{sup −} mobilization as well. Leakage of shallow groundwater and/or evaporite (gypsum and mirabilite) dissolution may be the major sources for F{sup −} in groundwater of the intermediate and deep aquifers. - Highlights: • High-F{sup −} groundwater widely occurs in Yuncheng Basin of northern China. • High-F{sup −} groundwater is Na and HCO{sub 3}-rich and Ca-poor, with high pH. • Major hydrogeochemical processes are mineral dissolution, ion exchange and evaporation. • Shallow groundwater leakage/evaporite dissolution may cause F enrichment in lower aquifers.

  5. Detection of the pandemic norovirus variant GII.4 Sydney 2012 in Rio Branco, state of Acre, northern Brazil

    Directory of Open Access Journals (Sweden)

    Luciana Damascena da Silva

    2013-12-01

    Full Text Available Noroviruses (NoVs are important cause of gastroenteritis in humans worldwide. Genotype GII.4 is responsible for the majority of outbreaks reported to date. This study describes, for the first time in Brazil, the circulation of NoV GII.4 variant Sydney 2012 in faecal samples collected from children aged less than or equal to eight years in Rio Branco, state of Acre, northern Brazil, during July-September 2012.

  6. Amazon river basin evapotranspiration and its influence on the rainfall in southern Brazil

    Science.gov (United States)

    Folegatti, M. V.; Wolff, W.

    2017-12-01

    Amazon river basin (ARB) presents a positive water balance, i.e. the precipitation is higher than evapotranspiration. Regarding the regional circulation, ARB evapotranspiration represents an important source of humidity for the South of Brazil. Thus, the aim of this work is to answer the question: how much is the correlation between ARB evapotranspiration and rainfall in South of Brazil? The shapefiles data of ARB and countries/states boundary were obtained through the Oak Ridge National Laboratory (ORNL) and Instituto Brasileiro de Geografia e Estatística (IBGE), respectively. According to rasters data, the precipitation was obtained from study of Numerical Terradynamic Simulation Group (NTSG) for images of Moderate Resolution Imaging Spectroradiometer (MODIS), under code MOD16A2, whereas rasters data for evapotranspiration were obtained from National Aeronautics and Space Administration (NASA) by Tropical Rainfall Measuring Mission Multi-Satellite Precipitation Analysis (TMPA), under code 3B43_V7. The products MOD16A2 and 3B43_V7 have a respective spatial resolution of 0.5º and 0.25º, and a monthly temporal resolution from January/2000 to December/2014. For ARB and South region of Brazil was calculated the mean evapotranspiration and mean precipitation through the pixels within of the respective polygons. To answer the question of this work was performed the cross-correlation analysis between these time series. We observed the highest value for the lag that corresponds the begin of spring (October), being 0.3 approximately. As a result, the mean precipitation on South region of Brazil during spring and summer was in the order of 15% to 30 %, explained by ARB evapotranspiration. For this reason, the maintenance of ARB is extremely important for water resource grant in South of Brazil.

  7. Hydrology of the Upper Capibaribe Basin, Pernambuco, Brazil - A reconnaissance in an Area of Crystalline Rocks

    Science.gov (United States)

    Chada Filho, Luiz Goncalves; Dias Pessoa, Mario; Sinclair, William C.

    1966-01-01

    The upper Capibaribe basin is the western three-fourths, approximately, of the valley of the river that empties into the Atlantic Ocean at Recife, the capital of the State of Pernambuco, Brazil. It is the part of the drainage basin that is within the Drought Polygon of northeast Brazil, and it totals about 5,400 square kilometers. It receives relatively abundant precipitation in terms of the annual average, yet is regarded as hot subhumid to semiarid because the precipitation is uneven from year to year and place to place. The dependable water supply, therefore, is small. The basin has water, which could be put to better use than at present, but the opportunities for augmenting the usable supply are not great. The streams are intermittent and therefore cannot be expected to fill surface reservoirs and to keep them filled. The ground-water reservoirs have small capacity--quickly filled and quickly drained. A rough estimate based on the records for 1964 suggests that, of 4,700 million cubic meters of precipitation in the upper Capibaribe basin, 2,700 million cubic meters (57 percent) left the basin as runoff and 2,000 million cubic meters {43 percent) went into underground storage or was evaporated or transpired. The bedrock of the upper Capibaribe basin is composed of granite, gneiss, schist, and other varieties of crystalline rocks, which have only insignificant primary permeability. They are permeable mainly where fractured. The principal fracture zones, fortunately, are in the valleys, where water accumulates and can feed into them, but the volume of fractured rock is small in relation to the basin as a whole. A well in a large water-filled fracture zone may yield up to 20,000 liters per hour, but the average well yields less than one-fourth this amount, and some wells yield none. The saprolite, or weathered rock, is many meters thick at some places especially in the eastern half of the upper Capibaribe basin. It contains water locally, but ordinarily will yield

  8. Detrital fission-track-compositional signature of an orogenic chain-hinterland basin system: The case of the late Neogene Quaternary Valdelsa basin (Northern Apennines, Italy)

    Science.gov (United States)

    Balestrieri, M. L.; Benvenuti, M.; Tangocci, F.

    2013-05-01

    Detrital thermochronological data collected in syn-tectonic basin deposits are a promising tool for deciphering time and processes of the evolution of orogenic belts. Our study deals with the Valdelsa basin, one of the wider basins of central Tuscany, Italy. The Valdelsa basin is located at the rear of the Northern Apennines, a collisional orogen whose late Neogene Quaternary development is alternatively attributed to extensional and compressional regimes. These contrasting interpretations mostly rely on different reconstructions of the tectono-sedimentary evolution of several basins formed at the rear of the chain since the late Tortonian. Here, we explore the detrital thermochronological-compositional signature of tectonic and surface processes during the Valdelsa basin development. For this aim, detrital apatite fission-track analysis of 21 sand samples from the latest Messinian Gelasian fluvial to shallow marine basin deposits, has been accompanied by a clast composition analysis of 7 representative outcrops of the conglomerate facies. The grain-age distributions of the sediment samples are generally characterized by two distinct components, one younger peak (P1) varying between 5.5 ± 2.8 and 9.5 ± 1.0 Ma and one older peak (P2) varying from 15.0 ± 8.0 to 41.0 ± 10 Ma. By comparison with some bedrock ages obtained from the E-NE basin shoulder, we attributed the P2 peak to the Ligurian Units and the P1 peak to the Macigno Formation (Tuscan Units). These units are arranged one upon the other in the complex nappe pile forming the Northern Apennines orogen. While the gravel composition indicates a predominant feeding from the Ligurian units all along the sedimentary succession with a subordinate occurrence of Macigno pebbles slightly increasing upsection, the P1 peak is present even in the oldest collected sandy sediments. The early P1 occurrence reveals that the Macigno was exposed in the E-NE basin shoulder since at least the latest Messinian-early Zanclean

  9. The flora of Early Permian coal measures from the Parana Basin in Brazil: A review

    International Nuclear Information System (INIS)

    Iannuzzi, Roberto

    2010-01-01

    This paper presents an updated overview integrating both previous and newly published data on the most important floras found associated with Early Permian coal seams in the Parana Basin, Brazil. These floras occur within the Rio Bonito Formation and correspond to the Gondwana ''Glossopteris Flora.'' For this review, five floras are selected, in ascending stratigraphic order: the ''Sao Joao do Triunfo,'' ''Figueira,'' ''Quiteria,'' ''Morro do Papaleo'' and ''Irapua Bed'' floras. They are the best-known floras of the basin in terms of taxonomic composition, paleoecology and environments of deposition. An early-mid Sakmarian to earliest Artinskian age is indicated for the Rio Bonito Formation based on absolute radiometric and relative biostratigraphic ages. Integration of available information about the selected floras allows evaluation of taphonomic and paleoecological factors to provide a more comprehensive understanding of the Early Permian floral record in the Parana Basin. The variation observed in both the taxonomic composition of individual floras and in the frequency of occurrence of different plant groups is due to the broad range of environmental/edaphic conditions that prevailed in the many different depositional settings represented in the Rio Bonito Formation. A more precise age determination obtained for the plant-bearing deposits permits the establishment of a more confident correlation between the Early Permian floral succession in the Parana Basin and other Early Permian floral successions in other basins. The Sakmarian global warming favored the appearance of pecopterid and sphenopterid ferns amongst the spore-producing plants, and the glossopterids amongst the pollen-producing plants. (author)

  10. The flora of Early Permian coal measures from the Parana Basin in Brazil: A review

    Energy Technology Data Exchange (ETDEWEB)

    Iannuzzi, Roberto [Centro de Investigacoes do Gondwana, Instituto de Geociencias, Universidade Federal do Rio Grande do Sul, Av. Bento Goncalves, 9500, Porto Alegre, RS, 91.509-900 (Brazil)

    2010-08-01

    This paper presents an updated overview integrating both previous and newly published data on the most important floras found associated with Early Permian coal seams in the Parana Basin, Brazil. These floras occur within the Rio Bonito Formation and correspond to the Gondwana ''Glossopteris Flora.'' For this review, five floras are selected, in ascending stratigraphic order: the ''Sao Joao do Triunfo,'' ''Figueira,'' ''Quiteria,'' ''Morro do Papaleo'' and ''Irapua Bed'' floras. They are the best-known floras of the basin in terms of taxonomic composition, paleoecology and environments of deposition. An early-mid Sakmarian to earliest Artinskian age is indicated for the Rio Bonito Formation based on absolute radiometric and relative biostratigraphic ages. Integration of available information about the selected floras allows evaluation of taphonomic and paleoecological factors to provide a more comprehensive understanding of the Early Permian floral record in the Parana Basin. The variation observed in both the taxonomic composition of individual floras and in the frequency of occurrence of different plant groups is due to the broad range of environmental/edaphic conditions that prevailed in the many different depositional settings represented in the Rio Bonito Formation. A more precise age determination obtained for the plant-bearing deposits permits the establishment of a more confident correlation between the Early Permian floral succession in the Parana Basin and other Early Permian floral successions in other basins. The Sakmarian global warming favored the appearance of pecopterid and sphenopterid ferns amongst the spore-producing plants, and the glossopterids amongst the pollen-producing plants. (author)

  11. Northern tamarisk beetle (Diorhabda carinulata) and tamarisk (Tamarix spp.) interactions in the Colorado River basin

    Science.gov (United States)

    Nagler, Pamela L.; Nguyen, Uyen; Bateman, Heather L.; Jarchow, Christopher; Glenn, Edward P.; Waugh, William J.; van Riper, Charles

    2018-01-01

    Northern tamarisk beetles (Diorhabda carinulata) were released in the Upper Colorado River Basin in the United States in 2004–2007 to defoliate introduced tamarisk shrubs (Tamarix spp.) in the region’s riparian zones. The primary purpose was to control the invasive shrub and reduce evapotranspiration (ET) by tamarisk in an attempt to increase stream flows. We evaluated beetle–tamarisk interactions with MODIS and Landsat imagery on 13 river systems, with vegetation indices used as indicators of the extent of defoliation and ET. Beetles are widespread and exhibit a pattern of colonize–defoliate–emigrate, so that riparian zones contain a mosaic of completely defoliated, partially defoliated, and refoliated tamarisk stands. Based on satellite data and ET algorithms, mean ET before beetle release (2000–2006) was 416 mm/year compared to postrelease (2007–2015) ET of 355 mm/year (p<0.05) for a net reduction of 61 mm/year. This is lower than initial literature projections that ET would be reduced by 300–460 mm/year. Reasons for the lower-than-expected ET reductions are because baseline ET rates are lower than initially projected, and percentage ET reduction is low because tamarisk stands tend to regrow new leaves after defoliation and other plants help maintain canopy cover. Overall reductions in tamarisk green foliage during the study are 21%. However, ET in the Upper Basin has shown a steady decline since 2007 and equilibrium has not yet been reached. Defoliation is now proceeding from the Upper Basin into the Lower Basin at a rate of 40 km/year, much faster than initially projected.

  12. Adaptation to changing water resources in the Ganges basin, northern India

    International Nuclear Information System (INIS)

    Moors, Eddy J.; Groot, Annemarie; Biemans, Hester; Terwisscha van Scheltinga, Catharien; Siderius, Christian; Stoffel, Markus; Huggel, Christian; Wiltshire, Andy; Mathison, Camilla; Ridley, Jeff; Jacob, Daniela; Kumar, Pankaj

    2011-01-01

    An ensemble of regional climate model (RCM) runs from the EU HighNoon project are used to project future air temperatures and precipitation on a 25 km grid for the Ganges basin in northern India, with a view to assessing impact of climate change on water resources and determining what multi-sector adaptation measures and policies might be adopted at different spatial scales. The RCM results suggest an increase in mean annual temperature, averaged over the Ganges basin, in the range 1-4 o C over the period from 2000 to 2050, using the SRES A1B forcing scenario. Projections of precipitation indicate that natural variability dominates the climate change signal and there is considerable uncertainty concerning change in regional annual mean precipitation by 2050. The RCMs do suggest an increase in annual mean precipitation in this region to 2050, but lack significant trend. Glaciers in headwater tributary basins of the Ganges appear to be continuing to decline but it is not clear whether meltwater runoff continues to increase. The predicted changes in precipitation and temperature will probably not lead to significant increase in water availability to 2050, but the timing of runoff from snowmelt will likely occur earlier in spring and summer. Water availability is subject to decadal variability, with much uncertainty in the contribution from climate change. Although global social-economic scenarios show trends to urbanization, locally these trends are less evident and in some districts rural population is increasing. Falling groundwater levels in the Ganges plain may prevent expansion of irrigated areas for food supply. Changes in socio-economic development in combination with projected changes in timing of runoff outside the monsoon period will make difficult choices for water managers. Because of the uncertainty in future water availability trends, decreasing vulnerability by augmenting resilience is the preferred way to adapt to climate change. Adaptive policies are

  13. MECHANISMS CONTROLLING SURFACE WATER QUALITY IN THE COBRAS RIVER SUB-BASIN, NORTHEASTERN BRAZIL

    Directory of Open Access Journals (Sweden)

    ALEXANDRE DE OLIVEIRA LIMA

    2017-01-01

    Full Text Available Stream water quality is dependent on many factors, including the source and quantity of the streamflow and the types of geology and soil along the path of the stream. This study aims to evaluate the origin and the mechanisms controlling the input of ions that effect surface water quality in the sub-basin of the Rio das Cobras, Rio Grande do Norte state, Northeastern Brazil. Thirteen ponds were identified for study: three in the main river and ten in the tributaries between, thus covering the whole area and lithology of the sub-basin. The samples were collected at two different times (late dry and rainy periods in the hydrological years 2009 and 2010, equating to total of four collection times. We analyzed the spatial and seasonal behavior of water quality in the sub-basin, using Piper diagrams, and analyzed the source of the ions using Guibbs diagram and molar ratios. With respect to ions, we found that water predominate in 82% sodium and 76% bicarbonate water (cations and anions, respectively. The main salinity control mechanism was related to the interaction of the colloidal particles (minerals and organic sediment with the ions dissolved in water. Based on the analysis of nitrates and nitrites there was no evidence of contamination from anthropogenic sources.

  14. Origin of the tertiary red beds in the Northern part of the Duero Basin (Spain), II. Composition and genesis

    NARCIS (Netherlands)

    Mabesoone, J.M.

    1961-01-01

    In this second paper the red beds outcropping in the northern part of the Duero basin have been treated regarding their mineral and pebble composition, chemical parameters, and surface textures of quartz sand grains, taking as basis the results reported in the first paper. These deposits originate

  15. Trends in the development and updating of the fishing fleet in the Northern Basin

    Directory of Open Access Journals (Sweden)

    Kuranov Yu. F.

    2017-12-01

    Full Text Available The practice and need to update and form the production and technical base of fishery enterprises have an increasing impact on performance of the fisheries complex and become decisive when considering the prospects for its development on an innovative basis. The paper examines the current state and development trends of the Northern Basin fishing fleet, its production capabilities in developing available bioresources, the need and prospects for renewal. During the research the influence of the main factors determining the formation of the quantitative and structural composition of the fishing fleet has been shown. The most stable and long-term impact is the state of commercial stocks of aquatic biological resources, their variability under the influence of natural factors and anthropogenic load. The second important factor is institutional changes. Initially, since the beginning of the 1990s, this took place due to the transformation of economic relations, and later – to institutional changes in the legislatively approved principles of granting fishing enterprises the right to access water biological resources. The following data have been presented: adaptation of the fleet's production capacities for specialization of fishing activities, ways of modernization and re-equipment, construction of new vessels, acquisition of vessels being in operation in the countries with developed fisheries. These changes had reduced the fleet's production potential raising its qualitative indicators (productivity, depth of processing of raw materials at sea. At the same time, the noted positive trends have been accompanied by some increase in the aging indicators for all groups and types of vessels. The institutional and economic instruments for supporting and stimulating the construction of new fishing vessels have been justified. Nowadays, in the Northern Basin the priority areas of support should be the construction of ships for pelagic fishing and coastal

  16. Mapping and monitoring cheatgrass dieoff in rangelands of the Northern Great Basin, USA

    Science.gov (United States)

    Boyte, Stephen P.; Wylie, Bruce K.; Major, Donald J.

    2015-01-01

    Understanding cheatgrass (Bromus tectorum) dynamics in the Northern Great Basin rangelands, USA, is necessary to effectively manage the region’s lands. This study’s goal was to map and monitor cheatgrass performance to identify where and when cheatgrass dieoff occurred in the Northern Great Basin and to discover how this phenomenon was affected by climatic, topographic, and edaphic variables. We also examined how fire affected cheatgrass performance. Land managers and scientists are concerned by cheatgrass dieoff because it can increase land degradation, and its causes and effects are not fully known. To better understand the scope of cheatgrass dieoff, we developed multiple ecological models that integrated remote sensing data with geophysical and biophysical data. The models’ R2 ranged from 0.71 to 0.88, and their root mean squared errors (RMSEs) ranged from 3.07 to 6.95. Validation of dieoff data showed that 41% of pixels within independently developed dieoff polygons were accurately classified as dieoff, whereas 2% of pixels outside of dieoff polygons were classified as dieoff. Site potential, a long-term spatial average of cheatgrass cover, dominated the development of the cheatgrass performance model. Fire negatively affected cheatgrass performance 1 year postfire, but by the second year postfire performance exceeded prefire levels. The landscape-scale monitoring study presented in this paper helps increase knowledge about recent rangeland dynamics, including where cheatgrass dieoffs occurred and how cheatgrass responded to fire. This knowledge can help direct further investigation and/or guide land management activities that can capitalize on, or mitigate the effects of, cheatgrass dieoff.

  17. Integrative assessment of sediment quality in lower basin affected by former mining in Brazil.

    Science.gov (United States)

    Bonnail, Estefanía; Buruaem, Lucas M; Morais, Lucas G; Araujo, Giuliana S; Abessa, Denis M S; Sarmiento, Aguasanta M; Ángel DelValls, T

    2017-06-13

    The Ribeira de Iguape River (Southeast Brazil) is metal contaminated by mining activities. Despite it has been cataloged as "in via of restoration" by the literature, this basin is still a sink of pollution in some segments of the fluvial system. This study aimed to assess the sediment quality in the lower part of the RIR basin. The employed approach was based on biological responses of the freshwater clam Corbicula fluminea after 7-day exposure bioassays using as the reference site the Perequê Ecological Park. Toxic responses (burial activity and lethality) and biochemical biomarkers (GST, GR, GPx, LPO, MTs, AChE and DNA damage) were evaluated and then integrated with metal bioavailability and chemical concentrations to address the sediment quality in the area through the weight-of-evidence approach. A multivariate analysis identified linkages between biological responses and contamination. Results pointed that, despite being below the benchmarks of the US Environmental Protection Agency, there is slight metal contamination in the lower part of the basin which induces oxidative stress in C. fluminea; other toxic responses were sometimes attributed to As and Cr bioaccumulation. The sediment quality values (TEL-PEL values in mg/kg) were calculated for the current study for As (0.63-1.31), Cr (3.5-11.05), Cs (1.0-1.17), Cu (6.32-7.32), Ni (6.78-7.46), Ti (42.0-215), V (1.77-8.00). By comparison with other international guidelines, the sediment quality of the lower basin of the Vale de Ribeira does not identify a significant environmental risk.

  18. Radon measurements along active faults in the Langadas Basin, northern Greece

    Directory of Open Access Journals (Sweden)

    C. Papastefanou

    2001-01-01

    Full Text Available A network of three radon stations has been established in the Langadas Basin, northern Greece for radon monitoring by various techniques in earthquake prediction studies. Specially made devices with plastic tubes including Alpha Tracketch Detectors (ATD were installed for registering alpha particles from radon and radon decay products exhaled from the ground, every 2 weeks, by using LR-115, type II, non-strippable Kodak films, starting from December 1996. Simultaneous measurements started using Lucas cells alpha spectrometer for instantaneous radon measurements in soil gas, before and after setting ATDs at the radon stations. Continuous monitoring of radon gas exhaling from the ground started from the middle of August 1999 by using silicon diode detectors, which simultaneously register meteorological parameters, such as rainfall, temperature and barometric pressure. The obtained data were studied together with the data of seismic events, such as the magnitude, ML, of earthquakes that occurred at the Langadas Basin during the period of measurements, as registered by the Laboratory of Geophysics, Aristotle University of Thessaloniki, in order to find out any association between them.

  19. Source identification of fine-grained suspended sediment in the Kharaa River basin, northern Mongolia

    Energy Technology Data Exchange (ETDEWEB)

    Theuring, Philipp [Department of Aquatic Ecosystem Analysis and Management — ASAM, Helmholtz Centre for Environmental Research — UFZ, Brückstrasse 3a, D-39114 Magdeburg (Germany); Collins, Adrian L. [Sustainable Soils and Grassland Systems Department, Rothamsted Research, North Wyke, Okehampton, Devon EX20 2SB (United Kingdom); Rode, Michael [Department of Aquatic Ecosystem Analysis and Management — ASAM, Helmholtz Centre for Environmental Research — UFZ, Brückstrasse 3a, D-39114 Magdeburg (Germany)

    2015-09-01

    Fine sediment inputs into river systems can be a major source of nutrients and heavy metals and have a strong impact on water quality and ecosystem functions of rivers and lakes, including those in semiarid regions. However, little is known to date about the spatial distribution of sediment sources in most large scale river basins in Central Asia. Accordingly, a sediment source fingerprinting technique was used to assess the spatial sources of fine-grained (< 10 μm) sediment in the 15 000 km{sup 2} Kharaa River basin in northern Mongolia. Variation in geochemical composition (e.g. in Ti, Sn, Mo, Mn, As, Sr, B, U, Ca and Sb) was used for sediment source discrimination with geochemical composite fingerprints based on Genetic Algorithm (GA)-driven Discriminant Function Analysis, the Kruskal–Wallis H-test and Principal Component Analysis. All composite fingerprints yielded a satisfactory GOF (> 0.97) and were subsequently used for numerical mass balance modelling with uncertainty analysis. The contributions of the individual sub-catchment spatial sediment sources varied from 6.4% (the headwater sub-catchment of Sugnugur Gol) to 36.2% (the Kharaa II sub-catchment in the middle reaches of the study basin), generally showing higher contributions from the sub-catchments in the middle, rather than the upstream, portions of the study area. The importance of river bank erosion is shown to increase from upstream to midstream tributaries. The source tracing procedure provides results in reasonable accordance with previous findings in the study region and demonstrates the applicability and associated uncertainties of the approach for fine-grained sediment source investigation in large scale semi-arid catchments. - Highlights: • Applied statistical approach for selecting composite fingerprints in Mongolia. • Geochemical fingerprinting for the definition of source areas in semiarid catchment. • Test of applicability of sediment sourcing in large scale semi-arid catchments

  20. Source identification of fine-grained suspended sediment in the Kharaa River basin, northern Mongolia

    International Nuclear Information System (INIS)

    Theuring, Philipp; Collins, Adrian L.; Rode, Michael

    2015-01-01

    Fine sediment inputs into river systems can be a major source of nutrients and heavy metals and have a strong impact on water quality and ecosystem functions of rivers and lakes, including those in semiarid regions. However, little is known to date about the spatial distribution of sediment sources in most large scale river basins in Central Asia. Accordingly, a sediment source fingerprinting technique was used to assess the spatial sources of fine-grained (< 10 μm) sediment in the 15 000 km 2 Kharaa River basin in northern Mongolia. Variation in geochemical composition (e.g. in Ti, Sn, Mo, Mn, As, Sr, B, U, Ca and Sb) was used for sediment source discrimination with geochemical composite fingerprints based on Genetic Algorithm (GA)-driven Discriminant Function Analysis, the Kruskal–Wallis H-test and Principal Component Analysis. All composite fingerprints yielded a satisfactory GOF (> 0.97) and were subsequently used for numerical mass balance modelling with uncertainty analysis. The contributions of the individual sub-catchment spatial sediment sources varied from 6.4% (the headwater sub-catchment of Sugnugur Gol) to 36.2% (the Kharaa II sub-catchment in the middle reaches of the study basin), generally showing higher contributions from the sub-catchments in the middle, rather than the upstream, portions of the study area. The importance of river bank erosion is shown to increase from upstream to midstream tributaries. The source tracing procedure provides results in reasonable accordance with previous findings in the study region and demonstrates the applicability and associated uncertainties of the approach for fine-grained sediment source investigation in large scale semi-arid catchments. - Highlights: • Applied statistical approach for selecting composite fingerprints in Mongolia. • Geochemical fingerprinting for the definition of source areas in semiarid catchment. • Test of applicability of sediment sourcing in large scale semi-arid catchments.

  1. Estimation of Phosphorus Emissions in the Upper Iguazu Basin (brazil) Using GIS and the More Model

    Science.gov (United States)

    Acosta Porras, E. A.; Kishi, R. T.; Fuchs, S.; Hilgert, S.

    2016-06-01

    Pollution emissions into the drainage basin have direct impact on surface water quality. These emissions result from human activities that turn into pollution loads when they reach the water bodies, as point or diffuse sources. Their pollution potential depends on the characteristics and quantity of the transported materials. The estimation of pollution loads can assist decision-making in basin management. Knowledge about the potential pollution sources allows for a prioritization of pollution control policies to achieve the desired water quality. Consequently, it helps avoiding problems such as eutrophication of water bodies. The focus of the research described in this study is related to phosphorus emissions into river basins. The study area is the upper Iguazu basin that lies in the northeast region of the State of Paraná, Brazil, covering about 2,965 km2 and around 4 million inhabitants live concentrated on just 16% of its area. The MoRE (Modeling of Regionalized Emissions) model was used to estimate phosphorus emissions. MoRE is a model that uses empirical approaches to model processes in analytical units, capable of using spatially distributed parameters, covering both, emissions from point sources as well as non-point sources. In order to model the processes, the basin was divided into 152 analytical units with an average size of 20 km2. Available data was organized in a GIS environment. Using e.g. layers of precipitation, the Digital Terrain Model from a 1:10000 scale map as well as soils and land cover, which were derived from remote sensing imagery. Further data is used, such as point pollution discharges and statistical socio-economic data. The model shows that one of the main pollution sources in the upper Iguazu basin is the domestic sewage that enters the river as point source (effluents of treatment stations) and/or as diffuse pollution, caused by failures of sanitary sewer systems or clandestine sewer discharges, accounting for about 56% of the

  2. ESTIMATION OF PHOSPHORUS EMISSIONS IN THE UPPER IGUAZU BASIN (BRAZIL USING GIS AND THE MORE MODEL

    Directory of Open Access Journals (Sweden)

    E. A. Acosta Porras

    2016-06-01

    Full Text Available Pollution emissions into the drainage basin have direct impact on surface water quality. These emissions result from human activities that turn into pollution loads when they reach the water bodies, as point or diffuse sources. Their pollution potential depends on the characteristics and quantity of the transported materials. The estimation of pollution loads can assist decision-making in basin management. Knowledge about the potential pollution sources allows for a prioritization of pollution control policies to achieve the desired water quality. Consequently, it helps avoiding problems such as eutrophication of water bodies. The focus of the research described in this study is related to phosphorus emissions into river basins. The study area is the upper Iguazu basin that lies in the northeast region of the State of Paraná, Brazil, covering about 2,965 km2 and around 4 million inhabitants live concentrated on just 16% of its area. The MoRE (Modeling of Regionalized Emissions model was used to estimate phosphorus emissions. MoRE is a model that uses empirical approaches to model processes in analytical units, capable of using spatially distributed parameters, covering both, emissions from point sources as well as non-point sources. In order to model the processes, the basin was divided into 152 analytical units with an average size of 20 km2. Available data was organized in a GIS environment. Using e.g. layers of precipitation, the Digital Terrain Model from a 1:10000 scale map as well as soils and land cover, which were derived from remote sensing imagery. Further data is used, such as point pollution discharges and statistical socio-economic data. The model shows that one of the main pollution sources in the upper Iguazu basin is the domestic sewage that enters the river as point source (effluents of treatment stations and/or as diffuse pollution, caused by failures of sanitary sewer systems or clandestine sewer discharges, accounting for

  3. Spatial distribution of pelagic fish larvae in the northern main basin of Lake Huron

    Science.gov (United States)

    Roseman, Edward F.; O'Brien, Timothy P.

    2013-01-01

    Larval fish occurrence in inshore and offshore zones in the northern main basin of Lake Huron was assessed during 2007 as part of a larger ecological examination of Lake Huron foodwebs and habitats. Day and night collections using neuston and conical nets at inshore (1.5–15 m depths) and offshore (37 and 91 m depths) locations at De Tour and Hammond Bay to assess the abundance, phenology, and spatial distribution of pelagic ichthyoplankton during spring and early summer were made. In general, densities of larval fishes were higher at De Tour than Hammond Bay during daytime neuston net collections, with the exception of Longnose Sucker, which were only collected at Hammond Bay. Lake Whitefish, Burbot, and Rainbow Smelt dominated inshore catches in early spring with Cisco, Deepwater Sculpin, Emerald Shiner, Bloater, Slimy Sculpin, Ninespine Stickleback, and Yellow Perch larvae also collected.Nighttime nearshore and offshore sampling revealed that Rainbow Smelt and Burbot larvae were present in relatively high abundances compared to inshore densities. Concentrations of larvae of deepwater demersal fishes such as Lake Whitefish and Deepwater Sculpin suggest that inshore zones in northern Lake Huron are important nursery habitats emphasizing a critical production and recruitment linkage between inshore and deepwater zones.

  4. A Miocene wave-dominated estuarine system in the Paraíba Basin, northeastern Brazil

    Science.gov (United States)

    Gandini, Rosana; Rossetti, Dilce de Fátima; Netto, Renata Guimarães; Góes, Ana Maria

    2017-11-01

    A number of publications have documented the effect of the Miocene transgression on several coasts of the world. However, this event is incompletely documented along the Brazilian margin, despite the existence of an impressive record of Miocene deposits exposed mostly as several coastal cliffs along more than 5000 km of distance. The transgressive nature of Miocene deposits, so far recognized only in a few localities of northeastern Brazil, needs to be amplified in order to better characterize the impact of the Miocene transgression in eastern South America. In this work, we provide facies analysis of early/middle Miocene strata exposed in the Paraíba Basin, northeastern Brazil, aiming reconstruct the depositional paleoenvironments and analyze their evolution within the context of relative sea-level fluctuations data. The results revealed deposits characterized by several features that were related to the action of tidal currents, such as alternating thicker/thinner forest packages, abundant reactivation surfaces, mud drapes and oppositely-dipping (herringbone) cross sets. These sedimentary structures were associated with an ichnological assemblage indicative of marine-influenced and brackish water, best represented by Ophiomorpha, Planolites-Palaeophycus-Thalassinoides and Thallassinoides-Planolites-Palaeophycus ichnofabrics. Sedimentation occurred in environments consisting of estuarine channel, estuarine central basin, tidal inlet/tidal channel, tidal delta/washover, tidal flat/shoal and foreshore, which were related to an estuarine setting, at least in part of a wave-dominated type. Analysis of facies stratal patterns led to suggest that the estuarine deposits of the Paraíba Basin reflect a rise in relative sea level probably during the transgressive and/or highstand stage of a depositional sequence formed directly overlying Cretaceous rocks. This rise can be correlated with the worldwide early/mid Miocene marine transgression. However, while the eustatic sea

  5. Composition and natural history notes of the coastal snake assemblage from Northern Bahia, Brazil

    Science.gov (United States)

    Marques, Ricardo; Mebert, Konrad; Fonseca, Érica; Rödder, Dennis; Solé, Mirco; Tinôco, Moacir Santos

    2016-01-01

    Abstract Information about the snake diversity and their natural history from the Atlantic forest domain in Brazil refer mostly to inland forests than to coastal region. Within the state of Bahia, this knowledge is concentrated to the southeastern coastal stretch. Herein we report on the diversity of snakes from the restinga, ombrophilous forest and anthropogenic environment from the northern Atlantic coast of Bahia. We sampled nine sites for three years and visited four museum collections. Furthermore, we provide anecdotal natural history information, voucher analyses, literature complements, and a key to fascilitate species identification. We report a total of 774 snakes belonging to 50 species and 23 new distribution records for northeastern coast of Bahia, supplemented by new data on feeding and reproduction. The number of detected species is similar to numbers obtained in comparable studies from other Brazilian ecoregions. This study reports and focuses for the first time on all known species of snakes from the northeastern coast of Bahia. PMID:27594800

  6. Parasitic infections in tambaqui from eight fish farms in Northern Brazil

    Directory of Open Access Journals (Sweden)

    M.K.R. Dias

    2015-08-01

    Full Text Available The aim of this study was to evaluate the parasites and parasite-host relationship in Colossoma macropomum from eight fish farms in Amapá State, Northern Brazil. A total of 12,242,559 parasites were recovered from hosts in the eight fish farms, and 87.4% of fish were infected by one or more parasite species, such as Ichthyophthirius multifiliis, Piscinoodinium pillulare, Trichodinasp. and Tetrahymena sp. (Protozoa, Anacanthorus spathulatus, Linguadactyloides brinkmanni, Mymarothecium boegeri and Notozothecium janauachensis (Monogenoidea, Procamallanus(Spirocamallanus inopinatus (Nematoda and Perulernaea gamitanae and Braga patagonica (Crustacea. Ichthyophthirius multifiliis presented dominance, but the greatest levels of parasitism were caused by I. multifiliis, P. pilulare, monogenoideans species and P. gamitanae, and all these parasites had an aggregate dispersion. The eight fish farms have differences in the parasitic infection levels, management and water quality, which are further discussed here.

  7. Strontium isotopic signature of groundwater from Adamantina aquifer, Bauru Basin, Brazil

    Energy Technology Data Exchange (ETDEWEB)

    Maldaner, Carlos [Centre for Applied Groundwater Research, University of Guelph, 50 Stone Rd, Guelph, ON, N1G 2W1 (Canada); Martins, Veridiana; Bertolo, Reginaldo; Hirata, Ricardo [Centro de Pesquisas de Aguas Subterraneas do Instituto de Geociencias da Universidade de Sao Paulo, Sao Paulo - SP (Brazil)

    2013-07-01

    Using {sup 87}Sr/{sup 86}Sr ratios and the geochemistry of groundwater we were able to identify different hydrochemical facies in the Adamantina aquifer, Bauru Basin (Brazil). Samples from shallow wells show Cl-NO{sub 3}-Ca-Mg water with low pH due to natural and anthropogenic recharge. The {sup 87}Sr/{sup 86}Sr ratios are greatest in the shallower parts of the aquifer (0.7134) and decrease with increasing well screen interval depth. The nitrate concentration gradually decreases with depth and aquifer pH increases, HCO{sub 3} predominates as the main anion, and the groundwater becomes saturated with respect to calcite, with average {sup 87}Sr/{sup 86}Sr ratios of 0.708694 at depth. (authors)

  8. Geochemical evaluation of marginal basins in the south of Bahia state, Brazil

    International Nuclear Information System (INIS)

    Gaglianone, P.C.; Trindade, L.A.F.; Nascimento, M.M. do

    1987-01-01

    Geochemical analyses were performed on more than 700 rock samples and 4 oil samples, from Mucuri, Cumuruxatiba and Jequitinhonha basins, offshore Bahia state, Brazil. The methods employed in this study includes the evaluation of organic carbon contents, Rock-Eval pyrolysis, vitrinite reflectance, carbon isotopes, assessment of oils and extrats by liquid and gas chromatography and gas chromatography - spectrometry. Three main source rock systems have been identified in offshore Bahia: the Mucuri shales from Rio da Serra and Aratu Stages lower Neocomian related to a lacustrine fresh water environment; the Jiquia shales (Upper Neocomian) deposited in a lacustrine saline water environment, and the Alagoas Shales related to an evaporitic environment of Aptian age. (author) [pt

  9. Status and understanding of groundwater quality in the northern San Joaquin Basin, 2005

    Science.gov (United States)

    Bennett, George L.; Fram, Miranda S.; Belitz, Kenneth; Jurgens, Bryant C.

    2010-01-01

    Groundwater quality in the 2,079 square mile Northern San Joaquin Basin (Northern San Joaquin) study unit was investigated from December 2004 through February 2005 as part of the Priority Basin Project of the Groundwater Ambient Monitoring and Assessment (GAMA) Program. The GAMA Priority Basin Project was developed in response to the Groundwater Quality Monitoring Act of 2001 that was passed by the State of California and is being conducted by the California State Water Resources Control Board in collaboration with the U.S. Geological Survey and the Lawrence Livermore National Laboratory. The Northern San Joaquin study unit was the third study unit to be designed and sampled as part of the Priority Basin Project. Results of the study provide a spatially unbiased assessment of the quality of raw (untreated) groundwater, as well as a statistically consistent basis for comparing water quality throughout California. Samples were collected from 61 wells in parts of Alameda, Amador, Calaveras, Contra Costa, San Joaquin, and Stanislaus Counties; 51 of the wells were selected using a spatially distributed, randomized grid-based approach to provide statistical representation of the study area (grid wells), and 10 of the wells were sampled to increase spatial density and provide additional information for the evaluation of water chemistry in the study unit (understanding/flowpath wells). The primary aquifer systems (hereinafter, primary aquifers) assessed in this study are defined by the depth intervals of the wells in the California Department of Public Health database for each study unit. The quality of groundwater in shallow or deep water-bearing zones may differ from quality of groundwater in the primary aquifers; shallow groundwater may be more vulnerable to contamination from the surface. Two types of assessments were made: (1) status, assessment of the current quality of the groundwater resource; and (2) understanding, identification of the natural and human factors

  10. Differential proteomic analysis of noncardia gastric cancer from individuals of northern Brazil.

    Science.gov (United States)

    Leal, Mariana Ferreira; Chung, Janete; Calcagno, Danielle Queiroz; Assumpção, Paulo Pimentel; Demachki, Samia; da Silva, Ismael Dale Cotrim Guerreiro; Chammas, Roger; Burbano, Rommel Rodríguez; de Arruda Cardoso Smith, Marília

    2012-01-01

    Gastric cancer is the second leading cause of cancer-related death worldwide. The identification of new cancer biomarkers is necessary to reduce the mortality rates through the development of new screening assays and early diagnosis, as well as new target therapies. In this study, we performed a proteomic analysis of noncardia gastric neoplasias of individuals from Northern Brazil. The proteins were analyzed by two-dimensional electrophoresis and mass spectrometry. For the identification of differentially expressed proteins, we used statistical tests with bootstrapping resampling to control the type I error in the multiple comparison analyses. We identified 111 proteins involved in gastric carcinogenesis. The computational analysis revealed several proteins involved in the energy production processes and reinforced the Warburg effect in gastric cancer. ENO1 and HSPB1 expression were further evaluated. ENO1 was selected due to its role in aerobic glycolysis that may contribute to the Warburg effect. Although we observed two up-regulated spots of ENO1 in the proteomic analysis, the mean expression of ENO1 was reduced in gastric tumors by western blot. However, mean ENO1 expression seems to increase in more invasive tumors. This lack of correlation between proteomic and western blot analyses may be due to the presence of other ENO1 spots that present a slightly reduced expression, but with a high impact in the mean protein expression. In neoplasias, HSPB1 is induced by cellular stress to protect cells against apoptosis. In the present study, HSPB1 presented an elevated protein and mRNA expression in a subset of gastric cancer samples. However, no association was observed between HSPB1 expression and clinicopathological characteristics. Here, we identified several possible biomarkers of gastric cancer in individuals from Northern Brazil. These biomarkers may be useful for the assessment of prognosis and stratification for therapy if validated in larger clinical study

  11. Cryptosporidium spp. and Giardia sp. in aquatic mammals in northern and northeastern Brazil.

    Science.gov (United States)

    Borges, João Carlos; Lima, Danielle Dos; da Silva, Edson Moura; Moreira, André Lucas de Oliveira; Marmontel, Miriam; Carvalho, Vitor Luz; Amaral, Rodrigo de; Lazzarini, Stella Maris; Alves, Leucio Câmara

    2017-09-20

    Cryptosporidium and Giardia are protozoans that can infect humans and wild and domestic animals. Due to the growing importance of diseases caused by protozoan parasites in aquatic species, we aimed to evaluate the frequency of infection by Cryptosporidium spp. and Giardia sp. in aquatic and marine mammals in the northern and northeastern regions of Brazil. We collected 553 fecal samples from 15 species of wild-ranging and captive aquatic mammals in northern and northeastern Brazil. All samples were analyzed by the Kinyoun technique for identification of Cryptosporidium spp. oocysts. Giardia sp. cysts were identified by means of the centrifugal-flotation technique in zinc sulfate solution. Subsequently, all samples were submitted for direct immunofluorescence testing. The overall frequency of infection was 15.55% (86/553) for Cryptosporidium spp. and 9.04% (50/553) for Giardia sp. The presence of Cryptosporidium spp. was detected in samples from 5 species: neotropical river otter Lontra longicaudis (15.28%), giant otter Pteronura brasiliensis (41.66%), Guiana dolphin Sotalia guianensis (9.67%), Amazonian manatee Trichechus inunguis (16.03%), and Antillean manatee T. manatus (13.79%). Giardia sp. was identified in L. longicaudis (9.23%), P. brasiliensis (29.16%), pygmy sperm whale Kogia breviceps (100%), dwarf sperm whale K. sima (25%), S. guianensis (9.67%), T. inunguis (3.81%), and T. manatus (10.34%). This is the first report of Cryptosporidium spp. in L. longicaudis, P. brasiliensis, and S. guianensis, while the occurrence of Giardia sp., in addition to the 2 otter species, was also identified in manatees, thus extending the number of hosts susceptible to these parasitic agents.

  12. The MITMOTION Project - A seismic hazard overview of the Mitidja Basin (Northern Algeria)

    Science.gov (United States)

    Borges, José; Ouyed, Merzouk; Bezzeghoud, Mourad; Idres, Mouloud; Caldeira, Bento; Boughacha, Mohamed; Carvalho, João; Samai, Saddek; Fontiela, João; Aissa, Saoussen; Benfadda, Amar; Chimouni, Redouane; Yalaoui, Rafik; Dias, Rui

    2017-04-01

    The Mitidja Basin (MB) is located in northern Algeria and is filled by quaternary sediments with a length of about 100 km on the EW direction and approximately 20 km width. This basin is limited to the south by the Boumerdes - Larbaa - Blida active fault system and to the north by the Thenia - Sahel fault system. Both fault systems are of the reverse type with opposed dips and accommodate a general slip rate of 4 mm/year. This basin is associated with important seismic events that affected northern Algeria since the historical period until the present. The available earthquake catalogues reported numerous destructive earthquakes that struke different regions, such as Algiers (1365, Io= X; 1716, Io = X). Recently, on May 2003 the Bourmedes earthquake (Mw = 6.9) affected the area of Zemmouri and caused 2.271 deaths. The event was caused by the reactivation of the MB boundary faults. The epicenter was located offshore and generated a maximum uplift of 0.8 m along the coast with a horizontal maximum slip of 0.24 m. Recent studies show that the Boumerdes earthquake overloaded the system of adjacent faults with a stress increase between 0.4 and 1.5 bar. This induced an increase of the seismic hazard potential of the region and recommends a more detailed study of this fault system. The high seismogenic potential of the fault system bordering the MB, the exposure to danger of the most densely populated region of Algiers and the amplification effect caused by the basin are the motivation for this project proposal that will focus on the evaluation of the seismic hazard of the region. The general purpose of the project is to improve the seismic hazard assessment on the MB producing realistic predictions of strong ground motion caused by moderate and large earthquakes. To achieve this objective, it is important to make an effort in 3 directions: 1) the development of a detailed 3D velocity/structure model of the MB that includes geological constraints, seismic reflection data

  13. Seroepidemiological inquiry on bovine neosporosis in northern Mato Grosso state, Brazil

    Directory of Open Access Journals (Sweden)

    Riciely Vanessa Justo

    2014-02-01

    Full Text Available This work involved the study of anti-Neospora caninum antibodies by indirect immunofluorescence assay in serum samples of 205 cows (Bos taurus indicus Nellore, pure origin, aged over 24 months, reared on farms in the municipalities of Sinop, Itaúba, Colíder, Carlinda and Guarantã do Norte, Mato Grosso state, Brazil. An epidemiological evaluation through an interview with employees responsible for taking care of the animals during the period of 2010-2012. The studied area revealed epidemiological conditions favorable for the occurrence of bovine neosporosis, with 37.56% seropositive animals for anti-N. caninum. Sinop (70% and Carlinda (50% showed a frequency of seropositive animals was statistically equal to that observed (26.67% in other studies for other cities in Brazil. By confronting the serological status of the animals with variables of questionnaire, there was association (p < 0.01 between seropositivity of cows and the natural sources of drinking water, the incidence of abortion and repeating estrus. However, there was no statistical association between seropositive cows and the occurrence of neonatal deaths (p = 0.075, stillbirths (p = 0.02, presence of domestic dogs (p = 0.9 and the habit of giving raw offal to dogs (p = 0.93. Besides the occurrence of N. caninum, it was evidenced misinformation about bovine neosporosis and its control among interviewed people. This first study shows the need for further research on the epidemiology of bovine neosporosis in northern Mato Grosso state.

  14. Histophilus somni-induced thrombotic meningoencephalitis in cattle from northern Paraná, Brazil

    Directory of Open Access Journals (Sweden)

    Selwyn A. Headley

    2015-04-01

    Full Text Available Thrombotic meningoencephalitis (TME is a fatal neurological disease of cattle, predominantly from North America, that is caused by Histophilus somni with sporadic descriptions from other countries. This manuscript describes the occurrence of spontaneous TME in cattle from northern Paraná, Brazil. Most cattle had acute neurological manifestations characteristic of brain dysfunction. Hematological and cerebrospinal fluid analyses were not suggestive of bacterial infections of the brain. Histopathology revealed meningoencephalitis with vasculitis and thrombosis of small vessels that contained discrete neutrophilic and/or lymphocytic infiltrates admixed with fibrin at the brainstem, cerebral cortex, and trigeminal nerve ganglion of all animals. All tissues from the central nervous system used during this study were previously characterized as negative for rabies virus by the direct immunofluorescence assay. PCR and RT-PCR assays investigated the participation of infectious agents associated with bovine neurological disease by targeting specific genes of H. somni, Listeria monocytogenes, bovine herpesvirus -1 and -5, bovine viral diarrhea virus, and ovine herpesvirus-2. PCR and subsequent sequencing resulted in partial fragments of the 16S rRNA gene of H. somni from brain sections of all animals with histopathological diagnosis of TME; all other PCR/RT-PCR assays were negative. These findings confirmed the participation of H. somni in the neuropathological disease observed in these animals, extend the geographical distribution of this disease, and support previous findings of H. somni from Brazil.

  15. Hydrocarbon potential, palynology and palynofacies of four sedimentary basins in the Benue Trough, northern Cameroon

    Science.gov (United States)

    Bessong, Moïse; Hell, Joseph Victor; Samankassou, Elias; Feist-Burkhardt, Susanne; Eyong, John Takem; Ngos, Simon, III; Nolla, Junior Désiré; Mbesse, Cecile Olive; Adatte, Thierry; Mfoumbeng, Marie Paule; Dissombo, Edimo André Noel; Ntsama, Atangana Jacqueline; Mouloud, Bennami; Ndjeng, Emmanuel

    2018-03-01

    Organic geochemical, palynological and palynofacies analyses were carried out on 79 selected samples from four sedimentary basins (Mayo-Rey, Mayo-Oulo-Lere, Hamakoussou and Benue) in northern Cameroon. Rock-Eval pyrolysis and Total Organic Carbon results indicate that most of the samples of the studied basins are thermally immature to mature. The organic matter consists of terrestrial components (peat, lignite, bituminous coal, and anthracite) associated with organic matter of marine origin. Based on the appraisal of multiple parameters: Total Organic Carbon (TOC), maximum Temperature (T-max), Hydrogen Index (HI), Oxygen Index (OI) and Production Index (PI), some samples are organically rich both in oil and/or gas-prone kerogen Type-II, II/III and III. The source rock quality ranges from poor to very good. The source material is composed of both algae and higher plants. Samples from these basins yielded palynological residue composed of translucent and opaque phytoclasts, Amorphous Organic Matter (AOM), fungal remains, algal cysts pollen and pteridophyte spores. Abundance and diversity of the palynomorphs overall low and include Monoporopollenites annulatus (= Monoporites annulatus), indeterminate periporate pollen, indeterminate tetracolporate pollen, indeterminate tricolporate pollen, indeterminate triporate pollen, indeterminate trilete spores, Polypodiaceoisporites spp., Biporipsilonites sp., Rhizophagites sp., Striadiporites sp., Botryococcus sp. (colonial, freshwater green algae), and Chomotriletes minor (cyst of zygnematalean freshwater green algae). Age assigned confidently for all these basins the palynological data except for one sample of Hamakoussou that can be dated as Early to Mid-Cretaceous in age. Callialasporites dampieri, Classopollis spp., Eucommiidites spp. and Araucariacites australis indicate, an Aptian to Cenomanian age. The other pollen and spores recovered may indicate a Tertiary or younger age (especially Monoporopollenites annulatus), or

  16. New seismo-stratigraphic data of the Volturno Basin (northern Campania, Tyrrhenian margin, southern Italy: implications for tectono-stratigraphy of the Campania and Latium sedimentary basins

    Directory of Open Access Journals (Sweden)

    Ennio Marsella

    2011-07-01

    Full Text Available A geological section of the Volturno Basin (northern Campania, continental margin, Italy has been constructed based on new multi-channel seismic data, to show the stratigraphic relationships between the filling in the Quaternary basin and the Meso-Cenozoic acoustic basement. The new seismic sections presented here outline the underlying structures of the basin and their relationships to the filling in the Quaternary basin. Deep exploration wells in Campania and Latium on the Tyrrhenian margin have gathered litho-stratigraphic and commercial multi-channel seismic data that can be used for better integration of the geological data for the area under study. The trending of the seismic units is controlled by the Massico Structural High, which forms the boundary of the Volturno Basin towards the north-west. This produces a geometry that is characteristic of a fan complex, with NE-SW trending. This qualitative calibration of the seismic sequences that fill the sedimentary basin was carried out through the litho-stratigraphic data of the «Castelvolturno 2» well, which highlights the pyroclastic layers and conglomeratic strata of the lagoon and delta environments as they evolve upwards towards marine sediments. Seismo-stratigraphic analysis shows the complex depositional geometries of the filling in the Volturno Basin, which overlie the Meso-Cenozoic carbonatic basement and the related flysch deposits. Coupled with regional geological evidence, the data interpretation here suggests that the Volturno Basin represents a half-graben structure that is characterized by down-thrown blocks along normal faults.

  17. Radionuclide levels in fish from Lake Athabasca February 1993. Northern River Basins Study project report no.26

    International Nuclear Information System (INIS)

    Smithson, G.

    1993-12-01

    The Northern River Basins Study was initiated through the 'Canada-Alberta-Northwest Territories Agreement Respecting the Peace-Athabasca-Slave River Basin Study, Phase II - Technical Studies' which was signed September 27, 1991. The purpose of the study is to understand and characterize the cumulative effects of development on the water and aquatic environment of the Study Area by coordinating with existing programs and undertaking appropriate new technical studies. This publication reports the method and findings of particular work conducted as part of the Northern River Basins Study. As such, the work was governed by a specific terms of reference and is expected to contribute information about the Study Area within the context of the overall study as described by the Study Final Report. This report has been reviewed by the Study Science Advisory Committee in regards to scientific content and has been approved by the Study Board of Directors for public release. It is explicit in the objectives of the Study to report the results of technical work regularly to the public. This objective is served by distributing project reports to an extensive network of libraries, agencies, organizations and interested individuals and by granting universal permission to reproduce the material. This report contains referenced data obtained from external to the Northern River Basins Study. Individuals interested in using external data must obtain permission to do so from the donor agency. (author). 47 refs., 9 tabs., 2 figs

  18. Major transgression during Late Cretaceous constrained by basin sediments in northern Africa: implication for global rise in sea level

    Science.gov (United States)

    An, Kaixuan; Chen, Hanlin; Lin, Xiubin; Wang, Fang; Yang, Shufeng; Wen, Zhixin; Wang, Zhaoming; Zhang, Guangya; Tong, Xiaoguang

    2017-12-01

    The global rise in sea level during the Late Cretaceous has been an issue under discussion by the international geological community. Despite the significance, its impact on the deposition of continental basins is not well known. This paper presents the systematic review on stratigraphy and sedimentary facies compiled from 22 continental basins in northern Africa. The results indicate that the region was dominated by sediments of continental facies during Early Cretaceous, which were replaced by deposits of marine facies in Late Cretaceous. The spatio-temporal distribution of sedimentary facies suggests marine facies deposition reached as far south as Taoudeni-Iullemmeden-Chad-Al Kufra-Upper Egypt basins during Turonian to Campanian. These results indicate that northern Africa underwent significant transgression during Late Cretaceous reaching its peak during Turonian to Coniacian. This significant transgression has been attributed to the global high sea-level during this time. Previous studies show that global rise in sea level in Late Cretaceous may have been driven by an increase in the volume of ocean water (attributed to high CO2 concentration and subsequently warm climate) and a decrease in the volume of the ocean basin (attributed to rapid production of oceanic crust and seamounts). Tectonic mechanism of rapid production of oceanic crust and seamounts could play a fundamental role in driving the global rise in sea level and subsequent transgression in northern Africa during Late Cretaceous.

  19. Advances in ammonite biostratigraphy of the marine Atacama basin (Lower Cretaceous), northern Chile, and its relationship with the Neuquén basin, Argentina

    Science.gov (United States)

    Mourgues, Francisco Amaro

    2004-09-01

    Preliminary results about the Lower Cretaceous ammonite biostratigraphy of northern Chile reveal eight fossiliferous levels: Lower-Upper Valanginian neocomitid and olcostephanid faunas in the Punta del Cobre and Abundancia Formations and Upper Hauterivian-Barremian crioceratid in the Nantoco, Totoralillo, and Pabellón Formations. The faunal affinities with the Neuquén are strong during the Valanginian and Hauterivian. In contrast, during the Barremian and Aptian, the ammonites show affinities with Austral, California, and Tethys basinal faunas. The Lower Valanginian-lower Upper Aptian series in northern Chile comprises two sedimentary cycles separated by a regressive pulse of Upper Hauterivian-Lower Barremian age. This pulse may be equivalent to the regression that ended the Early Cretaceous marine cycle in central Chile and central west Argentina, where the second marine sedimentary cycle observed in northern Chile is not represented.

  20. Instrumental Neutron Activation Analysis- INAA: environmental studies in Das Velhas Basin, Minas Gerais, Brazil

    Energy Technology Data Exchange (ETDEWEB)

    Rabelo V, M.A.; Andrade Q, M.T. [Researcher of National Council for Scientific and Technological Development, CNPq, Center University of the East of Minas Gerais State, UNILESTE-MG (Brazil); Araujo M, R. [CDTN (Brazil); Albernaz A, I. [SCA- CNRS/USR/059, Lyon (France); Oliveira, A.H. de [Federal University of Minas Gerais State (Brazil)]. e-mail: marvv@cdtn.br

    2006-07-01

    The Instrumental Neutron Activation Analysis - INAA was applied to determine concentrations of several elements in unpolluted areas and in the mining and farming region of the Das Velhas Basin, Minas Gerais State, Brazil. INAA was applied using the TRIGA Mark I IPR - R1 reactor at the Nuclear Technology Development Center of the National Committee of Nuclear Energy (CDTN/CNEN), in Belo Horizonte city, Minas Gerais State. At 100 kW of potency the flux of neutrons is 6.6 10{sup 11} n.cm{sup -2}.s{sup -1}. The samples analyzed were: water; sediment; gravel of gold mine and forage. The obtained results for the Das Velhas Basin in water and sediment samples - mining companies region - show a high level ({mu}g/g) of contamination with the analyzed elements, mainly in the sediment samples. During the period of floods, in farming region hundreds of kilometers away, contamination is found in fish and forage, reaching and harming both people and animals that live in the marginal region. (Author)

  1. Instrumental Neutron Activation Analysis- INAA: environmental studies in Das Velhas Basin, Minas Gerais, Brazil

    International Nuclear Information System (INIS)

    Rabelo V, M.A.; Andrade Q, M.T.; Araujo M, R.; Albernaz A, I.; Oliveira, A.H. de

    2006-01-01

    The Instrumental Neutron Activation Analysis - INAA was applied to determine concentrations of several elements in unpolluted areas and in the mining and farming region of the Das Velhas Basin, Minas Gerais State, Brazil. INAA was applied using the TRIGA Mark I IPR - R1 reactor at the Nuclear Technology Development Center of the National Committee of Nuclear Energy (CDTN/CNEN), in Belo Horizonte city, Minas Gerais State. At 100 kW of potency the flux of neutrons is 6.6 10 11 n.cm -2 .s -1 . The samples analyzed were: water; sediment; gravel of gold mine and forage. The obtained results for the Das Velhas Basin in water and sediment samples - mining companies region - show a high level (μg/g) of contamination with the analyzed elements, mainly in the sediment samples. During the period of floods, in farming region hundreds of kilometers away, contamination is found in fish and forage, reaching and harming both people and animals that live in the marginal region. (Author)

  2. Metal contamination in benthic macroinvertebrates in a sub-basin in the southeast of Brazil.

    Science.gov (United States)

    Chiba, W A C; Passerini, M D; Tundisi, J G

    2011-05-01

    Benthic macroinvertebrates have many useful properties that make possible the use of these organisms as sentinel in biomonitoring programmes in freshwater. Combined with the characteristics of the water and sediment, benthic macroinvertebrates are potential indicators of environmental quality. Thus, the spatial occurrence of potentially toxic metals (Al, Zn, Cr, Co, Cu, Fe, Mn and Ni) in the water, sediment and benthic macroinvertebrates samples were investigated in a sub-basin in the southeast of Brazil in the city of São Carlos, São Paulo state, with the aim of verifying the metals and environment interaction with benthic communities regarding bioaccumulation. Hypothetically, there can be contamination by metals in the aquatic environment in the city due to lack of industrial effluent treatment. All samples were analysed by the USEPA adapted method and processed in an atomic absorption spectrophotometer. The sub-basin studied is contaminated by toxic metals in superficial water, sediment and benthic macroinvertebrates. The Bioaccumulation Factor showed a tendency for metal bioaccumulation by the benthic organisms for almost all the metal species. The results show a potential human and ecosystem health risk, contributing to metal contamination studies in aquatic environments in urban areas.

  3. Metal contamination in benthic macroinvertebrates in a sub-basin in the southeast of Brazil

    Directory of Open Access Journals (Sweden)

    WAC Chiba

    Full Text Available Benthic macroinvertebrates have many useful properties that make possible the use of these organisms as sentinel in biomonitoring programmes in freshwater. Combined with the characteristics of the water and sediment, benthic macroinvertebrates are potential indicators of environmental quality. Thus, the spatial occurrence of potentially toxic metals (Al, Zn, Cr, Co, Cu, Fe, Mn and Ni in the water, sediment and benthic macroinvertebrates samples were investigated in a sub-basin in the southeast of Brazil in the city of São Carlos, São Paulo state, with the aim of verifying the metals and environment interaction with benthic communities regarding bioaccumulation. Hypothetically, there can be contamination by metals in the aquatic environment in the city due to lack of industrial effluent treatment. All samples were analysed by the USEPA adapted method and processed in an atomic absorption spectrophotometer. The sub-basin studied is contaminated by toxic metals in superficial water, sediment and benthic macroinvertebrates. The Bioaccumulation Factor showed a tendency for metal bioaccumulation by the benthic organisms for almost all the metal species. The results show a potential human and ecosystem health risk, contributing to metal contamination studies in aquatic environments in urban areas.

  4. Ostracoda (Arthropoda, Crustacea from the Riachuelo Formation, Sergipe-Alagoas Basin, Brazil, Upper Aptian-Albian

    Directory of Open Access Journals (Sweden)

    Lucas Silveira Antonietto

    2016-11-01

    Full Text Available The Sergipe-Alagoas Basin has one of the most complete, exposed lithological successions of the Cretaceous period in the continental margin of Brazil. It captures several phases of the evolution of the South Atlantic Ocean, including rift, gulf and drift. The upper Aptian–Albian Riachuelo Formation corresponds to the first stages of the southern proto-Atlantic Ocean invasion in that basin. The present study reviews the taxonomic identification and ecology of 39 ostracod species of this formation, proposing a new genus – Gabonorygma gen. nov. – and three new species – Praebythoceratina deltalata sp. nov., Gabonorygma sergipana gen. et sp. nov. and Brachycythere smithsoniana sp. nov. Other taxa include Conchoecia? sp. 1, Cytherella sp. 1, C. besrineensis comb. nov., Cytherelloidea aff. globosa, C. btaterensis, Bairdoppilata sp. 1, Bairdoppilata sp. 2, B. comanchensis comb. nov., B. pseudoseptentrionalis, Robsoniella falklandensis, Cetacella sp. 1, Paracypris eniotmetos, Harbinia sinuata?, H. crepata, Liasina sp. 1, Praebythoceratina amsittenensis comb. nov., P. trinodosa comb. nov., Patellacythere sp. 1, P. shimonensis comb. nov., Xestoleberis? sp. 1, Xestoleberis? sp. 2, Apatocythere? sp. 1, Neocythere? aff. pseudovanveeni, N. (Physocythere tenuis, Aracajuia antiqua comb. nov., A. benderi, A. fragilis comb. nov., Eocytheropteron sp. 1, Metacytheropteron aff. minuta, Microceratina? sp. 1, M. azazoulensis, Veenia guianensis, Algeriana? sp. 1, Quasihermanites? sp. 1 and Sergipella viviersae.

  5. Oligocene-miocene mammalian fossils from Hongyazi Basin and its bearing on tectonics of Danghe Nanshan in northern Tibetan plateau.

    Science.gov (United States)

    Li, Qiang; Wang, Xiaoming; Xie, Guangpu; Yin, An

    2013-01-01

    A shortage of Cenozoic vertebrate fossils in the Tibetan Plateau has been an obstacle in our understanding of biological evolution in response to changes in tectonism, topography, and environment. This is especially true for Paleogene records, so far known by only two sites along the northern rim of the Plateau. We report a Hongyazi Basin in northern Tibetan Plateau that produces at least three mammalian faunas that span Oligocene through late Miocene. Located at the foothills of the Danghe Nanshan and presently connected to the northern margin of the Suganhu Basin through the Greater Haltang River, the intermountain basin is controlled by the tectonics of the Danghe Nanshan to the north and Chahan'ebotu Mountain to the south, making the basin sediments well suited for inferring the evolutionary history of these two mountain ranges. At the bottom of the local section, the Oligocene Haltang Fauna is best compared to the early Oligocene Desmatolagus-Karakoromys decessus assemblage in the Dingdanggou Fauna in Tabenbuluk Basin. The Middle Miocene Ebotu Fauna from the middle Hongyazi section shares many taxa with the late Middle Miocene Tunggur mammal assemblage in Inner Mongolia, such as Heterosminthus orientalis, Megacricetodon sinensis, Democricetodon lindsayi, and Alloptox gobiensis. Toward the top of the section, the Hongyazi Fauna includes late Miocene elements typical of Hipparion faunas of North China. All three faunas are of typical North China-Central Asian characteristics, suggesting a lack of geographic barriers for faunal differentiation through the late Miocene. Sedimentary packages producing these faunas are arrayed from north to south in progressively younger strata, consistent with a compressive regime to accommodate shortening between Danghe Nanshan and Chahan'ebotu Mountain by thrust faults and folds. With additional constraints from vertebrate fossils along the northern flanks of the Danghe Nanshan, an eastward propagation of the Danghe Nanshan is

  6. Oligocene-miocene mammalian fossils from Hongyazi Basin and its bearing on tectonics of Danghe Nanshan in northern Tibetan plateau.

    Directory of Open Access Journals (Sweden)

    Qiang Li

    Full Text Available A shortage of Cenozoic vertebrate fossils in the Tibetan Plateau has been an obstacle in our understanding of biological evolution in response to changes in tectonism, topography, and environment. This is especially true for Paleogene records, so far known by only two sites along the northern rim of the Plateau. We report a Hongyazi Basin in northern Tibetan Plateau that produces at least three mammalian faunas that span Oligocene through late Miocene. Located at the foothills of the Danghe Nanshan and presently connected to the northern margin of the Suganhu Basin through the Greater Haltang River, the intermountain basin is controlled by the tectonics of the Danghe Nanshan to the north and Chahan'ebotu Mountain to the south, making the basin sediments well suited for inferring the evolutionary history of these two mountain ranges. At the bottom of the local section, the Oligocene Haltang Fauna is best compared to the early Oligocene Desmatolagus-Karakoromys decessus assemblage in the Dingdanggou Fauna in Tabenbuluk Basin. The Middle Miocene Ebotu Fauna from the middle Hongyazi section shares many taxa with the late Middle Miocene Tunggur mammal assemblage in Inner Mongolia, such as Heterosminthus orientalis, Megacricetodon sinensis, Democricetodon lindsayi, and Alloptox gobiensis. Toward the top of the section, the Hongyazi Fauna includes late Miocene elements typical of Hipparion faunas of North China. All three faunas are of typical North China-Central Asian characteristics, suggesting a lack of geographic barriers for faunal differentiation through the late Miocene. Sedimentary packages producing these faunas are arrayed from north to south in progressively younger strata, consistent with a compressive regime to accommodate shortening between Danghe Nanshan and Chahan'ebotu Mountain by thrust faults and folds. With additional constraints from vertebrate fossils along the northern flanks of the Danghe Nanshan, an eastward propagation of the

  7. Jurassic sedimentary evolution of southern Junggar Basin: Implication for palaeoclimate changes in northern Xinjiang Uygur Autonomous Region, China

    Directory of Open Access Journals (Sweden)

    Shun-Li Li

    2014-04-01

    Full Text Available Junggar Basin, located in northern Xinjiang, presents continuous and multikilometer-thick strata of the Jurassic deposits. The Jurassic was entirely terrestrial fluvial and lacustrine deltaic sedimentation. Eight outcrop sections across the Jurassic strata were measured at a resolution of meters in southern Junggar Basin. Controlling factors of sedimentary evolution and palaeoclimate changes in Junggar Basin during the Jurassic were discussed based on lithology, fossils and tectonic setting. In the Early to Middle Jurassic, the warm and wide Tethys Sea generated a strong monsoonal circulation over the central Asian continent, and provided adequate moisture for Junggar Basin. Coal-bearing strata of the Badaowan, Sangonghe, and Xishanyao Formations were developed under warm and humid palaeoclimate in Junggar Basin. In the late Middle Jurassic, Junggar Basin was in a semi-humid and semi-arid environment due to global warming event. Stratigraphy in the upper part of the Middle Jurassic with less plant fossils became multicolor or reddish from dark color sediments. During the Late Jurassic, collision of Lhasa and Qiangtang Block obstructed monsoon from the Tethys Sea. A major change in climate from semi-humid and semi-arid to arid conditions took place, and reddish strata of the Upper Jurassic were developed across Junggar Basin.

  8. Measurements and modelling of evapotransiration to assess agricultural water productivity in basins with changing land use patterns : a case study in the São Francisco River basin, Brazil

    NARCIS (Netherlands)

    Castro Teixeira, de A.H.

    2008-01-01

    Key words: Vineyards, mango, energy balance, evapotranspiration, water productivity, Bowen ratio, eddy correlation, water balance, natural vegetation, latent heat flux, sensible heat flux, biomass, water productivity, remote sensing, water management. . The São Francisco River basin in Brazil is

  9. Phytogeographical patterns of dry forests sensu stricto in northern Minas Gerais State, Brazil.

    Science.gov (United States)

    Arruda, Daniel M; Ferreira-Júnior, Walnir G; Duque-Brasil, Reinaldo; Schaefer, Carlos E R

    2013-01-01

    The Deciduous Complex that occurs in northern Minas Gerais State, Brazil, raises questions about the floristic affinities of these formations in relation to neighboring phytogeographical domains. Little is known about the identity of the seasonal forest formations that comprise this complex, or about its relationships to abiotic components, such as soils, topography and climate. This study aimed to recognize the patterns of floristic similarity of all studied fragments of dry forest of northern Minas Gerais with soil and climate attributes, based on the available database. Cluster analysis indicated the existence of two floristic groups that had clear associations with either the Koppen's BSh (semi-arid) or Aw (seasonal tropical) climates. Likewise, the subdivisions of these groups showed clear associations with the dominant soil classes in the region. The Red-Yellow Latosol is the dominant soil classes in the BSh climatic domain, seconded by alluvial areas associated with Fluvic Neosols. The Aw domain comprised a much varied set of soils: Nitosols, Argisols, Cambisols and Litholic Neosols, most derived from the Bambuí limestone/slate formation. The ecotonal nature of northern Minas Gerais State provides a complex interaction between the flora of neighboring phytogeographical domains. This, allied to pedogeomorphological factors, allowed a better understanding of the effects of late Quaternary climate changes for the Deciduous Complex evolution. We conclude that the Latosols under present-day semi-arid climates (BSh) are relicts of former wetter climates, during which humid forest (semideciduous) expansion took place. Later, these semideciduous forests were subjected to a much drier climate, when selection for deciduousness led to the present-days Deciduous Complex scenario.

  10. Paleocene calcareous nannofossils biostratigraphy from the Sergipe Sub-basin, northeastern Brazil: Implications for this depositional environment

    Science.gov (United States)

    Andrade Oliveira, Geize Carolinne Correia; de Oliveira, Rick Souza; Monte Guerra, Rodrigo; de Lima Filho, Mario Ferreira

    2018-03-01

    This study reports on the biostratigraphy of Paleocene calcareous nannofossils and paleoenvironmental inferences based on five wells drilled on the offshore portion of the Sergipe Sub-basin. Five biostratigraphic zones were defined for the Paleocene in zones of Brazilian continental margin basins N-305, N-307, N-330, N-340 and N-350, and four hiatuses were identified based on the absence of marker species. These hiatuses were interpreted as excavations originated by turbulent to hyperpycnal flows, revealing an important application of biostratigraphy to better understand depositional environments that are often limited by little variation in lithology or low variation in the well log patterns. In Paleoecological terms, the Sergipe Sub-basin, in the Paleocene, experienced geological and environmental events similar to those of other sedimentary basins on the eastern passive continental margin of Brazil, but has a more complete biostratigraphic record of calcareous nannofossils.

  11. Cultural landscapes of the Araucaria Forests in the northern plateau of Santa Catarina, Brazil.

    Science.gov (United States)

    Machado Mello, Anna Jacinta; Peroni, Nivaldo

    2015-06-09

    The Araucaria Forest is associated with the Atlantic Forest domain and is a typical ecosystem of southern Brazil. The expansion of Araucaria angustifolia had a human influence in southern Brazil, where historically hunter-gatherer communities used the pinhão, araucaria's seed, as a food source. In the north of the state of Santa Catarina, the Araucaria Forest is a mosaic composed of cultivation and pasture inserted between forest fragments, where pinhão and erva-mate are gathered; some local communities denominate these forest ecotopes as caívas. Therefore, the aim of this study is to understand how human populations transform, manage and conserve landscapes using the case study of caívas from the Araucaria Forests of southern Brazil, as well as to evaluate the local ecological knowledge and how these contribute to conservation of the Araucaria Forest. This study was conducted in the northern plateau of the state of Santa Catarina, Brazil in local five communities. To assess ethnoecological perceptions the historical use and management of caívas, semi-structured interviews, checklist interviews and guided tours were conducted with family units. In total 28 family units participated in the study that had caívas on their properties. During the course of the study two main perceptions of the ecotope caíva were found, there is no consensus to the exact definition; perception of caívas is considered a gradient. In general caívas are considered to have the presence of cattle feeding on native pasture, with denser forest area that is managed, and the presence of specific species. Eleven management practices within caívas were found, firewood collection, cattle grazing, trimming of the herbaceous layer, and erva-mate extraction were the most common. Caívas are perceived and defined through the management practices and native plant resources. All participants stated that there have been many changes to the management practices within caívas and to the ca

  12. Geomorphic evolution of the San Luis Basin and Rio Grande in southern Colorado and northern New Mexico

    Science.gov (United States)

    Ruleman, Cal; Machette, Michael; Thompson, Ren A.; Miggins, Dan M; Goehring, Brent M; Paces, James B.

    2016-01-01

    The San Luis Basin encompasses the largest structural and hydrologic basin of the Rio Grande rift. On this field trip, we will examine the timing of transition of the San Luis Basin from hydrologically closed, aggrading subbasins to a continuous fluvial system that eroded the basin, formed the Rio Grande gorge, and ultimately, integrated the Rio Grande from Colorado to the Gulf of Mexico. Waning Pleistocene neotectonic activity and onset of major glacial episodes, in particular Marine Isotope Stages 11–2 (~420–14 ka), induced basin fill, spillover, and erosion of the southern San Luis Basin. The combined use of new geologic mapping, fluvial geomorphology, reinterpreted surficial geology of the Taos Plateau, pedogenic relative dating studies, 3He surface exposure dating of basalts, and U-series dating of pedogenic carbonate supports a sequence of events wherein pluvial Lake Alamosa in the northern San Luis Basin overflowed, and began to drain to the south across the closed Sunshine Valley–Costilla Plain region ≤400 ka. By ~200 ka, erosion had cut through topographic highs at Ute Mountain and the Red River fault zone, and began deep-canyon incision across the southern San Luis Basin. Previous studies indicate that prior to 200 ka, the present Rio Grande terminated into a large bolson complex in the vicinity of El Paso, Texas, and systematic, headward erosional processes had subtly integrated discontinuously connected basins along the eastern flank of the Rio Grande rift and southern Rocky Mountains. We propose that the integration of the entire San Luis Basin into the Rio Grande drainage system (~400–200 ka) was the critical event in the formation of the modern Rio Grande, integrating hinterland basins of the Rio Grande rift from El Paso, Texas, north to the San Luis Basin with the Gulf of Mexico. This event dramatically affected basins southeast of El Paso, Texas, across the Chisos Mountains and southeastern Basin and Range province, including the Rio

  13. ITCZ-monsoonal association during the last glacial (Cariaco Basin, Northern Arabian Sea)

    Science.gov (United States)

    Deplazes, G.; Haug, G. H.; Lueckge, A.

    2010-12-01

    The anoxic Cariaco Basin on the northern shelf of Venezuela preserves detailed records of past tropical climate variability. The sediment formation in this basin is controlled by the migration of the Atlantic Intertropical Convergence Zone (ITCZ) and the corresponding rain belt and trade winds. In the oxygen minimum zone off Pakistan in the northeastern Arabian Sea sediment archives of low-latitude monsoonal climate are preserved. In this study sediments from the two settings that cover the last 80,- to 110,000 years were analysed. Sediment color analysis resulted in reflectance records with a down to annual resolution. An age model was set up by correlation of these records to the δ18O record of Greenland ice (NGRIP). The major element chemistry of the sediments was analysed with X-ray fluorescence scanning. The new high resolution proxy records indicate an unbroken association between warm climate conditions over Greenland, a northerly position of the Atlantic Intertropical Convergence Zone, and a strong Indian summer monsoon since the last glacial. The tight coupling is explained by a dominant role of the North Atlantic that is communicated largely through the atmosphere. New insights of dynamical mechanisms arise from comparison of individual Dansgaard-Oeschger events. The tropical records and the Greenland δ18O record show both an abrupt change at the beginning of an interstadial. The δ18O of Greenland ice peaks early in the interstadials and then decreases more or less constantly toward stadial values. However, the tropical records have a tendency to maintain dark interstadial color on a similar level over several centuries. The following centennial-scale lightening toward the next stadial appears to be delayed compared to the δ18O ice record. This “resistance” of the tropics to the interstadial-stadial transitions suggests a threshold response of the tropics to North Atlantic cooling.

  14. Thick sedimentary sequence around Bahraich in the northern part of the central Ganga foreland basin

    Science.gov (United States)

    Manglik, A.; Adilakshmi, L.; Suresh, M.; Thiagarajan, S.

    2015-06-01

    We present the results of a magnetotelluric study along a 285 km long profile between Hamirpur and Rupadia (Nepal border) across the central Ganga basin. The electrical resistivity image obtained by combining 1-D Occam inversion models for 39 sites reveals a significant contrast in the subsurface structure from south to north along the profile. At the southern end, the Bundelkhand massif is delineated as a high resistivity block buried beneath 250-300 m thick sediments. The thickness of sediments gradually increases to about 500-600 m at Kanpur, and to about 1.2 km at Lucknow. Here, the basement depth increases to more than 2.5 km within a profile distance of 20 km, which could be attributed to the Lucknow fault. The underlying rocks also have moderate resistivity and possibly represent the Vindhyans. The sedimentary sequence at the northern end of the profile around Bahraich is more than 9 km thick. Integrating the resistivity image with a published seismic velocity structure from the region and the lithology from the 3927 m deep Matera-I well reveals that the top 4 km succession is constituted of highly conductive Oligocene and younger rocks of the Matera Formation and the Siwaliks, and recent sediments whereas the underlying > 5 km section is composed of sedimentary rocks of the Bahraich Group overlying the Archean basement. The high conductivity of sediments in conjunction with the low seismic velocity and large Vp/Vs obtained by receiver function analysis implies poor consolidation of sediments and thus high seismic hazard potential. The present results have implications for hydrocarbon exploration, hazard potential scenario of the central Ganga basin, and flexural strength of the Indian Plate.

  15. Spatial and temporal variability of groundwater recharge in Geba basin, Northern Ethiopia

    Science.gov (United States)

    Yenehun, Alemu; Walraevens, Kristine; Batelaan, Okke

    2017-10-01

    WetSpa, a physically based, spatially distributed watershed model, has been used to study the spatial and temporal variation of recharge in the Geba basin, Northern Ethiopia. The model covers an area of about 4, 249 km2 and integrates elevation, soil and land-use data, hydrometeorological and river discharge data. The Geba basin has a highly variable topography ranging from 1000 to 3280 m with an average slope of 12.9%. The area is characterized by a distinct wet and long dry season with a mean annual precipitation of 681 mm and temperatures ranging between 6.5 °C and 32 °C. The model was simulated on daily basis for nearly four years (January 1, 2000 to December 18, 2003). It resulted in a good agreement between measured and simulated streamflow hydrographs with Nash-Sutcliffe efficiency of almost 70% and 85% for, respectively, the calibration and validation. The water balance terms show very strong spatial and temporal variability, about 3.8% of the total precipitation is intercepted by the plant canopy; 87.5% infiltrates into the soil (of which 13% percolates, 2.7% flows laterally off and 84.2% evapotranspired from the root zone), and 7.2% is surface runoff. The mean annual recharge varies from about 45 mm (2003) to 208 mm (2001), with average of 98.6 mm/yr. On monthly basis, August has the maximum (73 mm) and December the lowest (0.1 mm) recharge. The mean annual groundwater recharge spatially varies from 0 to 371 mm; mainly controlled by the distribution of rainfall amount, followed by soil and land-use, and to a certain extent, slope. About 21% of Geba has a recharge larger than 120 mm and 1% less than 5 mm.

  16. Cenozoic sediment flux in the Qaidam Basin, northern Tibetan Plateau, and implications with regional tectonics and climate

    Science.gov (United States)

    Bao, Jing; Wang, Yadong; Song, Chunhui; Feng, Ying; Hu, Chunhua; Zhong, Sirui; Yang, Jiwei

    2017-08-01

    As the largest Mesozoic-Cenozoic terrestrial intermountain basin in the northern Tibetan Plateau, the Qaidam Basin is an ideal basin to examine the influences of regional tectonics and climate on sediment flux. Research conducted over the last two decades has provided abundant information about paleoclimatology and tectonic histories. In this study, we used the restoration of seven balanced cross-sections and compiled thickness data of ten outcrop sections and four boreholes to reconstruct the basin boundaries, develop isopach maps, and calculate the sediment flux in the Qaidam Basin. Our results show that the sediment flux in the Qaidam Basin increased gradually between 53.5 and 35.5 Ma, decreased to its lowest value from 35.5 to 22 Ma, increased between 22 and 2.5 Ma, and then increased dramatically after 2.5 Ma. By comparing the changes in the sediment flux with our reconstructed shortening rate in the Qaidam Basin, and the records of regional tectonic events and regional and global climate changes, we suggest that the gradual increase in the sediment flux from 53.5 to 40.5 Ma was controlled by both the tectonic uplift of the Tibetan Plateau and the relatively warm and humid climate, and that the high sediment flux from 40.5 to 35.5 Ma was mainly controlled by tectonics. The low sediment flux from 35.5 to 22 Ma was a response to the relatively cold and arid climate in a stable tectonic setting. The relatively high sediment flux between 22 and 15.3 Ma was related to tectonic activity and the warm and humid climate. The intense tectonic uplift of the northern Tibetan Plateau and the frequent climate oscillations after 15.3 Ma, particularly the glacial-interglacial cycles after 2.5 Ma, caused the high sediment flux after 15.3 Ma and the dramatic increase after 2.5 Ma, respectively.

  17. Peat accumulation in drained thermokarst lake basins in continuous, ice-rich permafrost, northern Seward Peninsula, Alaska

    Science.gov (United States)

    Jones, Miriam C.; Grosse, Guido; Jones, Benjamin M.; Anthony, Katey Walter

    2012-01-01

    Thermokarst lakes and peat-accumulating drained lake basins cover a substantial portion of Arctic lowland landscapes, yet the role of thermokarst lake drainage and ensuing peat formation in landscape-scale carbon (C) budgets remains understudied. Here we use measurements of terrestrial peat thickness, bulk density, organic matter content, and basal radiocarbon age from permafrost cores, soil pits, and exposures in vegetated, drained lake basins to characterize regional lake drainage chronology, C accumulation rates, and the role of thermokarst-lake cycling in carbon dynamics throughout the Holocene on the northern Seward Peninsula, Alaska. Most detectable lake drainage events occurred within the last 4,000 years with the highest drainage frequency during the medieval climate anomaly. Peat accumulation rates were highest in young (50–500 years) drained lake basins (35.2 g C m−2 yr−1) and decreased exponentially with time since drainage to 9 g C m−2 yr−1 in the oldest basins. Spatial analyses of terrestrial peat depth, basal peat radiocarbon ages, basin geomorphology, and satellite-derived land surface properties (Normalized Difference Vegetation Index (NDVI); Minimum Noise Fraction (MNF)) from Landsat satellite data revealed significant relationships between peat thickness and mean basin NDVI or MNF. By upscaling observed relationships, we infer that drained thermokarst lake basins, covering 391 km2 (76%) of the 515 km2 study region, store 6.4–6.6 Tg organic C in drained lake basin terrestrial peat. Peat accumulation in drained lake basins likely serves to offset greenhouse gas release from thermokarst-impacted landscapes and should be incorporated in landscape-scale C budgets.

  18. PALEOENVIRONMENTAL EVOLUTION OF THE ITARARÉ GROUP (PARANÁ BASIN IN THE REGIONS OF SALTO AND ITU, EAST OF SÃO PAULO STATE, BRAZIL

    Directory of Open Access Journals (Sweden)

    Sérgio Bergamaschi

    2016-03-01

    Full Text Available Itararé Group represents the glacial record of Gondwana Continent in the intracratonic Paraná Basin, encompassing regions of Southern Brazil, Eastern Paraguay, Northeast Argentina and Northern Paraguay. Itararé Group is the thickest sedimentary package of Paraná Basin, and was deposited over 36 million years during the end of the Carboniferous and the beginning of the Permian. However, in relation to its paleoenvironmental evolution, it is generally understood that more research is necessary, in order to better understand the genesis of the Itararé Group in different places. The present work entailed mapping facies associations for the Itararé Group in the city of Salto, in São Paulo State, by identifying and classifying sedimentary facies that, in turn, were utilized to develop a paleoenvironmental evolution model. This model was based on geological mapping carried out over 125 km². Petrological and petrographic descriptions of 32 outcrops of Itararé Group also were studied. These results were compared with subsurface data obtained by Sistema de Informações de Águas Subterrâneas, Serviços Geológicos do Brasil (SIAGAS-CPRM; System Water Information Groundwater, Geological Survey of Brazil. Through lithofacies and petrographic analyses and making a comparison between five column sections, surface and subsurface data, a stratigraphic correlation model was established for the region. Through this model was possible to identify four facies associations, which, together, indicate how the paleoenvironmental evolution of the region occurred. The first three associations (A, B, C were interpreted as being formed in subaqueous environment, being related to sandy lobe systems, followed by the last association (D, pertaining to a fluvial system.

  19. Neogene Basin Evolution Along the Northern Flank of the Papuan Peninsula, Goodenough Bay, Eastern Papua New Guinea

    Science.gov (United States)

    Horton, B. K.; Gillis, R. J.; Mann, P.

    2009-12-01

    Although large-magnitude extension in the Woodlark Rift of eastern Papua New Guinea (PNG) and the D’Entrecasteaux Islands has been addressed through previous research on the late Cenozoic structure and cooling history of metamorphic domes, few studies have evaluated the exhumational record contained within adjacent sedimentary basins. Onshore exposures of Neogene basin fill in PNG along the northern flank of the Papuan peninsula (east of the Dayman metamorphic dome and west-southwest of the domes of the D’Entrecasteaux Islands) provide a record of basin evolution prior to and during growth of the active spreading center that defines the boundary between the Australian plate and Woodlark microplate. Along the northern margin of the Papuan peninsula, a collection of lithofacies associations consisting of sandstone and subordinate conglomerate and mudstone represent deposition in bottomset, foreset, and topset subenvironments in a series of marine Gilbert-type deltas. Internal angular unconformities within the basin-fill succession indicate slope instability likely related to syndepositional deformation. This deformation is attributed to principally down-to-the north motion along extensional and strike-slip structures bordering the northern margin of Papuan peninsula, notably the ESE-striking Goodenough fault zone. Small-scale folding is interpreted as the product of late Miocene to Quaternary fault-related folding in an extensional setting, although we cannot rule out possible contraction coeval with significant collision-related shortening on the southern flank of the Papuan peninsula within the south-directed Papuan fold-thrust belt. Differences in sandstone petrographic results for the northern margin of the Papuan peninsula and the smaller Vogel peninsula suggest a multiphase history of basin evolution, with early Neogene subsidence of uncertain origin and late Neogene subsidence linked to regional extension. The timing of basin evolution will be assessed

  20. Biomarkers of contaminant exposure in northern pike (Esox lucius) from the Yukon River Basin, Alaska

    Science.gov (United States)

    Hinck, J.E.; Blazer, V.S.; Denslow, N.D.; Myers, M.S.; Gross, T.S.; Tillitt, D.E.

    2007-01-01

    As part of a larger investigation, northern pike (n = 158; Esox lucius) were collected from ten sites in the Yukon River Basin (YRB), Alaska, to document biomarkers and their correlations with organochlorine pesticide (total p,p'-DDT, total chlordane, dieldrin, and toxaphene), total polychlorinated biphenyls (PCBs), and elemental contaminant (arsenic, cadmium, copper, lead, total mercury, selenium, and zinc) concentrations. A suite of biomarkers including somatic indices, hepatic 7-ethoxyresorufin O-deethylase (EROD) activity, vitellogenin concentrations, steroid hormone (17B- ustradiol and 16-kebtestosteront) concentrations, splenic macrophage aggregates (MAs), oocyte atresia, and other microscopic anomalies in various tissues were documented in YRB pike. Mean condition factor (0.50 to 0.68), hepatosomatic index (1.00% to 3.56%), and splenosomatic index (0.09% to 0.18%) were not anomalous at any site nor correlated with any contaminant concentration. Mean EROD activity (0.71 to 17.51 pmol/min/mg protein) was similar to basal activity levels previously measured in pike and was positively correlated with selenium concentrations (r = 0.88, P contaminant exposure but provide information on the general health of YRB pike. The most common histologic anomalies were parasitic infestations in various organs and developing nephrons and nephrocalcinosis in posterior kidney tissues. Overall, few biomarker responses in YRB pike were correlated with chemical contaminant concentrations, and YRB pike generally appeared to be healthy with no site having multiple anomalous biomarker responses. ?? 2007 Springer Science+Business Media, LLC.

  1. Thermal maturity of northern Appalachian Basin Devonian shales: Insights from sterane and terpane biomarkers

    Science.gov (United States)

    Hackley, Paul C.; Ryder, Robert T.; Trippi, Michael H.; Alimi, Hossein

    2013-01-01

    To better estimate thermal maturity of Devonian shales in the northern Appalachian Basin, eleven samples of Marcellus and Huron Shale were characterized via multiple analytical techniques. Vitrinite reflectance, Rock–Eval pyrolysis, gas chromatography (GC) of whole rock extracts, and GC–mass spectrometry (GCMS) of extract saturate fractions were evaluated on three transects that lie across previously documented regional thermal maturity isolines. Results from vitrinite reflectance suggest that most samples are immature with respect to hydrocarbon generation. However, bulk geochemical data and sterane and terpane biomarker ratios from GCMS suggest that almost all samples are in the oil window. This observation is consistent with the presence of thermogenic gas in the study area and higher vitrinite reflectance values recorded from overlying Pennsylvanian coals. These results suggest that vitrinite reflectance is a poor predictor of thermal maturity in early mature areas of Devonian shale, perhaps because reported measurements often include determinations of solid bitumen reflectance. Vitrinite reflectance interpretations in areas of early mature Devonian shale should be supplanted by evaluation of thermal maturity information from biomarker ratios and bulk geochemical data.

  2. Cross-fault pressure depletion, Zechstein carbonate reservoir, Weser-Ems area, Northern German Gas Basin

    Energy Technology Data Exchange (ETDEWEB)

    Corona, F.V.; Brauckmann, F.; Beckmann, H.; Gobi, A.; Grassmann, S.; Neble, J.; Roettgen, K. [ExxonMobil Production Deutschland GmbH (EMPG), Hannover (Germany)

    2013-08-01

    A cross-fault pressure depletion study in Upper Permian Zechstein Ca2 carbonate reservoir was undertaken in the Weser-Ems area of the Northern German Gas Basin. The primary objectives are to develop a practical workflow to define cross-fault pressures scenarios for Zechstein Ca2 reservoir drillwells, to determine the key factors of cross-fault pressure behavior in this platform carbonate reservoir, and to translate the observed cross-fault pressure depletion to fault transmissibility for reservoir simulation models. Analysis of Zechstein Ca2 cross-fault pressures indicates that most Zechstein-cutting faults appear to act as fluid-flow baffles with some local occurrences of fault seal. Moreover, there appears to be distinct cross-fault baffling or pressure depletion trends that may be related to the extent of the separating fault or fault system, degree of reservoir flow-path tortuosity, and quality of reservoir juxtaposition. Based on the above observations, a three-part workflow was developed consisting of (1) careful interpretation and mapping of faults and fault networks, (2) analysis of reservoir juxtaposition and reservoir juxtaposition quality, and (3) application of the observed cross-fault pressure depletion trends. This approach is field-analog based, is practical, and is being used currently to provide reliable and supportable pressure prediction scenarios for subsequent Zechstein fault-bounded drill-well opportunities.

  3. Precipitation thresholds for triggering floods in Corgo hydrographic basin (Northern Portugal)

    Science.gov (United States)

    Santos, Monica; Fragoso, Marcelo

    2016-04-01

    The precipitation is a major cause of natural hazards and is therefore related to the flood events (Borga et al., 2011; Gaál et al., 2014; Wilhelmi & Morss, 2013). The severity of a precipitation event and their potential damage is dependent on the total amount of rain but also on the intensity and duration event (Gaál et al., 2014). In this work, it was established thresholds based on critical combinations: amount / duration of flood events with daily rainfall data for Corgo hydrographic basin, in northern Portugal. In Corgo basin are recorded 31 floods events between 1865 and 2011 (Santos et al., 2015; Zêzere et al., 2014). We determined the minimum, maximum and pre-warning thresholds that define the boundaries so that an event may occur. Additionally, we applied these thresholds to different flood events occurred in the past in the study basin. The results show that the ratio between the flood events and precipitation events that occur above the minimum threshold has relatively low probability of a flood happen. These results may be related to the reduced number of floods events (only those that caused damage reported by the media and produced some type of damage). The maximum threshold is not useful for floods forecasting, since the majority of true positives are below this limit. The retrospective analysis of the thresholds defined suggests that the minimum and pre warning thresholds are well adjusted. The application of rainfall thresholds contribute to minimize possible situations of pre-crisis or immediate crisis, reducing the consequences and the resources involved in emergency response of flood events. References Borga, M., Anagnostou, E. N., Blöschl, G., & Creutin, J. D. (2011). Flash flood forecasting, warning and risk management: the HYDRATE project. Environmental Science & Policy, 14(7), 834-844. doi: 10.1016/j.envsci.2011.05.017 Gaál, L., Molnar, P., & Szolgay, J. (2014). Selection of intense rainfall events based on intensity thresholds and

  4. Susceptibility and Vulnerability to Landslides—Case Study: Basin of River Bengalas—City of Nova Friburgo—Brazil

    OpenAIRE

    Silva, L.T.; Sampaio, E.P.; Corte-Real, J.A.; Rodriguez, D.A.; Medeiros, F.C.; Moraes, B.E.; França, D.G.M.

    2015-01-01

    Landslides have frequently occurred in last years, due to the disorderly grownth of the cities and the occupation of risk areas by the poor population, causing social, environmental and economic impacts. Urban areas in expansion move to geologically unstable areas and topographically inclined, such as the Basin of River Bengalas, located in the city of Nova Friburgo, mountainous region of the State of Rio de Janeiro, Brazil. This article aims to present the model developed and used to evaluat...

  5. Ageneiosus uranophthalmus, a new species of auchenipterid catfish (Osteichthyes: Siluriformes from river channels of the central Amazon basin, Brazil

    Directory of Open Access Journals (Sweden)

    Frank Raynner V Ribeiro

    Full Text Available Ageneiosus uranophthalmus is described from river channels of the central Amazon basin, Brazil. The new species is widely distributed in the Amazon and is distinguished from its congeners by the V-shape snout and eye laterally placed and dorsally oriented, more visible in dorsal view than in ventral view. Ageneiosus uranophthalmus shows a range of variation on color pattern when compared with its congeners. This and other differences are described and discussed herein.

  6. Palaeobotanical evidence of wildfires in the Late Palaeozoic of South America - Early Permian, Rio Bonito Formation, Paraná Basin, Rio Grande do Sul, Brazil

    Science.gov (United States)

    Jasper, André; Uhl, Dieter; Guerra-Sommer, Margot; Mosbrugger, Volker

    2008-12-01

    Fossil charcoal, as direct evidence of palaeowildfires, has repeatedly been reported from several plant-bearing deposits from the Late Palaeozoic of the Northern Hemisphere. In contrast charcoal reports from the Late Palaeozoic deposits of the Southern Hemisphere are relatively rare in comparison to the Northern Hemisphere. Although the presence of pyrogenic coal macerals has repeatedly been reported from Late Palaeozoic coals from South America, no detailed anatomical investigations of such material have been published so far. Here is presented an anatomical analysis of charcoal originating from Early Permian sediments of the Quitéria Outcrop, Rio Bonito Formation, Paraná Basin, located in the central-eastern portion of Rio Grande do Sul, Brazil. This charcoal comes from two different coaly facies, and it was possible to scrutinize between three types, based on anatomical characters of the charcoal. Two of these charcoal types can be correlated to gymnosperm woods, and the other type corresponds to strongly permineralized bark with characteristic features of lycopsids. The presence of charcoal in different facies, ranging from parautochtonous to allochtonous origin, indicates that different vegetation types, i.e. plants which grew under wet conditions in the lowland as well as in the more dry hinterland, have experienced wildfires. Taking into account previous petrographic and lithological analyses from the facies in which the charcoal occurs and from the conditions of the wood and bark fragments, it was possible to speculate that the intensity of such wildfires most probably corresponds to forest-crown fires. Moreover, it is possible to state that wildfires have been a more or less common element in distinct Late Palaeozoic terrestrial ecosystems in the South American part of Gondwana. The data support previous assumptions on the occurrence of wildfires in the Early Permian of the Paraná Basin which were based solely on coal-petrographic data.

  7. Risk factors and prevalence of newborn hearing loss in a private health care system of Porto Velho, Northern Brazil

    OpenAIRE

    Oliveira, Juliana Santos de; Rodrigues, Liliane Barbosa; Aurélio, Fernanda Soares; Silva, Virgínia Braz da

    2013-01-01

    OBJECTIVE: To determine the prevalence of hearing loss and to analyze the results of newborn hearing screening and audiological diagnosis in private health care systems. METHODS Cross-sectional and retrospective study in a database of newborn hearing screening performed by a private clinic in neonates born in private hospitals of Porto Velho, Rondônia, Northern Brazil. The screening results, the risk for hearing loss, the risk indicators for hearing loss and the diagnosis were descriptively a...

  8. Anurofauna of an Atlantic Rainforest fragment and its surroundings in Northern Rio de Janeiro State, Brazil

    Directory of Open Access Journals (Sweden)

    M Almeida-Gomes

    Full Text Available We carried out a study on the anurofaunal community from an Atlantic Forest fragment (Monte Verde mountains and the surrounding area in Cambuci municipality, Rio de Janeiro State, Brazil, which constitutes one of the largest fragments remaining in the largely deforested landscape of the northern portion of the State. We combined three sampling methods: plot sampling, transects and pit-fall traps. We recorded twenty species of amphibians, of which only eleven were found within the forest fragment (and five of these also occurred in the surrounding matrix. Two of the species recorded in the present study (Crossodactylus sp. and Ischnocnema cf. parva may represent undescribed taxa. Our records expand the distribution range of one species (Scinax trapicheiroi to the north, and fill a geographic distribution gap for another one (Ischnocnema oea. The estimated overall density of frogs living in the leaf litter of the fragment (based on results of plot sampling was 3.1 individuals/100 m², with Haddadus binotatus being the most abundant species (2.4 individuals/100 m². Comparisons of our data with those of other studies suggest that anuran communities in forest fragments ca. 1,000 ha or smaller may be severely limited in their richness, and often include a large proportion of species tolerant to open areas, such as many hylids. Our results show the importance of increasing knowledge about the anurofaunal community of the northern portion of the State of Rio de Janeiro and preserve the forest remnants that still exist in the region.

  9. Range extension of Moenkhausia oligolepis (Günther,1864 to the Pindaré river drainage, of Mearim river basin, and Itapecuru river basin of northeastern Brazil (Characiformes: Characidae

    Directory of Open Access Journals (Sweden)

    Erick Cristofore Guimarães

    2016-08-01

    Full Text Available The present study reports range extansion of Moenkhausia oligolepis to the Pindaré river drainage, of the Mearim river basin, and Itapecuru river basin, Maranhão state, northeastern Brazil. This species was previously known only from Venezuela, Guianas, and the Amazon River basins. In addition, we present some meristic and morphometric data of the specimens herein examined and discuss on its diagnostic characters.

  10. Detection of brucellosis in water buffaloes for exportation in northern and northeastern of Brazil

    Directory of Open Access Journals (Sweden)

    José Diomedes Barbosa

    2016-11-01

    Full Text Available ABSTRACT. Barbosa J.D., Bomjardim H.dosA., Lima D.H.daS., Reis A.dosS.B., Barboza F.B., Albernaz T.T., Oliveira C.M.C., Fonseca A.H., Nicolino R.R. & da Silva J.B. Detection of brucellosis in water buffaloes for exportation in northern and northeastern of Brazil. [Detecção de brucelose em búfalos d’agua para exportação no norte e nordeste do Brasil}. Revista Brasileira de Medicina Veterinária, 38(supl. 3: 129-135, 2016. Laboratório de Doenças Parasitárias, Departamento de Epidemiologia e Saúde Pública, Instituto de Veterinária, Universidade Federal Rural de Rio de Janeiro, BR 465, Km 7 Seropédica, RJ 23890-000, Brazil. E-mail: adivaldofonseca@yahoo.com The prevalence of brucellosis in buffaloes was evaluated by the Buffered Acidified Plate Antigen (BAPA in 5.163 water buffaloes from Maranhão state, Pará state and Marajó Island, Brazil. The detection of buffaloes positive for brucellosis by BAPA was 7.37% in Marajó Island, 8.45% in Pará state and 29.86% in Maranhão state. The locations with the highest prevalences were Santa Cruz do Arari, in Marajó Island (12.50%; Ipixuna, in Pará state (30.25%; and Santa Inês, in Maranhão state (34.76%. After the confirmatory test (Complement Fixation Test, only 7 animals remained positive in Marajó Island, and 22 remained positive in the state of Pará. None of the 66 animals that reacted positively in the BAPA test in Maranhão reacted positively in the CF. The high prevalence of B. abortus that was observed in animals, especially in the state of Maranhão, is worrisome for the health system for the control and eradication of bovine brucellosis.

  11. Formulation of fracture gradient extension equations in the Sergipe Basin-Brazil

    Energy Technology Data Exchange (ETDEWEB)

    Suzart, J. Walter P.; Moreto, Rodrigo [Halliburton, Rio de Janeiro, RJ (Brazil); Luduvice, Roberto; Gomes, Isaac Santana; Richard Junior, Emerson [PETROBRAS S.A., Rio de Janeiro, RJ (Brazil)

    2008-07-01

    One of the challenges of drilling exploration wells is to accurately estimate fracture gradients. This may cause formation damage and lead to premature hydraulic fracturing and prevent an optimum hydraulic design during completion. To avoid this scenario, it is important to know the minimum pressure that causes fractures. This estimation may be based on density, overburden, Poisson's ratio, and minimum horizontal stress. It is now possible to monitor fracturing stimulation operations in real time, which allows real-time understanding of formation pressure response, including fracture extension behavior and screen out. It is possible to avoid risks related to unexpected high pressure applied on the formation while drilling and maintain well and equipment integrities. This may prevent non-productive time (NPT) caused by unplanned well-cleaning operations and material expenses. Real-time fracturing information is usually obtained from step-rate and/or mini-frac analyses. However, there are some scenarios where these tests and analyses may be uneconomical. This paper details an alternative solution. It uses modified Eaton's equations that are representative of the area of interest, which in the present case is the Sergipe Basin located in northeast Brazil. The modified Eaton's equations are used to estimate parameters of the minimum horizontal stress, fracture extension gradient, overburden, and Poisson's ratio. This is based on hydraulic fracturing jobs and density logs available from different locations within the Sergipe Basin. To validate the present method, the estimation results were compared with available step-rate test results for the area. (author)

  12. Paleoenvironmental reconstruction and evolution of an Upper Cretaceous lacustrine-fluvial-deltaic sequence in the Parecis Basin, Brazil

    Science.gov (United States)

    Rubert, Rogerio R.; Mizusaki, Ana Maria Pimentel; Martinelli, Agustín G.; Urban, Camile

    2017-12-01

    The Cretaceous in the Brazilian Platform records events of magmatism, tectonism and sedimentation coupled to the Gondwana breakup. Some of these events are registered as sedimentary sequences in interior basins, such as in the Cretaceous sequence of the Alto Xingu Sub-basin, Parecis Basin, Central Brazil. This article proposes the faciologic characterization and paleoenvironmental reconstruction of the Cretaceous sequence of the eastern portion of the Parecis Basin and its relation with some reactivated structures as, for instance, the Serra Formosa Arch. Based on both data from outcrops and core drillings a paleoenvironmental and evolutionary reconstruction of the sequence is herein presented. The base of the studied section is characterized by chemical and low energy clastic sedimentation of Lake Bottom and Shoreline, in a context of fast initial subsidence and low sedimentation rate. As the subsidence process decreased, a deltaic progradation became dominant with deposition in a prodelta environment, followed by a deltaic front and deltaic plain interbedded with fluvial plain, and aeolian deposition completing the sequence. The inferred Coniacian-Santonian age is based on vertebrate (fishes and notosuchians) and ostracod fossils with regional chrono-correlates in the Adamantina (Bauru Group), Capacete (Sanfranciscana Basin), and Bajo de la Carpa (Neuquén Group, in Argentina) formations. The formation of a Coniacian depocenter in the Alto Xingu Sub-basin is associated to the Turonian-Coniacian reactivation event in the Peruvian Orogenic Phase of the Andean Orogeny, with the transference of stresses to interplate setting, reactivating Proterozoic structures of the basement.

  13. Oral health and feeding frequency of preschool children in a city in northern Brazil

    Directory of Open Access Journals (Sweden)

    Piero Maia Fernandes

    2014-03-01

    Oral health and healthy eating habits are related to socioeconomic and cultural conditions of the population and imply the biopsychosocial health of the individual. This study investigated the oral health and feeding frequency of children attending a daycare in the municipality of Ananindeua, Pará State, northern Brazil. This was a cross-sectional study, quantitative and qualitative, descriptive, involving the examination of the oral cavity of children and questionnaires to parents, caregivers and those responsible for the daycare. Forty-seven children aged one to six years participated in this study; most were girls (57.5%. The daycare had no specific place for tooth brushing that was performed only once daily, without flossing. It was reported by parents that 48.94% of children have never visited a dentist. On examination of the oral cavity we observed carious lesion (51.10%, dental calculus (42.55%, fluorosis (10.64% and gingivitis (2.13%. It was found that the children had 3 or more meals and had the habit of consuming cariogenic foods such as soft drinks, candy and/or gum, even not being provided by the daycare. Most of the children had at least one decayed tooth, and the daycare offered a healthy diet, but the children had the habit of eating cariogenic foods.

  14. Sanitary conditions of mozzarella and Minas frescal cheese production in northern Paraná, Brazil

    Directory of Open Access Journals (Sweden)

    Aline Marangon Oliveira

    2017-11-01

    Full Text Available The cheese due its rich nutritional composition provides a favorable environment for the multiplication of many kinds of microorganisms. The excess of total and thermotolerant coliforms indicates contamination from environmental and fecal origin, respectively, which characterizes low microbiological quality and unsatisfactory hygienic-sanitary conditions during the cheese production process, besides the possibility of enteropathogens. The aim of the present study was to evaluate the hygienic condition of the production of Mozzarella and Minas Frescal cheeses, produced in Northern region of Paraná State, Brazil. Fifty samples were analyzed, of which 14 were of Mozzarella cheese and 36 were of Minas Frescal cheese covering the period from June 2011 to June 2016. The sanitary conditions of production were evaluated by counting the total and thermotolerant coliforms according to the methodology recommended by the Brazilian legislation. For the Mozzarella cheese, it was observed that all the samples presented counts according to the recommended standards for total and thermotolerant coliforms. However, it was observed that 55.6% of the Minas Frescal cheese samples were in disagreement with the standards established by the legislation for total coliforms, as well as 27.8% for thermotolerant coliforms. These results indicate that a considerable part of the Minas Frescal cheeses present unsatisfactory hygienic conditions during the stages of production, increasing consumer health risk. Therefore, it is necessary to adopt good practices of manufacturing, take corrective actions to fix the contamination problem and compliance with microbiological quality standards established and microbiological safety assurance.

  15. Late Pleistocene carnivores (Carnivora: Mammalia from a cave sedimentary deposit in northern Brazil

    Directory of Open Access Journals (Sweden)

    SHIRLLEY RODRIGUES

    2014-12-01

    Full Text Available The Brazilian Quaternary terrestrial Carnivora are represented by the following families: Canidae, Felidae, Ursidae, Procyonidae Mephitidae and Mustelidae. Their recent evolutionary history in South America is associated with the uplift of the Panamanian Isthmus, and which enabled the Great American Biotic Interchange (GABI. Here we present new fossil records of Carnivora found in a cave in Aurora do Tocantins, Tocantins, northern Brazil. A stratigraphical controlled collection in the sedimentary deposit of the studied cave revealed a fossiliferous level where the following Carnivora taxa were present: Panthera onca, Leopardus sp., Galictis cuja, Procyon cancrivorus, Nasua nasua and Arctotherium wingei. Dating by Electron Spinning Resonance indicates that this assemblage was deposited during the Last Glacial Maximum (LGM, at least, 22.000 YBP. The weasel, G. cuja, is currently reported much further south than the record presented here. This may suggest that the environment around the cave was relatively drier during the LGM, with more open vegetation, and more moderate temperatures than the current Brazilian Cerrado.

  16. Forewarning system for controlling Yellow Sigatoka in Northern Minas Gerais, Brazil

    Directory of Open Access Journals (Sweden)

    Sara de Almeida Rios

    2013-09-01

    Full Text Available This trial aimed to evaluate the Biological Forewarning System (BFS for controlling Yellow Sigatoka in Northern Minas Gerais, Brazil. It was carried out in the town of Nova Porteirinha. One tested 7 treatments, using 6 gross sum (GS values (1,000; 1,300; 1,600; 1,900; 2,200, and 2,500 and the systematic disease control every 15 days. The treatments were distributed into 7 plots (120 plants/plot with ‘Prata-Anã’ and 10 plants from each plot were weekly evaluated with regard to leaf emission rate and disease incidence on the leaves 2, 3 and 4. The more advanced lesion stages and their intensity were used to calculate the gross sum, which aided in decision-making for chemical control. One collected data on production and firmness, pH, and acidity analysis of fruits. For the GS 2,500 treatment, taking into account 2-year evaluation, there was a reduction from 12 to 3 applications, i.e. 75% less fungicide was applied, without loss in productivity. Therefore, one suggests, taking into account the conditions of Nova Porteirinha, the application of BFS for chemical control of Yellow Sigatoka, using the GS value of 2,500 as an indicator of the correct time to perform pulverization.

  17. Paratrichodina africana (Ciliophora: Trichodinidae) of wild and cultured Nile tilapia in the Northern Brazil.

    Science.gov (United States)

    Tavares-Dias, Marcos; Marchiori, Natália da Costa; Martins, Maurício Laterça

    2013-01-01

    The present work morphologically characterizes Paratrichodina africana from the gills of wild and farmed Nile tilapia from Northern Brazil (eastern Amazonia). Ninety fish were captured for parasitological analysis in Macapá, State of Amapá, from a wetland area bathed by the Amazon River commonly called 'Ressaca do Zerão' (n = 52), as well as from a local fish farm (n = 38). Wet smears of the skin and gills of the captured fish were air dried at room temperature and impregnated with silver nitrate by Klein's method for posterior examination of the adhesive disc structures. Total prevalence of parasitism was 16.6% (23% in fish from wetland and 7.8% in farmed fish). Characterized as a small-sized trichodinid, it presented the following measures: 33.2 ± 4.7 µm body diameter, 17.5 ± 2.1 µm adhesive disc, 10.0 ± 0.9 µm denticulate ring, and 22.6 ± 2.0 denticles. Paratrichodina africana reported in this study strongly resembles those described for other localities, but it differs by presenting greater body length. This is the fourth report of P. africana parasitizing a host fish.

  18. Contribution to the stratigraphy of the onshore Paraíba Basin, Brazil

    Directory of Open Access Journals (Sweden)

    Dilce F. Rossetti

    2012-06-01

    Full Text Available Several publications have contributed to improve the stratigraphy of the Paraíba Basin in northeastern Brazil. However, the characterization and distribution of sedimentary units in onshore areas of this basin are still incomplete, despite their significance for reconstructing the tectono-sedimentary evolution of the South American passive margin. This work provides new information to differentiate among lithologically similar strata, otherwise entirely unrelated in time. This approach included morphological, sedimentological and stratigraphic descriptions based on surface and sub-surface data integrated with remote sensing, optically stimulated luminescence dating, U+Th/He dating of weathered goethite, and heavy mineral analysis. Based on this study, it was possible to show that Cretaceous units are constrained to the eastern part of the onshore Paraíba Basin. Except for a few outcrops of carbonatic rocks nearby the modern coastline, deposits of this age are not exposed to the surface in the study area. Instead, the sedimentary cover throughout the basin is constituted by mineralogically and chronologically distinctive deposits, inserted in the Barreiras Formation and mostly in the Post-Barreiras Sediments, of early/middle Miocene and Late Pleistocene-Holocene ages, respectively. The data presented in this work support tectonic deformation as a factor of great relevance to the distribution of the sedimentary units of the Paraíba Basin.Várias publicações têm contribuído para melhorar a estratigrafia da Bacia Paraíba no nordeste do Brasil. Entretanto, a caracterização e distribuição das unidades sedimentares em áreas continentais desta bacia são ainda incompletas, apesar de sua importância para reconstruir a evolução tectono-sedimentar da margem passiva sulamericana. Este trabalho fornece novas informações para diferenciar entre estratos litologicamente similares que, por outro lado, não são relacionados no tempo. Esta

  19. Seasonality of macroalgal communities in a subtropical drainage basin in Paraná state, southern Brazil.

    Science.gov (United States)

    Branco, C C Z; Krupek, R A; Peres, C K

    2008-11-01

    Seasonal dynamics of macroalgal communities was analyzed monthly by samplings in three stream segments of the Pedras River Basin, mid-south region of Paraná State, southern Brazil, from April 2004 to March 2005. The seasonal fluctuations in macroalgal species richness and abundance were correlated with selected environmental variables. In general, the seasonal distribution patterns of these communities were distinct from those reported from other tropical and temperate regions, with higher macroalgal richness and abundance observed from late spring to late fall. Multiple linear regression analysis revealed that the stream variable most closely related with the temporal distribution pattern observed was temperature, which had a very similar seasonal pattern to the biological parameters. On the other hand, the floristic composition was quite diverse in the streams sampled. Among the 25 taxa identified, only two were common to the three streams whereas 15 were restricted to a single sampling site. These data indicate that, although temperature seems to be an effective relationship with global temporal pattern, particular characteristics of each stream can strongly influence the seasonal tendencies in local scale. The results of Detrended Correspondence Analysis (DCA) and Cluster Analysis corroborated this observation.

  20. Carbonaceous aerosol characterization in the Amazon basin, Brazil: novel dicarboxylic acids and related compounds

    Science.gov (United States)

    Kubátová, Alena; Vermeylen, Reinhilde; Claeys, Magda; Cafmeyer, Jan; Maenhaut, Willy; Roberts, Greg; Artaxo, Paulo

    High-resolution capillary gas chromatography (GC) and GC/mass spectrometry (MS) were employed for the quantitative determination of dichloromethane-extractable organic compounds in total and size-fractionated aerosol samples which were collected in the Amazon basin, Brazil, during the wet season, as part of the LBA-CLAIRE-98 experiment. Special emphasis was placed on the characterization and identification of several novel unknown dicarboxylic acids and related oxidative degradation products. This class of acidic products was enriched in the fine size fraction, suggesting that they were secondary organic aerosol products formed by gas-to-particle conversion. Some of the unknowns contributed more to the class of dicarboxylic acids than the major known compound, nonadioic acid (azelaic acid). The same unknowns were also observed in urban aerosol samples collected on hot summer days in Gent, Belgium. For the characterization and structure elucidation of the unknowns, various types of derivatizations and fractionation by solid-phase extraction were employed in combination with GC/MS. Four unknowns were identified. The most abundant were two derivatives of glutaric acid, 3-isopropyl pentanedioic acid and 3-acetyl pentanedioic acid. The other two identified unknowns were another oxo homologue, 3-acetyl hexanedioic acid, and, interestingly, 3-carboxy heptanedioic acid. To our knowledge, the occurrence of these four compounds in atmospheric aerosols has not yet been reported. The biogenic precursors of the novel identified compounds could not be pinpointed, but most likely include monoterpenes and fatty acids.

  1. [Work-related accidents on oil drilling platforms in the Campos Basin, Rio de Janeiro, Brazil].

    Science.gov (United States)

    Freitas, C M; Souza, C A; Machado, J M; Porto, M F

    2001-01-01

    The offshore oil industry is characterized by complex systems in relation to technology and organization of work. Working conditions are hazardous, resulting in accidents and even occasional full-scale catastrophes. This article is the result of a study on work-related accidents in the offshore platforms in the Campos Basin, Rio de Janeiro State. The primary objective was to provide technical back-up for both workers' representative organizations and public authorities. As a methodology, we attempt to go beyond the immediate causes of accidents and emphasize underlying causes related to organizational and managerial aspects. The sources were used in such a way as to permit classification in relation to the type of incident, technological system, operation, and immediate and underlying causes. The results show the aggravation of safety conditions and the immediate need for public authorities and the offshore oil industry in Brazil to change the methods used to investigate accidents in order to identify the main causes in the organizational and managerial structure of companies.

  2. Energetic aspects and opportunities for reusing water on offshore platforms in Campos Basin, Brazil

    Directory of Open Access Journals (Sweden)

    Victor Magalhães Duarte

    2017-09-01

    Full Text Available In the drilling and production of oil at sea, a large quantity of potable water used is most commonly transported to oil platforms using offshore supply vessels (OSVs. Sea water desalination is used as well, but only in a few oil platforms. To minimize energy consumption, water supply options were studied. The desalination of seawater and the reusing of streams of grey water and black water were evaluated and compared with the characteristics of the current supply via OSVs. In both desalination and OSV water supply options an electrolytic wastewater treatment plant is used. The objective of this study was to analyze the current situation regarding water supply on offshore platforms located in the Campos Basin, Rio de Janeiro, Brazil, and to propose measures to take advantage of opportunities to reuse water and reduce energy expenditure. Two alternative scenarios were developed that involved the reuse of water that comes from the effluent of a biological wastewater treatment plant (WWTP. Information on the logistics of supplying water to platforms was obtained through direct consultation with companies and sources in the literature. The results show that annual energy consumption (uptake, treatment, transportation, use and waste water treatment of water on offshore platforms is currently 1.89 GWh, and that a reduction of 1.8 GWh of the energy consumed can be achieved using advanced reuse treatments. Energy consumption in the water reuse treatment is more competitive than those of transport by OSVs or seawater desalination.

  3. Paleogeographic evolution of carbonate reservoirs: geological and geophysical analysis at the Albian Campos Basin, Brazil

    Science.gov (United States)

    Castillo Vincentelli, Maria Gabriela; Favoreto, Julia; Roemers-Oliveira, Eduardo

    2018-02-01

    An integrated geophysical and geological analysis of a carbonate reservoir can offer an effective method to better understand the paleogeographical evolution and distribution of a geological reservoir and non-reservoir facies. Therefore, we propose a better method for obtaining geological facies from geophysical facies, helping to characterize the permo-porous system of this kind of play. The goal is to determine the main geological phases from a specific hydrocarbon producer (Albian Campos Basin, Brazil). The applied method includes the use of a petrographic and qualitative description from the integrated reservoir with seismic interpretation of an attribute map (energy, root mean square, mean amplitude, maximum negative amplitude, etc), all calculated at the Albian level for each of the five identified phases. The studied carbonate reservoir is approximately 6 km long with a main direction of NE-SW, and it was sub-divided as follows (from bottom to top): (1) the first depositional sequence of the bank was composed mainly of packstone, indicating that the local structure adjacent to the main bank is protected from environmental conditions; (2) characterized by the presence of grainstone developed at the higher structure; (3) the main sequence of the peloidal packstone with mudstones oncoids; (4) corresponds to the oil production of carbonate reservoirs formed by oolitic grainstone deposited at the top of the carbonate bank; at this phase, rising sea levels formed channels that connected the open sea shelf with the restricted circulation shelf; and (5) mudstone and wackestone represent the system’s flooding phase.

  4. Seasonality of macroalgal communities in a subtropical drainage basin in Paraná state, southern Brazil

    Directory of Open Access Journals (Sweden)

    CCZ. Branco

    Full Text Available Seasonal dynamics of macroalgal communities was analyzed monthly by samplings in three stream segments of the Pedras River Basin, mid-south region of Paraná State, southern Brazil, from April 2004 to March 2005. The seasonal fluctuations in macroalgal species richness and abundance were correlated with selected environmental variables. In general, the seasonal distribution patterns of these communities were distinct from those reported from other tropical and temperate regions, with higher macroalgal richness and abundance observed from late spring to late fall. Multiple linear regression analysis revealed that the stream variable most closely related with the temporal distribution pattern observed was temperature, which had a very similar seasonal pattern to the biological parameters. On the other hand, the floristic composition was quite diverse in the streams sampled. Among the 25 taxa identified, only two were common to the three streams whereas 15 were restricted to a single sampling site. These data indicate that, although temperature seems to be an effective relationship with global temporal pattern, particular characteristics of each stream can strongly influence the seasonal tendencies in local scale. The results of Detrended Correspondence Analysis (DCA and Cluster Analysis corroborated this observation.

  5. STRATIGRAPHIC EVOLUTION, PALEOENVIRONMENTS AND HYDROCARBON POTENTIALS OF THE BENUE/DAHOMEY BASINS, NIGERIAN AND POTIGUAR/CEARA BASINS, NE BRAZIL

    International Nuclear Information System (INIS)

    Akande, S.O; Adekeye, O.A.; Oj, O.J; Erdtmann, B.D.; Koutsokous, E.I.

    2004-01-01

    The stratigraphy, facies relationship and paleoenvironment of selected West African and the Brazillian rift basins permit the recognition of at least two major petroleum systems apart from the prolific Niger Delta petroleum system. The Lower Cretaceous fluivio-lacustrine petroleum system and Upper Cretaceous to Lower Tertiary, marine dominated petroleum system. Our combined studies of the stratigraphic, structural framework, paleoenvironment and time-space relationships of the petroleum systems in the Benue/Dahomey and the Potiguar/Ceara basins indicated that rifting and subsequent drifting during the opening of the South Atlantic controlled subsidence, sediment deposition and facies associations in individual basins. Whereas in the Potiguar/Ceara basins, the best developed source rocks are within the Neomacin-Aptian fluvio- lacustrine sequence of the Pendencia and Alagamar Formations which generated reserved hydrocarbon in the Acu Formation, empirical evidence for this petroleum system in the contiguous Benue/Dahomey basins are only based on the geochemical characteristics of the lower parts of the Bima Formation and the Abeokuta Group. In contrast, the Upper Cretaceous-Lower Tertiary marine petroleum system, which is constrained by poor development of reservoirs in the Potiguar/Ceara basin is productive in the Benue/Dahomey basins where source rocks, reservoir and sealing facies occur at this interval. Considering the recent hydrocarbon discoveries of the East Niger basin, the Doba (southern Chad), the Muglad basin (southern Sudan) sourced from the fluvio-lacustrine rift sequences, we suggest that this petroleum system needs more detailed exploration and has some potentials in the Benue/Dahomey frontier basins

  6. Palaeoenvironment and its control on the formation of Miocene marine source rocks in the Qiongdongnan Basin, northern South China Sea.

    Science.gov (United States)

    Li, Wenhao; Zhang, Zhihuan; Wang, Weiming; Lu, Shuangfang; Li, Youchuan; Fu, Ning

    2014-01-01

    The main factors of the developmental environment of marine source rocks in continental margin basins have their specificality. This realization, in return, has led to the recognition that the developmental environment and pattern of marine source rocks, especially for the source rocks in continental margin basins, are still controversial or poorly understood. Through the analysis of the trace elements and maceral data, the developmental environment of Miocene marine source rocks in the Qiongdongnan Basin is reconstructed, and the developmental patterns of the Miocene marine source rocks are established. This paper attempts to reveal the hydrocarbon potential of the Miocene marine source rocks in different environment and speculate the quality of source rocks in bathyal region of the continental slope without exploratory well. Our results highlight the palaeoenvironment and its control on the formation of Miocene marine source rocks in the Qiongdongnan Basin of the northern South China Sea and speculate the hydrocarbon potential of the source rocks in the bathyal region. This study provides a window for better understanding the main factors influencing the marine source rocks in the continental margin basins, including productivity, preservation conditions, and the input of terrestrial organic matter.

  7. Hydrogeochemical processes identification and groundwater pollution causes analysis in the northern Ordos Cretaceous Basin, China.

    Science.gov (United States)

    An, Yongkai; Lu, Wenxi

    2017-10-23

    It is necessary to identify the hydrogeochemical processes and analyze the causes of groundwater pollution due to the lack of knowledge about the groundwater chemical characteristics and the endemic diseases caused by groundwater pollution in the northern Ordos Cretaceous Basin. In this paper, groundwater chemical facies were obtained using the piper trilinear diagram based on the analysis of 190 samples. The hydrogeochemical processes were identified using ionic ratio coefficient, such as leaching, evaporation and condensation. The causes and sources of groundwater pollution were analyzed by correspondence analysis, and the spatial distribution and enrichment reasons of fluoride ion were analyzed considering the endemic fluorosis emphatically. The results show that leaching, evaporation and condensation, mixing, and anthropogenic activities all had significant impact on hydrogeochemical processes in the study area. However, cation exchange and adsorption effects were strong in the S2 and S3 groundwater flow systems, but weak in S1. Groundwater is mainly polluted by Mn and COD Mn in the study area. The landfill leachate, domestic sewage, and other organic pollutants, excessive use of pesticides and fertilizers in agriculture, and pyrite oxidation from long-term and large-scale exploitation of coal are the sources of groundwater pollution. The S1 has the highest degree of groundwater pollution, followed by S2 and S3. High concentration of fluoride ion is mainly distributed in the north and west of study area. Evaporation and condensation and groundwater chemistry component are the most important causes of fluoride ion enrichment. The results obtained in this study will be useful for understanding the groundwater quality for effective management and utilization of groundwater resources and assurance of drinking water safety.

  8. FACIES ANALYSIS, STRATIGRAPHY AND PALAEONTOLOGY (MOLLUSCS AND VERTEBRATES IN THE UPPER PLIOCENE SANDY FLOOD-BASIN DEPOSITS OF THE UPPER VALDARNO BASIN (NORTHERN APENNINES

    Directory of Open Access Journals (Sweden)

    MASSIMILIANO GHINASSI

    2005-11-01

    Full Text Available The Upper Valdarno Basin, one of the most investigated Neogene–Quaternary basins of the Northern Apennines, developed during three main phases, as testified by the occurrence of three unconformity-bounded stratigraphic units (UBSUs in the basin infill. Despite numerous studies having been carried out, biochronological, paleoecological and stratigraphical issues in the lower portion of the Montevarchi Synthem (second phase have yet to be understood. Sandy deposits (Montecarlo Sand and Silt Unit, stratigraphically located in this portion of the Montevarchi Synthem, are the focus of this multidisciplinary study. These deposits conformably overlie sandy fluvio-eolian sediments and are, in turn, capped by fluvio-palustrine deposits through a progressive unconformity. Facies analysis suggest a sandy flood-basin environment for these deposits, characterised by variations in water discharge and flood event energy. Mollusc and fish remains, pointing to quiet or slow-moving shallow waters, have been affected by transport processes before final burial in overbank areas. Fish remains of the primary marine family Mugilids highlight a connection between the basin and the sea that was previously only supposed. Small mammal remains, referred to the rodent Mimomys polonicus, are coherent with a water-rich environment. Cyclic variations in shell content and sedimentological characteristics testify to the occurrence of short-term climatic oscillations during this warming phase. This study fits with paleomagnetic and radiometric datings and mammal biochronology, in indicating that the Montecarlo Sand and Silt Unit belongs to a time interval preceding the Reunion paleomagnetic event. The depositional evolution of the Montecarlo Unit was driven by climatic change from arid to humid conditions, related to a global increase in temperature that occurred between 2.4 and 2.2 Ma.

  9. Stress state variations among the clay and limestone formations of the molasse basin of Northern Switzerland

    International Nuclear Information System (INIS)

    Vietor, Tim; Mueller, Herwig; Frieg, Bernd; Klee, Gerd

    2012-01-01

    Document available in extended abstract form only. Full text of publication follows: The design of geological repositories for radioactive waste responds to the requirements of technical feasibility and long-term safety in the context of a specific geological setting. An important aspect of the geological setting is the primary stress field. To a large extent the stress state controls repository induced effects such as the excavation damage zone and the associated potential changes in the waste isolation properties of the host rock. Therefore the measurement of the stress state receives some attention where the site selection for geological repositories focuses onto relatively weak host rocks such as clay-stones and marly shales that tend to develop a significant excavation damage zone. Measurements of the minimum stress magnitudes in a recently drilled geothermal well in the Molasse Basin of northern Switzerland have yielded a stress profile reaching from 592 m to 1455 m depth. It straddles several rock units and includes the top of the crystalline basement. The sedimentary sequence consists of Marine limestones, shales and marls unconformably covered by Tertiary rocks of the Molasse. In other parts of the basin the evaporitic rocks of the Triassic Muschelkalk formation at the base of the sedimentary layer served as a regional detachment and enabled thin skinned thrusting and the formation of the Jura Fold and Thrust Belt in the Late Miocene. The stress measurements have been performed in the open hole by Mini-frac tests. The method uses a double packer system to isolate a one meter long interval of the borehole that is then pressurized at high injection rates up to the breakdown of the formation. Repeated pressurization of the interval allows to determine the stress that acts on the newly created fracture. The total injected volume during such a test is in the range of a few litres and the size of the fracture that extends from the borehole normal to the minimum

  10. Taxonomic revision of the fossil pulmonate mollusks of Itaboraí Basin (Paleocene, Brazil

    Directory of Open Access Journals (Sweden)

    Rodrigo Brincalepe Salvador

    2013-01-01

    Full Text Available The limestones of Itaboraí Basin (Middle Paleocene, Rio de Janeiro, Brazil, harbor a rich fossil molluscan fauna consisting exclusively of pulmonate snails, both terrestrial and freshwater. An extensive taxonomic revision of this paleofauna is conducted here. A new genus, Cortana, is described as well as two new species, Eoborus fusiforme and Gastrocopta itaboraiensis. The revised classification is as follows: Austrodiscus lopesi (Charopidae; Biomphalaria itaboraiensis (Planorbidae; "Brachypodella" britoi (Urocoptidae; Brasilennea arethusae, Brasilennea guttula, Brasilennea minor (Cerionidae; Bulimulus fazendicus, Bulimulus trindadeae, Cortana carvalhoi, Cyclodontina coelhoi, Itaborahia lamegoi, Leiostracus ferreirai, Plagiodontes aff. dentatus (Orthalicidae; Cecilioides sommeri (Ferussaciidae; Eoborus rotundus, Eoborus sanctijosephi, Eoborus fusiforme (Strophocheilidae; Gastrocopta mezzalirai, Gastrocopta itaboraiensis (Gastrocoptidae; Temesa magalhaesi (Clausiliidae. The species Strobilopsis mauryae was considered a synonym of Brasilennea arethusae; Bulimulus sommeri a synonym of Itaborahia lamegoi; and Vorticifex fluminensis a synonym of Eoborus sanctijosephi. Itaboraí Basin has the most ancient records of the families Orthalicidae, Gastrocoptidae, Ferussaciidae and Strophocheilidae. Moreover, the basin's records of Charopidae, Clausiliidae, Cerionidae, and Urocoptidae are among the most ancient in the world and, among these, those of Cerionidae, Clausiliidae and Urocoptidae deserve special attention since they are greatly removed from these families' current distribution. Additionally, Itaboraí has the most ancient records for the genera Austrodiscus, Brachypodella, Bulimulus, Cecilioides, Cyclodontina, Eoborus, Gastrocopta, Leiostracus, Plagiodontes and Temesa. There are three endemic genera in the basin: Brasilennea, Cortana and Itaborahia. Further discussion on paleobiogeography and evolution of this paleofauna is also provided.Os calc

  11. Radiometric age determination of tonsteins and stratigraphic constraints for the Lower Permian coal succession in southern Parana Basin, Brazil

    Energy Technology Data Exchange (ETDEWEB)

    Guerra-Sommer, Margot; Cazzulo-Klepzig, Miriam; Hartmann, Leo Afraneo; Formoso, Milton Luis Laquintinie [Instituto de Geociencias, Universidade Federal do Rio Grande do Sul, Avenida Bento Goncalves, 9500, 91501-970 Porto Alegre, Rio Grande do Sul (Brazil); Santos, Joao Orestes Schneider [Centre for Global Targeting, University of Western Australia, Crawley, Perth 6009, WA (Australia); Ketzer, Joao Marcelo [Instituto de Meio Ambiente, Pontificia Universidade Catolica, Avenida Ipiranga, Porto Alegre, Rio Grande do Sul (Brazil)

    2008-03-03

    Ion microprobe (SHRIMP II) dating of zircons from tonsteins interbedded with coal seams from the Candiota and Faxinal coalfields (Early Permian, Rio Bonito Formation, Parana Basin, Brazil) is presented. The mean ages obtained (290.6 {+-} 1.5 Ma) are more precise than previously published intervals. Calibrations of chronostratigraphic data with radiometric ages show that the main coal succession from the southern Basin is constrained to the Middle Sakmarian. The {+-} 2 Ma time interval of deposition supports the hypothesis that the coal-generating process was quite rapid in terms of geological time. In a general context, Faxinal and Candiota coals are assigned, into the Protohaploxypinus goraiensis Subzone, besides some paleocological differences evidenced by palynological studies. This bio-interval does not correspond to a consistent palynostratigraphic tool and more accurate biostratigraphic zonation for the Carboniferous-Permian interval must be delineated. The new results have far-reaching significance for correlations of the Basin with sequences of the Argentinian Paganzo Basin (302 {+-} 6 Ma and 288 {+-} 7 Ma) and also with the Karoo Basin, with the lowermost Ecca Group (288 {+-} 3 Ma and 289.6 {+-} 3.8 Ma). This new evidence supports the presence of an active and widespread Lower Permian explosive volcanic event in western Gondwana, which is interpreted as the same volcanism which produced the Choiyoi Group in western Argentina. According to this correlation the ash-fall source is located about 1400 km to the southwest of their area of deposition. (author)

  12. Application of morphometry in neotectonic studies at the eastern edge of the Paraná Basin, Santa Catarina State, Brazil

    Science.gov (United States)

    Jacques, Patricia D.; Salvador, Elizete D.; Machado, Rômulo; Grohmann, Carlos H.; Nummer, Alexis R.

    2014-05-01

    The neotectonic evolution of the eastern edge of the Paraná Basin in the Santa Catarina State, Brazil was investigated using field data and detailed morphometric analysis along an east-west section. Analysis included generation of maps of isobase, hydraulic gradients, hypsometry, incision of drainage basins, drainage asymmetry and anomalous morphological features. All these maps generated results that agreed with field data and helped define recent faults in directions close to N-S and E-W, both probably reactivated faults of the Paraná Basin and the basement. Geomorphological features identified in topographic maps, possibly related to neotectonism, have a close agreement with our observations in the field. The asymmetry of basins as analysed by the T-Index method proved to be compatible with the influence of a E-W compressive tectonic regime and showed a movement from W to E. Application of the hypsometric integral technique helped establish a correlation between the younger basins with structures trending N-S (± 30°). The N-S faults were related to a compressional stress field (SHmax) close to E-W and SHmin (stress minimum) around N-S, thereby establishing a tectonic context of structures developed in a transpressive regime. The compressional field was caused by the subduction of the Nazca tectonic plate below the South American plate, whereas the transcurrent component exploited pre-existent E-W structures when the Atlantic Ocean was opening.

  13. Establishment of a metallogenetic prospecting model of a pilot area in the Resende Basin - RJ, Brazil, within it's geomorphic aspects

    International Nuclear Information System (INIS)

    Bidone, E.D.; Perrin, P.; Rocha, J.A. da

    1984-01-01

    The Resende Basin lies between the Mantiqueira Mountain range which rises up to 2800m in the alcaline massif of Itatiaia - Passa Quatro in the North, and the Serra do Mar Mountain range in the South. The basin is the most casterly of a series of elongate Tertiary sedimentary basins that stretch SW to NE between Sao Paulo and Barra Mansa in the state of Rio de Janeiro, Brazil (44 0 to 47 0 West). Considering: -The economic potential represented by source rocks for the basin sediments; -the known capacity of sediments to concentrate metals when weathering, transport and deposition conditions are favorable, a geochemical analysis was done to determine; -favorable sites of uranium and thorium concentrations; -the evolution of depositional environments through integration of sedimentalogical, mineralogical, and geochemical data in order that the metallogenetic analysis promotes more efficient prospecting. The results permit a better understanding of the sedimentological and geochemical setting of Tertiary sediments in the region, as well as establish a method of rapid, inexpensive and efficient prospection that can be used in other basins of this type. (Author) [pt

  14. A detrital record of continent-continent collision in the Early-Middle Jurassic foreland sequence in the northern Yangtze foreland basin, South China

    Science.gov (United States)

    Qian, Tao; Liu, Shaofeng; Wang, Zongxiu; Li, Wangpeng; Chen, Xinlu

    2016-12-01

    The Mesozoic northern Yangtze foreland basin system was formed by continental collision between the North China and South China plates along the Mianlue suture. Synorogenic stratigraphic sequences of Late Triassic to Early-Middle Jurassic age were developed in the northern Yangtze foreland basin. The upper Middle Jurassic Shaximiao Formation consists mainly of thick-bedded terrestrial successions that serve as the main body of the basin-filling sequences, suggesting intense tectonism in the peripheral orogeny of the foreland basin. Laser-ICP-MS U-Pb analysis of 254 detrital zircon grains from sandstone samples and several published Lower-Middle Jurassic samples, detrital compositions, petrofacies, and paleocurrent reconstructions in the northern Yangtze foreland basin indicate that discrete source areas included the Qinling-Dabieshan ranges and the Mianlue suture zone to the north, and the South China plate to the south. The stratigraphic succession and sediment provenance of the foreland basin imply that the early Mianlue oceanic basin, magmatic arc, and nonmarine molasse foreland basin during the period of deposition were modified or buried by the subsequent continent-continent collision between the North China-Qinling-Dabieshan plate and the Yangtze plate during the Jurassic, which followed the oblique amalgamation between these plates during the Middle-Late Triassic.

  15. The fish fauna in tropical rivers: The case of the Sorocaba river basin, SP, Brazil

    Directory of Open Access Journals (Sweden)

    Welber Senteio Smith

    2003-09-01

    Full Text Available A survey was carried out on the fish species in the Sorocaba River basin, the main tributary of the left margin of the Tietê River, located in the State of São Paulo, Brazil. The species were collected with gill nets. After identification of the specimens, their relative abundance, weight and standard length were determined. Up to the present moment there are not any studies that focus this subject in this hydrographic basin. Fifty-three species, distributed in eighteen families and six orders were collected. Characiformes were represented by twenty-eight species, Siluriformes by seventeen species, the Gymnotiformes by three species, Perciformes and Cyprinodontiformes by two species, and the Synbranchiformes by one species. Among the collected species there were two exotic. The most abundant species were Astyanax fasciatus and Hypostomus ancistroides. In relation to total weight the most representative species were Hoplias malabaricus and Hypostomus ancistroides. Cyprinus carpio, Prochilodus lineatus, Schizodon nasutus and Hoplias malabaricus were the most representative species in relation to average weight. Largest standard length were recorded for Sternopygus macrurus, Steindachnerina insculpta, Eigenmannia aff. virescens and Cyprinus carpioSe realizó un análisis de las especies de peces de la cuenca del Río Sorocaba, el principal tributario de la margen izquierda del Río Tietê, localizado en el estado de Sao Paulo, Brasil. Las especies fueron recolectadas con redes agalleras. Luego de la identificación de los especímenes, fue determinada su abundancia relativa, peso, y longitud estandar. Hasta el presente, no hay ningún otro estudio que analice estos aspectos en dicha cuenca hidrográfica. Fueron recolectados 55 especies, distribuidas en 18 familias y 6 ordenes. Los Characiformes estuvieron representados por 28 especies, Siluriformes por 17 especies, Gymnotiformes por 3 especies, Perciformes y Cyprinodontiformes por 2 especies, y

  16. Chagas disease ecoepidemiology and environmental changes in northern Minas Gerais state, Brazil

    Directory of Open Access Journals (Sweden)

    Elisa Neves Vianna

    Full Text Available BACKGROUND Triatoma sordida and Triatoma pseudomaculata are frequently captured triatomine species in the Brazilian savannah and caatinga biomes, respectively, and in Brazilian domiciles. OBJECTIVES This study identified eco-epidemiological changes in Chagas disease in northern Minas Gerais state, Brazil, and considered the influence of environmental shifts and both natural and anthropogenic effects. METHODS Domicile infestation and Trypanosoma cruzi infection rates were obtained from triatomines and sylvatic reservoirs during the following two time periods: the 1980s and 2007/2008. Entomological and climatic data with land cover classification derived from satellite imagery were integrated into a geographic information system (GIS, which was applied for atmospheric correction, segmentation, image classification, and mapping and to analyse data obtained in the field. Climatic data were analysed and compared to land cover classifications. RESULTS A comparison of current data with data obtained in the 1980's showed that T. sordida colonised domiciliary areas in both periods, and that T. pseudomaculata did not colonise these areas. There was a tendency toward a reduction in T. cruzi infection rates in sylvatic reservoirs, and of triatomines captured in both households and in the sylvatic environment. T. sordida populations have reduced in the sylvatic environment, while T. pseudomaculata showed an expanding trend in the region compared to counts observed in the 1980's in the sylvatic environment. This may be related to high deforestation rates as well as gradual increases in land surface temperature (LST and temperatures along the years. MAIN CONCLUSIONS Our results suggest a geographical expansion of species into new biomes as a result of anthropogenic and climatic changes that directly interfere with the reproductive and infection processes of vectors.

  17. Chagas disease ecoepidemiology and environmental changes in northern Minas Gerais state, Brazil.

    Science.gov (United States)

    Vianna, Elisa Neves; Souza E Guimarães, Ricardo José de Paula; Souza, Christian Rezende; Gorla, David; Diotaiuti, Liléia

    2017-11-01

    Triatoma sordida and Triatoma pseudomaculata are frequently captured triatomine species in the Brazilian savannah and caatinga biomes, respectively, and in Brazilian domiciles. This study identified eco-epidemiological changes in Chagas disease in northern Minas Gerais state, Brazil, and considered the influence of environmental shifts and both natural and anthropogenic effects. Domicile infestation and Trypanosoma cruzi infection rates were obtained from triatomines and sylvatic reservoirs during the following two time periods: the 1980s and 2007/2008. Entomological and climatic data with land cover classification derived from satellite imagery were integrated into a geographic information system (GIS), which was applied for atmospheric correction, segmentation, image classification, and mapping and to analyse data obtained in the field. Climatic data were analysed and compared to land cover classifications. A comparison of current data with data obtained in the 1980's showed that T. sordida colonised domiciliary areas in both periods, and that T. pseudomaculata did not colonise these areas. There was a tendency toward a reduction in T. cruzi infection rates in sylvatic reservoirs, and of triatomines captured in both households and in the sylvatic environment. T. sordida populations have reduced in the sylvatic environment, while T. pseudomaculata showed an expanding trend in the region compared to counts observed in the 1980's in the sylvatic environment. This may be related to high deforestation rates as well as gradual increases in land surface temperature (LST) and temperatures along the years. Our results suggest a geographical expansion of species into new biomes as a result of anthropogenic and climatic changes that directly interfere with the reproductive and infection processes of vectors.

  18. Analysis of longitudinal data of beef cattle raised on pasture from northern Brazil using nonlinear models.

    Science.gov (United States)

    Lopes, Fernando B; da Silva, Marcelo C; Marques, Ednira G; McManus, Concepta M

    2012-12-01

    This study was undertaken to aim of estimating the genetic parameters and trends for asymptotic weight (A) and maturity rate (k) of Nellore cattle from northern Brazil. The data set was made available by the Brazilian Association of Zebu Breeders and collected between the years of 1997 and 2007. The Von Bertalanffy, Brody, Gompertz, and logistic nonlinear models were fitted by the Gauss-Newton method to weight-age data of 45,895 animals collected quarterly of the birth to 750 days old. The curve parameters were analyzed using the procedures GLM and CORR. The estimation of (co)variance components and genetic parameters was obtained using the MTDFREML software. The estimated heritability coefficients were 0.21 ± 0.013 and 0.25 ± 0.014 for asymptotic weight and maturity rate, respectively. This indicates that selection for any trait shall results in genetic progress in the herd. The genetic correlation between A and k was negative (-0.57 ± 0.03) and indicated that animals selected for high maturity rate shall result in low asymptotic weight. The Von Bertalanffy function is adequate to establish the mean growth patterns and to predict the adult weight of Nellore cattle. This model is more accurate in predicting the birth weight of these animals and has better overall fit. The prediction of adult weight using nonlinear functions can be accurate when growth curve parameters and their (co)variance components are estimated jointly. The model used in this study can be applied to the prediction of mature weight in herds where a portion of the animals are culled before they reach the adult age.

  19. Soil quality indicators in a rhodic kandiudult under different uses in northern Parana, Brazil

    Directory of Open Access Journals (Sweden)

    Biana Harumi Kuwano

    2014-02-01

    Full Text Available Sustainable use of soil, maintaining or improving its quality, is one of the goals of diversification in farmlands. From this point of view, bioindicators associated with C, N and P cycling can be used in assessments of land-use effects on soil quality. The aim of this study was to investigate chemical, microbiological and biochemical properties of soil associated with C, N and P under different land uses in a farm property with diversified activity in northern Parana, Brazil. Seven areas under different land uses were assessed: fragment of native Atlantic Forest; growing of peach-palm (Bactrys gasipaes; sugarcane ratoon (Saccharum officinarum recently harvested, under renewal; growing of coffee (Coffea arabica intercropped with tree species; recent reforestation (1 year with native tree species, previously under annual crops; annual crops under no-tillage, rye (Cecale cereale; secondary forest, regenerated after abandonment (for 20 years of an avocado (Persea americana orchard. The soil under coffee, recent reforestation and secondary forest showed higher concentrations of organic carbon, but microbial biomass and enzyme activities were higher in soils under native forest and secondary forest, which also showed the lowest metabolic coefficient, followed by the peach-palm area. The lowest content of water-dispersible clay was found in the soil under native forest, differing from soils under sugarcane and secondary forest. Soil cover and soil use affected total organic C contents and soil enzyme and microbial activities, such that more intensive agricultural uses had deeper impacts on the indicators assessed. Calculation of the mean soil quality index showed that the secondary forest was closest to the fragment of native forest, followed by the peach-palm area, coffee-growing area, annual crop area, the area of recent reforestation and the sugarcane ratoon area.

  20. Depositional Record of the Bagua Basin, Northern Peru: Implications for Climate and Tectonic Evolution of Tropical South America

    Science.gov (United States)

    Moreno, F.; George, S. W. M.; Williams, L. A.; Horton, B. K.; Garzione, C. N.

    2015-12-01

    The Andes Mountains exert critical controls on the climate, hydrology, and biodiversity of South America. The Bagua Basin, a low elevation (400-600 m) intermontane basin in northern Peru, offers a unique opportunity to study the ecological, climatic, and structural evolution of the western topographic boundary of the Amazonian foreland. Situated between the Marañon fold-thrust belt of the Western Cordillera and basement block uplifts of the Eastern Cordillera, the Bagua region contains a protracted, semi-continuous record of Triassic through Pleistocene sedimentation. Whereas Triassic-Cretaceous marine deposits were potentially related to extension and regional thermal subsidence, a Paleocene-Eocene shift to shallow marine and fluvial systems marks the onset of foreland basin conditions. Oligocene-Miocene sedimentation corresponds to a braided-meandering fluvial system with exceptional development of paleosols. In this study, we use new detrital zircon U-Pb geochronologic and oxygen stable isotopic datasets to establish a chronology of pre-Andean and Andean processes within the Bagua Basin. Detrital zircon geochronology provides constraints on when the Western and Eastern cordilleras shed sediments into the basin. Syndepositional zircons within Eocene, Oligocene and Miocene strata provide key age control for a previously poorly constrained depositional chronology. Preliminary results suggest a dramatic provenance shift in which Paleocene deposits contain almost exclusively cratonic populations (500-1600 Ma) whereas Eocene deposits show a mix of syndepositional zircons from the magmatic arc, recycled Mesozoic zircons, and cratonic zircon populations. Oxygen stable isotopes (δ18O) of carbonate nodules from Neogene paleosols will help elucidate when the Eastern Cordillera became an orographic barrier intercepting moisture from the Amazon basin to the east. Together, these records will help uncover the history of tectonics and climate interaction in tropical South

  1. A new genus of aplodontid rodent (Mammalia, Rodentia from the late Oligocene of northern Junggar Basin, China.

    Directory of Open Access Journals (Sweden)

    Shundong Bi

    Full Text Available A new genus and species of aplodontid rodent, Proansomys dureensis, from the late Oligocene of the northern Junggar Basin of China is described. The new genus is referred to as Ansomyinae because the ectoloph on the upper cheek teeth, although not fully crested, has attained the same characteristic bucket-handle-shaped configuration as other members of the subfamily. It represents the earliest record of the subfamily yet discovered in Asia and is more plesiomorphic than species of the genus Ansomys in having a partly crested ectoloph, a lower degree of lophodonty, and less complex tooth basins (lacking accessory lophules. Proansomys has transitional features between Prosciurus and Ansomys, suggesting that the Ansomyinae derived from a group of aplodontids related to Prosciurus, as did other advanced aplodontid rodents. This provides new light on the paleobiogeography of the Ansomyinae.

  2. Cheatgrass percent cover change: Comparing recent estimates to climate change − Driven predictions in the Northern Great Basin

    Science.gov (United States)

    Boyte, Stephen P.; Wylie, Bruce K.; Major, Donald J.

    2016-01-01

    Cheatgrass (Bromus tectorum L.) is a highly invasive species in the Northern Great Basin that helps decrease fire return intervals. Fire fragments the shrub steppe and reduces its capacity to provide forage for livestock and wildlife and habitat critical to sagebrush obligates. Of particular interest is the greater sage grouse (Centrocercus urophasianus), an obligate whose populations have declined so severely due, in part, to increases in cheatgrass and fires that it was considered for inclusion as an endangered species. Remote sensing technologies and satellite archives help scientists monitor terrestrial vegetation globally, including cheatgrass in the Northern Great Basin. Along with geospatial analysis and advanced spatial modeling, these data and technologies can identify areas susceptible to increased cheatgrass cover and compare these with greater sage grouse priority areas for conservation (PAC). Future climate models forecast a warmer and wetter climate for the Northern Great Basin, which likely will force changing cheatgrass dynamics. Therefore, we examine potential climate-caused changes to cheatgrass. Our results indicate that future cheatgrass percent cover will remain stable over more than 80% of the study area when compared with recent estimates, and higher overall cheatgrass cover will occur with slightly more spatial variability. The land area projected to increase or decrease in cheatgrass cover equals 18% and 1%, respectively, making an increase in fire disturbances in greater sage grouse habitat likely. Relative susceptibility measures, created by integrating cheatgrass percent cover and temporal standard deviation datasets, show that potential increases in future cheatgrass cover match future projections. This discovery indicates that some greater sage grouse PACs for conservation could be at heightened risk of fire disturbance. Multiple factors will affect future cheatgrass cover including changes in precipitation timing and totals and

  3. Two new species of Curculionichthys (Siluriformes: Loricariidae) from the rio Amazonas basin, Brazil.

    Science.gov (United States)

    Roxo, Fábio F; Dias, Angelica C; Silva, Gabriel S C; Oliveira, Claudio

    2017-10-31

    In the present study, we describe two new species of Curculionichthys from rio Tapajós and rio Tocantins basins in Brazil. Both species present all diagnostic features of Curculionichthys. Furthermore, both species C. tukana and C. itaim are distinguished from congeners by the combination of seven characters: (1) a higher number of plates in abdominal lateral plates series; (2) the absence of large conspicuous odontodes forming rows on head and trunk; (3) the anterior profile of the head pointed; (4) a higher number of dentary teeth; (5) the lack of contrasting dark spots at the anterodorsal region of body; (6) the absence of an irregular concentration of chromatophores that entirely cover the anal-fin origin and adjacent region, and distal portion of the first unbranched anal-fin ray; and (7) the presence of odontodes forming aligned rows, more evident in the dorsal portion of head and in the lateral portion of caudal peduncle. Furthermore, C. tukana can be further distinguished from congeners by three characters: (1) the papillae aligned in series that extends from the distal portion of lower lip to dentary; (2) the absence of dark-brown spots scattered over the body; and (3) a higher number of maxillary teeth. The species C. itaim also can be further distinguished from congeners by five characters: (1) the papillae randomly distributed throughout the lower lip; (2) a smaller number of medial plates series on lateral portion of the body following the lateral line; (3) a smaller number of median plates series in abdomen; (4) the absence of dark-brown spots scattered over the body; and (5) the absence of one unpaired platelet on the dorsal portion of the caudal peduncle.

  4. Natural radionuclides in major aquifer systems of the Parana sedimentary basin, Brazil

    International Nuclear Information System (INIS)

    Bonotto, Daniel Marcos

    2011-01-01

    This paper describes the natural radioactivity of groundwater occurring in sedimentary (Bauru and Guarani) and fractured rock (Serra Geral) aquifer systems in the Parana sedimentary basin, South America that is extensively used for drinking purposes, among others. The measurements of gross alpha and gross beta radioactivity as well the activity concentration of the natural dissolved radionuclides 40 K, 238 U, 234 U, 226 Ra, 222 Rn, 210 Po and 210 Pb were held in 80 tubular wells drilled in 21 municipalities located at Sao Paulo State and its border with Mato Grosso do Sul State in Brazil. Most of the gross alpha radioactivity data were below 1 mBq/L, whereas values exceeding the gross beta radioactivity detection limit of 30 mBq/L were found. The radioelement solubility in the studied systems varied according to the sequence radon>radium>other radionuclides and the higher porosity of sandstones relatively to basalts and diabases could justify the enhanced presence of dissolved radon in the porous aquifer. The implications of the data obtained in terms of standards established for defining the drinking water quality have also been discussed. The population-weighted average activity concentration for these radionuclides was compared to the guideline value of 0.1 mSv/yr for the total effective dose and discussed in terms of the choice of the dose conversion factors. - Highlights: → Integration of distinct radiometric data acquired in groundwaters. → Radiation dose in important hydrological resources in South America. → Contribution of 226 Ra for the more accentuated radiation dose in aquifers. → Dose factors for Rn and generation of values exceeding the maximum of 0.1 mSv/yr.

  5. Paleohistology and lifestyle inferences of a dyrosaurid (Archosauria: Crocodylomorpha from Paraiba Basin (northeastern Brazil.

    Directory of Open Access Journals (Sweden)

    Rafael César Lima Pedroso de Andrade

    Full Text Available Among the few vertebrates that survived the mass extinction event documented at the Cretaceous-Paleocene boundary are dyrosaurid crocodylomorphs. Surprisingly, there is little information regarding the bone histology of dyrosaurids, despite their relatively common occurrence in the fossil record, and the potential to gain insight about their biology and lifestyle. We provide the first description of the long bone histology of the dyrosaurids. Specimens were collected from the Maria Farinha Formation, in the Paraíba Basin of northeast Brazil. Thin sections of a right femur and left tibia were made. In the left tibia, the cortex consists of lamellar-zonal bone with five lines of arrested growth (LAGs, spaced ∼300 µm apart. The tibia contains a small to medium-sized organized vascular network of both simple vascular canals and primary osteons that decrease in density periostially. The femur exhibits a similar histological pattern overall but has double-LAGs, and an EFS layer (the latter is rare in living crocodylians. Secondary osteons occur in the deep cortex near and inside the spongiosa as a result of remodeling in both bones. This tissue pattern is fairly common among slow-growing animals. These specimens were a sub-adult and a senescent. Patterns in the distribution of bone consistent with osteosclerosis suggest that these animals probably hada fast-swimming ecology. Although these results are consistent with the histology in anatomically convergent taxa, it will be necessary to make additional sections from the mid-diaphysis in order to assign their ecology.

  6. Past, present and future formation of groundwater resources in northern part of Baltic Artesian Basin

    Science.gov (United States)

    Marandi, A.; Vallner, L.; Vaikmae, R.; Raidla, V.

    2012-04-01

    Cambrian-Vendian Aquifer System (CVAS) is the deepest confined aquifer system used for water consumption in northern part of Baltic Artesian Basin (BAB). A regional groundwater flow and transport model (Visual Modflow) was used to investigate the paleohydrogeological scientific and contemporary management problems of CVAS. The model covers the territory of Estonia and its close surrounding, all together 88,000 km2 and includes all main aquifers and aquitards from ground surface to as low as the impermeable part of the crystalline basement. Three-dimensional distribution of groundwater heads, flow directions, velocities, and rates as well as transport and budget characteristics were simulated by the model. Water composition was changed significantly during the last glaciations.Strongly depleted O and H stable isotope composition, absence of 3H and low radiocarbon concentration are the main indicators of glacial origin of groundwater in the Cambrian-Vendian aquifer in northern Estonia. The noble gas analyses allowed concluding, that palaeorecharge took place at temperatures around the freezing point. While in North Estonia, most of water was changed by glacial melt water, high salinity water is till preserved in Southern part of Estonia.First results of modeling suggest that during the intrusion period lasting 7.3-9.3 ka the front of glacial thaw water movement had southeast direction and reachedto 180-220 kmfrom CVAS outcrop in Baltic Sea. Confining layer of CVAS is cut through by deep buried valleys in several places in North Estonia making possible for modern precipitation to infiltrate into aquifer system in present day. In case of natural conditions, the water pressure of CVAS is few meters above sea level and most of valleys act as discharge areas for aquifers system. Two regional depression ones have formed in North Estonia as a result of groundwater use from CVAS. Water consumption changes the natural groundwater gradient, flow direction and thereforerecharge

  7. Review of the Upper Jurassic-Lower Cretaceous stratigraphy in Western Cameros basin, Northern Spain

    DEFF Research Database (Denmark)

    Vidal, Maria del Pilar Clemente

    2010-01-01

    The Upper Jurassic-Lower Cretaceous stratigraphy of the Cameros basin has been reviewed. In Western Cameros the stratigraphic sections are condensed but they have a parallel development with the basin depocentre and the same groups have been identified. The Tera Group consists of two formations: ...

  8. Palynological and sedimentary analysis of the Igarapé Ipiranga and Querru 1 outcrops of the Itapecuru Formation (Lower Cretaceous, Parnaíba Basin), Brazil

    Science.gov (United States)

    Ferreira, Neila N.; Ferreira, Elizabete P.; Ramos, Renato R. C.; Carvalho, Ismar S.

    2016-03-01

    The siliciclastic sediments of the Itapecuru Formation occur in a large area of the Parnaíba Basin and its deposits crop out along the Itapecuru River, in Maranhão State, northern Brazil. The palynological analysis of the Igarapé Ipiranga and Querru 1 outcrops strata yields a rich and diversified data. The presence of index-palynofloras in assemblages allows the identification of the Complicatisaccus cearensis Zone, of Late Aptian-Early Albian age. Terrestrial palynomorphs are abundant in the assemblages, being represented by bryophytes and pteridophytes, especially perisporate trilete spores (Crybelosporites and Perotrilites), and gymnosperms and angiosperms (Afropollis and Elaterosporites). The composition of palynological assemblages suggests the presence of moist soils for both outcrops. Acritarchs were recovered in the Querru 1 outcrop, which suggest a marine setting supporting a tidal flat environment indicated by facies associations. Furthermore, reworked Paleozoic palynomorphs were observed in the Querru 1 outcrop. The microflora from Igarapé Ipiranga outcrop suggests terrestrial environment corroborating with floodplain environment indicated by facies association.

  9. Bryophyte and pteridophyte spores and other palynomorphs in quaternary marine sediments from Campos Basin, southeastern Brazil: Core BU-91-GL-05

    Directory of Open Access Journals (Sweden)

    Aline Gonçalves de Freitas

    2015-06-01

    Full Text Available This paper presents morphological descriptions and ecological data of cryptogam spores and other non-pollen palynomorphs from Quaternary sediments of Campos Basin, Rio de Janeiro, SE Brazil. The ages were derived from biostratigraphy of planktonic foraminifers and two radiocarbon dates, and suggest that sediment deposition started in the last 140,000 years BP. Thirty different types of palynomorphs were identified, described, and photographed: two bryophyte spores (sensu lato; 21 pteridophyte spores; four freshwater microalgae; onePseudoschizaea; and two microfungi. Some of the identified spores (Sphagnum, Blechnum, Cyatheaceae, Dennstaedtiaceae, Lycopodiella, Microgramma, Polypodium, Acrostichum, Pityrogramma, and Lygodium are related to the modern flora found on the northern coast of Rio de Janeiro State, at the Restinga of Jurubatiba, from vegetation types such as shrub swamp/coastal swamp formation, seasonally flooded forest, Clusia and Ericaceae woods, and disturbed vegetation. The freshwater microalgae and the microfungi are also presently recorded from the coastal lagoons of this region. The high spore concentration in slope sediments reflects the intense terrigenous influx, caused by a relative low sealevel during glacial stages. Palynological analysis suggests the presence of taxa from flooded forests and humid areas in the coastal plain during glacial and interglacial stages of the Late Pleistocene.

  10. Structure of the Wagner Basin in the Northern Gulf of California From Interpretation of Seismic Reflexion Data

    Science.gov (United States)

    Gonzalez, M.; Aguilar, C.; Martin, A.

    2007-05-01

    The northern Gulf of California straddles the transition in the style of deformation along the Pacific-North America plate boundary, from distributed deformation in the Upper Delfin and Wagner basins to localized dextral shear along the Cerro Prieto transform fault. Processing and interpretation of industry seismic data adquired by Petroleos Mexicanos (PEMEX) allow us to map the main fault structures and depocenters in the Wagner basin and to unravel the way strain is transferred northward into the Cerro Prieto fault system. Seismic data records from 0.5 to 5 TWTT. Data stacking and time-migration were performed using semblance coefficient method. Subsidence in the Wagner basin is controlled by two large N-S trending sub-parallel faults that intersect the NNW-trending Cerro Prieto transform fault. The Wagner fault bounds the eastern margin of the basin for more than 75 km. This fault dips ~50° to the west (up to 2 seconds) with distinctive reflectors displaced more than 1 km across the fault zone. The strata define a fanning pattern towards the Wagner fault. Northward the Wagner fault intersects the Cerro Prieto fault at 130° on map view and one depocenter of the Wagner basin bends to the NW adjacent to the Cerro Prieto fault zone. The eastern boundary of the modern depocenter is the Consag fault, which extends over 100 km in a N-S direction with an average dip of ~50° (up to 2s) to the east. The northern segment of the Consag fault bends 25° and intersects the Cerro Prieto fault zone at an angle of 110° on map view. The acoustic basement was not imaged in the northwest, but the stratigraphic succession increases its thickness towards the depocenter of the Wagner basin. Another important structure is El Chinero fault, which runs parallel to the Consag fault along 60 km and possibly intersects the Cerro Prieto fault to the north beneath the delta of the Colorado River. El Chinero fault dips at low-angle (~30°) to the east and has a vertical offset of about 0

  11. Evaluation and prediction of oil biodegradation: a novel approach integrating geochemical and basin modeling techniques in offshore Brazil

    Energy Technology Data Exchange (ETDEWEB)

    Baudino, Roger [YPF S.A. (Argentina); Santos, Glauce Figueiredo dos; Losilla, Carlos; Cabrera, Ricardo; Loncarich, Ariel; Gavarrino, Alejandro [RepsolYPF do Brasil, Sao Paulo, SP (Brazil)

    2008-07-01

    Oil fields accounting for a large portion of the world reserves are severely affected by biological degradation. In Brazil, giant fields of the Campos Basin are producing biodegraded oils with widely variable fluid characteristics (10 to 40 deg API) and no apparent logical distribution nor predictability. Modern geochemical techniques allow defining the level of biodegradation. When original (non-degraded) oil samples and other with varying degradation level are available it might be possible to define a distribution trend and to relate it to present day geological factors such as temperature and reservoir geometry. However, other critical factors must be taken into account. But most of all, it is fundamental to have a vision in time of their evolution. This can only be achieved through 3D Basin Models coupled with modern visualization tools. The multi-disciplinary work-flow described here integrates three-dimensional numerical simulations with modern geochemical analyses. (author)

  12. Susceptibility and compatibility of Biomphalaria tenagophila from the Río de la Plata basin with Schistosoma mansoni from Brazil.

    Science.gov (United States)

    Borda, Carlos Edgardo; Rea, María Josefa F

    2010-07-01

    Schistosomiasis has expanded to southern parts of Brazil. Between 2005-2007 the dispersion and the proliferation of Biomphalaria tenagophila was verified in the province of Corrientes near the Brazilian border. In order to study the possibility that schistosomiasis might spread into the basins of the Paraná and Uruguay Rivers, 440 B. tenagophila collected from 10 populations groups were experimentally exposed to infection with Schistosoma mansoni of the SJ2 strain. Snails from five localities were susceptible. Frandsen's index (TCP/100) shows that those snails from Mirungá (11%), Aguacerito (2%) and Curupicay (2%) were Class I and not very compatible. Meanwhile, snails from Copra (6%) and Pay-Ubre (22%), in the Paraná River basin, were Class II and poorly compatible.

  13. Hydrogeochemistry and stable isotopes of ground and surface waters from two adjacent closed basins, Atacama Desert, northern Chile

    Science.gov (United States)

    Alpers, Charles N.; Whittemore, D.O.

    1990-01-01

    The geochemistry and stable isotopes of groundwaters, surface waters, and precipitation indicate different sources of some dissolved constituents, but a common source of recharge and other constituents in two adjacent closed basins in the Atacama Desert region of northern Chile (24??15???-24??45???S). Waters from artesian wells, trenches, and ephemeral streams in the Punta Negra Basin are characterized by concentrations of Na>Ca>Mg and Cl ???SO4, with TDS Mg ??? Ca and SO4 > Cl, with TDS also Mg ??? Ca and SO4 > Cl, but with TDS up to 40 g/l. The deep mine waters have pH between 3.2 and 3.9, and are high in dissolved CO2 (??13 C = -4.8%PDB), indicating probable interaction with oxidizing sulfides. The deep mine waters have ??18O values of ???-1.8%.compared with values < -3.5??? for other Hamburgo Basin waters; thus the mine waters may represent a mixture of meteoric waters with deeper "metamorphic" waters, which had interacted with rocks and exchanged oxygen isotopes at elevated temperatures. Alternatively, the deep mine waters may represent fossil meteoric waters which evolved isotopically along an evaporative trend starting from values quite depleted in ??18O and ??Dd relative to either precipitation or shallow groundwaters. High I/Br ratios in the Hamburgo Basin waters and La Escondida mine waters are consistent with regionally high I in surficial deposits in the Atacama Desert region and may represent dissolution of a wind-blown evaporite component. Rain and snow collected during June 1984, indicate systematic ??18O and ??D fractionation with increasing elevation between 3150 and 4180 m a.s.l. (-0.21??.??18O and -1.7??.??D per 100 m). Excluding the deep mine waters from La Escondida, the waters from the Hamburgo and Punta Negra Basins have similar ??D and ??18O values and together show a distinct evaporative trend (??D = 5.0 ??18O - 20.2). Snowmelt from the central Andes Cordillera to the east is the most likely source of recharge to both basins. Some of the

  14. Fish fauna from Sapucaí-Mirim River, tributary of Grande River, upper Paraná River basin, Southeastern Brazil

    OpenAIRE

    Oliveira,Alexandre Kannebley de; Garavello,Julio Cesar; Cesario,Vinicius Vendramini; Cardoso,Rodrigo Torres

    2016-01-01

    The fish species composition of Sapucaí-Mirim River is herein reported and discussed in the faunistic context of Grande and Paranaíba river basins, both formers of the Paraná River. The Sapucaí-Mirim is an important tributary of this hydrographic system, flowing to the left bank of Grande River in a region occupied by the reservoir of the Porto Colombia hydroelectric power plant, at São Paulo state northeastern region, in southeastern Brazil. The poorly known fish diversity of the Sapucaí-Mir...

  15. Crustal structure beneath the Paleozoic Parnaíba Basin revealed by airborne gravity and magnetic data, Brazil

    Science.gov (United States)

    de Castroa, David L.; Fuck, Reinhardt A.; Phillips, Jeffrey D.; Vidotti, Roberta M.; Bezerra, Francisco H. R.; Dantas, Elton L.

    2014-01-01

    The Parnaíba Basin is a large Paleozoic syneclise in northeastern Brazil underlain by Precambrian crystalline basement, which comprises a complex lithostructural and tectonic framework formed during the Neoproterozoic–Eopaleozoic Brasiliano–Pan African orogenic collage. A sag basin up to 3.5 km thick and 1000 km long formed after the collage. The lithologic composition, structure, and role in the basin evolution of the underlying basement are the focus of this study. Airborne gravity and magnetic data were modeled to reveal the general crustal structure underneath the Parnaíba Basin. Results indicate that gravity and magnetic signatures delineate the main boundaries and structural trends of three cratonic areas and surrounding Neoproterozoic fold belts in the basement. Triangular-shaped basement inliers are geophysically defined in the central region of this continental-scale Neoproterozoic convergence zone. A 3-D gravity inversion constrained by seismological data reveals that basement inliers exhibit a 36–40.5 km deep crustal root, with borders defined by a high-density and thinner crust. Forward modeling of gravity and magnetic data indicates that lateral boundaries between crustal units are limited by Brasiliano shear zones, representing lithospheric sutures of the Amazonian and São Francisco Cratons, Tocantins Province and Parnaíba Block. In addition, coincident residual gravity, residual magnetic, and pseudo-gravity lows indicate two complex systems of Eopaleozoic rifts related to the initial phase of the sag deposition, which follow basement trends in several directions.

  16. Saghro Group in the Ougnat Massif (Morocco), an evidence for a continuous Cadomian basin along the northern West African Craton

    Science.gov (United States)

    Michard, André; Soulaimani, Abderrahmane; Ouanaimi, Hassan; Raddi, Youssef; Aït Brahim, Lahsen; Rjimati, Ech-Cherki; Baidder, Lahssen; Saddiqi, Omar

    2017-03-01

    The Saghro Group (SG) is a folded, low-grade volcano-sedimentary series up to 8 km thick that crops out within and to the north of the Pan-African suture zone in the central and eastern Anti-Atlas. Here we describe the SG of the Ougnat inliers that are exposed in the easternmost Anti-Atlas beneath the unconformable, Late Ediacaran Ouarzazate Group (OZG) volcanic rocks. The Ougnat SG mostly consists of volcaniclastic greywackes accumulated in a peritidal-to-shallow basin. The basin infilling was deformed by NNE-trending, mostly upright folds with axial-planar slaty cleavage and low-grade metamorphism. The deformed SG rocks were intruded by the ∼550 Ma Mellab hypovolcanic granodiorite. The latter also crosscuts the lowest OZG rocks that are dated to 574-571 Ma in the western Saghro region. The SG rocks that form the Siroua and Saghro inliers have an oldest age of 620-610 Ma and were folded at ∼610-580 Ma at the onset of the Cadomian orogenic events. We show that the SG rocks are similar to the ;Série verte; (SV) rocks that are exposed in the Ougarta and western Hoggar east of the Pan-African suture. We infer that the SG and SV rocks accumulated in a same, continuous basin that was bounding the West African Craton to the north and the east. This strongly subsiding basin formed close to a volcanic arc and was folded during the last Pan-African synmetamorphic events. Fold orientation and age of folding differ however along the edge of the West African Craton. The orogenic greywackes that form the remnants of the SG-SV basin thus constitute a precious record of the diachronic Cadomian event s.l. along the West African Craton northern margin.

  17. Hydrological application of the INCA model with varying spatial resolution and nitrogen dynamics in a northern river basin

    Directory of Open Access Journals (Sweden)

    K. Rankinen

    2002-01-01

    Full Text Available As a first step in applying the Integrated Nitrogen model for CAtchments (INCA to the Simojoki river basin (3160 km2, this paper focuses on calibration of the hydrological part of the model and nitrogen (N dynamics in the river during the 1980s and 1990s. The model application utilised the GIS land-use and forest classification of Finland together with a recent forest inventory based on remote sensing. In the INCA model, the Hydrologically Effective Rainfall (HER is used to drive the water flow and N fluxes through the catchment system. HER was derived from the Watershed Simulation and Forecast System (WSFS. The basic component of the WSFS is a conceptual hydrological model which simulates runoff using precipitation, potential evapotranspiration and temperature data as inputs. Spatially uniform, lumped input data were calculated for the whole river basin and spatially semi-distributed input data were calculated for each of the nine sub-basins. When comparing discharges simulated by the INCA model with observed values, a better fit was obtained with the semi-distributed data than with the spatially uniform data (R2 0.78 v. 0.70 at Hosionkoski and 0.88 v. 0.78 at the river outlet. The timing of flow peaks was simulated rather well with both approaches, although the semi-distributed input data gave a more realistic simulation of low flow periods and the magnitude of spring flow peaks. The river basin has a relatively closed N cycle with low input and output fluxes of inorganic N. During 1982-2000, the average total N flux to the sea was 715 tonnes yr–1, of which 6% was NH4-N, 14% NO3-N, and 80% organic N. Annual variation in river flow and the concentrations of major N fractions in river water, and factors affecting this variation are discussed. Keywords: northern river basin, nitrogen, forest management, hydrology, dynamic modelling, semi-distributed modelling

  18. Improved Thermal Conductivity and Heat Flow for the Northern Denver Basin

    Science.gov (United States)

    Brokaw, Casey

    The Denver Basin is one of the most prodigious oil and gas producing basins in the Western United States, however, the data on the thermal properties of this basin, and in particular, deeper (Cretaceous) formations where significant hydrocarbons exist are sparse. To improve our understanding of thermal properties of Cretaceous sediments within the Denver Basin, I collected, processed, analyzed, and interpreted thermal conductivity on 73 core samples from the Niobrara Formation, Codell Sandstone, Greenhorn Limestone, Dakota and overlying Tertiary White River Formation. Conductivity values measured using a high-accuracy ( 30%). A clear inverse relationship exists between thermal conductivity and measured gamma ray log intensity: conductivity can be estimated to within 20% using only gamma ray logs in Cretaceous sediments in this Basin. Combining these new thermal conductivity measurements with equilibrium temperature-depth logs, I generated six high-fidelity heat flow measurements for the Denver Basin. From this, I produce two temperature-depth cross-sections transecting the Wattenberg oil field. The new cross sections indicate anomalously high heat flow values in the Wattenberg Field (82 mWm-2), and more tightly constrain temperature and conductivity below the Denver Basin. I briefly outlines why anomalously high heat flow exists in the Wattenberg field; a topic of future study.

  19. Fishing activity in Northern Rio de Janeiro State (Brazil and its relation with small cetaceans

    Directory of Open Access Journals (Sweden)

    Ana Paula Madeira Di Beneditto

    1998-01-01

    Full Text Available Research on fishing activity at Atafona village, in Northern Rio de Janeiro, Brazil (21°35'S, was carried out between 1987-96 for the purpose of relating it to the accidental capture of small cetaceans and of estimating the relationship between fishing activity and the diet of small cetaceans. Data on fishing operations were obtained at the cold storage plants management, from interviews with fishermen and personal observations. The most representative fishing resources were Xyphopenaeus kroyeri, Micropogonias furnieri, Carcharhinus plumbeus, C. acronotus,and Rhizoprionodon porosus. Gillnets are responsible for the accidental capture of small cetaceans in the region, mainly Pontoporia blainvillei and Sotalia fluviatilis (marine form. Four types of gillnets that are used on the region ("minjuada", "sarda", "caçoá" and "pescadinha" were dangerous to these species because they are placed in their preferred habitat. There is no competition between fishermen and small cetaceans due to the selection in the capture of commercialized fishesInvestigação sobre a atividade pesqueira na localidade de Atafona, Norte do Rio de Janeiro, Brasil (21º25`S, foi conduzida entre 1987-96 com o objetivo de relacioná-la com a captura acidental e a dieta dos pequenos cetáceos. Dados sobre as operações pesqueiras foram obtidos na administração dos entrepostos de pesca, através de entrevistas com pescadores e observações pessoais. Os recursos pesqueiros mais representativos foram Xyphopenaeus kroyeri, Micropogonias furnieri, Carcharhinus plumbeus, C. acronotus, and Rhizoprionodon porosus. As redes de espera são responsáveis pela captura acidental de pequenos cetáceos na região, principalmente de Pontoporia blainvillei e Sotalia fluviatilis (forma marinha. Quatro tipos de redes de espera que são usadas na região ("minjuada", "sarda", "caçoá" and "pescadinha" foram mais perigosas para essas espécies pois são colocadas no seu hábitat preferencial

  20. First record of non-native hybrid catfish Pseudoplatystoma reticulatum × Leiarius marmoratus in the Upper Paraná River basin, Brazil.

    Science.gov (United States)

    Yabu, M H S; Vidotto-Magnoni, A P; Casimiro, A C R; Garcia, D A Z; Costa, A D A; Prado, F D D; Porto-Foresti, F; Orsi, M L

    2018-01-01

    The aim of this study is to report the presence of a three non-native hybrid long-whiskered catfishes (family Pimelodidae) in the Upper Paraná River basin, Brazil. Genetic analyses demonstrated that the three presumptive hybrids were a result of the crossbreeding of Pseudoplatystoma reticulatum (central Amazonas River basin and Lower Paraná River) and Leiarius marmoratus (Amazonas, Essequibo and Orinoco rivers), producing a hybrid commonly known in Brazil as cachandiá. The potential threat to biodiversity, due to possible genetic contamination, competition and predation of wild stocks, of such artificially produced hybrid fishes is discussed. © 2017 The Fisheries Society of the British Isles.

  1. Hydrogeology, groundwater levels, and generalized potentiometric-surface map of the Green River Basin lower Tertiary aquifer system, 2010–14, in the northern Green River structural basin

    Science.gov (United States)

    Bartos, Timothy T.; Hallberg, Laura L.; Eddy-Miller, Cheryl

    2015-07-14

    In cooperation with the Bureau of Land Management, groundwater levels in wells located in the northern Green River Basin in Wyoming, an area of ongoing energy development, were measured by the U.S. Geological Survey from 2010 to 2014. The wells were completed in the uppermost aquifers of the Green River Basin lower Tertiary aquifer system, which is a complex regional aquifer system that provides water to most wells in the area. Except for near perennial streams, groundwater-level altitudes in most aquifers generally decreased with increasing depth, indicating a general downward potential for groundwater movement in the study area. Drilled depth of the wells was observed as a useful indicator of depth to groundwater such that deeper wells typically had a greater depth to groundwater. Comparison of a subset of wells included in this study that had historical groundwater levels that were measured during the 1960s and 1970s and again between 2012 and 2014 indicated that, overall, most of the wells showed a net decline in groundwater levels.

  2. Metal and trace element sediment assessment from Guarapiranga reservoir, Alto Tiete Basin, Sao Paulo, SP, Brazil

    International Nuclear Information System (INIS)

    Guimaraes, Guilherme Moura

    2011-01-01

    The Guarapiranga Reservoir, located in Sao Paulo metropolitan region, Brazil, is responsible for supplying about 20% of the entire population's water needs of this region or approximately 3.7 million people. However, this system has shown significant degradation in water quality, due to untreated domestic sewage and industrial effluents. In this study sediment samples were collected at five points along the reservoir and total concentration of some major (Fe, K and Na), trace (As, Ba, Br, Co, Cr, Cs, Hf, Hg, Rb, Sb, Sc, Ta, Tb, Th, U, V and Zn) and rare earth (Ce, Eu, La, Lu, Nd, Sm, Tb and Yb) elements were determined by instrumental neutron activation analysis (INAA). By inductively coupled plasma optical emission spectrometry (ICP OES) the concentrations of Al, Ba, Be, Ca, Co, Cr, Cu, Fe, K, Li, Mg, Mn, Na, Ni, Pb, Ti, V e Zn were determined after digestion procedure following US EPA 3051 methodology. The concentrations of metals Cd and Pb were determined by graphite furnace atomic absorption spectrometry (GFAAS) and total Hg by cold vapor atomic absorption spectrometry (CVAAS). Methodology validation according to precision and accuracy was performed by reference materials analyses for the three different analytical techniques used. Multielemental results obtained by INAA were compared to NASC (North American Shale Composite), Upper Continental Crust (UCC) and soil from Guarapiranga park values. The Enrichment Factor (EF) and Geo accumulation Index (Igeo) were also evaluated for these data. Metal concentration results by ICP OES and AAS in the samples were compared to the TEL and PEL oriented values established by the Canadian Council of Ministers of the Environment and also adopted by CETESB (Environmental Protection Agency of the Sao Paulo State). The results were also compared to regional reference values (VRR) of limnic sediments from the Alto Tiete Basin. From these data an assessment of metal and trace element accumulated in the sediments from the

  3. Analysis of subsurface temperature data to quantify groundwater recharge rates in a closed Altiplano basin, northern Chile

    Science.gov (United States)

    Kikuchi, C. P.; Ferré, T. P. A.

    2017-01-01

    Quantifying groundwater recharge is a fundamental part of groundwater resource assessment and management, and is requisite to determining the safe yield of an aquifer. Natural groundwater recharge in arid and semi-arid regions comprises several mechanisms: in-place, mountain-front, and mountain-block recharge. A field study was undertaken in a high-plain basin in the Altiplano region of northern Chile to quantify the magnitude of in-place and mountain-front recharge. Water fluxes corresponding to both recharge mechanisms were calculated using heat as a natural tracer. To quantify in-place recharge, time-series temperature data in cased boreholes were collected, and the annual fluctuation at multiple depths analyzed to infer the water flux through the unsaturated zone. To quantify mountain-front recharge, time-series temperature data were collected in perennial and ephemeral stream channels. Streambed thermographs were analyzed to determine the onset and duration of flow in ephemeral channels, and the vertical water fluxes into both perennial and ephemeral channels. The point flux estimates in streambeds and the unsaturated zone were upscaled to channel and basin-floor areas to provide comparative estimates of the range of volumetric recharge rates corresponding to each recharge mechanism. The results of this study show that mountain-front recharge is substantially more important than in-place recharge in this basin. The results further demonstrate the worth of time-series subsurface temperature data to characterize both in-place and mountain-front recharge processes.

  4. Structural characteristics of an active fold-and-thrust system in the southeastern Atacama Basin, northern Chile

    Science.gov (United States)

    Lin, Yen-Sheng; Chuang, Yi-Rung; Shyu, J. Bruce H.; González, Gabriel; Shen, Chuan-Chou; Lo, Ching-Hua; Liou, Ya-Hsuan

    2016-08-01

    The western South American margin is one of the most active plate boundaries in the world. Using various remote sensing data sets, we mapped the neotectonic characteristics of an area at the southeastern corner of the Atacama Basin, northern Chile, in the Andean forearc. There, one major N-S trending ridge is clearly visible both in the satellite images and in the field. This ridge reaches 250 m above the basin floor in its middle part and is asymmetrical, with a steep eastern slope and a much gentler western slope. The geometry of the ridge indicates that it formed as an asymmetrical anticline. This anticline is likely formed as a shear fault-bend fold, with a major décollement at a depth of about 2.5 km in the Naranja Formation. We suggest that this décollement is a major structure of the Atacama Basin area. From the ages of the ignimbrites and lake deposits that were deformed by this anticline, we obtained a long-term shortening rate of the major underlying structure at about 0.2 mm/yr. This thin-skinned fold-and-thrust system appears to be active since at least about 3 Ma, and could be as long as since middle Miocene. Therefore, crustal structures may play important roles in the Neogene development of the western Andean margin.

  5. Provenance evolution of the Jurassic northern Qaidam Basin (West China) and its geological implications: evidence from detrital zircon geochronology

    Science.gov (United States)

    Yu, Long; Xiao, Ancheng; Wu, Lei; Tian, Yuntao; Rittner, Martin; Lou, Qianqian; Pan, Xiaotian

    2017-03-01

    The Jurassic system is the major hydrocarbon source rock and of crucial importance for understanding the Mesozoic intra-continental tectonics in West China. This paper presents systematic detrital zircon geochronology of the Jurassic outcropping at the Dameigou locality in the northern Qaidam Basin, and reports 1000 single-grain U-Pb zircon ages that have implications for the provenance, the corresponding basin property as well as the tectonic setting of West China during Jurassic. Zircon ages exhibit two major clusters at 250 and 2400 Ma whereas two minor clusters at 450 and 850 Ma, suggesting primary sources from the East Kunlun Shan and Oulongbuluke Block, secondary sources from the North Qaidam UHP belt and South Qilian Shan. Combined with observation of lithology and sedimentary facies, two rifting periods were inferred in the earliest Jurassic and the early stage of the Middle Jurassic, respectively, accompanied by further extension throughout the Jurassic. Our results do not support a foreland basin related to the Jurassic southward thrusting of the South Qilian Shan, but favor that the Mesozoic intra-continental tectonics in West China were characterised by pulsed responses to specific collisions rather than a persisting contractional setting during Jurassic period.

  6. Raft tectonics in northern Campos Basin; Tectonica de jangada (raft tectonics) na area norte da Bacia de Campos

    Energy Technology Data Exchange (ETDEWEB)

    Castro, Marilia R. de [Universidade Estadual do Norte Fluminense (UENF), Campos dos Goytacases, RJ (Brazil)]|[PETROBRAS, Macae, RJ (Brazil). Unidade de Negocio da Bacia de Campos; Fugita, Adhemar M. [Universidade do Estado, Rio de Janeiro, RJ (Brazil). Programa de Recursos Humanos da ANP

    2004-07-01

    In the northern area of Campos Basin salt gliding/spreading processes promoted the break-up and transport of Cretaceous and Tertiary rocks overlying the evaporites. This process is known as raft tectonics, and it represents the most extreme form of thin-skinned extension above the salt decollement surface. Three distinct geotectonic domains were recognized that formed in response to the raft tectonics. The first one, confined to the shallower shelf portion of the basin, is characterized by minor extension (pre-raft domain), probably because of small salt thickness and low gradient. In the second domain (or disorganized rafts domain), located in distal platformal and slope areas, seismic sections show the occurrence of blocks or rafts with angular shapes, sometimes imbricated and frequently discontinuous. In the third domain, or domain of organized rafts, located in bacinal region, seismic sections show a more continuous raft pattern, often folded because of salt compression in the distal portions of the basin. The main purposes of this work is to characterize these three tectonic domains distinguished by raft tectonics, as well as their importance in hydrocarbon accumulations in calcarenites. (author)

  7. Genetic structure of lake whitefish, Coregonus clupeaformis, populations in the northern main basin of Lake Huron

    Science.gov (United States)

    Stott, Wendylee; Ebener, Mark P.; Mohr, Lloyd; Schaeffer, Jeff; Roseman, Edward F.; Harford, William J.; Johnson, James E.; Fietsch, Cherie-Lee

    2012-01-01

    Genetic analysis of spawning lake whitefish (Coregonus clupeaformis) from six sites in the main basin of Lake Huron was conducted to determine population structure. Samples from fisheryindependent assessment surveys in the northwest main basin were analyzed to determine the relative contributions of lake whitefish genetic populations. Genetic population structure was identified using data from seven microsatellite DNA loci. One population was identified at Manitoulin Island, one to two were observed in the east-central main basin (Fishing Island and Douglas Point), and one to two populations were found in the northwest (Thunder Bay and Duncan Bay). The genetic identity of collections from Duncan Bay and Thunder Bay was not consistent among methods used to analyze population structure. Low genetic distances suggested that they comprised one population, but genic differences indicated that they may constitute separate populations. Simulated data indicated that the genetic origins of samples from a mixed-fishery could be accurately identified, but accuracy could be improved by incorporating additional microsatellite loci. Mixture analysis and individual assignment tests performed on mixed-stock samples collected from the western main basin suggested that genetic populations from the east-central main basin contributed less than those from the western main basin and that the proportional contribution of each baseline population was similar in each assessment sample. Analysis of additional microsatellite DNA loci may be useful to help improve the precision of the estimates, thus increasing our ability to manage and protect this valuable resource.

  8. Late-Miocene thrust fault-related folding in the northern Tibetan Plateau: Insight from paleomagnetic and structural analyses of the Kumkol basin

    Science.gov (United States)

    Lu, Haijian; Fu, Bihong; Shi, Pilong; Xue, Guoliang; Li, Haibing

    2018-05-01

    Constraints on the timing and style of the Tibetan Plateau growth help spur new understanding of the tectonic evolution of the northern Tibetan Plateau and its relation to the India-Asia continental collision. In this regard, records of tectonic deformation with accurate ages are urgently needed, especially in regions without relevant studies. The Kumkol basin, located between two major intermontane basins (the Hoh Xil and Qaidam basins), may hold clues to how these major basins evolve during the Cenozoic. However, little has been known about the exact ages of the strata and tectonic deformation of the basin. Herein, detailed paleomagnetic and structural studies are conducted on the southern Baiquanhe section in the central Kumkol basin, northern Tibetan Plateau. The magnetostratigraphic study indicates that the southern Baiquanhe section spans a time interval of 8.2-4.2 Ma. Well-preserved growth strata date to 7.5 Ma, providing evidence for a significant thrust fault-related folding. This thrust-related folding has also been identified in the Tian Shan foreland and in the northern Tibetan Plateau, most likely implying a pulsed basinward deformation during the late Miocene.

  9. Relationship among local and functional factors in the development of denture stomatitis in denture wearers in northern Brazil

    Directory of Open Access Journals (Sweden)

    Lurdete Maria Rocha GAUCH

    Full Text Available OBJECTIVE: The aim of this study was to evaluate the relationship among functional and qualitative factors in the development of denture stomatitis (DS (according to Newton's classification in acrylic-based denture wearers residents from northern Brazil.MATERIAL AND METHOD: A total of 99 patients who wore partial or total acrylic resin-based upper dentures were included in this study. The subjects completed an epidemiological data form that includes the patient's gender, age, local factors (hygiene habits, remove denture to sleep, use of mouthwash, present condition of the denture, age of the denture and functional factors (vertical dimension at rest, vertical dimension of occlusion, occlusion, retention, and static and dynamic stability. To detect yeasts, samples were collected from the inner surface of the dentures and from the palatal mucosa in contact with it. Subsequently, the samples were cultured on Sabouraud dextrose agar, observing macro and microscopic characteristics.RESULT: In the present study, we did not find any significant relationship between the gender and disease onset. Based on the Newton classification, 36.3% of the patients presented with DS and 89.0% were colonized by yeasts; of these subjects, 50% had type I lesions, 33.3% had type II lesions, and 16.6% had type III lesions. All of the qualitative and local factors, except the use of mouthwash, were clinically relevant to the development of disease.CONCLUSION: Denture stomatitis in denture users in northern Brazil was multifactorial, involving local, functional and microbiological factors.

  10. Structural and geological analysis of the northern Pescadero basin: preliminary results based on the analysis of 2D multichannel seismic reflection profiles

    Science.gov (United States)

    Spelz, R. M.; Ramirez-Zerpa, N. A.; Gonzalez-Fernandez, A.; Yarbuh, I.; Contreras, J.

    2017-12-01

    The Pacific-North America plate boundary along the Gulf of California is characterized by an array of right-stepping, right-lateral, transform faults connecting a series of pull-apart basins distributed along the gulf axis. Altogether, these structures accommodate an oblique-divergent component of deformation characterizing the modern tectonic regime along the gulf. The northern Pescadero complex, in the southern Gulf of California, is one of the deepest and probably least studied transtensional fault-termination basins in the gulf. The complex is bounded to the north and south by Atl and Farallon transform faults, respectively, and consists of two asymmetric, rhomboidal-shaped, basins with a series of intrabasinal high-angle normal faults and ramps connecting their depocenters. In this study we present preliminary results derived from the processing and analysis of 400 km of seismic reflection profiles, collected in 2006 onboard the R/V Francisco de Ulloa in northern Pescadero, providing new insights into the geology and internal structure of the basin. Northern Pescadero is a deep and narrow basin characterized by a maximum sedimentary infill of 1 km, and depths to the basin floor exceeding 3500 m. Deformation is chiefly accommodated by an array of self-parallel half-graben structures that appear to grow towards the northern flank of the basin. Faults-scarps located farther from the deformation axis appear to be more degraded, suggesting a progressively younger age of the half-grabens near the basin's depocenter. Another important feature revealed in the seismic images is the lack of sediments on top of the crystalline basement that floors the narrow central portion of the basin. In this area the reflectors at the basin's floor show a pronounced increase in amplitude and coherence, indicating the emplacement of magmatic extrusions. Likewise, in those areas with the greater sediment infill, the occurrence of high-amplitude reflectors, located 150 m below the

  11. Biological and Genetic Characterization of Cryptosporidium spp. and Giardia duodenalis Isolates from Five Hydrographical Basins in Northern Portugal

    Science.gov (United States)

    Moreira, Maria João; Soares, Sónia; de Lurdes Delgado, Maria; Figueiredo, João; Magalhães, Elisabete Silva; Castro, António; Viana Da Costa, Alexandra; Correia da Costa, José Manuel

    2010-01-01

    To understand the situation of water contamination with Cryptosporidium spp. and Giardia spp. in the northern region of Portugal, we have established a long-term program aimed at pinpointing the sources of surface water and environmental contamination, working with the water-supply industry. Here, we describe the results obtained with raw water samples collected in rivers of the 5 hydrographical basins. A total of 283 samples were analyzed using the Method 1623 EPA, USA. Genetic characterization was performed by PCR and sequencing of genes 18S rRNA of Cryptosporidium spp. and β-giardin of Giardia spp. Infectious stages of the protozoa were detected in 72.8% (206 of 283) of the water samples, with 15.2% (43 of 283) positive for Giardia duodenalis cysts, 9.5% (27 of 283) positive for Cryptosporidium spp. oocysts, and 48.1% (136 of 283) samples positive for both parasites. The most common zoonotic species found were G. duodenalis assemblages A-I, A-II, B, and E genotypes, and Cryptosporidium parvum, Cryptosporidium andersoni, Cryptosporidium hominis, and Cryptosporidium muris. These results suggest that cryptosporidiosis and giardiasis are important public health issues in northern Portugal. To the authors' knowledge, this is the first report evaluating the concentration of environmental stages of Cryptosporidium and Giardia in raw water samples in the northern region of Portugal. PMID:20585525

  12. Diet and potential feeding overlap between Trichiurus lepturus (Osteichthyes: Perciformes and Pontoporia blainvillei (Mammalia: Cetacea in Northern Rio de Janeiro, Brazil

    Directory of Open Access Journals (Sweden)

    Vanessa T. Bittar

    2009-06-01

    Full Text Available This study describes the diet and assesses potential overlap in the feeding habits of Trichiurus lepturus Linnaeus, 1758 and Pontoporia blainvilleiGervais & D'Orbigny, 1844 in northern Rio de Janeiro, southeastern Brazil. Fishes were numerically dominant in both diets, followed by cephalopods for P. blainvillei and crustaceans for T. lepturus. Both predators move along similar coastal feeding areas in northern Rio de Janeiro, but our results indicate differences in their resource exploitation, what allows for their coexistence.

  13. Reservoir storage and hydrologic responses to droughts in the Paraná River basin, south-eastern Brazil

    Directory of Open Access Journals (Sweden)

    D. D. C. D. Melo

    2016-11-01

    Full Text Available Droughts are particularly critical for Brazil because of impacts on water supply and because most (70 % of its electricity is derived from hydroelectric generation. The Paraná basin (PB, a major hydroelectric producing region with 32 % (60 million people of Brazil's population, recently experienced the most severe drought since the 1960s, compromising the water supply for 11 million people in São Paulo. The objective of this study is to quantify linkages between meteorological and hydrological droughts based on remote sensing, modelling, and monitoring data using the Paraná River basin in south-eastern Brazil as a case study. Two major meteorological droughts were identified in the early 2000s and 2014, with precipitation 20–50 % below the long-term mean. Total water storage change estimated from the Gravity Recovery and Climate Experiment (GRACE satellites declined by 150 km3 between April 2011 and April 2015. Simulated soil moisture storage declined during the droughts, resulting in decreased runoff into reservoirs. As a result, reservoir storage decreased by 30 % relative to the system's maximum capacity, with negative trends ranging from 17 (May 1997–April 2001 to 25 km3 yr−1 (May 2011–April 2015. Storage in upstream reservoirs is mostly controlled by natural climate forcing, whereas storage in downstream reservoirs also reflects dam operations. This study emphasizes the importance of integrating remote sensing, modelling, and monitoring data to evaluate droughts and to establish a preliminary understanding of the linkages between a meteorological and hydrological drought for future management.

  14. Hydrological Responses to Changes in the Rainfall Regime are Less Pronounced in Forested Basins: an Analysis of Southern Brazil, 1975-2010

    Science.gov (United States)

    Chagas, V. B. P.; Chaffe, P. L. B.

    2017-12-01

    It is unknown to what extent the hydrological responses to changes in the rainfall regime vary across forested and non-forested landscapes. Southern Brazil is approximately 570000 km² and was naturally covered mostly by tropical and subtropical forests. In the last century, a large proportion of forests were replaced by agricultural activities. The rainfall regime has also changed substantially in the last decades. The annual rainfall, number and magnitude of extreme events, and number of non-rainy days have increased in most of the area. In this study, we investigated the changes in the regime of 142 streamflow gauges and 674 rainfall gauges in Southern Brazil, from 1975 to 2010. The changes in the regime were analyzed for forested basins (i.e., with more than 50% forest coverage) and non-forested basins (i.e., with less than 20% forest coverage). The area of the river basins ranged from 100 to 60000 km². We analyzed a total of six signatures that represent the regime, including annual averages, seasonality, floods, and droughts. The statistical trends of the signatures were calculated using the Mann-Kendall test and the Sen's slope. The results showed that the majority of basins with opposing signal trends for mean annual streamflow and rainfall are non-forested basins (i.e., basins with higher anthropogenic impacts). Forested basins had a lower correlation between trends in the streamflow and rainfall trends for the seasonality and the average duration of drought events. There was a lower variability in the annual maximum 1-day streamflow trends in the forested basins. Additionally, despite a decrease in the 31-day rainfall minima and an increase in the seasonality, in forested basins the 7-day streamflow minima increases were substantially larger than in non-forested basins. In summary, the forested basins were less responsive to the changes in the precipitation 1-day maxima, seasonality, number of dry days, and 31-day minima.

  15. A qualitative model of Riacho Fundo (DF, Brazil) water basin sustainability

    NARCIS (Netherlands)

    Salles, P.; Bredeweg, B.

    2009-01-01

    This paper presents a model aiming at supporting stakeholders to improve their understanding of the effects of land use changes using the Brazilian Riacho Fundo water basin as a case study. The paper makes two contributions: it presents a model about sustainability in a small tropical water basin,

  16. Impact of climate change and agricultural developments in the Taquari River basin, Brazil

    NARCIS (Netherlands)

    Querner, E.P.; Jonker, R.N.J.; Padovani, C.; Soriano, B.; Galdino, S.

    2005-01-01

    The Pantanal wetland is part of the Upper Paraguay River basin. The major driving force of the wetland system is the annual oscillation between dry and wet seasons. This study focussed on the Taquari basin, a tributary of the Paraguay River, where erosion takes place and parts of the river silt up,

  17. Provenance of Miocene Hinterland Basins in Ecuador: Implications for the Growth of Topographic Barriers in the Northern Andes

    Science.gov (United States)

    George, S. W. M.; Horton, B. K.; Vallejo, C.; Nogales, V.

    2017-12-01

    Establishment of the Eastern Cordillera of Ecuador as an Andean topographic barrier caused significant drainage reorganization, perhaps even as dramatic as the reversal of the Amazon River. Cenozoic growth of this barrier coincided with substantial increases in speciation rates in Andean and Amazonian environments. Situated in the Interandean Depression between the Eastern Cordillera and Western Cordillera of Ecuador, a series of well-preserved Miocene intermontane basins offer a unique opportunity to constrain the along-strike development of the flanking north-trending cordilleras as drainage divides in the Northern Andes. Here were provide detrital zircon U-Pb geochronological results for 17 samples from Ecuadorian hinterland basins (Cuenca, Giron-Santa Isabel, Nabón, Loja, and Vilcabamba), supplemented with measured sections in the Cuenca Basin, to provide insights on orogenic development of the cordilleras of Ecuador during the Miocene. In addition, we characterize the age distributions of basement units to more precisely determine sediment routing patterns through time. Detrital zircon geochronological data yields regional upsection trends throughout Miocene stratigraphic sections marked by: (1) middle Miocene deposits containing a strong syndepositional age peak, with a complementary Eocene-Oligocene peak in varying abundances, and subsidiary low-intensity Paleozoic-Proterozoic age peaks; and (2a) upper Miocene deposits maintaining similar trends to that of the middle Miocene, or (2b) upper Miocene deposits showing a dramatic shutoff of most Cenozoic populations and a switch to Paleozoic-Proterozoic sources, as seen in the Nabón and Loja basins. Syndepositional signatures reflect derivation from the magmatic arc, while varying inputs of Eocene-Oligocene zircons were derived from the Eocene-Oligocene volcanic rocks that comprise the effective basement of much of the Interandean Depression. The late Miocene shift to Paleozoic-Proterozoic sources observed in

  18. Fish, tributaries of middle Rio Mogi Guaçu, upper rio Paraná basin, São Paulo state, Southeastern Brazil

    OpenAIRE

    Oliveira, A. K.; Apone, F.; Birindelli, J. L. O.; Perez Jr, O. R.

    2009-01-01

    In this paper we compiled a fish list obtained from field collections performed between 1999 and 2005 in four tributaries of the Rio Mogi Guaçu, upper Rio Paraná basin, São Paulo State, Brazil. The collected fishes belong to six orders, 21 families, 60 genera and 82 species. The number of species represents 20 to 30% of the fish richness for the entire upper Rio Paraná basin according to recent estimates. A comparison to earlier published fish lists of the Rio Mogi Guaçu basin, chiefly from i...

  19. Fish, tributaries of middle Rio Mogi Guaçu, upper rio Paraná basin, São Paulo state, Southeastern Brazil

    Directory of Open Access Journals (Sweden)

    Oliveira, A. K.

    2009-01-01

    Full Text Available In this paper we compiled a fish list obtained from field collections performed between 1999 and 2005 infour tributaries of the Rio Mogi Guaçu, upper Rio Paraná basin, São Paulo State, Brazil. The collected fishes belong tosix orders, 21 families, 60 genera and 82 species. The number of species represents 20 to 30% of the fish richness forthe entire upper Rio Paraná basin according to recent estimates. A comparison to earlier published fish lists of the RioMogi Guaçu basin, chiefly from its main river channel, is also presented.

  20. New occurrences of fossilized feathers: systematics and taphonomy of the Santana Formation of the Araripe Basin (Cretaceous, NE, Brazil

    Directory of Open Access Journals (Sweden)

    Gustavo M.E.M. Prado

    2016-07-01

    Full Text Available Here we describe three fossil feathers from the Early Cretaceous Santana Formation of the Araripe Basin, Brazil. Feathers are the most complex multiform vertebrate integuments; they perform different functions, occurring in both avian and non-avian dinosaurs. Despite their rarity, fossil feathers have been found across the world. Most of the Brazilian feather fossil record comes from the Santana Formation. This formation is composed of two members: Crato (lake and Romualdo (lagoon; both of which are predominantly reduced deposits, precluding bottom dwelling organisms, resulting in exceptional preservation of the fossils. Despite arid and hot conditions during the Cretaceous, life teemed in the adjacency of this paleolake. Feathered non-avian dinosaurs have not yet been described from the Crato Member, even though there are suggestions of their presence in nearby basins. Our description of the three feathers from the Crato laminated limestone reveals that, despite the small sample size, they can be referred to coelurosaurian theropods. Moreover, based on comparisons with extant feather morphotypes they can be identified as one contour feather and two downy feathers. Despite their rareness and low taxonomic potential, fossilized feathers can offer insights about the paleobiology of its owners and the paleoecology of the Araripe Basin.

  1. Mechanical Erosion in a Tropical River Basin in Southeastern Brazil: Chemical Characteristics and Annual Fluvial Transport Mechanisms

    Directory of Open Access Journals (Sweden)

    Alexandre Martins Fernandes

    2012-01-01

    Full Text Available This study aims to evaluate the mechanical erosion processes that occur in a tropical river basin, located in the São Paulo state, southeastern Brazil, through the chemical characterization of fine suspended sediments and the transport mechanisms near the river mouth, from March 2009 to September 2010. The chemical characterization indicated the predominance of SiO2, Al2O3, and Fe2O3 and showed no significant seasonal influences on the major element concentrations, expressed as oxides. The concentration variations observed were related to the mobility of chemical species. The evaluation of the rock-alteration degree indicated that the physical weathering was intense in the drainage basin. The fine suspended sediments charge was influenced by the variation discharges throughout the study period. The solid charge estimate of the surface runoff discharge was four times higher in the rainy season than the dry season. The transport of fine suspended sediments at the Sorocaba River mouth was 55.70 t km−2 a−1, corresponding to a specific physical degradation of 37.88 m Ma−1, a value associated with the mechanical erosion rate that corresponds to the soil thickness reduction in the drainage basin.

  2. Oligocene-Miocene spreading history of the northern South Fiji Basin and implications for the evolution of the New Zealand plate boundary

    Science.gov (United States)

    Herzer, R. H.; Barker, D. H. N.; Roest, W. R.; Mortimer, N.

    2011-02-01

    A tectonic model of the evolution of the northern half of the South Fiji Basin, including the Minerva Triple Junction and Cook Fracture Zone, is developed from regional gravity, multibeam bathymetry, and a new interpretation of magnetic anomalies pinned to radiometric dates of oceanic crust in the basin. The geometry and age of a portion of the Minerva Triple Junction and the Cook-Minerva spreading center (the connection from the triple junction to the Cook Fracture Zone, which accommodated coeval opening of the Norfolk Basin), are resolved with multibeam bathymetry and magnetics. The South Fiji Basin opened from about 34 to 15 Ma in an anticlockwise sweep about an Euler pole located at the northern end of the present Lau Ridge. This rotation and a rigidly straight southeastward motion of the Three Kings Ridge were accommodated by the configuration of the triple junction changing from ridge-fault-fault to ridge-ridge-fault to ridge-ridge-ridge. During this evolution the southeastern arm of the system, the Julia Fracture Zone, underwent several transformations and the Cook-Minerva spreading center experienced repeated ridge jumps. The kinematics of the northern South Fiji Basin dictate, to a large extent, the evolution of the southern South Fiji Basin and the Norfolk Basin. This in turn leads to the interpretation of a complex trench-trench-double transform fault framework at the northern New Zealand margin, which explains most aspects of the geology, structure, and arc volcanic history of the margin and provides a radical new setting for the origin of the Northland Allochthon.

  3. Seasonal variation in the copepod community structure from a tropical Amazon estuary, Northern Brazil

    Directory of Open Access Journals (Sweden)

    André Magalhães

    2009-06-01

    Full Text Available The main purpose of this study was to investigate the seasonal variation of copepod community structure during the months of July, September and November 2003 (dry season and January, March and May 2004 (rainy season in the Curuçá estuary, northern Brazil. Samples were collected during neap tides via gentle 200µm mesh net tows from a small powerboat. Measurements of surface water conductivity were accomplished in situ using an electronic conductivimeter and salinity was later obtained through the transformation of the conductivity values. Salinity varied seasonally from 7.2 ± 0.1 to 39.2 ± 1.8 (mean ± standard deviation and was influenced mainly by differences in the amount of rainfall between the studied sampling seasons. In total, 30 Copepoda taxa were identified and Acartia tonsa comprised the most representative species throughout the entire studied period followed by Acartia lilljeborgii, Subeucalanus pileatus and Paracalanus quasimodo. In the present study, the density values, ecological indexes and copepod species dominance presented a clear seasonal pattern, showing that the studied area may be considered seasonally heterogeneous in relation to the investigated parameters.O presente estudo teve como objetivo principal avaliar a variação sazonal na estrutura da comunidade dos copépodos durante os meses de julho, setembro e novembro de 2003 (período seco e janeiro, março e maio de 2004 (período chuvoso no estuário do Curuçá, Norte do Brasil. As amostras foram coletadas nas marés de quadratura com auxílio de uma rede deplâncton com 200µm de abertura de malha, rebocada por meio de uma pequena embarcação a motor. As medidas de condutividade da água foram realizadas in situ utilizando-se um condutivímetro eletrônico e a salinidade foi posteriormente obtida através da transformação dos valores de condutividade. Os valores de salinidade variaram sazonalmente de 7, 2 ± 0, 1a 39, 2 ± 1, 8 (média ± desvio padr

  4. Effects of plant cover on the macrofauna of Spartina marshes in northern Brazil

    Directory of Open Access Journals (Sweden)

    Cesar França Braga

    2009-12-01

    Full Text Available Data on macrofauna density and diversity, and the height and density of Spartina brasiliensis, were obtained from salt marsh beds of a tropical estuary in northern Brazil. Sampling was carried out at four distinct times of the year, during the wet and dry seasons and in the transition periods between these. Sampling was also carried out in salt marshes of three size classes, small, medium and large. Variables were analyzed in relation to time of year and salt marsh size class. Overall, 46 taxa were found, with polychaetes, isopods and the gastropod Neritina virginea dominating the fauna. Macrofauna density and diversity were positively correlated with culm density, indicating a possible role in protection from predation. All the three variables were higher during the transitional periods between the wet and dry seasons and seasonal changes in rainfall, salinity and light availability may influence mortality, food availability and settlement of the macrofauna. There was no effect of salt marsh size on either the macrofauna or the vegetation.Dados sobre a densidade e diversidade da macrofauna em relação à altura e densidade de Spartina brasiliensis foram obtidos em bancos de marismas em um estuário tropical no norte do Brasil. A amostragem foi realizada quatro vezes durante um ano, nas estações chuvosa, seca e nos períodos de transição entre estas. A amostragem foi realizada em marismas de três classes de tamanho: pequeno, médio e grande. As variáveis foram analisadas em relação às estações do ano e das classes de tamanho das marismas. Um total de 46 táxons foram encontrados, com os poliquetos, isopodos e o gastropódo Neritina virginea dominando a fauna, resultados similares a estudos realizados em marismas no sul do Brasil. A densidade e a diversidade da macrofauna foram correlacionadas positivamente com a densidade de colmos da vegetação, indicando um possível papel da vegetação em proteção contra predação. Todas as

  5. Capture fishery in northern Todos os Santos Bay, tropical southwestern Atlantic, Brazil

    Directory of Open Access Journals (Sweden)

    Lucy Satiko Hashimoto Soares

    2011-03-01

    Full Text Available Information on marine and estuarine capture fishery activity in northern Todos os Santos Bay, northeastern Brazil, based on daily data collected between September 2003 and June 2005 is presented. Small-scale artisanal fishery in this area includes the use of traditional vessels both nonmotorized and motorized for locomotion, being carried out mainly by canoe or on foot, and involves many different kinds of gear, including gillnet, hook and line, seine nets, and traps. A total of 113 taxa were grouped into 77 resources, including 88 fish, 10 crustaceans, and 15 mollusks. Data on nominal catches of fish, crustaceans and mollusks are presented by month and location. A total of 345.2 tonnes of fishery resources were produced (285.4 tonnes of fish, 39.2 tonnes of fresh invertebrates, and 20.6 tonnes of processed invertebrates. Temporal variation in the fish catch was associated with the life cycle of the species or with the hydrographic conditions. The first-sale value of this catch amounted to around US$ 615,000.00, fishes representing 71.3% of it. A table of the average price of each fishery resource is presented. The results produced in this study may be considered a reference for future monitoring programs of fishery resources in the area.Informações sobre a atividade pesqueira extrativa da região norte da Baía de Todos os Santos, Bahia, nordeste do Brasil são apresentadas, baseadas em coleta diária de dados, realizada entre setembro de 2003 e junho de 2005. Trata-se de uma atividade extrativa artesanal, na qual são utilizadas embarcações tradicionais para o deslocamento ao local da extração. Em cada pescaria foram utilizadas várias artes, tais como rede de espera, linha e anzol, rede de cerco, armadilhas. Foram identificadas 113 categorias taxonômicas de peixes (88, crustáceos (10 e moluscos (15, arranjadas em 77 tipos de pescados comercializados. A produção total no período foi de 345,2 t (285.4 t de peixes, 39,2 t de

  6. Geochronological data from the Faxinal coal succession, southern Parana Basin, Brazil: A preliminary approach combining radiometric U-Pb dating and palynostratigraphy

    Energy Technology Data Exchange (ETDEWEB)

    Guerra-Sommer, M.; Cazzulo-Klepzig, M.; Menegat, R.; Formoso, M.L.L.; Basei, M.A.; Barboza, E.; Simas, M.W. [Universidade Federal do Rio Grande do Sul, Porto Alegre (Brazil)

    2008-03-15

    A radiometric zircon age of 285.4 {+-} 8.6 Ma (IDTIMS U-Pb) is reported from a tonstein layer interbedded with coal seams in the Faxinal coalfield, Rio Grande do Sul, Brazil. Calibration of palynostratigraphic data with the absolute age shows that the coal depositional interval in the southern Parana Basin is constrained to the Sakmarian. Consequently, the basal Gondwana sequence in the southern part of the basin should lie at the Carboniferous-Permian boundary, not within the Sakmarian as previously considered. The new results are significant for correlations between the Parana Basin and the Argentinian Paganzo Basin (302 {+-} 6 Ma and 288 {+-} 7 Ma) and with the Karoo Basin, specifically with the top of the Dwyka Tillite (302 {+-} 3 Ma and 299.2 {+-} 3.2 Ma) and the lowermost Ecca Group (288 {+-} 3 Ma and 289.6 {+-} 3.8 Ma). The evidence signifies widespread latest Carboniferous volcanic activity in western Gondwana.

  7. Crop water parameters of irrigated wine and table grapes to support water productivity analysis in the Sao Francisco river basin, Brazil

    NARCIS (Netherlands)

    Castro Teixeira, de A.H.; Bastiaanssen, W.G.M.; Bassoi, L.H.

    2007-01-01

    Energy and water balance parameters were measured in two commercial vineyards in the semiarid region of the São Francisco river basin, Brazil. Actual evapotranspiration (ET) was acquired with the Bowen ratio surface energy balance method. The ratio of the latent heat flux to the available energy, or

  8. Assessment of continuous oil and gas resources of Solimões, Amazonas, and Parnaíba Basin Provinces, Brazil, 2016

    Science.gov (United States)

    Schenk, Christopher J.; Tennyson, Marilyn E.; Klett, Timothy R.; Finn, Thomas M.; Mercier, Tracey J.; Hawkins, Sarah J.; Gaswirth, Stephanie B.; Marra, Kristen R.; Brownfield, Michael E.; Le, Phuong A.; Leathers-Miller, Heidi M.

    2017-03-27

    Using a geology-based assessment methodology, the U.S. Geological Survey estimated undiscovered, technically recoverable mean continuous resources of 5 billion barrels of oil and 47 trillion cubic feet of gas in the Paleozoic Solimões, Amazonas, and Parnaíba Basin Provinces, Brazil

  9. National Account Energy Alliance Final Report for the Basin Electric Project at Northern Border Pipeline Company's Compressor Station #7, North Dakota

    Energy Technology Data Exchange (ETDEWEB)

    Sweetzer, Richard [Exergy Partners Corp.; Leslie, Neil [Gas Technology Institute

    2008-02-01

    A field research test and verification project was conducted at the recovered energy generation plant at Northern Border Pipeline Company Compressor Station #7 (CS#7) near St. Anthony. Recovered energy generation plant equipment was supplied and installed by ORMAT Technologies, Inc. Basin Electric is purchasing the electricity under a purchase power agreement with an ORMAT subsidiary, which owns and operates the plant.

  10. Asymmetrical cross-current turbidite facies tract in a structurally-confined mini-basin (Priabonian-Rupelian, Ranzano Sandstone, northern Apennines, Italy)

    NARCIS (Netherlands)

    Tinterri, R.; Laporta, M.; Ogata, K.

    2017-01-01

    This work discusses the stratigraphy and facies analysis of the Ranzano Sandstone, in the northern Apennines (Italy), a confined low-efficiency turbidite system deposited in a series of small piggy-back basins, which show strong analogies with intraslope minibasins commonly observed in divergent

  11. Origin of the tertiary red beds in the Northern part of the Duero Basin (Spain). I. Grain size, roundness, and sphericity

    NARCIS (Netherlands)

    Mabesoone, J.M.

    1961-01-01

    Red sediments of Tertiary age crop out alongside the southern border of the Cantabrian Mountains in the northern part of the Duero basin. They consist mainly of conglomerates with quartzite pebbles, sandstones, and sandy, loamy, and marly deposits, all with a deep red colour. Detailed analyses were

  12. Morphodynamics of the Kulsi River Basin in the northern front of ...

    Indian Academy of Sciences (India)

    Watinaro Imsong

    2018-02-14

    Feb 14, 2018 ... (Geographic Information System) platform. Lately, morphotectonic .... If the ks differs at segments, then the river basin is undergoing ..... segments. Very high and high ksn values in the upstream and midstream segments of the river cor- respond well with the knickpoints observed in the. Kulsi River profile ...

  13. Morphodynamics of the Kulsi River Basin in the northern front of ...

    Indian Academy of Sciences (India)

    65

    uplift and climatic variability (Seeber and Gornitz 1983; Oberlander 1985; Burbank 1992;. 22. Zhisheng et al. 2001) or controlled by plate tectonics and modified by the influence of climate. 23. (Brookfield 1998). In the northeastern sub Himalaya, fluvial geomorphological process of the. 24. Brahmaputra River Basin w.r.t ...

  14. Paleoenvironmental changes and influence on Operculodinium centrocarpum during the Quaternary in the Campos Basin, southwestern Brazil

    Science.gov (United States)

    Santos, Alessandra; de Araujo Carvalho, Marcelo; de Oliveira, Antônio Donizeti; Mendonça Filho, João Graciano

    2017-12-01

    The purpose of this paper is to document the changes observed in the Quaternary dinoflagellate assemblages from 80 core samples from the Campos Basin. The Interglacial (Subzone X1), Glacial (Subzones Y5 to Y2), Last Glacial Maximum (Subzone Y1) and Post-Glacial (Zone Z) intervals were identified. High abundance of Operculodinium centrocarpum suggests the warm, high salinity and nutrient-poor water conditions dominated the upper water column of the Campos Basin. The climate and oceanic current dynamic of the continental slope of the Campos Basin appears to has been a significant controlling factor in the distribution of dinocysts, particularly of O. centrocarpum, during the Pleistocene/Holocene transition.

  15. A new species of Microglanis (Siluriformes: Pseudopimelodidae from upper rio Paraná basin, Brazil

    Directory of Open Access Journals (Sweden)

    Oscar Akio Shibatta

    Full Text Available Microglanis garavelloi, new species, collected in tributaries of rio Paranapanema and rio Tietê, is the first species of the genus described from upper rio Paraná basin. The new species can be distinguished from other species of Microglanis on morphometric characters, color pattern, caudal-fin shape, pectoral-spine morphology and lateral line development. Characters used specifically to distinguish M. garavelloi from M. cottoides (laguna dos Patos and rio Uruguay basins and M. parahybae (rio Paraíba do Sul basin include morphometrics, color pattern and pectoral-spine serration.

  16. Mercury in sediments from shelf and continental slope at Campos Basin near Rio de Janeiro, Brazil

    Science.gov (United States)

    Araujo, Beatriz; Hintelmann, Holger; Dimock, Brian; Gomes de Almeida, Marcelo; Falcão, Ana Paula; de Rezende, Carlos Eduardo

    2016-04-01

    Mercury (Hg) is a global pollutant due to its ability to undergo long-range transport from source regions to remote parts of the world, and its ubiquitous presence in aquatic ecosystems. The Hg isotope ratios could be an effective tool for tracing the sources and process of Hg in the environment. This study aimed to establish the distribution of mercury in surface sediments of three transects (25- 3000m water depth) in continental shelf and slope in Campos Basin-RJ-Brazil, using the Hg isotopes to understand the geochemical processes relating to Hg cycling that occur in a subtropical coastal environment. The study area was divided into three transects: A (located to the south and close to a upwelling area), D (located opposite the mouth of the Paraiba do Sul River) and I (located north near the top of Vitória-ES). Sampling isobaths were 25, 50, 75, 100, 150, 400, 700, 1000, 1300, 1900, 2500 and 3000m. The Total Hg, MMHg and Hg stable isotopes were determined based on EPA Method 1631, EPA method 1630 and Foucher and Hintelmann (2006), respectively. The silt/clay ranged from 0.05 to 95%, and the organic carbon (OC) from 0.07 to 1.43 % for all transects. THg and MMHg concentrations in the shelf were 11.9 ± 7.2 (1.7- 22.2) ng.g-1 and 0.15 ± 0.12 (0.02 - 0.40) ng.g-1; in the slope 30.3 ± 9.2 (11.6 - 51.6) ng.g-1 and 0.13 ± 0.06 (0.03 -0.29) ng.g-1 , respectively. The δ202Hg and Δ199Hg varied from -0.32 to -1.85 ‰ (-0.79 ± 0.44‰) and -0.41 to 0.09 ‰ (-0.03 ± 0.12 ‰) for all transects, respectively. The delta values between both regions are significantly different, the shelf region showed δ202Hg from -0.59 to -2.19 ‰ (mean: -1.52 ±0.65) and Δ199Hg from - 0.53 to 0.08 ‰ (mean: -0.27 ±0.55) and the slope region were observed δ202Hg values from -0.32 to -1.82 ‰ (mean: -0.73 ±0.39 ‰ n=18) and gΔ199Hg from -0.23 to 0.09‰ (mean: -0.02 ±0.08‰ n=5). The slope appears to be enriched with heavier isotopes compared to the shelf, however, in the

  17. Geomorphological and morphometric analysis of the river basin of Salsa, south coast of the state of Paraiba / Brazil

    International Nuclear Information System (INIS)

    Barbosa, M.E.; Nascimento, J.; Furrier, M.

    2010-01-01

    This paper aims to extend the knowledge on the geomorphology of the river basin of Salsa , located in the municipality of Conde, State of Paraíba / Brazil . The research was to develop guiding object thematic maps related to morphometric aspects of the basin such as fluvial hierarchy , hypsometric and slope . After obtaining the morphometric data can assess the likely tectonic influences on the morphology of this basin. Literature searches , acquisition and analysis of cartographic data (satellite imagery , topographic and thematic maps), where with the help of software SPRING 5:03 , were made the thematic maps of the basin : For this research, the following milestones have been met. In addition, there have been two topographic profiles of the area through which it was possible to further analyze the geomorphological aspects and clinográficos watershed. Already in possession of the first results of this research it was observed with the analysis of charts and topographic profiles the high level of dissection Barriers Training and dissection of this discrepancy between the left and right margins . Barriers in Education, was observed indicative of tectonics from setbacks headwater quite different slots and obsequente towards the River Salsa (SN), which is discordant from the direction of the main waterways and Training Barriers own inclination is that WE . These findings are important because the geomorphological analysis of litoestatigráfica unit is of paramount importance for the understanding of the mechanisms governing the morphology of the northeast coast, mainly in relation to the mechanisms that govern the morphology of watersheds coast of Paraiba

  18. Evaluation of uranium anomalies in the Hylas zone and northern Richmond basin, east-central Virginia

    International Nuclear Information System (INIS)

    Baillieul, T.A.; Dexter, J.J.

    1982-01-01

    Conclusions from this study are: (1) Radon values in ground water from the Hylas Zone and the adjacent Richmomd Basin are anomalous and may indicate nearby uranium-enriched source rocks. (2) Pegmatites, protomylonitic granite, and the Petersburg Granite can be good sources of uranium for ground water. The pegmatites described in this report appear to be the best source rocks because of uranium values ranging from 82 to 235 ppM eU and corresponding low values of Th as well (average Th/U = 0.18). The protomylonitic granite has an average Th/U ratio of 0.5. Ground-water samples (ranging from 70 to 270 ppB uranium) from southwest Richmond are believed to have originated from a major ground-water system at the contact of the Petersburg Granite and overlying coastal plain sediments. Thus, the Petersburg Granite may be considered a possible source of uranium available to ground water entering the Richmond Basin. (3) The Richmond Basin could host uranium deposits of the sandstone class. As mentioned above, there appears to be an adequate supply of uranium in rocks surrounding the basin. The basin environment is presently classified as unevaluated. Further work is warranted on the basis of this study. (4) Pegmatites in the Hylas Zone could be favorable for the occurrence of uranium deposits of the pegmatitic class. However, it is not known how the uranium occurs in the pegmatites, and only pegmatites exposed in the Boscobel quarry were examined. Therefore, this environment remains unevaluated. 3 figures, 4 tables

  19. Small-scale variability of seafloor features in the northern Peru Basin: Results from acoustic survey methods

    Science.gov (United States)

    Wiedicke, Michael H.; Weber, Michael E.

    1996-10-01

    During RV SONNE cruise SO-79 to the eastern Pacific Ocean, two areas of about 65×80 km in the northern Peru Basin were surveyed with the acoustic mapping systems HYDROSWEEP (bathymetry), PARASOUND (3.5 kHz high-resolution seismic system), and a deep-towed side-scan sonar system. In addition, we sampled sediments using piston and box corers. The data show an unexpected variability of seafloor features: The bathymetry is characterized by an abyssal hill topography with predominately N-S ridges up to 300 m high, and scattered volcanic hills. Moreover, one 2000-m-high seamount was mapped. PARASOUND shows several distinct reflectors within the sediment cover, all of which are attributed to carbonate-rich strata. In the northern area, the uppermost prominent reflector is related to the Mid-Brunhes Event (0.45 Ma) in the sediment cores, while the lowermost represents acoustic basement. In the southern area, the seismic pattern reveals an upper opaque zone and a lower transparent zone. The base of the opaque zone is marked by a distinct reflector which corresponds to a huge carbonate peak (6 7 Ma) in the sediment cores. However, despite this general pattern, the PARASOUND records show a highly variable situation, with the distribution of sediment echo types strongly influenced by the seafloor topography. The side-scan sonar revealed the existence of numerous small volcanic cones up to 25 m high and nearly free of sediment. Additionally, the sonar records show a patchy (up to 800 m across) seafloor reflectiviti. We interpret this patchiness as a local lack of manganese nodule coverage. Volcanic cones and the most distinct nodule-free patches are usually on ridges. We interpret this variability as caused by winnowing and erosion, an interpretation that is supported by the occurrence of outcrops of Tertiary strata. This regional small-scale variability argues for a highly dynamic depositional history of the Peru Basin.

  20. Herpesviral infection in a Guiana dolphin ( Sotalia guianensis) from the northern coast of Brazil.

    Science.gov (United States)

    Seade, Gisele C C; Cerqueira, Valíria D; Sierra, Eva; Chaves, Jaese F; Moura, Márcio A O; Montão, Daniele P; Riet-Correa, Gabriela; Oliveira, Carlos A; Siciliano, Salvatore; Emin-Lima, Renata; Costa, Alexandra Fernandes; Fernández, Antonio; Bezerra Júnior, Pedro S

    2017-11-01

    We describe herein herpesvirus-associated genital lesions in a Guiana dolphin ( Sotalia guianensis) from the northern Brazilian coast. Papillary lesions on the vulva, with epithelial hyperplasia, swollen keratinocytes, and intranuclear inclusions, were positive for a herpesvirus ( Gammaherpesvirinae subfamily).

  1. Geochemical behavior of radionuclides and heavy metals in soils from Corumbatai River basin (SP), Brazil

    International Nuclear Information System (INIS)

    Conceicao, Fabiano Tomazini da

    2004-01-01

    The purpose of this research was to study the geochemical behavior of radionuclides and heavy metals in soils of agricultural use at Corumbatai River basin (SP). The natural concentration and variability in sedimentary rocks at Corumbatai river basin follow the trend Ca > Mg > K > Na, with the concentration of heavy metals and radionuclides. The distribution of exposure rate in soils shows the occurrence of higher values towards south of the Corumbatai river basin, region where are applied phosphate fertilizers, amendments and 'vinhaca' in sugar cane crops. Heavy metals and radionuclides incorporated in phosphate fertilizers and amendments are annually added during the fertilization process in the sugar cane crops, but if they are utilized in accordance with the recommended rate, they do not rise the concentration levels in soils up to hazards levels. Thus, they are lower transferred from soils to sugar cane at Corumbatai river basin, not offering hazard to the ecosystem and animal or human health. (author)

  2. Drought propagation in the Paraná Basin, Brazil: from rainfall deficits to impacts on reservoir storage

    Science.gov (United States)

    Melo, D. D.; Wendland, E.

    2017-12-01

    The sensibility and resilience of hydrologic systems to climate changes are crucial for estimating potential impacts of droughts, responsible for major economic and human losses globally. Understanding how droughts propagate is a key element to develop a predictive understanding for future management and mitigation strategies. In this context, this study investigated the drought propagation in the Paraná Basin (PB), Southeast Brazil, a major hydroelectricity producing region with 32 % (60 million people) of the country's population. Reservoir storage (RESS), river discharge (Q) and rainfall (P) data were used to assess the linkages between meteorological and hydrological droughts, characterized by the Standard Precipitation Index (SPI) and Streamflow Drought Index (SDI), respectively. The data are from 37 sub-basins within the PB, consisting of contributing areas of 37 reservoirs (250 km3 of stored water) within the PB for the period between 1995 and 2015. The response time (RT) of the hydrologic system to droughts, given as the time lag between P, Q and RESS, was quantified using a non-parametric statistical method that combines cumulative sums and Bootstrap resampling technique. Based on our results, the RTs of the hydrologic system of the PB varies from 0 to 6 months, depending on a number of aspects: lithology, topography, dam operation, etc. Linkages between SPI and SDI indicated that the anthropogenic control (dam operation) plays an important role in buffering drought impacts to downstream sub-basins: SDI decreased from upstream to downstream despite similar SPI values over the whole area. Comparisons between sub-basins, with variable drainage sizes (5,000 - 50,000 km2), confirmed the benefice of upstream reservoirs in reducing hydrological droughts. For example, the RT for a 4,800 km2 basin was 6 months between P and Q and 9 months between Q and RESS, under anthropogenic control. Conversely, the RT to precipitation for a reservoir subjected to natural

  3. Contribution of the institutions in the Northern region of Brazil to the development of plant cultivars and their impact on agriculture

    Directory of Open Access Journals (Sweden)

    Aparecida das Graças Claret de Souza

    2012-12-01

    Full Text Available This paper describes the development of breeding programs in northern Brazil and their main impacts on agriculture. Their contribution to the breeding of the species palm oil, acai fruit, cacao, cupuaçu, guarana, tomato, camu-camu, cocona, peach palm, and rubber was laid out in detail. Advances in breeding programs of institutions such as Embrapa, Ceplac, Inpa, and Universities require investments in infrastructure and in human and financial resources to ensure continuity and efficiency in economic, social and environmental gains. The improvement of native species, the main focus of the breeding programs of the institutions in the Northern region of Brazil, is a form of exploiting the Amazonian biodiversity for the benefit of society. Therefore, policies to foster research institutions should be a subject of deliberation and action of the scientific and technological community in Brazil.

  4. Tectonic-stratigraphic evolution of Cumuruxatiba Basin - Brazil; Evolucao tectono-estratigrafica da Bacia de Cumuruxatiba

    Energy Technology Data Exchange (ETDEWEB)

    Lobato, Gustavo; Fernandes, Flavio L.; Silva, Eric Zagotto; Ferreira Neto, Walter Dias [Universidade Federal do Rio de Janeiro (UFRJ), RJ (Brazil). Coordenacao dos Programas de Pos-graduacao de Engenharia (COPPE). Lab. de Modelagem Multidisciplinar de Bacias Sedimentares; Ribeiro, Juliana [Agencia Nacional do Petroleo, Gas Natural e Biocombustiveis (ANP), Brasilia, DF (Brazil)

    2008-07-01

    In recent years, the exploratory interest on Cumuruxatiba Basin has been inconstant, with modest discoveries of oil. Aiming to deepen the geological knowledge of the basin and in order to attract the interest of oil companies, the ANP (National Agency of Petroleum, Natural Gas and Biofuels) signed contract with COPPE/UFRJ for carrying out an analysis basin project. The project was developed by the Basin Analysis Multidisciplinary Modeling Laboratory (Lab2M/UFRJ) in the period 2006/2007, and was with the main objective outline the main structural and seismo-stratigraphic features of the basin, and in an integrated and multidisciplinary way, build a model of its sedimentation and tectono-stratigraphic evolution. This paper presents the results of the regional seismic mapping, aided by well and potential methods data. The stratigraphic succession the basin has been divided into genetic units (UN-B, UN-C e UN-D) corresponding to second order depositional sequences, they are: UN-B, corresponding by a rift and sag-rift siliciclastic deposits, plus the Aptian evaporitic deposits; UN-C, characterized by carbonatic deposits, and shelf related sediments; and UN-D, corresponding by a final transgressive (siliciclastic) - regressive (mix) cycle, between Cenomanian and actual days. (author)

  5. An integrated quantitative basin analysis study of the northern part of the Arctic national Wildlife Refuge, Northeastern Alaska

    Science.gov (United States)

    Yu, Z.; Lerche, Ian

    1992-06-01

    An integrated basin analysis was conducted using one- and two-dimensional quantitative dynamic models (1-D and 2-D) in the northern part of the Arctic National Wildlife Refuge (ANWR), Northeastern Alaska. Exploratory well data have been used in the reconstructions of: (1) geohistory including basement subsidence, sediment deposition, change of porosity and compaction, permeability, fluid pressure and fluid flow with time and depth; (2) thermal history including heat flux evolution with time, temperature change with time and depth, and thermal maturation history; and (3) hydrocarbon generation history including the change in the amount of hydrocarbons generated with time and depth, and determining the time and depth of peak hydrocarbon generation. 1-D and 2-D basin modeling codes were used with selected wells, and also with a 18 km section, west of ANWR, with five well controls. It is concluded that: (1) the main source rock west of ANWR area matured first about 40-30 Ma ago in the south and gradually to the north about 10-8 Ma ago on the coastal plain; (2) the modeled erosion thickness at Beli Unit-1 location, northeastern Brooks Range, was 1500-3000 m and at least 3000 m at Canning River Unit B-1; and (3) an overpressure zone within the Hue shale and the lowest part of the Canning Formation caused by rapid Tertiary deposition retained porosity, increased the temperature and speeded hydrocarbon generation in the lower part of the coastal plain.

  6. [Assessment of heavy metal pollution in surface sediments of rivers in northern area of Haihe River Basin, China].

    Science.gov (United States)

    Shang, Lin-Yuan; Sun, Ran-Hao; Wang, Zhao-Ming; Ji, Yu-He; Chen, Li-Ding

    2012-02-01

    Using Håkanson potential ecological risk index, the paper assesses heavy metal risk levels in northern parts of Haihe River basin based on 39 sampling sites. The results indicate that, the concentrations of Cu, Zn, Cd, and Cr in Haihe River basin are higher than the background values of heavy metals in China mainland, while the concentration of Pb is close to the background value in China mainland. Based on the potential ecological risk index for single heavy metal, the risk of Cu, Pb, Zn and Cr belongs to the "slight" level, while Cd has various risk levels at different sampling sites. Generally, the risk order of the heavy metals is Cd > Pb > Cu > Cr > Zn. According to Håkanson potential ecological risk index, 32 monitoring sites belong to "slight" level, 5 sampling sites belong to "middle" level, and 2 monitoring sites belong to "very strong" level. The most polluted sites are Tang River and Dashi River of Beijing, Juma River in Baoding. Therefore, these rivers should be taken more considerations in the river management.

  7. A Systematic Regional Trend in Helium Isotopes Across the NorthernBasin and Range Province, Western North America

    Energy Technology Data Exchange (ETDEWEB)

    Kennedy, B. Mack; van Soest, Matthijs C.

    2005-03-22

    An extensive study of helium isotopes in fluids collectedfrom surface springs, fumaroles and wells across the northern Basin andRange Province reveals a systematic trend of decreasing 3He/4He ratiosfrom west to east. The western margin of the Basin and Range ischaracterized by mantle-like ratios (6-8 Ra) associated with active orrecently active crustal magma systems (e.g. Coso, Long Valley, Steamboat,and the Cascade volcanic complex). Moving towards the east, the ratiosdecline systematically to a background value of ~;0.1 Ra. The regionaltrend is consistent with extensive mantle melting concentrated along thewestern margin and is coincident with an east-to-west increase in themagnitude of northwest strain. The increase in shear strain enhancescrustal permeability resulting in high vertical fluid flow rates thatpreserve the high helium isotope ratios at the surface. Superimposed onthe regional trend are "helium spikes", local anomalies in the heliumisotope composition. These "spikes" reflect either local zones of mantlemelting or locally enhanced crustal permeability. In the case of theDixie Valley hydrothermal system, it appears to be a combination ofboth.

  8. Extraction and Validation of Geomorphological Features from EU-DEM in The Vicinity of the Mygdonia Basin, Northern Greece

    Science.gov (United States)

    Mouratidis, Antonios; Karadimou, Georgia; Ampatzidis, Dimitrios

    2017-12-01

    The European Union Digital Elevation Model (EU-DEM) is a relatively new, hybrid elevation product, principally based on SRTM DEM and ASTER GDEM data, but also on publically available Russian topographic maps for regions north of 60° N. More specifically, EU-DEM is a Digital Surface Model (DSM) over Europe from the Global Monitoring for Environment and Security (GMES) Reference Data Access (RDA) project - a realisation of the Copernicus (former GMES) programme, managed by the European Commission/DG Enterprise and Industry. Even if EU-DEM is indeed more reliable in terms of elevation accuracy than its constituents, it ought to be noted that it is not representative of the original elevation measurements, but is rather a secondary (mathematical) product. Therefore, for specific applications, such as those of geomorphological interest, artefacts may be induced. To this end, the purpose of this paper is to investigate the performance of EU-DEM for geomorphological applications and compare it against other available datasets, i.e. topographic maps and (almost) global DEMs such as SRTM, ASTER-GDEM and WorldDEM™. This initial investigation is carried out in Central Macedonia, Northern Greece, in the vicinity of the Mygdonia basin, which corresponds to an area of particular interest for several geoscience applications. This area has also been serving as a test site for the systematic validation of DEMs for more than a decade. Consequently, extensive elevation datasets and experience have been accumulated over the years, rendering the evaluation of new elevation products a coherent and useful exercise on a local to regional scale. In this context, relief classification, drainage basin delineation, slope and slope aspect, as well as extraction and classification of drainage network are performed and validated among the aforementioned elevation sources. The achieved results focus on qualitative and quantitative aspects of automatic geomorphological feature extraction from

  9. Influence of urbanization on the original vegetation cover in urban river basin: case study in Campinas/SP, Brazil

    Science.gov (United States)

    Leite Silva, Alessandra; Márcia Longo, Regina

    2017-04-01

    ABSTRACT: In most Brazilian municipalities, urban development was not based on adequate planning; one of the consequences was the reduction of the original vegetation, limiting the forest formations to scarce and isolated fragments. In Campinas, São Paulo, Brazil, the vegetation fragmentation was mainly related to the expeditions and to the cycles of sugar cane and coffee. In this way, the present study aims to identify, quantify and evaluate the remaining arboreal vegetation spatial distribution in the Anhumas River Basin - Campinas/SP, Brazil. This study was developed with the aid of GIS software and field visits in order to construct a diagnosis of these areas and subsidize future actions required and to discuss the influence of urbanization on the original vegetation cover. The area was initially occupied by the Atlantic Forest (semi-deciduous forest) and drains one of the oldest urban occupation areas in the municipality; according to researchers, based on the water and geomorphological conditions of the basin, it can be subdivided into high, medium and low course. With a total area of 156,514 km2, only 16.74% are classified as green areas; where just 1.07% and 6.17% of total area represents forests and reforestation areas, respectively. The remaining green areas consists of: wetlands close to water bodies, but with no presence of trees and shrubs (area of 0.12% of the basin); urban green space, including parks and squares (2.19%); and natural field, constituted by natural non-arboreous vegetation (7.18%). In a scenario like this, a characteristic situation is the forest fragmentation; this process results in native vegetation remnants, isolated and more susceptible to external interference, coming from, for example, the proximity to agricultural areas or others land uses. The ecological knowledge of the remnants and their correct management can not only make it possible to diagnose current problems and to estimate future influences, but also to point out the

  10. Stratigraphy of the Roraima Supergroup along the Brazil-Guyana border in the Guiana shield, Northern Amazonian Craton - results of the Brazil-Guyana Geology and Geodiversity Mapping Project

    Directory of Open Access Journals (Sweden)

    Nelson Joaquim Reis

    Full Text Available ABSTRACT: The Geological and Geodiversity Mapping binational program along the Brazil-Guyana border zone allowed reviewing and integrating the stratigraphy and nomenclature of the Roraima Supergroup along the Pakaraima Sedimentary Block present in northeastern Brazil and western Guyana. The area mapped corresponds to a buffer zone of approximately 25 km in width on both sides of the border, of a region extending along the Maú-Ireng River between Mount Roraima (the triple-border region and Mutum Village in Brazil and Monkey Mountain in Guyana. The south border of the Roraima basin is overlain exclusively by effusive and volcaniclastic rocks of the Surumu Group of Brazil and its correlated equivalent the Burro-Burro Group of Guyana.

  11. Subsurface images of the northern Newark basin, New York, USA and their implications for carbon sequestration

    Science.gov (United States)

    Olsen, P. E.; Withjack, M. O.; Schlische, R. W.; Goldberg, D.; Kent, D. V.; Tamulonis, K.; Couëslan, M.; Collins, D. J.

    2011-12-01

    The Triassic-Jurassic Newark rift, a large onshore sedimentary basin close to northeast US metropolitan areas, may have potential for safe geological storage of CO2 in a suitably deep formation overlain by appropriate confining units. Filled with continental synrift sedimentary rocks and CAMP (Central Atlantic Magmatic Province) basaltic intrusions and flows, the basin is bounded on the NW by the NE-striking, SE-dipping Ramapo fault. Funded by the Department of Energy's (DOE) National Energy Technology Laboratory's (NETL) Carbon Sequestration Program's portion of the American Recovery and Reinvestment Act of 2009 (ARRA) and NYSERDA, the TriCarb Consortium for Carbon Sequestration acquired two seismic-reflection profiles in Rockland County, NY that were processed to obtain depth-migrated images of the basin's subsurface geometry. The E-trending dip profile crosses most of the basin, while the shorter N-trending profile provides a strike-view. Five seismic facies are present: (1) shallow continuous, closely spaced, W-dipping reflections suggestive of lacustrine deposits; (2) short, non-coherent reflections suggestive of conglomeritic fluvial strata; (3) high-amplitude parallel reflections, locally exhibiting reverse separation, suggestive of prerift early Paleozoic strata Cambro-Ordovician carbonates; (4) a facies at the bottom of both lines and the western end of the ESE-trending line that lacks reflections, suggestive of prerift metamorphic rocks such as Precambrian gneiss, and/or highly deformed Taconic (Ordovician) phyllites; and (5) a seismically transparent band commonly bounded by high-amplitude reflections that cuts across the stratigraphy of facies 1-3, suggestive of a scoop-shaped intrusive diabase sheet that projects to the surface to outcrops of the CAMP-related Palisade sill. Basin geometry is well-imaged conforming to a deeply eroded half graben. Reflections of facies 3 are truncated by facies 2 marking the angular pre-rift unconformity. Distinct

  12. Soil map, area and volume calculations in Orrmyrberget catchment basin at Gideaa, Northern Sweden

    International Nuclear Information System (INIS)

    Ittner, T.; Tammela, P.T.; Gustafsson, E.

    1991-06-01

    Fallout studies in the Gideaa study site after the Chernobyl fallout in 1986, has come to the point that a more exact surface mapping of the studied catchment basin is needed. This surface mapping is mainly made for area calculations of different soil types within the study site. The mapping focus on the surface, as the study concerns fallout redistribution and it is extended to also include materials down to a depth of 0.5 meter. Volume calculations are made for the various soil materials within the top 0.5 m. These volume and area calculations will then be used in the modelling of the migration and redistribution of the fallout radionuclides within the studied catchment basin. (au)

  13. Quality and safety of maize (Zea mays L.) from Rondônia state storage units, Northern Brazil.

    Science.gov (United States)

    Valmorbida, Roberta; Savi, Geovana D; Silva, Juliana R; Yanez, Monica M O; Soares, Carlos E S; Runtzel, Cristina; Nascimento, Priscila N; Scussel, Vildes M

    2018-03-01

    The quality and safety of maize (Zea mays L.) from different grain storage units (GSUs), located in the main producing region of Rondônia State, Northern Brazil, were evaluated. Maize grains (n = 76) stored in four GSUs were collected from July to November 2014 and evaluated for grain damages, humidity, fungi and fumonisins (FBs) content. The climate conditions data were also obtained from plant growing to storage periods. Regarding the moisture content and water activity (a w ), these varied from 10.0% to 16.1% and 0.5 to 0.8, respectively. As expected, fungi spores were present in 94.8% of the samples, prevailing Fusarium genera, with a fungi colony maximum of 2.2 × 10 4 CFU g -1 . Regarding FBs, 60.5% of the samples were contaminated, below Brazilian and United States maximum limits, but 9.2% had levels higher than the European legislation.

  14. Prevalence of HCV infection and associated factors among illicit drug users in Breves, State of Pará, northern Brazil

    Directory of Open Access Journals (Sweden)

    Suzy Danielly Barbosa Pacheco

    2014-06-01

    Full Text Available Introduction: Illicit drug users (DUs are vulnerable to hepatitis C virus (HCV infection. The shared use of illicit drugs is the main method of HCV transmission. Methods: A cross-sectional study was conducted in Breves, in northern Brazil. We surveyed 187 DUs to determine the prevalence of and factors associated with HCV infection. Results: The prevalence of anti-HCV antibodies was 36.9%, and the prevalence of hepatitis C virus-ribonucleic acid (HCV-RNA was 31%. Hepatitis C virus infection was associated with tattoos, intravenous drug use, shared use of equipment for drug use, drug use for longer than 3 years, and daily drug use. Conclusions: Strategies for preventing and controlling HCV transmission should be implemented among DUs.

  15. Oligosarcus jacuiensis (Characiformes: Characidae, a new species from the Uruguay and Jacuí River basins, southern Brazil

    Directory of Open Access Journals (Sweden)

    Naércio Aquino Menezes

    Full Text Available The new species herein described, collected in the Jacuí and Uruguay River basins, Rio Grande do Sul, Brazil, can be distinguished from the already known species of the genus, but Oligosarcus jenynsii, O. perdido, O. acutirostris, O. solitarius and O. hepsetus, by the number of perforated lateral line scales. It shares with the first two species the absence of a premaxillary foramen, present in the last three species and differs from O. jenynsii by having a smaller orbital diameter and the tip of the pectoral fin failing to reach the pelvic-fin origin, and from O. perdido by the presence of more horizontal scale rows around the caudal peduncle.

  16. A new species of the catfish genus Centromochlus (Siluriformes: Auchenipteridae: Centromochlinae from the upper rio Paraná basin, Brazil

    Directory of Open Access Journals (Sweden)

    Luisa Maria Sarmento-Soares

    Full Text Available Centromochlus comprises twelve species, distributed in the main inland watersheds of South America, including the Orinoco, Essequibo, coastal rivers of Suriname, Amazon, upper Paraná and São Francisco basins. The new species is described from the upper rio Paraná based on material collected in 1965 during the construction of the UHE Ilha Solteira, São Paulo, Brazil. The new species is easily distinguished from all congeners due to absence of adipose fin, a condition otherwise restricted to Gelanoglanis nanonocticolus, among centromochlin catfishes. The new species comprises small catfishes (adults ranging from 35 to 39 mm SL, in which modified anal fin of males is devoid of denticulations or spines, and most posterior rays reduced in length. In addition, Tatia simplex Mees is transferred to Centromochlus and its generic reassignment discussed.

  17. Provenance and paleogeography of the Mesozoic strata in the Muang Xai Basin, northern Laos: petrology, whole-rock geochemistry, and U-Pb geochronology constraints

    Science.gov (United States)

    Wang, Yanlu; Wang, Licheng; Wei, Yushuai; Shen, Lijian; Chen, Ke; Yu, Xiaocan; Liu, Chenglin

    2017-06-01

    The Muang Xai Basin, located in northern Laos, is associated with the Simao, Vientiane, and Khorat Basins. The paleogeographic link of these basins has not been investigated in great detail; thus, the investigation presented in this study is a comprehensive analysis of petrology, whole-rock geochemistry, and detrital zircon U-Pb chronology used to characterize the provenance of the Muang Xai Basin. Results suggest that the sedimentary source includes felsic rocks from an active continental margin or continental arc with minor amounts of recycled passive continental margin sediments. Sandstones of the Muang Xai Basin contain detrital zircons with varying U-Pb peak ages. The youngest age peak of all the zircons is 103 Ma, which limits the age of the Mesozoic strata to the Late Cretaceous. Detrital zircon U-Pb and trace element data, combined with geochemical result, reveal that the pre-Ordovician zircons were derived from recycled sediments of the Yangtze Block, which are originally sourced from the Qinling Orogenic belt. This provenance is shared with coeval sediments in the Simao and Khorat Basins, while magmatic rocks of the Ailaoshan, Truong Son Belt, and Lincang terrane are responsible for zircons of 416-466 and 219-308 Ma in age. Zircons of 101-110 and 149-175 Ma in age were sourced from magmatic rocks of the southwestern South China Block and northern Vietnam. These provenance results suggest that sediments flow into the Khorat red beds was likely from the Great Simao Basin and northern Vietnam, and not directly from the Yangtze Block.

  18. Water resources: the prerequisite for ecological restoration of rivers in the Hai River Basin, northern China.

    Science.gov (United States)

    Tang, Wenzhong; Mao, Zhanpo; Zhang, Hong; Shan, Baoqing; Zhao, Yu; Ding, Yuekui

    2015-01-01

    The competition for water resources between humans and river ecosystems is becoming ever more intense worldwide, especially in developing countries. In China, with rapid socioeconomic development, water resources to maintain river ecosystems are progressively decreasing, especially in the Hai River Basin (HRB), which has attracted much attention from the Chinese government. In the past 56 years, water resources have continuously decreased in the basin, such that there is 54.2 % less surface water now compared with then. Water shortages, mainly due to local anthropogenic activities, have emerged as the main limiting factor to river ecological restoration in the HRB. However, the South-to-North Water Diversion Project, the largest such project in the world, presents a good opportunity for ecological restoration of rivers in this basin. Water diverted from the Danjiangkou Reservoir will restore surface water resources in the HRB to levels of 30 years ago and will amount to more than 20 billion m(3). Our findings highlight the fact that water resources are crucial for river ecological restoration.

  19. Heavy metal accumulation by periphyton is related to eutrophication in the Hai River Basin, Northern China.

    Directory of Open Access Journals (Sweden)

    Wenzhong Tang

    Full Text Available The Hai River Basin (HRB is one of the most polluted river basins in China. The basin suffers from various types of pollutants including heavy metals and nutrients due to a high population density and rapid economic development in this area. We assessed the relationship between heavy metal accumulation by periphyton playing an important role in fluvial food webs and eutrophication in the HRB. The concentrations of the unicellular diatoms (type A, filamentous algae with diatoms (type B, and filamentous algae (type C varied along the river, with type A dominating upstream, and types B then C increasing in concentration further downstream, and this was consistent with changes in the trophic status of the river. The mean heavy metal concentrations in the type A, B and C organisms were Cr: 18, 18 and 24 mg/kg, respectively, Ni: 9.2, 10 and 12 mg/kg, respectively, Cu: 8.4, 19 and 29 mg/kg, respectively, and Pb: 11, 9.8 and 7.1 mg/kg respectively. The bioconcentration factors showed that the abilities of the organisms to accumulate Cr, Ni and Pb decreased in the order type A, type B, then type C, but their abilities to accumulate Cu increased in that order. The Ni concentration was a good predictor of Cr, Cu and Pb accumulation by all three periphyton types. Our study shows that heavy metal accumulation by periphyton is associated with eutrophication in the rivers in the HRB.

  20. The zooplankton biodiversity of some freshwater environments in Parnaíba basin (Piauí, Northeastern Brazil

    Directory of Open Access Journals (Sweden)

    JDN. Paranhos

    Full Text Available The plankton fauna of the state of Piauí, Northeastern Brazil, especially in the Parnaíba basin, is still poorly known; the results of most studies of the subject have not been published and can only be found in grey literature (unpublished scientific works, such as course completion work and consulting reports. Thus, this paper presents data from samples taken recently from different water bodies in Piauí and represents the second study to be published on the region's zooplankton since the pioneering work of Spandl (1926. A total of 38 species were recorded, including 23 new occurrences of rotifers, 10 of cladocerans and 2 of copepods for the state of Piauí. The greatest richness was observed for the rotifers, of which the genus Brachionus must be highlighted, especially at the Joana reservoir. Among the crustaceans, the greatest richness was observed at the Bezerra reservoir, where cladocerans of the genus Bosmina were prominent. The rotifers Brachionus havanaensis Rousselet, 1911 and Filinia longiseta (Ehrenberg, 1834; the cladocerans Diaphanosoma spinulosum Herbst, 1967 and Moina micrura Kurz, 1874; and the copepods Notodiaptomus cearensis Wright, 1936 and Thermocyclops decipiens Kiefer, 1927 occurred in all or in most environments in which the respective groups were studied. The results presented here expand the taxonomic list of zooplankton for the state of Piauí, including a total fauna of 30 species of rotifers, 15 of cladocerans and 3 of copepods. The zooplankton richness was considered low in the studied reservoirs compared to other freshwater ecosystems from Northeastern Brazil; however, the few studies developed in the Parnaíba basin suggest that the diversity for these organisms should be higher.

  1. Patterns of Woody Growth for Brazilian Savanna (Cerrado) Trees in the Cuiaba Basin and Pantanal of Mato Grosso, Brazil

    Science.gov (United States)

    Zappia, A. J.; Vourlitis, G. L.; Pinto-Jr, O. B.

    2015-12-01

    The Brazilian savanna, locally known as cerrado, is a major ecosystem that covers a vast majority of central Brazil. Little is known about how woody growth within the cerrado is affected by soil properties such as texture and/or nutrient availability. Thus, in this study we assessed the relationship between woody growth and soil properties in the Cuiaba Basin and Pantanal of Mato Grosso, Brazil. We sampled 4-5 vegetation stands in each site that varied in hydrology, soil type, and vegetation composition and structure, and measured diameter at breast height, wood density, and soil nutrient concentration and physical properties every 5-10 m along a 100 m long transect. We hypothesized that as tree diameter at breast height increases, annual tree growth rate will decrease and that woody carbon (C) storage will increase as a function of soil nutrient availability. Our preliminary data support our hypotheses. Tree growth rates declined with tree size in both the Cuiaba Basin and the Pantanal. Rates of woody C storage, both on a per tree basis (kgC tree-1 year-1) and on a per unit ground area basis (kgC m-2 year-1) were significantly positively correlated with soil extractable phosphorus (P), calcium (Ca), and clay content, while only woody C storage on a per tree basis was positively correlated with potassium (K), magnesium (Mg), and cation exchange capacity (CEC). These data suggest that rates of woody C storage in cerrado are nutrient limited, while correspondence between C storage and soil physical properties could indicate both nutrient and water limitations to C storage.

  2. The Evolution of the Hydrogeologic System in the Taipei Basin, Northern Taiwan

    Science.gov (United States)

    Lin, M.; Chia, Y.

    2011-12-01

    Taipei basin is the largest metropolitain area in Taiwan, and thus the change of its hydrogeologic system is closely associated with the economic development of the urban area. In this study, we integrated the core data and groundwater level data to construct the hydrogeologic framework of the Taipei basin. Then the long-term elevation data and groundwater data were analyzed to understand the impact of urban development on the hydrogeologic system. By analyzing the long-term change of groundwater level in the Taipei basin, we found two groups of wells with a different range of water level and pattern of water level variation. The first group of wells is relatively shallow. Their hydraulic heads fluctuated between 0 and 5m. Generally the water level is rarely affected by pumping, but sensitive to the rainfall. These wells were placed in sand layers of the Songshan formation. However, the second group of wells, where the hydraulic head ranges from -40m to 0m, is relatively deep. They were installed in the Jingmei formation and Wugu formation. Pumping activities have significantly influenced the change in groundwater level. For these reasons, we proposed two hydrogeologic units in the Taipei basin. One is the Songshan aquifer characterized by interbeded local aquifer and aquitard. The other is the Taipei aquifer which combines the lower Songshan formation, Jingmei formation, and Wugu formation. Extensive pumping from the Taipei aquifer has caused serious land subsidence since the rapid expansion of the urban area in 1950s. The cumulative amount of settlement in the Taipei basin is about 2.2 m by 1983. The subsidence appeared to be inelastic with little recovery. The groundwater level has declined approximately 50 m by 1976. The decline was followed by a rapid recovery in the Taipei aquifer starting from late 1970s. In the past two decades, however, small subsidence ranging from 3~5 cm have been induced by the extensive pumping during the construction of Metro system

  3. Integrated modeling of water quantity and quality in the Araguari River basin, Brazil

    Directory of Open Access Journals (Sweden)

    Marcio Ricardo Salla

    2014-03-01

    Full Text Available The Araguari River basin has a huge water resource potential. However, population and industrial growth have generated numerous private and collective conflicts of interest in the multiple uses of water, resulting in the need for integrated management of water quantity and quality at the basin scale. This study used the AQUATOOL Decision Support System. The water balance performed by the SIMGES module for the period of October 2006 to September 2011 provided a good representation of the reality of this basin. The parameters studied were dissolved oxygen, biochemical oxygen demand, organic nitrogen, ammonia, nitrate and total phosphorus. The coefficients of biochemical reactions, sedimentation rates and sediment dissolved oxygen release for this period were calibrated and validated in the quality modeling using the GESCAL module. A sensitivity analysis indicated that the coefficients of carbonaceous matter decomposition, nitrification, water temperature, and sediment oxygen demand interfered more significantly in the variables of state. To prevent eutrophication in the Nova Ponte reservoir and in the other cascade reservoirs, the local River Basin Committee should adopt restrictive actions against the use of agricultural fertilizers. On the other hand, in the sub basin of the Uberabinha River, new alternatives for public water supply to the city of Uberlândia and improvements in the treatment efficiency of the main wastewater treatment plant (WWTP should be proposed, since the biochemical oxygen demand, ammonia and total phosphorus failed to meet the requirements of COPAM (2008 in the driest months.

  4. The Research of Tectonic Framework and the Fault Activity in Large Detachment Basin System on Northern Margin of South China Sea

    Science.gov (United States)

    Pan, L., Sr.; Ren, J.

    2017-12-01

    The South China Sea (SCS) is one of the largest marginal sea on southeast Asia continental margin, developed Paleogene extension-rifting continental margin system which is rare in the world and preserving many deformed characterizes of this kind system. With the investigation of the SCS, guiding by the development of tectonics and geo-physics, especially the development of tectonics and the high quality seismic data based on the development of geo-physics, people gradually accept that the northern margin of the SCS has some detachment basin characterizes. After researching the northern margin of the SCS, we come up with lithosphere profiles across the shelf, slope and deep sea basin in the northeast of the SCS to confirm the tectonic style of ocean-continental transition and the property of the detachment fault. Furthermore, we describe the outline of large detachment basins at northern SCS. Based on the large number of high-quality 2D and 3D deep seismic profile(TWT,10s), drilling and logging data, combined with domestic and international relevant researches, using basin dynamics and tectono-stratigraphy theory, techniques and methods of geology and geophysics, qualitative and quantitative, we describe the formation of the detachment basin and calculate the fault activity rate, stretching factor and settlement. According to the research, we propose that there is a giant and complete detachment basin system in the northern SCS and suggest three conclusions. First of all, the detachment basin system can be divided into three domains: proximal domain covering the Yangjiang Sag, Shenhu uplift and part of Shunde Sag, necking zone covering part of the Shunde Sag and Heshan Sag, distal domain covering most part of Heshan Sag. Second, the difference of the stretching factor is observed along the three domains of the detachment basin system. The factor of the proximal domain is the minimum among them. On the other side, the distal domain is the maximum among them. This

  5. Fish, lower Ivinhema River basin streams, state of Mato Grosso do Sul, Brazil.

    Directory of Open Access Journals (Sweden)

    Súarez, Y. R.

    2008-01-01

    Full Text Available The Ivinhema River basin is one of the main tributaries of the western portion of Paraná River. However,few data are available on the fish communities of its streams. Monthly samples were made in seven streams of the lowerportion of the basin, in the state of Mato Grosso do Sul, using a rectangular sieve 1.2 x 0.8 m, with 2 mm mesh size.Forty-six fish species were found in these streams. The richness estimated according to the bootstrap procedure was 50species. At least two of the captured species were not previously recorded for the upper Paraná basin, indicating theneed of new sampling effort in this region.

  6. Dinosaur ichnofauna of the Upper Jurassic/Lower Cretaceous of the Paraná Basin (Brazil and Uruguay)

    Science.gov (United States)

    Francischini, H.; Dentzien–Dias, P. C.; Fernandes, M. A.; Schultz, C. L.

    2015-11-01

    Upper Jurassic and Lower Cretaceous sedimentary layers are represented in the Brazilian Paraná Basin by the fluvio-aeolian Guará Formation and the Botucatu Formation palaeoerg, respectively, overlapped by the volcanic Serra Geral Formation. In Uruguay, the corresponding sedimentary units are named Batoví and Rivera Members (both from the Tacuarembó Formation), and the lava flows constitute the Arapey Formation (also in Paraná Basin). Despite the lack of body fossils in the mentioned Brazilian formations, Guará/Batoví dinosaur fauna is composed of theropod, ornithopod and wide-gauge sauropod tracks and isolated footprints, as well as theropod teeth. In turn, the Botucatu/Rivera dinosaur fauna is represented by theropod and ornithopod ichnofossils smaller than those from the underlying units. The analysis of these dinosaur ichnological records and comparisons with other global Mesozoic ichnofauna indicates that there is a size reduction in dinosaur fauna in the more arid Botucatu/Rivera environment, which is dominated by aeolian dunes. The absence of sauropod trackways in the Botucatu Sandstone fits with the increasingly arid conditions because it is difficult for heavy animals to walk on sandy dunes, as well as to obtain the required amount of food resources. This comparison between the Upper Jurassic and Lower Cretaceous dinosaur fauna in south Brazil and Uruguay demonstrates the influence of aridization on the size of animals occupying each habitat.

  7. Stratigraphy and facies analysis of the Cenomanian Turonian boundary succession in the Japaratuba area, Sergipe Basin, Brazil

    Science.gov (United States)

    Walter, Simone; Herrmann, Achim D.; Bengtson, Peter

    2005-08-01

    A facies analysis of the Cenomanian-Turonian (Cretaceous) boundary beds was carried out in the Japaratuba area, Sergipe Basin, north-eastern Brazil, on the basis of seven outcrop sections. The lower part of the succession is represented by dolomitic limestones and marly limestones, whereas the upper part is dominated by chalky, nodular limestones and bedded and coquinoid limestones. Three microfacies types are recognized in the upper part of the succession, where biostratigraphic work has indicated the position of the Cenomanian-Turonian boundary. Two of these microfacies types (foraminiferal mudstone, wackestone) occur only in the nodular limestone unit and are referred to an outer carbonate ramp setting. The uppermost part of the succession is dominated by echinoderm-inoceramid packstones, which probably were deposited in a mid-ramp setting. In the late Cenomanian, deposition took place in the outer-ramp distal area of an open-marine basin, which gradually became shallower during the Cenomanian-Turonian transition, as evidenced by the increase in macrofaunal debris to the northeast. In addition to macrofossil fragments, some thin sections contain abundant planktic and benthic foraminifers, calcispheres, and roveacrinids; the latter are potentially useful for stratigraphic purposes. Biostratigraphic data suggest that the lowermost Turonian is missing in the southern part of the Japaratuba area.

  8. Spectroscopic analysis and X-ray diffraction of trunk fossils from the Parnaíba Basin, Northeast Brazil.

    Science.gov (United States)

    Alencar, Wemerson J; Santos, F Eroni P; Cisneros, Juan C; da Silva, João H; Freire, Paulo T C; Viana, Bartolomeu C

    2015-01-25

    The Parnaiba Sedimentary Basin is of the Paleozoic age and is located in Northeast Brazil, covering the states of Piauí, Maranhão and Tocantins and a small part of Ceará and Pará. In this work we applied several chemical analytical techniques to characterize trunk fossils found in the Parnaíba Sedimentary Basin, collected from four different sites, and discuss their fossilization process. We performed a study of the trunk fossils through X-ray diffraction, energy dispersive spectroscopy, infrared and Raman spectroscopy. The analysis allow us to identify the different compositions which are present in the trunk fossils: kaolinite (Al2Si2O5(OH)4), hematite (Fe2O3) and quartz (SiO2). Based in these results we were able to identify that the main fossilization mechanism of the trunk fossil was silicification. Furthermore, through Raman spectroscopy, we have observed the presence of carbonaceous materials in the Permian fossils, as evidenced by the D and G Raman bands. The relative intensities and bandwidths of the D and G bands indicated that the carbon has a low crystallinity. Thus, most of trunk fossils analyzed were permineralized and not petrified, because there is the presence of carbon that characterizes the partial decomposition of the organic matter in some trunks. Copyright © 2014 Elsevier B.V. All rights reserved.

  9. Seasonal study of contamination by metal in water and sediment in a sub-basin in the southeast of Brazil

    Directory of Open Access Journals (Sweden)

    WAC. Chiba

    Full Text Available The spatial and temporal occurrence of heavy metals (Al, Cd, Pb, Zn, Cr, Co, Cu, Fe, Mn and Ni in water and sediment samples was investigated in a sub-basin in the southeast of Brazil (São Carlos, SP. All samples were analysed using the USEPA adapted metal method and processed in an atomic absorption spectrophotometer. The discriminant analysis demonstrated that there are significant seasonal differences of metal distribution in the water data, but there are no differences to sediment. The basin studied has high levels of contamination by toxic metals in superficial water and sediment. The superficial water, in the rainy season, presented high levels of Cr, Ni, Pb and Cd, while in the dry season it presented high levels of Zn and Ni. The Principal Component Analysis demonstrated that the season has a huge influence on the levels, types and distribution of metals found in water. The source of contamination was probably diffuse, due to products such as batteries and fluorescent lamps, whose dump discharge can contaminate the bodies of water in the region in the rainy season. Due to fires from the harvest of sugar cane, high levels of Zn were found into the environment, in the dry season.

  10. Corridors of crestal and radial faults linking salt diapirs in the Espírito Santo Basin, SE Brazil

    Science.gov (United States)

    Mattos, Nathalia H.; Alves, Tiago M.

    2018-03-01

    This work uses high-quality 3D seismic data to assess the geometry of fault families around salt diapirs in SE Brazil (Espírito Santo Basin). It aims at evaluating the timings of fault growth, and suggests the generation of corridors for fluid migration linking discrete salt diapirs. Three salt diapirs, one salt ridge, and five fault families were identified based on their geometry and relative locations. Displacement-length (D-x) plots, Throw-depth (T-z) data and structural maps indicate that faults consist of multiple segments that were reactivated by dip-linkage following a preferential NE-SW direction. This style of reactivation and linkage is distinct from other sectors of the Espírito Santo Basin where the preferential mode of reactivation is by upwards vertical propagation. Reactivation of faults above a Mid-Eocene unconformity is also scarce in the study area. Conversely, two halokinetic episodes dated as Cretaceous and Paleogene are interpreted below a Mid-Eocene unconformity. This work is important as it recognises the juxtaposition of permeable strata across faults as marking the generation of fault corridors linking adjacent salt structures. In such a setting, fault modelling shows that fluid will migrate towards the shallower salt structures along the fault corridors first identified in this work.

  11. GROUNDWATER QUALITY EVALUATION OF PERMANENT PRESERVATION AREAS (GUARANI AQUIFER SYSTEM - GAS, RIO PARDO HYDROGRAPHICAL BASIN, RS, BRAZIL

    Directory of Open Access Journals (Sweden)

    Adilson Ben da Costa

    2010-06-01

    Full Text Available The aim of this research was to evaluate the quality of groundwater in areas of permanent preservation (Guarani Aquifer System – GAS in the Rio Pardo Hydrographical Basin, RS, Brazil, using physical, chemical and microbiological variables, based on resolution no. 396/2008 of the National Council on the Environment - CONAMA. Nine sampling points were distributed throughout the basin, where groundwater was classified as the major ions through the Piper diagram. The results indicated that most of the wells evaluated were classified in Class 4, accounting for water uses less restrictive. However, it should be considered that the aquifers are characterize by different geological conditions, having intrinsical physical, chemical and biological variables with hydrogeochemical variations, requiring that their quality levels are often based on these characteristics, as noted in diagram Piper, where the samples P1, P2, P3, P5 and P9 were classified as calcium bicarbonate, the waters of the points P4, P6, P7 as sodium bicarbonate and P8 as sulfated. It was found that the quality of water from wells with depths less than 6 m are becoming more vulnerable due to anthropogenic activities, as showing by the concentration of nitrate, total and thermotolerant coliforms, while the quality of water from deeper wells basically depends on their hydrogeological and hydrogeochemical characteristics based on the concentration of sodium and sulfate variables. However, they also showed contamination by human activities, mainly by the nitrate variable.

  12. Can proximity to roads influence forest fragmentation? A case study in northern Rio Grande do Sul, Brazil

    Directory of Open Access Journals (Sweden)

    Tiago Rezzadori

    2016-09-01

    Full Text Available The establishment and use of roads interfere with the atmosphere, soil, vegetation, fauna, and human communities surrounding them. One of the main effects caused by the implementation and operation of a road is fragmentation of natural landscapes, which consequently generates edge effects and isolation of populations. Thus, this study aimed to quantify and compare the distribution of vegetation cover in areas with and without ecological influence of roads in the Alto Uruguai region, northern Rio Grande do Sul, Brazil. To do this, a geo-relational database was created, where satellite images taken by Landsat V and CBERS 2b were entered. The size and amount of forest fragments were estimated in areas with and without influence of roads. The area with ecological influence of roads had less and smaller sized forest fragments when compared to the area without ecological influence. High forest fragmentation seems to be enhanced by proximity to roads in northern Rio Grande do Sul, contributing to isolate and reduce the size of native populations that occupy these areas.

  13. Actual stage of organic geochemical knowledge from Campos and Espirito Santo basins, Brazil

    International Nuclear Information System (INIS)

    Gaglianone, P.C.; Trindade, L.A.F.

    1987-01-01

    Campos and Espirito Santo basins display several similar geochemical aspects. The microbial and other degradation processes caused changes in the composition of the oils in the reservoir rocks. The oils are biodegraded in different degrees, with the reservoir temperature developing an important role in the control of the biodegradation process. The migration pathway model is similar for Campos and Espirito Santo basins, involving the upward secondary migration through a window in the evaporitic seals. The oils passed to the marine sequence where migration and accumulation were controlled by faults, regional unconformities and by reservoirs. The geochemical correlation of oils are realized by gaseous and liquid chromatography analysis, carbon isotopes and biolabelled compounds. (author)

  14. Tectonic-stratigraphic evolution of mini-basins and salt provinces of Espirito Santo Basin-Brazil; Analise da evolucao tectono sedimentar de mini-bacias e provincias de sal da Bacia do Espirito Santo

    Energy Technology Data Exchange (ETDEWEB)

    Ferreira Neto, Walter Dias; Fernandes, Flavio Luis [Petroleum Geoscience Technology Ltda. (PGT), Rio de Janeiro, RJ (Brazil); Mohriak, Webster [PETROBRAS S.A., Rio de Janeiro, RJ (Brazil); Universidade do Estado do Rio de Janeiro (UERJ), Rio de Janeiro, RJ (Brazil)

    2008-07-01

    The Espirito Santo Basin integrates the group of basins along the eastern Brazilian continental margin. It is located between 18 deg and 21 deg S, encompassing an area of approximately 220,000 km{sup 2}, onshore and offshore the Espirito Santo State. Its geological limit with the Campos Basin to the south is defined by a Precambrian basement high (Vitoria Arch), and its northern limit with the Mucuri Basin is defined by a geopolitical limit. The study of salt tectonics processes in the Espirito Santo Basin allowed the deformational analysis and interpretation of the chronological evolution of the mini-basins developed between salt diapirs. We observe an intrinsic relationship between halokinesis and creation of subsidence troughs that may be important for trapping hydrocarbon reservoirs, and consequently form oil and gas accumulations in this portion of the basin. This geodynamics evolution of these structures is marked by a strong linkage between salt movement and coeval sedimentation in the interdomal basins, forming structures and stratigraphic traps that may constitute important aspects for the petroleum geology. (author)

  15. Description of a new species of Microglanis (Siluriformes: Pseudopimelodidae from the Amazon basin, Amazonas State, Brazil

    Directory of Open Access Journals (Sweden)

    Lucas Ribeiro Jarduli

    Full Text Available The first species of Microglanis from the rio Amazonas, Amazonas State, Brazil is described. This species differs from all congeners by the forked caudal fin, and color pattern of the supraoccipital region consisting of two elliptical and juxtaposed pale spots, besides a combination of morphometrics characters.

  16. CLIMATE CHANGE IN NORTHERN AFRICA: TOWARDS A RETURN OF RAINFALL ON THE SOUTHERN MEDITERRANEAN BASIN

    Directory of Open Access Journals (Sweden)

    NOUACEUR ZEINEDDINE

    2014-03-01

    Full Text Available To determine to what extent climate change affects the rainfall recorded on the southern Mediterranean basin, a trend analysis is proposed. This study is based on the chronological graphic method of processing information (MGCTI of type "Matrice Bertin". Results show an extreme variability of the precipitations and a severe drought, especially for Morocco, observed since 1970s. Finally, a gradual return to humid conditions is observed from the beginning of the 2000s in Algeria and Tunisia and since 2008 in Morocco. This new trend is also confirmed by recent results provided by agricultural data of 2011/2012 and 2012/2013.

  17. The fish community as an indicator of biotic integrity of the streams in the Sinos River basin, Brazil

    Directory of Open Access Journals (Sweden)

    PF. Costa

    Full Text Available The basin of the Sinos River, located in the northeastern part of Rio Grande do Sul state, Brazil, has been highly impacted by industrial and urban activities. Water quality is low because of domestic and industrial sewage discharges. Most of the tributaries have suffered drastic structural interventions like canalisations and the removal of riparian vegetation. The aims of this study were to: 1 assess the diversity of fish at 34 sampling sites in twenty-four tributaries of the Sinos River basin; 2 quantify impact level by the Shannon-Wiener diversity index and an adapted Index of Biotic Integrity (IBI; and 3 check the interference of environmental impacts, formerly quantified in a Stream Corridor Assessment Survey (SCAS, on the fish assembly and 4 compare the relationship between the IBI with stream order. Fish sampling was performed by electric fishing in the period from April 2004 to August 2006. A total of 4,869 individuals were sampled, representing 61 species, 14 families and six orders. Significant relationships of the Shannon-Wiener index and IBI with SCAS scores and stream orders were found. Of all impacts that make up the SCAS score, only channel modifications were significantly correlated with IBI. These results indicate that the adaptation of the IBI was effective and performed better than the Shannon-Wiener diversity index when related directly to specific impact categories. The application of the IBI with the SCAS and the other variables was efficient in the tributaries of the Sinos River basin because it showed the biotic degradation in accordance with changes in physical habitat.

  18. The fish community as an indicator of biotic integrity of the streams in the Sinos River basin, Brazil.

    Science.gov (United States)

    Costa, P F; Schulz, U H

    2010-12-01

    The basin of the Sinos River, located in the northeastern part of Rio Grande do Sul state, Brazil, has been highly impacted by industrial and urban activities. Water quality is low because of domestic and industrial sewage discharges. Most of the tributaries have suffered drastic structural interventions like canalisations and the removal of riparian vegetation. The aims of this study were to: 1) assess the diversity of fish at 34 sampling sites in twenty-four tributaries of the Sinos River basin; 2) quantify impact level by the Shannon-Wiener diversity index and an adapted Index of Biotic Integrity (IBI); and 3) check the interference of environmental impacts, formerly quantified in a Stream Corridor Assessment Survey (SCAS), on the fish assembly and 4) compare the relationship between the IBI with stream order. Fish sampling was performed by electric fishing in the period from April 2004 to August 2006. A total of 4,869 individuals were sampled, representing 61 species, 14 families and six orders. Significant relationships of the Shannon-Wiener index and IBI with SCAS scores and stream orders were found. Of all impacts that make up the SCAS score, only channel modifications were significantly correlated with IBI. These results indicate that the adaptation of the IBI was effective and performed better than the Shannon-Wiener diversity index when related directly to specific impact categories. The application of the IBI with the SCAS and the other variables was efficient in the tributaries of the Sinos River basin because it showed the biotic degradation in accordance with changes in physical habitat.

  19. Evolution of the Rodgers Creek–Maacama right-lateral fault system and associated basins east of the northward-migrating Mendocino Triple Junction, northern California

    Science.gov (United States)

    McLaughlin, Robert J.; Sarna-Wojcicki, Andrei M.; Wagner, David L.; Fleck, Robert J.; Langenheim, V.E.; Jachens, Robert C.; Clahan, Kevin; Allen, James R.

    2012-01-01

    The Rodgers Creek–Maacama fault system in the northern California Coast Ranges (United States) takes up substantial right-lateral motion within the wide transform boundary between the Pacific and North American plates, over a slab window that has opened northward beneath the Coast Ranges. The fault system evolved in several right steps and splays preceded and accompanied by extension, volcanism, and strike-slip basin development. Fault and basin geometries have changed with time, in places with younger basins and faults overprinting older structures. Along-strike and successional changes in fault and basin geometry at the southern end of the fault system probably are adjustments to frequent fault zone reorganizations in response to Mendocino Triple Junction migration and northward transit of a major releasing bend in the northern San Andreas fault. The earliest Rodgers Creek fault zone displacement is interpreted to have occurred ca. 7 Ma along extensional basin-forming faults that splayed northwest from a west-northwest proto-Hayward fault zone, opening a transtensional basin west of Santa Rosa. After ca. 5 Ma, the early transtensional basin was compressed and extensional faults were reactivated as thrusts that uplifted the northeast side of the basin. After ca. 2.78 Ma, the Rodgers Creek fault zone again splayed from the earlier extensional and thrust faults to steeper dipping faults with more north-northwest orientations. In conjunction with the changes in orientation and slip mode, the Rodgers Creek fault zone dextral slip rate increased from ∼2–4 mm/yr 7–3 Ma, to 5–8 mm/yr after 3 Ma. The Maacama fault zone is shown from several data sets to have initiated ca. 3.2 Ma and has slipped right-laterally at ∼5–8 mm/yr since its initiation. The initial Maacama fault zone splayed northeastward from the south end of the Rodgers Creek fault zone, accompanied by the opening of several strike-slip basins, some of which were later uplifted and compressed

  20. Hydrogeochemistry of high iodine groundwater: a case study at the Datong Basin, northern China.

    Science.gov (United States)

    Li, Junxia; Wang, Yanxin; Xie, Xianjun; Zhang, Liping; Guo, Wei

    2013-04-01

    High iodine concentrations in groundwater have seldom been reported and there have been few systematic studies on high iodine groundwater worldwide. To better understand the sources and processes responsible for iodine enrichment in the groundwater of the Datong Basin, the hydrochemical characteristics of groundwater and geochemical features of aquifer sediments were studied. High iodine groundwater mainly occurs in the center of the Datong Basin with iodine concentrations ranging between 3.31 and 1890 μg L(-1). Most samples with iodine concentrations higher than 500 μg L(-1) are from wells with depths between 75 and 120 m. High pH and a reducing environment are favorable for iodine enrichment in the groundwater, with iodide as the dominant species that accounts for 63.2-99.3% of the total iodine. Sediment samples from a borehole specifically drilled for this study contain 0.18-1.46 mg kg(-1) iodine that is moderately correlated with total organic carbon (TOC). The results of sequential extraction experiments show that iodine is mostly bound to iron oxyhydroxides and organic matter in the sediments. The mobilization processes of iodine are proposed to include reductive dissolution of iron oxyhydroxides and transformations among iodide, iodate and organic iodine driven by microbial activities under alkaline and reducing conditions.

  1. Snow cover dynamics and hydrological regime of the Hunza River basin, Karakoram Range, Northern Pakistan

    Directory of Open Access Journals (Sweden)

    A. A. Tahir

    2011-07-01

    Full Text Available A major proportion of flow in the Indus River is contributed by its snow- and glacier-fed river catchments situated in the Himalaya, Karakoram and Hindukush ranges. It is therefore essential to understand the cryosphere dynamics in this area for water resource management. The MODIS MOD10A2 remote-sensing database of snow cover products from March 2000 to December 2009 was selected to analyse the snow cover changes in the Hunza River basin (the snow- and glacier-fed sub-catchment of the Indus River. A database of daily flows for the Hunza River at Dainyor Bridge over a period of 40 yr and climate data (precipitation and temperature for 10 yr from three meteorological stations within the catchment was made available to investigate the hydrological regime in the area. Analysis of remotely sensed cryosphere (snow and ice cover data during the last decade (2000–2009 suggest a rather slight expansion of cryosphere in the area in contrast to most of the regions in the world where glaciers are melting rapidly. This increase in snow cover may be the result of an increase in winter precipitation caused by westerly circulation. The impact of global warming is not effective because a large part of the basin area lies under high altitudes where the temperature remains negative throughout most of the year.

  2. Miocene–Pliocene planktonic foraminiferal biostratigraphy of the Pearl River Mouth Basin, northern South China Sea

    Directory of Open Access Journals (Sweden)

    Liu Chunlian

    2012-07-01

    Full Text Available The present study deals with the planktonic foraminiferal biostratigraphy of the Miocene–Pliocene sequence of three petroleum exploration wells (BY7-1-1, KP6-1-1 and KP9-1-1 in the Pearl River Mouth Basin (PRMB. In general, the three wells contain a fairly well-preserved, abundant foraminiferal fauna. The proposed planktonic foraminiferal zonation follows the scheme updated by Wade et al. (2011. Nineteen planktonic foraminiferal zones have been recognized, 14 zones (zones M1–M14 for the Miocene and 5 zones (zones PL1–PL5 for the Pliocene. The zonation is correlated with previously published biostratigraphic subdivisions of the Neogene succession in the PRMB and with international foraminiferal zonations. The zonal boundaries are mostly defined by the last appearance datum of zonal taxa of planktonic foraminifera, which is more reliable than the FAD (first appearance datum events for ditch cutting sampling. Changes in the coiling of Globorotalia menardii (s. l. are also used to define the zonal boundaries, where no LADs (last appearance datum are available. The Fohsella fohsi group, comprising useful taxa for delimiting zonal boundaries of the middle Miocene in other areas, has a poor record within the Pearl River Mouth Basin due to unfavorable ecological conditions, and cannot be used for the studied wells. Different from the previously reported zonal scheme for the PRMB, the present zonation is based on correlation with the current standard planktonic foraminiferal zonation, with calibrated absolute ages.

  3. Late Permian non-marine-marine transitional profiles in the central Southern Permian Basin, northern Germany

    Science.gov (United States)

    Legler, B.; Gebhardt, U.; Schneider, J. W.

    2005-12-01

    The transition from Rotliegend to Zechstein within the Southern Permian Basin is one from continental desert to a marine environment. During the Upper Rotliegend II a huge playa lake existed there. This lake was temporarily influenced by precursors of the Zechstein transgression. Therefore the mega-playa evolved into a sabkha system. One of these early marine ingressions is known from an outcrop in Schleswig-Holstein. Laminated silt- and claystones, deposited within a standing water body, are intercalated in siltstones of a salt-flat environment. The lake sediments are characterised by high frequency cyclicity, shown by the sedimentary record and also by palaeontological data. The section contains fresh water as well as brackish-marine and marine fauna. Climatically forced cycles interact with marine incursions. After the Zechstein transgression had flooded the basin completely, sedimentation was controlled by sea-level fluctuations. Two sections, in the southern North Sea and in Schleswig-Holstein, are presented in this paper. Cyclicities with different frequencies controlled the sedimentation of the Kupferschiefer (T1) and the Werra Carbonate (Ca1). Sediments of the North Sea sequence were deposited within a shallow bay at the margin of an elevation. Therefore, the high frequency cyclicity became obvious within the sedimentary patterns and in the faunal content.

  4. Water-quality assessment of the Central Arizona Basins, Arizona and northern Mexico; environmental setting and overview of water quality

    Science.gov (United States)

    Cordy, Gail E.; Rees, Julie A.; Edmonds, Robert J.; Gebler, Joseph B.; Wirt, Laurie; Gellenbeck, Dorinda J.; Anning, David W.

    1998-01-01

    The Central Arizona Basins study area in central and southern Arizona and northern Mexico is one of 60 study units that are part of the U.S. Geological Survey's National Water-Quality Assessment program. The purpose of this report is to describe the physical, chemical, and environmental characteristics that may affect water quality in the Central Arizona Basins study area and present an overview of water quality. Covering 34,700 square miles, the study area is characterized by generally north to northwestward-trending mountain ranges separated by broad, gently sloping alluvial valleys. Most of the perennial rivers and streams are in the northern part of the study area. Rivers and streams in the south are predominantly intermittent or ephemeral and flow in response to precipitation such as summer thunderstorms. Effluent-dependent streams do provide perennial flow in some reaches. The major aquifers in the study area are in the basin-fill deposits that may be as much as 12,000 feet thick. The 1990 population in the study area was about 3.45 million, and about 61 percent of the total was in Maricopa County (Phoenix and surrounding cities). Extensive population growth over the past decade has resulted in a twofold increase in urban land areas and increased municipal water use; however, agriculture remains the major water use. Seventy-three percent of all water with drawn in the study area during 1990 was used for agricultural purposes. The largest rivers in the study area-the Gila, Salt, and Verde-are perennial near their headwaters but become intermittent downstream because of impoundments and artificial diversions. As a result, the Central Arizona Basins study area is unique compared to less arid basins because the mean surface-water outflow is only 528 cubic feet per second from a total drainage area of 49,650 square miles. Peak flows in the northern part of the study area are the result of snowmelt runoff; whereas, summer thunderstorms account for the peak flows in

  5. Taphonomic and paleoenvironmental considerations for the concentrations of macroinvertibrate fossils in the Romualdo Member, Santana Formation, Late Aptian - Early Albian, Araripe Basin, Araripina, NE, Brazil

    Science.gov (United States)

    Prado, Ludmila Alves Cadeira Do; Pereira, Priscilla Albuquerque; Sales, Alexandre Magno Feitosa; Barreto, Alcina Magnólia Franca

    2015-10-01

    Benthic macroinvertebrate fossils can be seen towards to the top of the Romualdo Member of the Santana Formation, in the Araripe Basin, Northeast Brazil, and can provide paleoenvironmental and paleobiogeographical information regarding the Cretaceous marine transgression which reached the interior basins in Northeast Brazil. We analyse taphonomic characteristics of macroinvertebrate concentrations of two outcrops (Torrinha and Torre Grande) within the municipality Araripina, Pernambuco, in order to enhance our understanding of the Cretaceous paleoenvironment in the western portion of the Araripe Basin. At the outcrop Torrinha, proximal tempestitic taphofacies were identified. These predominantly consist of ceritid, cassiopid, and later, naticid gastropods as well as undetermined bivalves. Given this lack of variability it can be deduced that there were no significant paleoenvironmental changes during the successive stages tempestitic sedimentation. In the Torre Grande outcrop distal to proximal tempestitic taphofacies were identified from the base to the top respectively pointing to a decrease in paleodepth. Asides from the macroinvertebrates present in Torrinha, there are also echinoids - unequivocal evidence for marine conditions. These occurrences appear to be restricted to Romualdo Member outcrops in the Araripina municipality (the Southeast portion of the Araripe Basin) confirming a previously published hypothesis suggesting that the Cretaceous marine transgression originated from the neighbouring Parnaíba Basin to the west. This study identified marine molluscs of a similar age to those in the Romualdo Member's equivalent rock units in the Parnaíba and Sergipe-Alagoas (SE-AL) basins suggesting a marine connection between these basins and the Araripe Basin during the Early Cretaceous.

  6. Miocene fish faunas from the northwestern Amazonia basin (Colombia, Peru, Brazil) with evidence of marine incursions

    NARCIS (Netherlands)

    Monsch, KA

    1998-01-01

    New evidence indicates marine influences during the Miocene in the northwestern Amazonia basin. This is the first major survey of the ichthyofauna from this area in the Miocene. Fossil fish remains from taxa such as the Dasyatoidea, Myliobatoidea, Characiformes, Siluriformes and Sciaenidae are

  7. Early Devonian (Late Emsian) shark fin remains (Chondrichthyes) from the Paraná Basin, southern Brazil.

    Science.gov (United States)

    Richter, Martha; Bosetti, Elvio P; Horodyski, Rodrigo S

    2017-01-01

    We report on the pioneering discovery of Devonian fish remains in the Paraná Basin, which represents the southernmost record of fishes from that period in mainland South America. The material comes from an outcrop at the lower portion of the São Domingos Formation, within Sequence C of the Paraná-Apucarana sub-basin in Tibagi, State of Paraná. Marine invertebrates are abundant in the same strata. The dark colored fish remains were collected in situ and represent natural moulds of partially articulated shark fin rays (radials). No elements such as teeth or prismatic cartilage have been preserved with the fins rays. This can be attributed to the dissolution of calcium-phosphatic minerals at the early stages of fossilization due to diagenetic processes possibly linked to strong negative taphonomic bias. This may have contributed to the fact that fishes remained elusive in the Devonian strata of this basin, despite substantial geological work done in the Paraná State in recent decades. In addition, the scarcity of fish fossils may be explained by the fact that the Devonian rock deposits in this basin originated in a vertebrate impoverished, cold marine environment of the Malvinokaffric Realm, as previously suspected.

  8. Early Devonian (Late Emsian shark fin remains (Chondrichthyes from the Paraná Basin, southern Brazil

    Directory of Open Access Journals (Sweden)

    MARTHA RICHTER

    Full Text Available ABSTRACT We report on the pioneering discovery of Devonian fish remains in the Paraná Basin, which represents the southernmost record of fishes from that period in mainland South America. The material comes from an outcrop at the lower portion of the São Domingos Formation, within Sequence C of the Paraná-Apucarana sub-basin in Tibagi, State of Paraná. Marine invertebrates are abundant in the same strata. The dark colored fish remains were collected in situ and represent natural moulds of partially articulated shark fin rays (radials. No elements such as teeth or prismatic cartilage have been preserved with the fins rays. This can be attributed to the dissolution of calcium-phosphatic minerals at the early stages of fossilization due to diagenetic processes possibly linked to strong negative taphonomic bias. This may have contributed to the fact that fishes remained elusive in the Devonian strata of this basin, despite substantial geological work done in the Paraná State in recent decades. In addition, the scarcity of fish fossils may be explained by the fact that the Devonian rock deposits in this basin originated in a vertebrate impoverished, cold marine environment of the Malvinokaffric Realm, as previously suspected.

  9. Reinterpretation of the tectonics and formation of the Pernambuco Plateau Basin, NE Brazil.

    Science.gov (United States)

    Hoggett, Murray; Jones, Stephen M.; Dunkley Jones, Tom; Reston, Timothy; Barbosa, Antonio; Biondo, Vanessa; Mort, Haydon P.

    2017-04-01

    The continental margin from Alagoas to Natal represents arguably the most frontier region for exploration on the Brazillian margin. High quality seismic data was not collected in the region for many decades as it was believed that only a few kilometers of sediment existed, and thus there was no exploration potential. Here we present the results of work done as part of an IODP virtual site survey. The work has resulted in a total reinterpretation of the basin structure and tectonics, including finding sediment filled half grabens holding up to 8km thick stratigraphic sections. The two deepest grabens likely represent rift jumps during breakup, which may imply different age sediments in the different grabens. The basin is also found to contain a sizable salt accumulation, previously uninterpreted due to hard overlying carbonates hampering seismic imaging. This salt can be seen to have been highly mobile in the past, and has developed into kilometer scale diapirs flanked by typical rollover anticlines. For the first time we show the basin has all the elements needed for a working petroleum system, with the exception a source rock - which cannot be speculated on further as the basin is undrilled. However source rock sequences are present in the Alagoas basin to the south, and recent released seep data show evidence for both biogeneic and thermogenic seeps over the plateau basin, which could also signal source rock presence. We present seismic and potential fields data, including forward potential fields models and seismically derived crustal stretching and thinning estimates, to show that the half grabens terminate abruptly at the latitude of the Pernambuco Shear Zone, a major crustal scale Precambrian shear zone. Onshore boreholes, well away from the deep seismically imaged half grabens offshore, find crystalline basement to drop away rapidly across the shearzone, revealing a third graben to terminate at the shear zone. We interpret this as that the preexisting

  10. The intraplate Maranhão earthquake of 2017 January 3, northern Brazil: evidence for uniform regional stresses along the Brazilian equatorial margin

    Science.gov (United States)

    Dias, Fábio L.; Assumpção, M.; Bianchi, Marcelo B.; Barros, Lucas V.; Carvalho, Juraci M.

    2018-04-01

    Lithospheric stresses in intraplate regions can be characterized by many different wavelengths. In some areas, stresses vary over short distances of less than ˜100 km, but in other regions uniform stresses can be recognized for more than ˜1000 km or so. However, not all intraplate regions are well sampled with stress measurements to allow a good characterization of the lithospheric stresses. On 2017 January 3, a magnitude mb 4 earthquake occurred near the equatorial coast of the Maranhão State, an aseismic area of northern Brazil. Despite the few permanent stations in northern Brazil, a well-constrained strike-slip mechanism was obtained from regional moment-tensor inversion. A detailed analysis of the backazimuths of aftershocks recorded by the closest station (˜40 km away) allowed the identification of the fault plane to be the NNW-SSE trending nodal plane. An estimate of the rupture length, about 2 km, was also possible. The strike-slip mechanism has coast-parallel P axis and coast-perpendicular T axis, in agreement with most of the focal mechanisms found further to the east. The coast parallel P axis is also similar to the SHmax orientations from breakouts measurements further along the coast. The Maranhão earthquake fills an important gap of stress indicators in northern Brazil and suggests that the intraplate stress field is uniform along the 2000 km long northern coast.

  11. Assessment of undiscovered conventional oil and gas resources, onshore Claiborne Group, United Statespart of the northern Gulf of Mexico Basin

    Science.gov (United States)

    Hackley, P.C.; Ewing, T.E.

    2010-01-01

    The middle Eocene Claiborne Group was assessed for undiscovered conventional hydrocarbon resources using established U.S. Geological Survey assessment methodology. This work was conducted as part of a 2007 assessment of Paleogene-Neogene strata of the northern Gulf of Mexico Basin, including the United States onshore and state waters (Dubiel et al., 2007). The assessed area is within the Upper Jurassic-CretaceousTertiary composite total petroleum system, which was defined for the assessment. Source rocks for Claiborne oil accumulations are interpreted to be organic-rich, downdip, shaley facies of the Wilcox Group and the Sparta Sand of the Claiborne Group; gas accumulations may have originated from multiple sources, including the Jurassic Smackover Formation and the Haynesville and Bossier shales, the Cretaceous Eagle Ford and Pearsall (?) formations, and the Paleogene Wilcox Group and Sparta Sand. Hydrocarbon generation in the basin started prior to deposition of Claiborne sediments and is currently ongoing. Primary reservoir sandstones in the Claiborne Group include, from oldest to youngest, the Queen City Sand, Cook Mountain Formation, Sparta Sand, Yegua Formation, and the laterally equivalent Cockfield Formation. A geologic model, supported by spatial analysis of petroleum geology data, including discovered reservoir depths, thicknesses, temperatures, porosities, permeabilities, and pressures, was used to divide the Claiborne Group into seven assessment units (AUs) with three distinctive structural and depositional settings. The three structural and depositional settings are (1) stable shelf, (2) expanded fault zone, and (3) slope and basin floor; the seven AUs are (1) lower Claiborne stable-shelf gas and oil, (2) lower Claiborne expanded fault-zone gas, (3) lower Claiborne slope and basin-floor gas, (4) lower Claiborne Cane River, (5) upper Claiborne stable-shelf gas and oil, (6) upper Claiborne expanded fault-zone gas, and (7) upper Claiborne slope and basin

  12. Sedimentological and geochronological evidences of anthropogenic impacts on river basins in the Northern Latium coastal area (Italy)

    Science.gov (United States)

    Piazzolla, Daniele; Paladini de Mendoza, Francesco; Scanu, Sergio; Marcelli, Marco

    2015-04-01

    In this work we aimed to compare sedimentological and geochronological data from three sediment core samples (MIG50, MRT50, and GRT50) taken in the Northern Latium (Italy) coastal area, at -50 m depth, to data regarding rainfall, river flows and the land use in the three most important hydrographic basins (Mignone, Marta and Fiora) and in the coastal area. Different trends of sediment mass accumulation rate (MAR) are detected in the three cores: a strongly increasing trend was identified in MIG50 and MRT50 cores while GRT50 doesn't show significant variation. Data from the sedimentological analysis of GRT50 core identify a progressive decrease in the sandy component, which declined from about 30% to the current level of 7% over the last 36 years, while MRT50 and MIG50 cores (mainly composed by pelitic fraction > 95%) showed slight variations of textural ratio between silt and clay. According to the general decrease of pluviometric trend observed in Italy, related to teleconnection pattern tendency (NAO), the statistical analysis of rain identified significative decrease only in the Fiora river basin, whereas in the other two locations the decrease was not as significant. Regarding the Fiora river flow, a significative decreasing trend of average flow is detected, while the flood regime remained unaffected over the past 30 years. The analysis of the land use shows that the human activities are increased of 6-10% over the available time steps (1990 - 2006) in Fiora and Mignone river basins, while the Marta river basin has a strong human impact since 1990 highligting more than 80% of artificial soil covering. The largest variation is observed on the Fiora basin (10%) where the antrhopic activities have expanded to an area of about 85 Km2. Moreover, in the last ten years a large beach nourishment in 2004 (570000 m3) and dredging activities in the early second half of 2000s (1000000 m3 moved) were performed in Marina di Tarquinia beach and in front of the Torrevaldaliga

  13. Post-rift magmatism in the Pearl River Mouth Basin, northern South China Sea

    Science.gov (United States)

    Xu, H.; Zhao, F.; Xia, S.; Sun, J.; Fan, C.

    2017-12-01

    Multi-beam, 2D seismic reflection and borehole data reveal that post-rift magmatism are widespread in the northern margin of South China Sea. A large-scale volcanic complex was identified at water depths of 500 to 3000 m, covering an area of ca. 8000 km2. This volcanic complex includes seamounts, igneous sills, dykes and intruded volcanic bodies. Combining data from exploration wells BY7-1 and BY2 with published seismic stratigraphic data, we can highlight multiple extrusive events from the Early Oligocene to Early Miocene, reflecting progressive continental breakup in the South China Sea. Most intruded magma through the continental crust also uplifted sediments up to the T6 unconformity. Given the evidence in this work that Early Miocene magmatic bodies were developed above or along faults, we suggest that post-rift magmatism in the northern margin of the South China Sea was largely controlled by the faults. Reactivation events in the faults are suggested to have generated preferential vertical pathways for the ascent of magma within a context of progressive continental breakup and thinned continental crust, as the South China Sea was being formed.

  14. INNOVATIVE METHODOLOGY FOR DETECTION OF FRACTURE-CONTROLLED SWEET SPOTS IN THE NORTHERN APPALACHIAN BASIN

    Energy Technology Data Exchange (ETDEWEB)

    Robert Jacobi; John Fountain

    2001-02-28

    In the structure task, we completed a N-S transect east of Seneca Lake that indicated a N-striking fault near the southeastern shore of Seneca Lake, and also indicated NE and ENE-trending FIDs and faults north of Valois. The orientation and existence of the NE-striking FIDs and faults are thought to be controlled by basement faults, rather than thrust ramps above the Salina salt controlled only by a far-field Alleghanian stress field. Structure contour maps based on well log analyses have been constructed but not interpreted. Soil gas data displayed a number of ethane-charged soil gas ''spikes'' on a N-S transect from Ovid south to near Valois. The soil gas team found a larger number of spikes in the northern half of the survey, suggesting more open fractures (and faults) in the northern half of the survey. Seismic data has been purchased and reprocessed. Several grabens observed in the Trenton reflector are consistent with surface structure, soil gas, and aeromagnetic anomalies. The aeromagnetic survey is completed and the data is processed. Prominent magnetic anomalies suggest that faults in the Precambrian basement are located beneath regions where grabens in the Trenton are located.

  15. Biostratigraphic analysis based on palynomorphs and ostracods from core 2-JNS-01PE, Lower Cretaceous, Jatobá Basin, northeastern Brazil

    Science.gov (United States)

    Nascimento, Luiz R. D. S. L.; Tomé, Maria E. T. R.; Barreto, Alcina M. F.; Holanda de Oliveira, David; Neumann, Virgínio H. M. L.

    2017-07-01

    This manuscript presents a biostratigraphic analysis based on non-marine palynomorphs and ostracods during the interval corresponding to the Aptian - lower Albian (local Alagoas stage) in the Jatobá Basin, northeastern Brazil. The data used for the analysis were from 179 samples collected in core 2-JSN-01-PE, which was drilled in the locality of Serra Negra, municipality of Ibimirim, Pernambuco. Of the 179 samples collected and prepared, only 23 presented ostracods, whereas 64 levels were carriers of organic waste, which aided in the biostratigraphic correlation of the studied core. From the palynological data, it was possible to identify the upper limit of the Inaperturopollenites turbatus (P-260) palynozone and the Sergipea variverrucata (P-270) palynozone and the lower limit of the Complicatisaccus cearensis (P-280) palynozone in the core 2-JSN-01-PE. Among the palynozones, the upper limit of P-260, whose record is difficult to track in northeastern Brazil and has been identified only in the Sergipe/Alagoas basin, and the limit of P-270 and P-280 in the Jatobá Basin, which had not yet been identified, can be highlighted. From the data based on non-marine ostracods, it was possible identify the "Cytheridea"? spp. ex. Group 201/218 Biozone (herein designated Damonella grandiensis), code 011. Such record in the Jatobá Basin is represented for a diverse fauna when compared with the record of monospecific fauna initially proposed in the Sergipe/Alagoas Basin.

  16. Molecular differentiation of species of the genus Zungaro (Siluriformes, Pimelodidae) from the Amazon and Paraná-Paraguay River basins in Brazil.

    Science.gov (United States)

    Boni, T A; Padial, A A; Prioli, S M A P; Lucio, L C; Maniglia, T C; Bignotto, T S; Panarari-Antunes, R S; Prioli, R A; Prioli, A J

    2011-11-10

    Fish species of the Zungaro genus (Siluriformes, Pimelodidae) are amongst the largest migratory fish in Latin America and have considerable economic importance for commercial fishing in Brazil. However, natural populations of this large catfish are experiencing a severe decline. There are significant taxonomical inconsistencies for this fish. Two geographically separated species of the fish were initially described, one endemic in the Amazon and another in the Paraná-Paraguay River basins. A taxonomic review had recently proposed that there is only one Zungaro species in Brazil, based on morphological data. We made a molecular study of Zungaro populations in an attempt to solve taxonomical inconsistencies and to analyze genetic diversity in natural populations of this genus. We analyzed two regions of the mitochondrial DNA (the control region and the ATPase 6 gene region) of individuals sampled from the Paraná-Paraguay River and Amazon River basins. Analyses based on p-distances and maximum likelihood phylogenetic models showed a genetic difference between populations corresponding to different species. Genetic differentiation between Zungaro populations was at the same level as that observed between other Siluriformes species, using the same DNA sequences. We conclude that Zungaro species of the Paraná-Paraguay River basin do not belong to the same species found in the Amazon basin. This finding has a significant implication for conservation of this fish, given that populations are disappearing at a high rate in the Paraná-Paraguay River basin, mainly due to impoundments.

  17. Population structure of the deep sea hermit-crab Catapaguroides microps (Paguroidea, Anomura in the Campos Basin, RJ, Brazil

    Directory of Open Access Journals (Sweden)

    Luana S. F. Lins

    2010-01-01

    Full Text Available The population of Catapaguroides microps A. Milne-Edwards and Bouvier, 1892 in the Campos Basin was studied with an emphasis on its composition in the Northern and Southern parts of the Basin, the different gender sizes, sex ratio, and size class distribution. Specimens were collected under the "Program for the Environmental Characterization of the deep waters of the Campos Basin" ("Programa de Caracterização Ambiental das Águas Profundas da Bacia de Campos" in February and August 2003. A total of 339 hermit crabs were analyzed. Individual abundance was higher in the North. C. microps shows sexual dimorphism for body size, the males being larger than the females. The sex ratio is skewed in the female's favor (1:0.7, as shown by previous studies on shallow-water populations.A população de Catapaguroides microps A. Milne-Edwards and Bouvier, 1892 da foi analisada com foco na abundância de indivíduos, diferença de tamanho entre machos e fêmeas, razão sexual e distribuição dos indivíduos nas classes de tamanho, ao norte e ao sul da Bacia de Campos. As amostras foram coletadas pelo Programa de Caracterização Ambiental da Bacia de Campos em fevereiro e agosto de 2003. O total de indivíduos analizados foi de 339. A abundância foi maior no norte da Bacia de Campos. Catapaguroides microps mostrou dimorfismo sexual no tamanho do corpo, sendo os machos maiores que as fêmeas. A razão sexual favorece as fêmeas (1:0,7, de forma similar a outros estudos efetuados com populações de águas rasas.

  18. Hydrogeochemistry of co-occurring geogenic arsenic, fluoride and iodine in groundwater at Datong Basin, northern China

    Energy Technology Data Exchange (ETDEWEB)

    Pi, Kunfu; Wang, Yanxin, E-mail: yx.wang@cug.edu.cn; Xie, Xianjun, E-mail: xjxie@cug.edu.cn; Su, Chunli; Ma, Teng; Li, Junxia; Liu, Yaqing

    2015-12-30

    Highlights: • Co-mobilization of As, F and I was identified at Datong Basin. • Both As and I are released via reductive dissolution of Fe minerals. • Some amounts of As and I may be sequestered by FeS precipitates. • Intensive evaporation promotes retention of As but mobilization of F and I. - Abstract: Abnormal levels of co-occurring arsenic (As), fluorine (F) and iodine (I) in groundwater at Datong Basin, northern China are geochemically unique. Hydrochemical, {sup 18}O and {sup 2}H characteristics of groundwater were analyzed to elucidate their mobilization processes. Aqueous As, F and I ranged from 5.6 to 2680 μg/L, 0.40 to 3.32 mg/L and 10.1 to 186 μg/L, respectively. High As, F and I groundwater was characterized by moderately alkaline, high HCO{sub 3}{sup −}, Fe(II), HS{sup −} and DOC concentrations with H{sub 3}AsO{sub 3}, F{sup −} and I{sup −} as the dominant species. The plots of δ{sup 18}O values and Cl/Br ratios versus Cl{sup −} concentration demonstrate build-up of more oxidizing conditions and precipitation of carbonate minerals induced by vertical recharge and intensive evaporation facilitate As retention to Fe (hydr) oxides, but enhance F and I mobilization from host minerals. Under reducing conditions, As and I can be simultaneously released via reductive dissolution of Fe (hydr) oxides and reduction of As(V) and I(V) while F migration may be retarded due to effects of dissolution-precipitation equilibria between carbonate minerals and fluorite. With the prevalence of sulfate-reducing condition and lowering of HCO{sub 3}{sup −} concentration, As and I may be sequestered by Fe(II) sulfides and F is retained to fluorite and on clay mineral surfaces.

  19. Local climate change induced by groundwater overexploitation in a high Andean arid watershed, Laguna Lagunillas basin, northern Chile

    Science.gov (United States)

    Scheihing, Konstantin; Tröger, Uwe

    2017-08-01

    The Laguna Lagunillas basin in the arid Andes of northern Chile exhibits a shallow aquifer and is exposed to extreme air temperature variations from 20 to -25 °C. Between 1991 and 2012, groundwater levels in the Pampa Lagunillas aquifer fell from near-surface to 15 m below ground level (bgl) due to severe overexploitation. In the same period, local mean monthly minimum temperatures started a declining trend, dropping by 3-8 °C relative to a nearby reference station. Meanwhile, mean monthly maximum summer temperatures shifted abruptly upwards by 2.7 °C on average in around 1996. The observed air temperature downturns and upturns are in accordance with detected anomalies in land-surface temperature imagery. Two major factors may be causing the local climate change. One is related to a water-table decline below the evaporative energy potential extinction depth of 2 m bgl, which causes an up-heating of the bare soil surface and, in turn, influences the lower atmosphere. At the same time, the removal of near-surface groundwater reduces the thermal conductivity of the upper sedimentary layer, which consequently diminishes the heat exchange between the aquifer (constant heat source of 10 °C) and the lower atmosphere during nights, leading to a severe dropping of minimum air temperatures. The observed critical water-level drawdown was 2-3 m bgl. Future and existing water-production projects in arid high Andean basins with shallow groundwater should avoid a decline of near-surface groundwater below 2 m bgl and take groundwater-climate interactions into account when identifying and monitoring potential environmental impacts.

  20. Evaluation of high-resolution satellite precipitation products with surface rain gauge observations from Laohahe Basin in northern China

    Directory of Open Access Journals (Sweden)

    Shan-hu Jiang

    2010-12-01

    Full Text Available Three high-resolution satellite precipitation products, the Tropical Rainfall Measuring Mission (TRMM standard precipitation products 3B42V6 and 3B42RT and the Climate Precipitation Center's (CPC morphing technique precipitation product (CMORPH, were evaluated against surface rain gauge observations from the Laohahe Basin in northern China. Widely used statistical validation indices and categorical statistics were adopted. The evaluations were performed at multiple time scales, ranging from daily to yearly, for the years from 2003 to 2008. The results show that all three satellite precipitation products perform very well in detecting the occurrence of precipitation events, but there are some different biases in the amount of precipitation. 3B42V6, which has a bias of 21%, fits best with the surface rain gauge observations at both daily and monthly scales, while the biases of 3B42RT and CMORPH, with values of 81% and 67%, respectively, are much higher than a normal receivable threshold. The quality of the satellite precipitation products also shows monthly and yearly variation: 3B42RT has a large positive bias in the cold season from September to April, while CMORPH has a large positive bias in the warm season from May to August, and they all attained their best values in 2006 (with 10%, 50%, and −5% biases for 3B42V6, 3B42RT, and CMORPH, respectively. Our evaluation shows that, for the Laohahe Basin, 3B42V6 has the best correspondence with the surface observations, and CMORPH performs much better than 3B42RT. The large errors of 3B42RT and CMORPH remind us of the need for new improvements to satellite precipitation retrieval algorithms or feasible bias adjusting methods.

  1. Studying Petrophysical and Geomechanical Properties of Utica Point-Pleasant Shale and its Variations Across the Northern Appalachian Basin

    Science.gov (United States)

    Raziperchikolaee, S.; Kelley, M. E.; Burchwell, A.

    2017-12-01

    Understanding petrophysical and geomechanical parameters of shale formations and their variations across the basin are necessary to optimize the design of a hydraulic fracturing program aimed at enhancing long term oil/gas production from unconventional wells. Dipole sonic logging data (compressional-wave and shear-wave slowness) from multiple wells across the study area, coupled with formation bulk density log data, were used to calculate dynamic elastic parameters, including shear modulus, bulk modulus, Poisson's ratio, and Young's modulus for the shale formations. The individual-well data were aggregated into a single histogram for each parameter to gain an understanding of the variation in the properties (including brittleness) of the Utica Point-Pleasant formations across the entire study area. A crossplot of the compressional velocity and bulk density and a crossplot between the compressional velocity, the shear velocity, and depth of the measurement were used for a high level petrophysical characterization of the Utica Point-Pleasant. Detailed interpretation of drilling induced fractures recorded in image logs, and an analysis of shear wave anisotropy using multi-receiver sonic logs were also performed. Orientation of drilling induced fractures was measured to determine the maximum horizontal stress azimuth. Also, an analysis of shear wave anisotropy to predict stress anisotropy around the wellbore was performed to determine the direction of maximum horizontal stress. Our study shows how the detailed interpretation of borehole breakouts, drilling induced fractures, and sonic wave data can be used to reduce uncertainty and produce a better hydraulic fracturing design in the Utica Point Pleasant formations across the northern Appalachian Basin region of Ohio.

  2. Hydrological Responses to Various Land Use, Soil and Weather Inputs in Northern Lake Erie Basin in Canada

    Directory of Open Access Journals (Sweden)

    Prasad Daggupati

    2018-02-01

    Full Text Available In the last decade, Lake Erie, one of the great lakes bordering Canada and the USA has been under serious threat due to increased phosphorus levels originating from agricultural fields. Large scale watersheds contributing to Lake Erie from the USA side are being simulated using hydrological and water quality (H/WQ models such as the Soil and Water Assessment Tool (SWAT and the results from the model are being used by policy and decision makers to implement better management decisions to solve emerging phosphorus issues. On the Canadian side, modeling applications are limited to either small watersheds or one major watershed contributing to Lake Erie. To the best of our knowledge, no efforts have been made to model the entire contributing watersheds to Lake Erie from Canada. This study applied the SWAT model for Northern Lake Erie Basin (NLEB; entire contributing basin to Lake Erie. Various provincial, national and global inputs of weather, land use and soil at various resolutions was assessed to evaluate the effects of input data types on the simulation of hydrological processes and streamflows. Twelve scenarios were developed using the input combinations and selected scenarios were evaluated at selected locations along the Grand and Thames Rivers using model performance statistics, and graphical comparisons of time variable plots and flow duration curves (FDCs. In addition, various hydrological components such as surface runoff, water yield, and evapotranspiration were also evaluated. Global level coarse resolution weather and soil did not perform better compared to fine resolution national data. Interestingly, in the case of land use, global and national/provincial land use were close, however, fine resolution provincial data performed slightly better. This study found that interpolated weather data from Environment Canada climate station observations performed slightly better compared to the measured data and therefore could be a good choice

  3. Local climate change induced by groundwater overexploitation in a high Andean arid watershed, Laguna Lagunillas basin, northern Chile

    Science.gov (United States)

    Scheihing, Konstantin; Tröger, Uwe

    2018-05-01

    The Laguna Lagunillas basin in the arid Andes of northern Chile exhibits a shallow aquifer and is exposed to extreme air temperature variations from 20 to -25 °C. Between 1991 and 2012, groundwater levels in the Pampa Lagunillas aquifer fell from near-surface to 15 m below ground level (bgl) due to severe overexploitation. In the same period, local mean monthly minimum temperatures started a declining trend, dropping by 3-8 °C relative to a nearby reference station. Meanwhile, mean monthly maximum summer temperatures shifted abruptly upwards by 2.7 °C on average in around 1996. The observed air temperature downturns and upturns are in accordance with detected anomalies in land-surface temperature imagery. Two major factors may be causing the local climate change. One is related to a water-table decline below the evaporative energy potential extinction depth of 2 m bgl, which causes an up-heating of the bare soil surface and, in turn, influences the lower atmosphere. At the same time, the removal of near-surface groundwater reduces the thermal conductivity of the upper sedimentary layer, which consequently diminishes the heat exchange between the aquifer (constant heat source of 10 °C) and the lower atmosphere during nights, leading to a severe dropping of minimum air temperatures. The observed critical water-level drawdown was 2-3 m bgl. Future and existing water-production projects in arid high Andean basins with shallow groundwater should avoid a decline of near-surface groundwater below 2 m bgl and take groundwater-climate interactions into account when identifying and monitoring potential environmental impacts.

  4. Seismic reflection-based evidence of a transfer zone between the Wagner and Consag basins: implications for defining the structural geometry of the northern Gulf of California

    Science.gov (United States)

    González-Escobar, Mario; Suárez-Vidal, Francisco; Hernández-Pérez, José Antonio; Martín-Barajas, Arturo

    2010-12-01

    This study examines the structural characteristics of the northern Gulf of California by processing and interpreting ca. 415 km of two-dimensional multi-channel seismic reflection lines (data property of Petróleos Mexicanos PEMEX) collected in the vicinity of the border between the Wagner and Consag basins. The two basins appear to be a link between the Delfín Superior Basin to the south, and the Cerro Prieto Basin to the north in the Mexicali-Imperial Valley along the Pacific-North America plate boundary. The seismic data are consistent with existing knowledge of four main structures (master faults) in the region, i.e., the Percebo, Santa María, Consag Sur, and Wagner Sur faults. The Wagner and Consag basins are delimited to the east by the Wagner Sur Fault, and to the west by the Consag Sur Fault. The Percebo Fault borders the western margin of the modern Wagner Basin depocenter, and is oriented N10°W, dipping (on average) ˜40° to the northeast. The trace of the Santa María Fault located in the Wagner Basin strikes N19°W, dipping ˜40° to the west. The Consag Sur Fault is oriented N14°W, and dips ˜42° to the east over a distance of 21 km. To the east of the study area, the Wagner Sur Fault almost parallels the Consag Sur Fault over a distance of ˜86 km, and is oriented N10°W with an average dip of 59° to the east. Moreover, the data provide new evidence that the Wagner Fault is discontinuous between the two basins, and that its structure is more complex than previously reported. A structural high separates the northern Consag Basin from the southern Wagner Basin, comprising several secondary faults oriented NE oblique to the main faults of N-S direction. These could represent a zone of accommodation, or transfer zone, where extension could be transferred from the Wagner to the Consag Basin, or vice versa. This area shows no acoustic basement and/or intrusive body, which is consistent with existing gravimetric and magnetic data for the region.

  5. Zircon fission track and U–Pb dating methods applied to São Paulo and Taubaté Basins located in the southeast Brazil

    International Nuclear Information System (INIS)

    Curvo, E.A.C.; Tello S, C.A.; Carter, A.; Dias, A.N.C.; Soares, C.J.; Nakasuga, W.M.; Resende, R.S.; Gomes, M.R.; Alencar, I.; Hadler, J.C.

    2013-01-01

    Zircon samples from the Cenozoic São Paulo and Taubaté Basins and Mantiqueira Mountain Range (southeast Brazil) were concomitantly dated by zircon Fission Track Method (FTM) and in situ U–Pb dating method. While FTM detrital-zircon data are ideally used to provide low-temperature information, U–Pb single detrital grain ages record the time of zircon formation in igneous or high grade metamorphic environments. This methodology may be used to study the possible sources of the basins sediments. The results suggest that the São Paulo Basin is composed of sediments from just one source, the Mantiqueira Mountain Range. On the other hand, the Taubaté Basin presents further sediment sources besides the Mantiqueira Mountain Range. - Highlights: ► Zircons from São Paulo and Taubaté Basins were dated by FTM and U–Pb. ► The zircon ages were compared with ages from the Mantiqueira Mountain Range (source). ► Results suggest the Mantiqueira is the source of sediments for the São Paulo Basin. ► The Taubaté Basin presents further sediment sources besides the Mantiqueira

  6. Temporal and spatial constraints on the evolution of a Rio Grande rift sub-basin, Guadalupe Mountain area, northern New Mexico

    Science.gov (United States)

    Thompson, R. A.; Turner, K. J.; Cosca, M. A.; Drenth, B.; Hudson, M. R.; Lee, J.

    2013-12-01

    The Taos Plateau volcanic field (TPVF) in the southern San Luis Valley of northern New Mexico is the most voluminous of the predominantly basaltic Neogene (6-1 Ma) volcanic fields of the Rio Grande rift. Volcanic deposits of the TPVF are intercalated with alluvial deposits of the Santa Fe Group and compose the N-S-trending San Luis Basin, the largest basin of the northern rift (13,500 km2 in area). Pliocene volcanic rocks of the Guadalupe Mountain area of northern New Mexico are underlain by the southern end of one of the larger sub-basins of the San Luis Valley, the Sunshine sub-basin (~ 450 km2 in area) juxtaposed against the down-to-west frontal fault of the Precambrian-cored Sangre de Cristo Range. The sub-basin plunges northward and extends to near the Colorado-New Mexico border. The western margin (~15 km west of the Sangre de Cristo fault) is constrained by outcrops of Oligocene to Miocene volcanic rocks of the Latir volcanic field, interpreted here as a broad pre-Pliocene intra-rift platform underlying much of the northern TPVF. The southern sub-basin border is derived, in part, from modeling of gravity and aeromagnetic data and is interpreted as a subsurface extension of this intra-rift platform that extends southeastward to nearly the Sangre de Cristo range front. Broadly coincident with this subsurface basement high is the northwest-trending, curvilinear terminus of the down-to-northeast Red River fault zone. South of the gravity high, basin-fill alluvium and ~3.84 Ma Servilleta basalt lava flows thicken along a poorly exposed, down-to-south, basin-bounding fault of the northern Taos graben, the largest of the San Luis Valley sub-basins. The uppermost, western sub-basin fill is exposed along steep canyon walls near the confluence of the Rio Grande and the Red River. Unconformity-bound, lava flow packages are intercalated with paleo Red River fan alluvium and define six eruptive sequences in the Guadalupe Mountain area: (1) Guadalupe Mtn. lavas (dacite ~5

  7. Climate and Streamflow Reconstruction on the São Francisco Basin, Brazil, Using Tree-Ring Data

    Science.gov (United States)

    Pereira, G. D. A.; Barbosa, A. C. M. C.; Granato-Souza, D.; Stahle, D. W.; Torbenson, M.; dos Santos, R. M.; Rodrigues Alves Delfino Barbosa, J. P.

    2017-12-01

    The São Francisco River crosses the most drought-prone region of Brazil and regional economic dynamics are dependent on the water availability in the basin. The seasonally dry forests are widely distributed in the basin, where Cedrela fissilis Vell (cedro) are frequently found. This semi-arid region provides a favorable setting where the deciduous cedro trees form well-defined semi-ring porous annual rings that can be exactly crossdated and used to build climate sensitive chronologies. Therefore, we have developed chronologies of cedro from seasonally dry forest fragments of three sites located in the middle-sector of the São Francisco River basin and south limit of the Brazilian Drought Polygon. The samples were analyzed according to standard procedures: sample preparation, ring count, crossdating and measurement of the tree rings. Dating quality was tested using the computer program COFECHA and ring-width time series where detrended and standardized to produce the final index chronology using the ARSTAN program. The results show that crossdating within and among trees from different sites demonstrate the potential to expand the spatial sampling. The tree-ring chronologies are sensitive with wet season precipitation totals (October - March), and can explain approximately 40% of the variance (1961-2015). Significant correlation was also observed with total annual discharge of the Rio São Francisco River measured at Barra (r=0.48; 1961-2015). However, the correlation disapears after 1993 (r=0.64 for 1961-1993, but r=-0.004 for 1994-2015) and we suspect that the stream gage at Barra has been impacted by human activity. Tree-ring chronologies can provide important information on climate and streamflow variability of São Francisco River, where hydrological records are often short and discontinuous. This chronology is now being extended with 150-yr old trees from the region and may be used to reconstruct climate and streamflow records back to the pre

  8. Estimation of flow components by recursive filters: case study of Paracatu River Basin (SF-7), Brazil

    OpenAIRE

    Renato Moreira Hadad; Paulo Pereira Martins Junior; Vitor Vieira Vasconcelos

    2013-01-01

    The quantification of flow components is important for water resource management. The base, interflow, and runoff flows of nested basins of the Paracatu River (SF-7) were estimated with recursive signal filters in this study. At first, stationary analysis and multivariate gap filling were applied to the flow data. A methodology is presented, proposing filter calibration with the runoff influence and inflection of the recession curve for dry season. Filters are improved with a logic constraint...

  9. Fish, Barra Bonita River, upper Paraná River basin, state of Paraná, Brazil.

    Directory of Open Access Journals (Sweden)

    Bifi, A. G.

    2008-01-01

    Full Text Available The Barra Bonita River is an affluent of the left margin of the Ivaí River, upper Paraná River basin. Fishsamples were conduced in November 2006 (spring and in February 2007 (summer, in three sampling stations alongthe Barra Bonita River, using gill nets, casting nets, and sieves. Thirty one fish species were collected, which belong tofive orders, 14 families, and 25 genera. Among them, five are probably new to science.

  10. Hydrochemistry of the Parauari-Maues Acu river basin (Amazon region, Brazil)

    International Nuclear Information System (INIS)

    Bringel, S.R.B.

    1980-08-01

    The chemical composition of the Parauari-Maues Acu basin is studied through the determination of pH, calcium, magnesium, iron, chloride, sodium, potassium, zinc, copper and manganese. Four expeditions were made and samples were collected in 16 different points of the main course. Chemical analysis of the rivers waters shows seasonal flutuations of the concentrations of the elements in the main river as well as in the main afluents like Nambi river, Amana river and Urupadi river. (Author) [pt

  11. Morphology, sedimentary features and evolution of a large palaeo submarine canyon in Qiongdongnan basin, Northern South China Sea

    Science.gov (United States)

    Li, Xiangquan; Fairweather, Luke; Wu, Shiguo; Ren, Jianye; Zhang, Hongjie; Quan, Xiayun; Jiang, Tao; Zhang, Cheng; Su, Ming; He, Yunlong; Wang, Dawei

    2013-01-01

    The large Miocene-aged palaeo canyon that extents through the Qiongdongnan basin (QDNB) and Yinggehai basin (YGHB) of Northern South China Sea has been of considerable interest both economically and scientifically over the past decade. Stemmed from this, significant research has been employed into understanding the mechanism for its existence, incision, and sedimentary fill, yet debate remains. In the first case the canyon itself is actually quite anomalous. Alone from the size (over 570 km in length and more than 8 km in width (Yuan et al., 2009)), which is considerably more than most ancient deep-water channels (REFS), the canyon's sedimentary fill is also distinctly different. Some explanations have been given to explain the canyon's origin and existence, these include increased sediment supply from the Red River which is genetically linked to uplift of the Tibetan Plateau, lowstand turbidite and mass-transport activity, reactivation and dextral displacement of the Red River Fault zone inducing erosive gravity-flows, regional tilt of the QDNB and YGHB, paleo-seafloor morphology and seal-level fluctuations. With the application of new data obtained from interpretations of a large number of 2D seismic profiles, core and well log data, and tectonic and sedimentary analysis this contribution aims to: (1) Present models to explain the Canyon's sedimentary fill and basin plain deposits, which provided significant understanding of processes pre-, syn- and post-incision and; (2) review the plausibility and likelihood of each of the controlling mechanisms, hoping to shed light on this controversial aspect. We conclude that the final erosive event that shaped the canyon is dated at 5.5 Ma. The Canyon's unusual fill is a product of variation in the interaction between turbidity currents and MTD that blocked the canyon's axis, and the reduction in gravity flow energy through time; and therefore the complete succession represents one major erosive and cut event at 5.5 Ma and

  12. The 2001 - Present Triggered Seismicity Sequence in the Raton Basin of Southern Colorado/Northern New Mexico

    Science.gov (United States)

    Rubinstein, J. L.; Ellsworth, W. L.; McGarr, A.

    2012-12-01

    The occurrence of an earthquake of magnitude (M) 5.3 near Trinidad, CO, on 23 August 2011 renewed interest in the possibility that an earthquake sequence in this region that began in August 2001 is the result of industrial activities. Our investigation of this seismicity, in the Raton Basin of northern New Mexico and southern Colorado, led us to conclude that the majority, if not all of the earthquakes since August 2001 have been triggered by the deep injection of wastewater related to the production of natural gas from the coal-bed methane field here. The evidence that this earthquake sequence was triggered by wastewater injection is threefold. First, there was a marked increase in seismicity shortly after major fluid injection began in the Raton Basin. From 1970 through July of 2001, there were five earthquakes of magnitude 3 and larger located in the Raton Basin. In the subsequent 10 years from August of 2001 through the end of 2011, there were 95 earthquakes of magnitude 3 and larger. The statistical likelihood of this rate increase occurring naturally was determined to be 0.01%. Second, the vast majority of the seismicity is located close (within 5km) to active disposal wells in this region. Additionally, this seismicity is primarily shallow, ranging in depth between 2 and 8 km, with the shallowest seismicity occurring within 500 m depth of the injection intervals. Finally, these wells have injected exceptionally high volumes of wastewater. The 23 August 2011 M5.3 earthquake, located adjacent to two high-volume disposal wells, is the largest earthquake to date for which there is compelling evidence of triggering by fluid injection activities; indeed, these two nearly-co-located wells injected about 4.9 million cubic meters of wastewater during the period leading up to the M5.3 earthquake, more than 7 times as much as the disposal well at the Rocky Mountain Arsenal that caused damaging earthquakes in the Denver, CO, region in the 1960s. Much of the seismicity

  13. Late Neogene Sequence Stratigraphic Evolution of the Foz do Amazonas Basin, Brazil

    Science.gov (United States)

    Gorini, Christian; Haq, Bilal U.; Tadeu dos Reis, Antonio; Guizan Silva, Cleverson; Cruz, Alberto; Soares, Emilson; Grangeon, Didier

    2014-05-01

    The margin of the Foz do Amazonas Basin saw a shift from predominantly carbonate to siliciclastic sedimentation in the early late Miocene. By this time the Amazon shelf had also been incised by a canyon that allowed direct influx of sediment to the basin floor, thus confirming that the paleo-Amazon fan had already initiated by that time (9.5-8.3Ma). Above this interval, during a prolonged lowstand, Messinian third-order sequences are preserved only in the incised-valley fills of the canyon with no equivalent strata on the shelf. Third and fourth-order sequences younger than Messinian are preserved on the shelf after sea-level rise above the shelf by early Pliocene. Sequences younger than 3.8 Ma often show fourth-order cyclicity with average duration of 400 kyr (larger scale eccentricity cycles) often preserved in high sedimentation rate areas of river deltas. Mass wasting and transportation of slope sediments to the basin began to play an important role in sediment dispersal at least as far back as mid Pliocene, after rapid progradation had produced steeper slopes 23 more prone to failure.

  14. Conodont color alteration index and upper Paleozoic thermal history of the Amazonas Basin, Brazil

    Science.gov (United States)

    Cardoso, Cassiane Negreiros; Sanz-López, Javier; Blanco-Ferrera, Silvia; Lemos, Valesca Brasil; Scomazzon, Ana Karina

    2015-12-01

    The conodont color alteration index (CAI) was determined in elements from core samples of the Frasnian Barreirinha Formation (one well) and of the Pennsylvanian-Permian Tapajós Group (twenty three wells and one limestone quarry) in the Amazonas Basin. The thermal history of the basin is analyzed using the CAI value distribution represented in maps and stratigraphic sections through correlation schemes, and in conjunction with previously published data. The pattern of palaeotemperatures for CAI values of 1.5-3 is coincident with organic matter maturation under a sedimentary overburden providing diagenetic conditions in the oil/gas window. Locally, conodonts show metamorphism (CAI value of 6-7) in relation to the intrusion of diabase bodies in beds including high geothermal gradient evaporites. Microtextural alteration on the surface conodonts commonly shows several types of overgrowth microtextures developed in diagenetic conditions. Locally, recrystallization in conodonts with a high CAI value is congruent with contact metamorphism in relation to Mesozoic intrusions. The CAI values of 1.5 or 2 observed close to the surface in several areas of the basin may be interpreted in relation to a high thermal palaeogradient derived from the magmatic episode or/and to the local denudation of the upper part of the Paleozoic succession prior to this thermal event.

  15. The Neo-Alagoas in the Ceara, Araripe and Potiguar basins (Brazil): stratigraphic and paleoecologycal caracterization

    International Nuclear Information System (INIS)

    Hashimoto, A.T.; Appi, C.J.; Soldan, A.L.; Cerqueira, J.R.

    1987-01-01

    The stratigraphic analysis of the Alagoas Stage (local stage) in Ceara Basin allows the investigated interval to be divided into two parts, with distictive tectono-sedimentary and paleobiological features. The lower part shows non-marine environmental character and the upper part, informally named Aptian-Albian transition, contains marine organisms in certain levels. These records would represent the first phases of a primitive equatorial Atlantic Ocean in the area. The Trairi Beds at the top of the continental section were deposited in an environmental complex which includes a marginal sabkha, reflecting cyclical conditions of extreme aridity or humidity. Similar events have ocurred in the Potiguar Basin with the Ponta do Tubarao Beds and in Araripe Basin with the deposition of thinny calcareous and shale layers, here informally named ''Batateria Beds''. These environmental conditions provided an excellent setting for preservation of organic matter due to cyclical anoxic processes. The observation that the organic extracts from shales of all these strata are similar supports the hypothesis of correspondence of these events. (author) [pt

  16. Water seasonality in granting permits and impact of irrigation in the Dourados River basin, MS, Brazil

    Directory of Open Access Journals (Sweden)

    Diovany D. Ramos

    Full Text Available ABSTRACT The objective of this study was to evaluate water seasonality in the process of granting permits and the impact of irrigation in the Dourados River basin. For that, the hydrological behavior of the basin was analyzed. The minimal streamflows (Q7,10 and Q95, irrigation withdrawal flow (Qr and the percent variation of the grant flows relative to monthly seasonal period in relation to the monthly withdrawal flow were obtained. The results allowed to verify that using criteria based on the monthly streamflow allows for better management of water use, because it allows for greater utilization of this resource in times with high water availability and imposes a realistic restriction during critical periods. The average annual water withdrawal for irrigation in the basin during the studied period was on the order of 2.99 m3 s-1, and the withdrawal flow in the month of highest demand (August was 5.95 m3 s-1.

  17. A snapshot on prokaryotic diversity of the Solimões River basin (Amazon, Brazil).

    Science.gov (United States)

    Toyama, D; Santos-Júnior, C D; Kishi, L T; Oliveira, T C S; Garcia, J W; Sarmento, H; Miranda, F P; Henrique-Silva, F

    2017-05-18

    The Amazon region has the largest hydrographic basin on the planet and 
is well known for its huge biodiversity of plants and animals. However, 
there is a lack of studies on aquatic microbial biodiversity in the 
Solimões River, one of its main water courses. To investigate the 
microbial biodiversity of this region, we performed 16S rRNA gene clone 
libraries from Solimões River and adjacent rivers and lakes. Our question was which microorganisms inhabit the different types of aquatic 
environments in this part of the basin, and how diversity varies among 
these environments (rivers and lakes). The microbial 
diversity generating 13 clone libraries of the bacterial 16S rRNA gene 
and 5 libraries of the archaeal 16S rRNA gene was assessed. Diversity measured by several alpha diversity indices (ACE, Chao, Shannon and Simpson) revealed significant differences in diversity indices between lake and river samples. The site with higher microbial diversity was in the Solimões River (4S), downstream the confluence with Purus River. The most common bacterial taxon was the cosmopolitan Polynucleobacter genus, widely observed in all samples. The phylum Thaumarchaeota was the prevailing archaeal taxon. Our results provide the first insight into the microbial diversity of the world's largest river basin.

  18. Managing Waters of the Paraíba do Sul River Basin, Brazil: a Case Study in Institutional Change and Social Learning

    Directory of Open Access Journals (Sweden)

    Lori M. Kumler

    2008-12-01

    Full Text Available This article examines the implementation of integrated water-management institutions in the Paraíba do Sul River basin in southeast Brazil. It argues that social learning has been critical in facilitating reform implementation so far, and will likely continue to be an important factor for the future sustainability of the new management system. There has been a synergistic relationship between social learning and Brazil's water-reform hybrid governance institutions, in which social learning facilitated the implementation of the reform's new institutions, which in turn enabled further learning in the context of the river basin committee's decision-making process. Through interviews, surveys, and observations, we identified social-learning capacities, including trust, an ability to work together, and the committee's shared understanding of the institution's problems, possibilities, and mission. Effective management through social learning was demonstrated by the institution's adaptive capacity in the face of a severe drought.

  19. (Plio-)Pleistocene alluvial-lacustrine basin infill evolution in a strike-slip active zone (Northern Andes, Western-Central Cordilleras, Colombia)

    OpenAIRE

    SUTER, F.; NEUWERTH, R.; GORIN, G.; GUZMÁN, C.

    2009-01-01

    The (Plio)-Pleistocene Zarzal Formation was deposited in the Cauca Depression and Quindío-Risaralda Basin between the Western and Central Cordilleras (Northern Andes). This area is structurally located on the transcurrent Romeral Fault System (RFS). Because of the interaction between the Nazca plate and the Chocó-Panamá block (an active indenter), the RFS strike-slip component changes direction around the study zone (dextral in the south, senestral in the north). Zarzal sediments are the olde...

  20. Density and population structure of the natural regeneration of Scots pine (Pinus sylvestris L.) in the High Ebro Basin (Northern Spain)

    OpenAIRE

    González-Martínez, Santiago; Bravo, Felipe

    2001-01-01

    International audience; This paper presents the analysis of 11 natural regenerated stands in native Scots pine forests located in the High Ebro Basin (Northern Spain). The natural regeneration showed a continuous age distribution, early height differentiation and a high stability in the height position of seedlings. Total density and main crop (trees selected for future commercial harvest) density models were developed to study the relationship between natural regeneration and site variables....

  1. Growth of the Zagros Fold-Thrust Belt and Foreland Basin, Northern Iraq, Kurdistan

    Science.gov (United States)

    Koshnaw, Renas; Horton, Brian; Stockli, Daniel; Barber, Douglas; Ghalib, Hafidh; Dara, Rebwar

    2016-04-01

    The Zagros orogenic belt in the Middle Eastern segment of the Alpine-Himalayan system is among the youngest seismically active continental collision zones on Earth. However, due to diachronous and incremental collision, the precise ages and kinematics of shortening and deposition remain poorly understood. The Kurdistan region of the Zagros fold-thrust belt and foreland basin contains well-preserved Neogene wedge-top and foredeep deposits that include clastic nonmarine fill of the Upper Fars, Lower Bakhtiari, and Upper Bakhtiari Formations. These deposits record significant information about orogenic growth, fold-thrust dynamics, and advance of the deformation front. Thermochronologic and geochronologic data from thrust sheets and stratigraphic archives combined with local earthquake data provide a unique opportunity to address the linkages between surface and subsurface geologic relationships. This research seeks to constrain the timing and geometry of exhumation and deformation by addressing two key questions: (1) Did the northwestern Zagros fold-thrust belt evolve from initial thin-skinned shortening to later thick-skinned deformation or vice-versa? (2) Did the fold-thrust belt advance steadily under critical/supercritical wedge conditions involving in-sequence thrusting or propagate intermittently under subcritical conditions with out-of-sequence deformation? From north to south, apatite (U-Th)/He ages from the Main Zagros Thrust, the Mountain Front Flexure (MFF), and additional frontal thrusts suggest rapid exhumation by ~10 Ma, ~5 Ma, and ~8 Ma respectively. Field observations and seismic sections indicate progressive tilting and development of growth strata within the Lower Bakhtiari Formation adjacent to the frontal thrusts and within the Upper Bakhtiari Formation near the MFF. In the Kurdistan region of Iraq, a regional balanced cross section constrained by new thermochronometric results, proprietary seismic reflection profiles, and earthquake hypocenters

  2. Crustal structure of an exhumed IntraCONtinental Sag (ICONS): the Mekele Basin in Northern Ethiopia.

    Science.gov (United States)

    Alemu, T. B.; Abdelsalam, M. G.

    2017-12-01

    The Mekele Sedimentary Basin (MSB) in Ethiopia is a Paleozoic-Mesozoic IntraCONtinental Sag (ICONS) exposed due to Cenozoic domal and rift flank uplift associated with the Afar mantle plume and Afar Depression (AD). ICONS are formed over stable lithosphere, and in contrast to rift and foreland basins, show circular-elliptical shape in map view, saucer shaped in cross section, and concentric gravity minima. Surface geological features of the MSB have been shown to exhibit geologic characteristics similar to those of other ICONS. We used the World Gravity Map (WGM 2012) data to investigate subsurface-crustal structure of the MSB. We also used 2D power spectrum analysis and inversion of the gravity field to estimate the Moho depth. Our results show the Bouguer anomalies of the WGM 2012 ranges between 130 mGal and - 110 mGal with the highest values within the AD. Despite the effect of the AD on the gravity anomalies, the MSB is characterized by the presence of gravity low anomaly that reaches in places -110 mGal, especially in its western part. The Moho depth estimates, from both spectral analysis and inversion of the gravity data, is between 36 and 40 km depth over most of the western and southern margins of the MSB. However, as the AD is approached, in the eastern margins of the MSB, crustal thickness estimates are highly affected by the anomalously thin and magmatic segment of the AD, and the Moho depth range between 30 and 25 km. Our results are consistent with that of seismic studies in areas far from the MSB, but within the Northwestern Ethiopian Plateau where the MSB is located. Those studies have reported an abrupt decrease in Moho depth from 40 km beneath the Northwestern plateau, to 20 km in the adjacent AD. Though the MSB is small (100 kmX100 km) compared to other ICONS, and affected by the neighboring AD, it is characterized by elliptical gravity minima and a relatively thicker crust that gradually thickens away from the rift. In addition, seismic imaging

  3. Winter and spring mixing depths affect the trophic status and composition of phytoplankton in the northern meromictic basin of Lake Lugano

    Directory of Open Access Journals (Sweden)

    Marco SIMONA

    2003-08-01

    Full Text Available The trophic state of Lake Lugano is still too high to be acceptable, despite extensive recovery measures undertaken in recent decades which have resulted in a reduction of the external phosphorus load to the deepest of the lake's basins (northern basin; Zmax=286 m to fairly acceptable values. Since meromixis was established in the middle of last century, the deep hypolimnion of the northern basin (the layer between ca 100 m and the bottom has contained high quantities of nutrients (especially phosphorus which are a major potential source of internal load. When there are particularly strong winter mixing events, a portion of this phosphorus reserve is redistributed along the upper water column (0-100 m. The impact of meteo-climatic conditions on the plankton biocenosis were analysed using data collected in the northern basin (Gandria station during the three-year period 1998-2000. The phytoplankton composition, which is typical of eutrophicated waters, shows marked interannual variations, also depending on the degree of mixing of the waters at the start of the vegetative period. Though there is no steady pattern of typical dominant species / master species in the lake, there is a seasonal succession characterised by a marked development of diatoms in spring, and a predominance of chlorophyceans and cyanobacteria in summer and autumn. Under present conditions, the mechanisms of internal replenishment of nutrients towards the euphotic layer, due to the phenomena of late winter and spring mixing, constitute a significant source of nutrients for the spring and summer growth of phytoplankton. On the other hand, pronounced mixing phenomena, like those occurring in the two-year period 1999-2000, can reduce the hypolimnetic nutrient reserves and cause a decrease in the trophic potential of the basin, contrasting with an increase in algal biomass in the euphotic zone.

  4. A new occurrence of Anodontites tenebricosus (Bivalvia: Mycetopodidae) in the Sapucaí river basin, São Paulo, Brazil: environmental and conchological aspects

    OpenAIRE

    Troncon, EK.; Avelar, WEP

    2011-01-01

    The aim of this work was to register the occurrence of Anodontites tenebricosus (Bivalvia: Mycetopodidae) in the Sapucaí river basin, municipality of São Joaquim da Barra, São Paulo state, Brazil, associating its occurrence to the environment in which they are found, besides providing conchological data to contribute to the identification of the species. Fifty one specimens of Anodontites tenebricosus were studied regarding their conchological and morphometrical aspects. Strong correlations w...

  5. A new pale-spotted species of Hypostomus Lacépède (Siluriformes: Loricariidae from the rio Tocantins and rio Xingu basins in central Brazil

    Directory of Open Access Journals (Sweden)

    Cláudio H. Zawadzki

    Full Text Available A new species of the genus Hypostomus Lacépède (Siluriformes, Loricariidae from rio Tocantins and rio Xingu basins in central Brazil, is described. The new species is distinguished from its congeners by a unique combination of pale blotches over a darker background on head, body and fins, and conspicuous keels on head, predorsal region and lateral plates. Comments on the pale-spotted species of Hypostomus are provided.

  6. Intestinal parasites in a quilombola community of the Northern State of Espírito Santo, Brazil

    Directory of Open Access Journals (Sweden)

    Schayra Minine Damazio

    2013-06-01

    Full Text Available The aim of this study was to determine the occurrence of intestinal parasites in a quilombola community from the northern Espírito Santo, Brazil. Descendants of slaves who arrived in Brazil in the sixteenth century, this population settled in the municipality of São Mateus in 1858. Fresh fecal samples from 82 individuals who agreed to participate in the study were collected between August 2009 and July 2010, and immediately sent to the Clinical Laboratory of the Centro Universitário Norte do Espírito Santo of the Universidade Federal do Espírito Santo for analysis. Out of all the participants, 36 (43.9% were male and 46 (56.1% were female, whose ages ranged from six to 85 years. The study of the occurrence of intestinal parasites indicated that 35 individuals (42.7% were infected with at least one intestinal parasite. Among helminths, the most frequent were hookworms, with a rate of 14.6%. With regard to protozoa, Entamoeba coli, Entamoeba histolytica/Entamoeba dispar and Endolimax nana stood out, with frequencies of 23.2%, 8.5% and 4.9%, respectively. The occurrence of biparasitism was observed in 13 of the 82 subjects, accounting for 15.8%, and no cases of multiple parasitic infections were observed. It was concluded that the reduction of cases of intestinal diseases due to parasites will only be achieved with the improvement of basic sanitation and quality of life of quilombola populations.

  7. Recent changes in agrarian systems of the Microregion of Toledo and Northern Pioneer Territory in Paraná State, Brazil

    Directory of Open Access Journals (Sweden)

    Dimas Soares Júnior

    2017-05-01

    Full Text Available During the period of 1950 through 2000, a green-revolution-based model mostly for commodities boosted global agricultural production. From the 70’s, this design became consolidated in Brazil and other countries because of policies and strategies by states and private groups. However, some doubts has been raised on its environmental and socioeconomic issues, in special for family farming. This study aimed to contribute by identifying changes and resistance in agricultural structures, systems and demographic aspects of this model and its adoption by farmers. It was carried out in the state of Paraná - Brazil, within the microregion of Toledo and in the northern pioneer area, which represent the history and diversity of this state about socioeconomic and human aspects, as well as technical development. It was based on statistics of agricultural censuses (1970, 1975, 1980, 1985, 1996 and 2006, population censuses (1970, 1980, 1991, 2000 and 2010 and municipal agricultural production data (1980-2012. Data from both areas were compared to each other and analyzed in face of state changes. There has been a decrease in farming properties and rural population, with an outstanding decline in the number of young people and women. Moreover, results showed a large reduction of properties with 20 to 50 ha, and an increase in those of up to 2 ha. Such decline is due to technological standard changes throughout the period, as well as recent grants offered to rural areas, as housing and leisure spaces. Both regions showed expansion of soybean plantations, but integrating distinctively to agriculture and, finally, family farming continuity, despite the intense changes.

  8. Hydrogeochemistry of co-occurring geogenic arsenic, fluoride and iodine in groundwater at Datong Basin, northern China.

    Science.gov (United States)

    Pi, Kunfu; Wang, Yanxin; Xie, Xianjun; Su, Chunli; Ma, Teng; Li, Junxia; Liu, Yaqing

    2015-12-30

    Abnormal levels of co-occurring arsenic (As), fluorine (F) and iodine (I) in groundwater at Datong Basin, northern China are geochemically unique. Hydrochemical, (18)O and (2)H characteristics of groundwater were analyzed to elucidate their mobilization processes. Aqueous As, F and I ranged from 5.6 to 2680 μg/L, 0.40 to 3.32 mg/L and 10.1 to 186 μg/L, respectively. High As, F and I groundwater was characterized by moderately alkaline, high HCO3(-), Fe(II), HS(-) and DOC concentrations with H3AsO3, F(-) and I(-) as the dominant species. The plots of δ(18)O values and Cl/Br ratios versus Cl(-) concentration demonstrate build-up of more oxidizing conditions and precipitation of carbonate minerals induced by vertical recharge and intensive evaporation facilitate As retention to Fe (hydr) oxides, but enhance F and I mobilization from host minerals. Under reducing conditions, As and I can be simultaneously released via reductive dissolution of Fe (hydr) oxides and reduction of As(V) and I(V) while F migration may be retarded due to effects of dissolution-precipitation equilibria between carbonate minerals and fluorite. With the prevalence of sulfate-reducing condition and lowering of HCO3(-) concentration, As and I may be sequestered by Fe(II) sulfides and F is retained to fluorite and on clay mineral surfaces. Copyright © 2015 Elsevier B.V. All rights reserved.

  9. [Monitoring of soil salinization in Northern Tarim Basin, Xinjiang of China in dry and wet seasons based on remote sensing].

    Science.gov (United States)

    Yao, Yuan; Ding, Jian-Li; Zhang, Fang; Wang, Gang; Jiang, Hong-Nan

    2013-11-01

    Soil salinization is one of the most important eco-environment problems in arid area, which can not only induce land degradation, inhibit vegetation growth, but also impede regional agricultural production. To accurately and quickly obtain the information of regional saline soils by using remote sensing data is critical to monitor soil salinization and prevent its further development. Taking the Weigan-Kuqa River Delta Oasis in the northern Tarim River Basin of Xinjiang as test object, and based on the remote sensing data from Landsat-TM images of April 15, 2011 and September 22, 2011, in combining with the measured data from field survey, this paper extracted the characteristic variables modified normalized difference water index (MNDWI), normalized difference vegetation index (NDVI), and the third principal component from K-L transformation (K-L-3). The decision tree method was adopted to establish the extraction models of soil salinization in the two key seasons (dry and wet seasons) of the study area, and the classification maps of soil salinization in the two seasons were drawn. The results showed that the decision tree method had a higher discrimination precision, being 87.2% in dry season and 85.3% in wet season, which was able to be used for effectively monitoring the dynamics of soil salinization and its spatial distribution, and to provide scientific basis for the comprehensive management of saline soils in arid area and the rational utilization of oasis land resources.

  10. Stable isotope record of Eemian seasonal temperature from MIS 5e tufa stromatolite; Somme Basin, Northern France

    Science.gov (United States)

    Dabkowski, J.; Andrews, J.; Antoine, P.; Marca-Bell, A.

    2013-03-01

    In many modern to sub-fossil deposits tufa formations, very well crystallised deposits called stromatolites are preserved. These are often strongly laminated deposits, the laminae linked to seasonal climatic and environmental variations. Where found in fossil tufas such deposits have huge potential as high resolution archives of Pleistocene climate. One of the first investigations of this type has been performed on a 2.5 cm-radius stromatolite from the Eemian sequence of Caours (Somme Basin, Northern France), where precise observations in thin section have been combined with intra-lamina δ18O and δ13C analyses. Independent interpretations of petrographical and geochemical data are strongly coherent and demonstrate a clear seasonal signal. Moreover, as δ18O is temperature dependent, we have quantified likely maximum water temperature variations between summer and winter at Caours. A small mismatch between the δ18O derived temperature values and the typical modern range is observed, which may reflect a real difference between modern and Eemian temperature seasonality. This study supports previous investigations performed on a laminated tufa from central Greece and clearly confirms the potential of tufa stromatolites as records of seasonal climatic information and for the quantification of riverine water temperature variations.

  11. Impact of reclaimed water in the watercourse of Huai River on groundwater from Chaobai River basin, Northern China

    Science.gov (United States)

    Yu, Yilei; Song, Xianfang; Zhang, Yinghua; Zheng, Fandong; Liu, Licai

    2017-12-01

    Reclaimed water is efficient for replenishing the dry rivers in northern China, but regional groundwater may be at risk from pollution. Therefore, samples of reclaimed water, river water, and groundwater were collected at the Huai River in the Chaobai River basin in 2010. The water chemistry and isotopic compositions of the samples were analyzed in the laboratory. The reclaimed water had stable compositions of water chemistry and isotopes, and the Na·Ca-HCO3·Cl water type. The water chemistry of the river water was consistent with that of the reclaimed water. A June peak of total nitrogen was the prominent characteristic in the shallow groundwater, which also had the Na·Ca-HCO3·Cl water type. However, the water chemistry and isotopes in most of the deep groundwater remained stable, and the water type was Ca·Mg-HCO3. The amount of reclaimed water recharging the groundwater was about 2.5 × 107 m3/yr. All of the shallow groundwater was impacted by the reclaimed water, with the mixing proportion of reclaimed water ranging from 42% to 80 % in the dry season and from 20% to 86% in the wet season. Only one deep well, with proportions of 67% (dry season) and 28% (wet season), was impacted. TDS, EC, and major ions (Na, K, Cl, NH4-N, NO2-N, and NO3-N) were increased in the impacted wells.

  12. Norovirus diversity in diarrheic children from an African-descendant settlement in Belém, Northern Brazil.

    Directory of Open Access Journals (Sweden)

    Glicélia Cruz Aragão

    Full Text Available Norovirus (NoV, sapovirus (SaV and human astrovirus (HAstV are viral pathogens that are associated with outbreaks and sporadic cases of gastroenteritis. However, little is known about the occurrence of these pathogens in relatively isolated communities, such as the remnants of African-descendant villages ("Quilombola". The objective of this study was the frequency determination of these viruses in children under 10 years, with and without gastroenteritis, from a "Quilombola" Community, Northern Brazil. A total of 159 stool samples were obtained from April/2008 to July/2010 and tested by an enzyme immunoassay (EIA and reverse transcription-polymerase chain reaction (RT-PCR to detect NoV, SaV and HAstV, and further molecular characterization was performed. These viruses were detected only in the diarrheic group. NoV was the most frequent viral agent detected (19.7%-16/81, followed by SaV (2.5%-2/81 and HAstV (1.2%-1/81. Of the 16 NoV-positive samples, 14 were sequenced with primers targeting the B region of the polymerase (ORF1 and the D region of the capsid (ORF2. The results showed a broad genetic diversity of NoV, with 12 strains being classified as GII-4 (5-41.7%, GII-6 (3-25%, GII-7 (2-16.7%, GII-17 (1-8.3% and GI-2 (1-8.3%, as based on the polymerase region; 12 samples were classified, based on the capsid region, as GII-4 (6-50%, being 3-2006b variant and 3-2010 variant, GII-6 (3-25%, GII-17 (2-16.7% and GII-20 (1-8.3%. One NoV-strain showed dual genotype specificity, based on the polymerase and capsid region (GII-7/GII-20. This study provides, for the first time, epidemiological and molecular information on the circulation of NoV, SaV and HAstV in African-descendant communities in Northern Brazil and identifies NoV genotypes that were different from those detected previously in studies conducted in the urban area of Belém. It remains to be determined why a broader NoV diversity was observed in such a semi-isolated community.

  13. 26Al/10Be burial dating of Xujiayao-Houjiayao site in Nihewan Basin, northern China.

    Directory of Open Access Journals (Sweden)

    Hua Tu

    Full Text Available The Xujiayao-Houjiayao site in Nihewan Basin is among the most important Paleolithic sites in China for having provided a rich collection of hominin and mammalian fossils and lithic artifacts. Based on biostratigraphical correlation and exploratory results from a variety of dating methods, the site has been widely accepted as early Upper Pleistocene in time. However, more recent paleomagnetic analyses assigned a much older age of ∼500 ka (thousand years. This paper reports the application of 26Al/10Be burial dating as an independent check. Two quartz samples from a lower cultural horizon give a weighted mean age of 0.24 ± 0.05 Ma (million years, 1σ. The site is thus younger than 340 ka at 95% confidence, which is at variance with the previous paleomagnetic results. On the other hand, our result suggests an age of older than 140 ka for the site's lower cultural deposits, which is consistent with recent post-infrared infrared stimulated luminescence (pIR-IRSL dating at 160-220 ka.

  14. Probable mixing state of aerosols in the Indo-Gangetic Basin, northern India

    Science.gov (United States)

    Dey, Sagnik; Tripathi, S. N.; Mishra, S. K.

    2008-02-01

    To investigate the probable mixing state of aerosols in the Indo-Gangetic Basin, six different mixing cases, viz. external mixing, internal mixing, and four combinations of core-shell type mixing (black carbon, BC over dust, water-soluble over dust, BC over water-soluble and water-soluble over BC) have been considered. Composite single scattering albedo (SSA) have been computed for six cases for post-monsoon, winter and pre-monsoon seasons and are compared with the Aerosol Robotic Network (AERONET) retrieved SSA values. The most probable mixing state in the post-monsoon season seems either to be external mixing or water-soluble coating over dust and in the winter season, the external mixing seems to be the probable mixing state. However, in the pre-monsoon season, BC coating over dust seems to be the most probable mixing state. This type of mixing leads to enhanced absorption and needs future attention to better understand the aerosol radiative effect in this region.

  15. Using AMS to Help Interpret Glaciogenic Deposits of the Late Paleozoic Ice Age in the Parana Basin, Brazil

    Science.gov (United States)

    Amato, James Anthony

    The term 'diamictite' is used as a lithologic descriptive term without assigning a particular origin to a rock unit as either glacial deposits (till), proglacial, glacially influenced deposits (resulting from meltwater plumes and ice rafted debris), or mass transport deposits (glacial or non-glacial related). While in some cases, it is possible to delineate between the origins of diamictites, in other instances, weathering and lack of exposures make it difficult to determine. In general, the occurrence of diamictites within the Gondwana succession has been traditionally used to indicate the occurrence of subglacial deposition despite the potential occurrence of other depositional modes. Thus, the extent of glaciation during the Late Paleozoic Ice Age is interpreted to be much greater than it actually was. . One area of interest in Gondwana where interpretation of these deposits is problematic, and hence has resulted in problems determining ice extent, is the Parana Basin in Brazil. The ability to better differentiate subglacial processes from proglacial, subaqueous mass transport, glaciomarine/glaciolacustrine rainout, and/or ice rafting, in addition to determining glacier flow or mass transport directions, will allow researchers studying these deposits to more accurately reconstruct the environments timing and extent of glaciation during the LPIA. In sedimentary fabrics, anisotropy of magnetic susceptibility (AMS) is a geophysical method, which depicts the preferred orientation of magnetic particles during the final stages of transport and/or synsedimentary deformation. The technique is used to determine the preferred orientation of the constituent grains, therefore a useful indicator to help determine the mode of deposition, direction of sediment transport, and the nature of stress and strain during deformation. In August of 2016, samples were collected from deposits assigned to the Itarare Group, which outcrop along the southern and eastern margins of the Parana

  16. Natural Arsenic in Groundwater and Alkaline Lakes at the upper Paraguay basin, Pantanal, Brazil

    OpenAIRE

    Barbiero, Laurent; Furquim, S.A.C.; Vallès, Vincent; Furian, S.; Sakamoto, Arnaldo; Rezende Filho, A.,; Fort, Monique

    2007-01-01

    A distinctive feature of Nhecolândia, a sub-region of the Pantanal wetland in Brazil, is the presence of both saline (alkaline) and freshwater lakes. Saline lakes were attributed to a past arid phase during the Pleistocene, but recent studies have shown that the geochemistry of the saline lakes arises from the current concentration process of fresh waters that is supplied to the Pantanal every year. The region is mainly used for cattle farming, more recently eco-tourism is becoming widespread...

  17. Occurrence and distribution of fresh-water molluscs in the Riacho Fundo Creek Basin, Brasilia, Brazil.

    Science.gov (United States)

    Martins-Silva, M J; Barros, M

    2001-01-01

    To study the distribution of molluscs in the Riacho Fundo Creek (cerrado region of central Brazil), five creek sites were sampled once every two months for one year. Molluscs were sampled using standardized kick-net sampling. Four species of molluscs were found: Physella cubensis, Melanoides tuberculata, Biomphalaria straminea and Pisidium sp. The most abundant were P. cubensis and Pisidium sp. Physella cubensis was most abundant in the dry season and Pisidium sp. was most abundant in the rainy season, probably reflecting the rainy season increase of water currents.

  18. Factors controlling the abundance of organic sulfur in flash pyrolyzates of Upper Cretaceous kerogens from Sergipe Basin, Brazil

    Science.gov (United States)

    Carmo, A.M.; Stankiewicz, B.A.; Mastalerz, Maria; Pratt, L.M.

    1997-01-01

    The molecular and elemental composition of immature kerogens isolated from Upper Cretaceous marine carbonates from Sergipe Basin, Brazil were investigated using combined pyrolysis-gas chromatography/mass spectrometry and organic petrographic techniques. The kerogens are predominantly composed of reddish-fluorescing amorphous organic matter (AOM) and variable amounts of yellow-fluorescing alginite and liptodetrinite. The abundance of organic sulfur in the kerogens inferred from the ratio 2-ethyl-5-methylthiophene/(1,2-dimethylbenzene + dec-1-ene) in the pyrolyzates is variable and may be related to changes in the type of primary organic input and/or to variations in rates of bacterial sulfate reduction. A concomitant increase in S/C and O/C ratios determined in situ using the electron microprobe is observed in AOM and alginites and may be related to a progressive oxidation of the organic matter during sulfurization. The S/C ratio of the AOM is systematically higher than the S C ratio of the alginites. Combined with a thiophene distribution characteristic of pyrolyzates of Type II organic matter, the higher S/C of AOM in Sergipe kerogens suggests that sulfurization and incorporation of low-molecular weight lipids derived from normal marine organic matter into the kerogen structure predominated over direct sulfurization of highly aliphatic algal biomacromolecules.The molecular and elemental composition of immature kerogens isolated from Upper Cretaceous marine carbonates from Sergipe Basin, Brazil were investigated using combined pyrolysis-gas chromatography/mass spectrometry and organic petrographic techniques. The kerogens are predominantly composed of reddish-fluorescing amorphous organic matter (AOM) and variable amounts of yellow-fluorescing alginite and liptodetrinite. The abundance of organic sulfur in the kerogens inferred from the ratio 2-ethyl-5-methylthiophene/(1,2-dimethylbenzene+dec-1-ene) in the pyrolyzates is variable and may be related to changes in

  19. The evolution of Neoproterozoic magmatism in Southernmost Brazil: shoshonitic, high-K tholeiitic and silica-saturated, sodic alkaline volcanism in post-collisional basins

    Directory of Open Access Journals (Sweden)

    Sommer Carlos A.

    2006-01-01

    Full Text Available The Neoproterozoic shoshonitic and mildly alkaline bimodal volcanism of Southernmost Brazil is represented by rock assemblages associated to sedimentary successions, deposited in strike-slip basins formed at the post-collisional stages of the Brasilian/Pan-African orogenic cycle. The best-preserved volcano sedimentary associations occur in the Camaquã and Campo Alegre Basins, respectively in the Sul-riograndense and Catarinense Shields and are outside the main shear belts or overlying the unaffected basement areas. These basins are characterized by alternation of volcanic cycles and siliciclastic sedimentation developed dominantly on a continental setting under subaerial conditions. This volcanism and the coeval plutonism evolved from high-K tholeiitic and calc-alkaline to shoshonitic and ended with a silica-saturated sodic alkaline magmatism, and its evolution were developed during at least 60 Ma. The compositional variation and evolution of post-collisional magmatism in southern Brazil are interpreted as the result mainly of melting of a heterogeneous mantle source, which includes garnet-phlogopite-bearing peridotites, veined-peridotites with abundant hydrated phases, such as amphibole, apatite and phlogopite, and eventually with the addition of an asthenospheric component. The subduction-related metasomatic character of post-collisional magmatism mantle sources in southern Brazil is put in evidence by Nb-negative anomalies and isotope features typical of EM1 sources.

  20. Chemical elements in soils of riverside areas of the Piracicaba river basin, São Paulo, Brazil

    International Nuclear Information System (INIS)

    França, Elvis J.; Lira, Marcelo B.G.; Paiva, José D.S.; Fernandes, Elisabete A. de N.; Fonseca, Felipe Y.; Rodrigues, Vanessa S.; Cavalca, Isabel P.O.; Camilli, Leandro

    2017-01-01

    The monitoring of the soil quality of the Piracicaba River Basin, located in the State of São Paulo, is of extreme environmental importance, as it ensures the functionality of the basin ecosystems and environmental protection. However, there are few studies focused on the concentration of chemical elements in soils of environmental protection zones of highly populated riverside regions. In view of the above, this work aims to determine the concentration of chemical elements in the soils located on the banks of the Piracicaba River by the Instrumental Neutronic Activation Analysis - INAA. Soil samples were collected in the 0-5 cm, 5-10 cm and 10-15 cm profiles. Subsequently, the samples were dried in an oven at 80 deg C and comminuted with the aid of mortar and pistil. 250 mg portions were transferred to polyethylene capsules and irradiated in 10 13 cm -2 .s -1 neutron flux for 4 hours at the IEA-R1 Nuclear Research Reactor of the Nuclear and Energy Research Institute -IPEN / SP, Brazil. The determination of the chemical elements was conducted by the k0-INAA method from the Quantu program. Comparing the results obtained with the soil values of an untouched area of Atlantic Forest - Carlos Botelho State Park, the maximum values obtained of As (29 mg / kg) and Zn (185 mg / kg) were about 5 times greater. However, concentrations of terrigenous elements such as Fe and Sc were also high in some cases, indicating that there is also a contribution of the source material (rocks) to the high concentrations observed in the riverside soils

  1. Mesozoic lacustrine system in the Parnaíba Basin, northeastern Brazil: Paleogeographic implications for west Gondwana

    Science.gov (United States)

    Cardoso, Alexandre Ribeiro; Nogueira, Afonso César Rodrigues; Abrantes, Francisco Romério; Rabelo, Cleber Eduardo Neri

    2017-03-01

    The fragmentation of the West Gondwana during Early Triassic to Cretaceous was marked by intense climatic changes, concomitant with the establishment of extensive desertic/lacustrine systems. These deposits succeeded the emplacement and extrusion of lava flows, related to the pre-rift phase and initial opening of the Equatorial Atlantic Ocean. The thermal phase is recorded in the Upper Jurassic-Lower Cretaceous Pastos Bons Formation, exposed mainly in southeast parts of the Parnaíba Basin, Northeastern Brazil. The sedimentary facies of this unit were grouped in two facies associations (FA), representative of a shallow lacustrine system, influenced by episodic hyperpycnal and oscillatory flows. Central lake facies association (FA1) is composed by laminated mudstone (Ml), sandstone/mudstone rhythmite (S/Mr) and sandstone with even-parallel lamination (Sel). Flysch-like delta front (FA2) consists in sandstones with wave structures (Sw), sandstones with even-parallel stratification (Ses), massive sandstones (Sm), sandstones with soft-sediment deformation structures (Sd) and laminated mudstones (Ml). FA1 was deposited in the deepest portions of the lake, characterized by low energy, episodically disturbed by siliciclastic influx. FA2 presents sandy deposits generated by unconfined flow, probably fed by ephemeral stream flows that generated thickening upward of tabular sandstone beds. The progressive filling of the lake resulted in recurrent shoaling up of the water level and reworking by wave action. The installation of Pastos Bons lakes was controlled by thermal subsidence, mainly in restricted depocenters. The siliciclastic fluvial inflow can be related to the adjacent humid desertic facies, formed under climatic attenuation, typical of post-Triassic period, with reduced biological activity. Smectite and abundant feldspars, in lacustrine facies, corroborate an arid climate, with incipient chemical weathering. The new facies and stratigraphic data present in this

  2. Relationships among vegetation, geomorphology and hydrology in the Bananal Island tropical wetlands, Araguaia River basin, Central Brazil

    Science.gov (United States)

    Valente, C. R.; Latrubesse, E. M.; Ferreira, L. G.

    2013-10-01

    The Bananal Plain spreading on the Middle Araguaia River basin in Central Brazil at the Cerrado-Amazonia ecotone is a unique system that sustains the largest seasonal wetlands of the Cerrado biome. The huge Bananal Plain is an intracratonic sedimentary basin filled with Pleistocene sediments of the Araguaia formation. Covering approximately two million hectares, the Bananal Island is a major geomorphologic feature of the Bananal plain. Fieldwork and the analysis of a temporal series of MODIS-VI and Landsat ETM images allowed us to discriminate Cerrado phyto-physiognomies on the Bananal Island. Maps of vegetation and geomorphologic units were created, and from the correlation between landforms and vegetation types we identified morpho-vegetation units. Our approach allowed us to postulate that Pleistocene landforms strongly influence, if not dominate, the distribution of vegetation units. For example, the distribution of current gallery forest is not only controlled by active floodplains, but also by alluvial belts abandoned by avulsion. Additionally, arboreal Cerrado vegetation is supported by laterite developed on the sediments of the Araguaia Formation. Some of these inactive landforms are in part modified by the present day geomorphologic processes and colonized by successional vegetation that varies from alluvial forest to Cerrado. Characterized by a very flat landscape with a hindered drainage, the muddy sediments of the Araguaia Formation and the high seasonal rainfall favor the development of regional seasonal wetlands. The Bananal plain is a key area for understanding the Quaternary climatic and biogeographic changes in tropical South America. The control exerted by relict Quaternary landforms on the current vegetation units demonstrates the strong links between geomorphologic aspects of the landscape and ecological patterns. This multidisciplinary approach provides a better understanding of the biogeographic patterns in the Cerrado-Amazon ecotone, which is

  3. Many objective optimization and impact assessment of water management options in the Jaguaribe Basin of North East Brazil

    Science.gov (United States)

    Hurford, A. P.; Huskova, I.; Matrosov, E.; Harou, J. J.

    2012-12-01

    The Jaguaribe river basin in the north east of Brazil lies in the country's driest state, Ceará. Rainfall is concentrated in six months of the year, evapotranspiration can reach 2000 mm per year and a high proportion of the population relies on irrigated agriculture for their subsistence or livelihood. The current water management strategy involves negotiating monthly release rates from each of the basin's three major reservoirs twice a year. The state water management company leads these negotiations with representatives of various water user groups; releases are decided based on the currently stored volume and limited modelling of release scenarios. Presently reservoirs are managed such that municipal demands are guaranteed for 30 months from the date of negotiation. We use multi-objective optimization to search for the pareto-optimal number of months of municipal demand to be guaranteed, and the shape of release rules (based on stored volume). System performance is assessed by comparing flow-duration curves and livelihood factors, such as riparian farm land availability and fishery quality , in addition to the satisfaction of demands in the region supplied by each reservoir. Historical monthly flows are used to simulate the system over 90 years. Results shows the trade-offs between different performance measures and the effects of management option combinations on different water users. A few climate change projections of reservoir inflows are used to assess how a selection of the resulting release rules might perform against the same measures under altered future hydrological conditions. The proposed approach helps planners evaluate the impacts of management options and allows finding balanced stakeholder-backed ways to reduce negative impacts on the environment and the region's vulnerable groups while maintaining overall system performance.

  4. New petrified forest in Maranhão, Permian (Cisuralian) of the Parnaíba Basin, Brazil

    Science.gov (United States)

    da Conceição, Domingas Maria; de Andrade, Luiz Saturnino; Cisneros, Juan Carlos; Iannuzzi, Roberto; Pereira, Agostinha Araújo; Machado, Francisco Carlos

    2016-10-01

    This work presents a new fossil plant-bearing area located in the municipalities of Duque Bacelar and Coelho Neto, Maranhão State, Brazil, recovered from lower Permian (Cisuralian) strata of the Pedra de Fogo Formation, northeastern portion of the Parnaíba Basin. The area comprises more than five exposures with assemblages formed mostly of large gymnosperm woods, a number of them in life-position (reaching up to ∼2.30 m in height and 1.15 m in diameter) and, in lesser degree, of horizontal tree-fern stems (up to 5 m in length), some of them being referable to Psaronius sp. The fossils are recorded in sedimentary beds of continental origin that accumulated in shallow, nearshore areas of large lakes, which eventually were affected by rapid burial episodes generated by non-channelized, high energy fluvial systems. The new fossil assemblages are included within lacustrine rocks placed at the base of the Pedra de Fogo Formation, i.e., Sílex Basal Member, near the contact with the underlying Piauí Formation (Pennsylvanian). This observation contrasts with previous studies at the southwestern portion of the basin, where the stratigraphic position of plant fossils is referred to the upper Pedra de Fogo Formation (Trisidela Member) or even to the overlying Motuca Formation. The new sites currently suffer damage from human activities and require urgent actions in order to protect them. Based on the current laws, some measures of protection for these sites are discussed and proposed herein. xml:lang="pt"

  5. Analyses of infrequent (quasi-decadal) large groundwater recharge events in the northern Great Basin: Their importance for groundwater availability, use, and management

    Science.gov (United States)

    Masbruch, Melissa D.; Rumsey, Christine; Gangopadhyay, Subhrendu; Susong, David D.; Pruitt, Tom

    2016-01-01

    There has been a considerable amount of research linking climatic variability to hydrologic responses in the western United States. Although much effort has been spent to assess and predict changes in surface water resources, little has been done to understand how climatic events and changes affect groundwater resources. This study focuses on characterizing and quantifying the effects of large, multiyear, quasi-decadal groundwater recharge events in the northern Utah portion of the Great Basin for the period 1960–2013. Annual groundwater level data were analyzed with climatic data to characterize climatic conditions and frequency of these large recharge events. Using observed water-level changes and multivariate analysis, five large groundwater recharge events were identified with a frequency of about 11–13 years. These events were generally characterized as having above-average annual precipitation and snow water equivalent and below-average seasonal temperatures, especially during the spring (April through June). Existing groundwater flow models for several basins within the study area were used to quantify changes in groundwater storage from these events. Simulated groundwater storage increases per basin from a single recharge event ranged from about 115 to 205 Mm3. Extrapolating these amounts over the entire northern Great Basin indicates that a single large quasi-decadal recharge event could result in billions of cubic meters of groundwater storage. Understanding the role of these large quasi-decadal recharge events in replenishing aquifers and sustaining water supplies is crucial for long-term groundwater management.

  6. Constraints on Passive Margin Escarpment Evolution from River Basin Reorganization in Brazil

    Science.gov (United States)

    Douglas, M.; Perron, J. T.; Fernandes, N.; DA Silva, L. M.

    2016-12-01

    Escarpments are present on passive margins around the world, but their evolution is poorly understood. Some geologists interpret escarpments as stationary features, whereas others have argued that they are retreating inland faster than one kilometer per million years. We investigated six Brazilian escarpments by determining whether or not the river networks on either side of the escarpment are in erosional equilibrium with each other using the recently developed technique of chi mapping. Our approach was based on the premise that rivers on opposite sides of a stationary escarpment erode at the same rate (erosional equilibrium), whereas rivers on opposite sides of a mobile escarpment erode at different rates (erosional disequilibrium). For comparison, we also compiled erosion rates on either side of the escarpments from cosmogenic 10Be measurements in the existing literature, and used these to calculate recent retreat rates of the escarpments, which fall between 4 and 40 m/Myr. We determined that chi mapping and cosmogenic erosion rates agree on the direction of escarpment movement. There is a weakly positive relationship across all sites between the degree of river basin disequilibrium and the retreat rate inferred from cosmogenic nuclides, but it is not highly significant. We also estimated the percentage of drainage area that was exchanged by stream capture as the escarpment drainage divide moved across the landscape. Using two different methods, we estimated that less than 40% of drainage area was exchanged by stream capture, making divide migration the dominant mechanism of drainage basin reorganization. If our estimates of recent escarpment retreat rates are representative of long-term rates, the Brazilian escarpments have retreated up to 5 km since their formation during the Cretaceous rifting event. Our analysis shows that the topographic retreat of the Brazilian escarpments could have been driven by drainage basin disequilibrium resulting in divide

  7. Chemical, mineralogical and ceramic properties of clays from Northern Santa Catarina, Brazil

    International Nuclear Information System (INIS)

    Correia, S.L.; Bloot, E.L.; Folgueras, M.V.; Hotza, D.

    2009-01-01

    Clay materials crop out in the northern Santa Catarina mining district were investigated in order to assess their potential in the ceramic industry. Four different clays (A, B, C and D) were selected. Their chemical composition was obtained by Xray fluorescence and their mineralogy by X-ray diffraction, coupled with numerical rational analysis. Their thermal behaviour was studied by differential thermal analysis. Technological testing consisted in a simulation of the industrial processing performed at a laboratory scale. The test pieces were obtained by pressing and fired in the range of 850-1200 deg C. In each case their technological properties were studied. The main mineralogical phases detected were kaolinite, quartz and mica. Hematite and feldspars may be present in the clays. The clays show two groups of particle sizes almost equally frequent in the range of 1 to 60 μm. The northern Santa Catarina clays are suitable for the production of bricks and earthenware in the 900- 1100 deg C range. (author)

  8. Freshwater gastropods in the Northern littoral mesoregion of Espírito Santo, Brazil

    Directory of Open Access Journals (Sweden)

    Marco Antônio Andrade de Souza

    2017-09-01

    Full Text Available Studies on the distribution of molluscs in Brazilhave been conducted since the beginning of the twentieth and the knowledge of the species distributed in the country represent important findings, which contribute to the understanding of human diseases and those of veterinary importance, transmitted by them. In order to verify the distribution of freshwater gastropods in Espírito Santo, a malacological surveywas carried out in nine municipalities that comprise the Northern mesoregion of the State, between January 2010 and February 2015. Initially the water collections occurring in the municipality were verified and the lotic systems at different levels of use and conservation were determined. Molluscs were collected monthly using a hand net adapted to a stick steel. An individual sample effort of 30 minutes was applied, by scanning, at about ten meters in each one of the selected habitats. A total of 6,000 specimens were collected, represented by genera Melanoides, Drepanotrema, Physa, Biomphalaria and Pomacea. Among the molluscs, some specimens were positive for flatworm larvae of medical and veterinary importance. The results contributed to the knowledge of the current distribution of freshwater gastropods in the Northern region of Espírito Santo whose the only record for the region dates back to 1983.

  9. Soil gamma ray spectrometry of the Buquira river basin, SP, Brazil

    International Nuclear Information System (INIS)

    Rivera, Alice

    2002-12-01

    Natural radioactivity found in rocks and its evaluation been frequently used for studies of environmental geochemistry, particularly those of detection and control of pollutants and the consequent changes in environment after antropic interferences. In this work natural radioactivity in forty nine soil samples in the basin of Buquira river, at the Northeast region of Sao Paulo State, has been analysed and measured with a Ge-HP gamma ray spectrometer. A table with the most relevant results found in rocks is shown and discussed. (author)

  10. A new species of Moenkhausia Eigenmann, 1903 (Characiformes, Characidae) from the rio Amazonas basin, Brazil.

    Science.gov (United States)

    Oliveira, Gustavo D; Marinho, Manoela M F

    2016-03-24

    Moenkhausia abyss is herein described from the rio Amazonas basin lowlands. The new species can be distinguished from the congeners by presenting the combination of the following characters: a dark blotch located on the upper caudal-fin lobe and the lower lobe hyaline, 25-29 branched anal-fin rays, humeral spot rectangular, vertically oriented, extending horizontally through two or two and a half scales and located over the third to the fifth lateral line scales, five longitudinal scale rows above the lateral line, predorsal scales arranged in a single not interrupted median row and 30-34 perforated lateral line scales. Brief comments on Moenkhausia megalops are provided.

  11. Results of the marine biota monitoring during drilling activity on Campos Basin, Brazil

    Energy Technology Data Exchange (ETDEWEB)

    Petta, Claudia Brigagao de; Bastos, Fabio; Danielski, Monica; Ferreira, Mariana; Gama, Mariana; Coelho, Ana Paula Athanazio; Maia, Decio [Aecom do Brasil Ltda, Rio de Janeiro, RJ (Brazil)

    2012-07-01

    The Environmental Monitoring Project (PMA) aims to report environmental changes arising from drilling activity, in relation to the marine fauna. This project can also help in the monitoring of accidental spills. Since the professionals spend six hours of the day monitoring the ocean around the rigs, they can locate and identify oil stains, notify the responsible onboard, and also help in the monitoring of the oil stain. Such Project has been developed onboard a drilling unit working in Campos Basin. The results presented here were collected during the drilling activity in Bijupira and Salema fields, by Shell Brasil Petroleo Ltda, from July 13th to October 8th, 2011.

  12. Pockmark asymmetry and seafloor currents in the Santos Basin offshore Brazil

    Science.gov (United States)

    Schattner, U.; Lazar, M.; Souza, L. A. P.; ten Brink, Uri S.; Mahiques, M. M.

    2016-01-01

    Pockmarks form by gas/fluid expulsion into the ocean and are preserved under conditions of negligible sedimentation. Ideally, they are circular at the seafloor and symmetrical in profile. Elliptical pockmarks are more enigmatic. They are associated with seafloor currents while asymmetry is connected to sedimentation patterns. This study examines these associations through morphological analysis of new multibeam data collected across the Santos continental slope offshore Brazil in 2011 (353–865 mbsl). Of 984 pockmarks, 78% are both elliptical and asymmetric. Geometric criteria divide the pockmarks into three depth ranges that correlate with a transition between two currents: the Brazil Current transfers Tropical Water and South Atlantic Central Water southwestwards while the Intermediate Western Boundary Current transfers Antarctic Intermediate Water northeastwards. It is suggested that the velocity of seafloor currents and their persistence dictate pockmark ellipticity, orientation and profile asymmetry. Fast currents (>20 cm/s) are capable of maintaining pockmark flank steepness close to the angle of repose. These morphological expressions present direct evidence for an edge effect of the South Atlantic Subtropical Gyre and, in general, provide a correlation between pockmark geometry and seafloor currents that can be applied at other locations worldwide.

  13. Geological and geochronological evidence for the effect of Paleogene and Miocene uplift of the Northern Ordos Basin on the formation of the Dongsheng uranium district, China

    Science.gov (United States)

    Zhang, Chuang; Yi, Chao; Dong, Qian; Cai, Yu-Qi; Liu, Hong-Xu

    2018-02-01

    The Dongsheng uranium district, located in the northern part of the Ordos Basin, contains the largest known sandstone-hosted uranium deposit in China. This district contains (from west to east) the Daying, Nalinggou, and Dongsheng uranium deposits that host tens of thousands of metric tonnes of estimated recoverable uranium resources at an average grade of 0.05% U. These uranium orebodies are generally hosted by the lower member of the Zhiluo Formation and are dominantly roll or tabular in shape. The uranium deposits in this district formed during two stages of mineralization (as evidenced by U-Pb dating) that occurred at 65-60 and 25 Ma. Both stages generated coffinite, pitchblende, anatase, pyrite, and quartz, with or without sericite, chlorite, calcite, fluorite, and hematite. The post-Late Cretaceous uplift of the Northern Ordos Basin exposed the northern margins of the Zhiluo Formation within the Hetao depression at 65-60 Ma, introducing groundwater into the formation and generating the first stage of uranium mineralization. The Oligocene (∼25 Ma) uplift of this northern margin exposed either the entirety of the southern flank of the Hetao depression or only the clastic sedimentary part of this region, causing a second gravitational influx of groundwater into the Zhiluo Formation and forming the second stage of uranium mineralization.

  14. Biogeography and comparative cytogenetics between two populations of Hoplias malabaricus (Bloch, 1794 (Ostariophysi: Erythrinidae from coastal basins in the State of Bahia, Brazil

    Directory of Open Access Journals (Sweden)

    Uedson Pereira Jacobina

    Full Text Available The species Hoplias malabaricus is a predator fish found in nearly all cis-Andean basins. From a cytogenetic point of view, this species comprises, at least, seven differentiated karyomorphs. Several localities have been formerly analyzed in Brazil, however, some regions, such as Bahia State, remain underrepresented. Recently, the Brazilian Environment Ministry classified both Itapicuru and Contas river basins (entirely located within Bahia territory as priority conservation areas, whose biodiversity status lacks enough information. Therefore, the goal of the present work was to characterize, cytogenetically, populations of H. malabaricus from both basins, by using conventional staining, Ag-NOR and C-banding techniques. All specimens presented a diploid number of 2n = 40 with metacentric/submetacentric chromosomes, without differences between sexes, thereby representing the so-called "karyomorph F". The first metacentric pair presented a remarkably larger size in relation to the other pairs. The NORs were multiple, comprising the terminal region on long arms of two chromosomal pairs in both populations. However, the C-banding pattern was somewhat distinguishable between samples. Although sharing heterochromatic blocks at centromeric region of all chromosomes, the population from Itapicuru River basin appeared to have some more conspicuous blocks than those observed in the population from Contas River basin. The similar karyotype observed in both populations suggests a common geological history between them. The present results represent an advance in the knowledge about the cytogenetic pattern of H. malabaricus populations from poorly studied basins.

  15. RECONNAISSANCE ASSESSMENT OF CO2 SEQUESTRATION POTENTIAL IN THE TRIASSIC AGE RIFT BASIN TREND OF SOUTH CAROLINA, GEORGIA, AND NORTHERN FLORIDA

    Energy Technology Data Exchange (ETDEWEB)

    Blount, G.; Millings, M.

    2011-08-01

    A reconnaissance assessment of the carbon dioxide (CO{sub 2}) sequestration potential within the Triassic age rift trend sediments of South Carolina, Georgia and the northern Florida Rift trend was performed for the Office of Fossil Energy, National Energy Technology Laboratory (NETL). This rift trend also extends into eastern Alabama, and has been termed the South Georgia Rift by previous authors, but is termed the South Carolina, Georgia, northern Florida, and eastern Alabama Rift (SGFAR) trend in this report to better describe the extent of the trend. The objectives of the study were to: (1) integrate all pertinent geologic information (literature reviews, drilling logs, seismic data, etc.) to create an understanding of the structural aspects of the basin trend (basin trend location and configuration, and the thickness of the sedimentary rock fill), (2) estimate the rough CO{sub 2} storage capacity (using conservative inputs), and (3) assess the general viability of the basins as sites of large-scale CO{sub 2} sequestration (determine if additional studies are appropriate). The CO{sub 2} estimates for the trend include South Carolina, Georgia, and northern Florida only. The study determined that the basins within the SGFAR trend have sufficient sedimentary fill to have a large potential storage capacity for CO{sub 2}. The deeper basins appear to have sedimentary fill of over 15,000 feet. Much of this fill is likely to be alluvial and fluvial sedimentary rock with higher porosity and permeability. This report estimates an order of magnitude potential capacity of approximately 137 billion metric tons for supercritical CO{sub 2}. The pore space within the basins represent hundreds of years of potential storage for supercritical CO{sub 2} and CO{sub 2} stored in aqueous form. There are many sources of CO{sub 2} within the region that could use the trend for geologic storage. Thirty one coal fired power plants are located within 100 miles of the deepest portions of

  16. Structure and Stratigraphy of the Rift Basins in the Northern Gulf of California: Results from Analysis of Seismic Reflection and Borehole Data.

    Science.gov (United States)

    Martín, A.; González, M.; Helenes, J.; García, J.; Aragón, M.; Carreño, A.

    2008-12-01

    The northern Gulf of California contains two parallel, north-south trending rift basin systems separated by a basement-high. The interpretation of several exploration wells, and ~4500 km of seismic reflection data from PEMEX (Mexican national oil company) indicate that the tectonically active basins to the west (Wagner- Consag and Upper Delfin basins) may have initiated synchronously with the now abandoned Tiburón- Tepoca-Altar basins to the east in the Sonora margin. In both basin systems the lower sequence (A) is marine mudstone-siltstone, has parallel reflectors and a largely uniform thickness that reaches up to1.5 km, and gradually pinches out toward the lateral margins. This suggests that the unit was deposited prior to their segmentation by transtensional faulting. Marine microfossils from borehole samples from sequence A in the Tiburón and Consag basins indicates middle Miocene (>11.2 Ma) proto-Gulf conditions. Sequence B conformably overlies sequence A, and is characterized by up to 2 km growth strata with a fanning geometry that show a clear genetic relationship to the major transtensional faults that control the segmentation of the two basin systems. Sequence C in the Tiburón and Tepoca basins is comparatively thin (<800 m) and includes several unconformities, but is much less affected by faulting. In contrast, sequence C in the active Wagner, Consag and Upper Delfin basin is a much thicker (up to 2 km) growth sequence with abundant volcanic intrusions. Marked variations in sequence C in the different basin systems clearly demonstrate a major westward shift of deformation and subsidence at this time. The modern depocenter in Wagner-Consag basins is controlled by the Consag and Wagner faults, which trend parallel to the north ~20 km apart, and show opposite normal offset. These two faults merge at an oblique angle (70°-50°, respectively) into the Cerro Prieto transform fault to the north and likely accommodate an important amount of dextral shear. To

  17. Pisces, Perciformes, Cichlidae, Laetacara dorsigera (Heckel, 1840): distribution extension and first record for Uruguay River basin, and state of Rio Grande do Sul, southern Brazil

    OpenAIRE

    Lanés, Luis; Maltchik, Leonardo; Lucena, Carlos

    2010-01-01

    The present study records for the first time the small cichlidae fish Laetacara dorsigera (Heckel, 1840) at Uruguay River basin and state of Rio Grande do Sul, southern Brazil, previously known from Amazon, Paraná and Paraguay River basins. Although the ichthyofauna of Uruguay River basin is relatively well known, this record suggests that there are still unexplored environments, such as wetlands, where there may be species not yet reported, and found in other hydrographic systems.

  18. Urbanization and runoff in the Tucunduba hydrographic basin, Belém, PA, Brazil

    Directory of Open Access Journals (Sweden)

    Nelson Wellausen Dias

    2012-08-01

    Full Text Available The present work investigated the runoff resulting from urban sprawl in the area of Tucunduba basin, in Belem, in the period between 1972 and 2006, which is characterized by a urbanization process started in the 1960s by low income population without adequate infrastructure services. Urbanization modifies the soil surface interfering on the ground phase of the hydrological cycle, inasmuch as it reduces the area of infiltration, increases runoff, and the runoff coefficient. A geographic database with land use and land cover map layers extracted from orthophotos acquired in 1972, 1977, and 1998 and a SPOT satellite image acquired in 2006 were used. Digital maps and analysis of the urbanization processes were supported by tools available in ArcGIS™ software package. To estimate the infiltration potential (S and effective rainfall (Pe, as a function of rainfall duration equal to the maximum time of concentration of the water in the basin, Curve Number methodology proposed by the Natural Resources Conservation Service (NRCS was applied. Rainfall estimates were calculated using the maximum rain equation for the city of Belém, with return times specified at 2, 5, 10, 15, 20, 25, 50, 100, and 200 years. The results showed an increase in areas of high and medium population density (urban and reduced area of low population density (secondary forest growth for the years of 1972, 1977, 1998, and 2006, that generated a higher effective precipitation value and, therefore, a higher effective runoff coefficient value (C.

  19. Biodiversity and community structure of zooplankton in the Sub-basin of Rio Poxim, Sergipe, Brazil

    Directory of Open Access Journals (Sweden)

    Eliane Maria de Souza Nogueira

    2011-08-01

    Full Text Available The zooplankton of aquatic environments is composed mostly of protozoans, rotifers, cladocerans and copepods, which play an important role in the food chain, transferring mass and energy from primary producers to higher trophic levels. This work was prepared with the objective of contributing to the knowledge of zooplankton biodiversity that occurs in the Sub-basin of Rio Poxim. Water samples were taken at monthly intervals at four sampling stations located along the sub-basin in the period August 2009 to July 2010. To obtain the zooplankton community, 100 L of water were filtered on nylon net with an aperture of 50 mm. Were identified 72 taxa distributed in the following taxonomic categories Rotifera, Protozoa, Porifera, Nematoda, Anellida, Cladocera, Copepoda, Ostracoda, Isopoda and Insecta. In terms of species richness, the phylum Rotifera followed by the Protoctista were the most relevant with forty and fifteen taxa, respectively. The most representative taxa in numerical terms were Arcella vulgaris, Notholca sp. Rotary sp. and nematodes. Regarding the community diversity index, the community was characterized as low diversity, but the taxa were distributed evenly in all monitoring points.

  20. A new species of Hisonotus (Siluriformes, Loricariidae from rio São Francisco basin, Brazil

    Directory of Open Access Journals (Sweden)

    Fábio Roxo

    2015-04-01

    Full Text Available A new species of Hisonotus is described from the rio São Francisco basin. The new species can be distinguished from congeners by having (1 a unique coloration pattern of caudal fin with one black spot extending from its origin to the ventral lobe and two dark spots at the end of the lobe’s rays; (2 odontodes forming longitudinally aligned rows on head and trunk; (3 a functional V-shaped spinelet; (4 a single rostral plate at the tip of the snout; (5 by lacking contrasting dark geometric spots on the anterodorsal region of the body; (6 a lower caudal-peduncle depth; and (7 lower counts of the lateral median plates and (8 higher premaxillary and dentary teeth. The new species is the second described species of the genus Hisonotus in the rio São Francisco basin. It was found inhabiting the marginal vegetation of the rio São Francisco and three of its tributary, rio das Velhas, rio Paraopeba and rio Formoso.

  1. New insights into Gondwana paleography based on palinological data from Morro do Chaves Formation (Sergipe-Alagoas Basin, Brazil)

    Science.gov (United States)

    Gonçalves Garcia, Gustavo; Vasconcellos Garcia, Antônio Jorge; Henriques, Maria Helena

    2016-04-01

    The Sergipe-Alagoas basin (NE Brazil) has been widely studied in the frame of oil exploration, because it displays the most complete exposition of the stratigraphic sequences from the basins of the Brazilian continental margin. In this context, the aim of this workis to present the results of the bio-stratigraphic and paleo-environmental analysis of Morro do Chaves Formation (Lower Cretaceous), in Alagoas Sub-basin, part of the transitional section situated between the rift phase and restricted marine environment associated with the South Atlantic ocean opening. The material was analyzed from the palynological point of view and was collected in the InterCement quarry, located in São Miguel dos Campos, State of Alagoas. From 17 outcrop rock samples collected, nine had palynological content; among these only six were considered for biostratigraphic analysis purposes. In addition to outcrop samples, 28 samples were processed from four core drill. The paleoenvironmental analysis was based on the palynological content of the collected samples and on the paleontological and geological information available. The studied sedimentary package corresponds to carbonate and fine siliciclastic deposits, with approximately 70.0 m in thickness. The unit in question is formed by carbonatic "coquinóides" rocks interspersed with shale levels of dark green color. Palinofloristic assemblages were recuperated between 5.0 m and 70.0 m of the outcropping section. In the recovered material it was possible to identify 9 kinds of spores and 8 kinds of pollen grains, and two genera of fungi. Due to the degree of preservation of the material, age was established by the occurrence of Dicheiropollis etruscus specimens, which has enabled the recognition of the Dicheiropollis etruscus palinozone (upper Barremian). In microscopic observations under fluorescent light some algalic vesicles components were also recognized and classified as possible algae of the Prasinophyceae class, indicating

  2. Millenial-scale climatic and vegetation changes in a northern Cerrado (Northeast, Brazil) since the Last Glacial Maximum

    Science.gov (United States)

    Ledru, Marie-Pierre; Ceccantini, Gregorio; Gouveia, Susy E. M.; López-Sáez, José Antonio; Pessenda, Luiz C. R.; Ribeiro, Adauto S.

    2006-05-01

    In the Southern Hemisphere, lacustrine sediments started to be deposited with the beginning of the deglaciation at ca 19,000 cal yr BP. At this time the region of Lake Caço was dominated by sparse and shrubby vegetation with dominance of steppic grasses in a poor sandy soil. The landscape did not present any ecological characteristics of a modern Cerrado. However single pollen grains of two Cerrado indicators, Byrsonima and Mimosa, suggest that some Cerrado species were able to survive under the prevailing arid climate, probably as small shrubs. After 15,500 cal yr BP, a sudden increase in the moisture rates is evidenced with the progressive expansion of rainforest showing successive dominance of various associations of taxa. The development of the forest stopped abruptly at the end of the Pleistocene between 12,800 and 11,000 cal yr BP, as attested by strong fires and the expansion of Poaceae. In the early Holocene an open landscape with a relatively high level of water in the lake preceded the progressive expansion of Cerrado species towards a denser forested landscape; fires are recorded from then on, resulting in the physiognomy of the Cerrado we know today. Late Pleistocene paleoenvironmental records from northern Brazil reflect the interplay between insolation forcing of two hemispheres with the local components represented by the interannual shift of the Inter Tropical Convergence Zone and the influence of seasonal equatorwards polar air incursions.

  3. Prevalence and clinical features of respiratory syncytial virus in children hospitalized for community-acquired pneumonia in northern Brazil

    Directory of Open Access Journals (Sweden)

    Lamarão Letícia

    2012-05-01

    Full Text Available Abstract Background Childhood pneumonia and bronchiolitis is a leading cause of illness and death in young children worldwide with Respiratory Syncytial Virus (RSV as the main viral cause. RSV has been associated with annual respiratory disease outbreaks and bacterial co-infection has also been reported. This study is the first RSV epidemiological study in young children hospitalized with community-acquired pneumonia (CAP in Belém city, Pará (Northern Brazil. Methods With the objective of determining the prevalence of RSV infection and evaluating the patients’ clinical and epidemiological features, we conducted a prospective study across eight hospitals from November 2006 to October 2007. In this study, 1,050 nasopharyngeal aspirate samples were obtained from hospitalized children up to the age of three years with CAP, and tested for RSV antigen by direct immunofluorescence assay and by Reverse Transcription Polymerase Chain Reaction (RT-PCR for RSV Group identification. Results RSV infection was detected in 243 (23.1% children. The mean age of the RSV-positive group was lower than the RSV-negative group (12.1 months vs 15.5 months, pppppp Conclusion The present study highlights the relevance of RSV infection in hospitalized cases of CAP in our region; our findings warrant the conduct of further investigations which can help design strategies for controlling the disease.

  4. Identification and phylogenetic inferences on stocks of sharks affected by the fishing industry off the Northern coast of Brazil

    Directory of Open Access Journals (Sweden)

    Luis Fernando da Silva Rodrigues-Filho

    2009-01-01

    Full Text Available The ongoing decline in abundance and diversity of shark stocks, primarily due to uncontrolled fishery exploitation, is a worldwide problem. An additional problem for the development of conservation and management programmes is the identification of species diversity within a given area, given the morphological similarities among shark species, and the typical disembarkation of processed carcasses which are almost impossible to differentiate. The main aim of the present study was to identify those shark species being exploited off northern Brazil, by using the 12S-16S molecular marker. For this, DNA sequences were obtained from 122 specimens collected on the docks and the fish market in Bragança, in the Brazilian state of Pará. We identified at least 11 species. Three-quarters of the specimens collected were either Carcharhinus porosus or Rhizoprionodon sp, while a notable absence was the daggernose shark, Isogomphodon oxyrhyncus, previously one of the most common species in local catches. The study emphasises the value of molecular techniques for the identification of cryptic shark species, and the potential of the 12S-16S marker as a tool for phylogenetic inferences in a study of elasmobranchs.

  5. Structure of parasites community in Chaetobranchopsis orbicularis (Cichlidae), a host from the Amazon River system in northern Brazil.

    Science.gov (United States)

    Tavares-Dias, Marcos; Oliveira, Marcos Sidney Brito

    2017-08-01

    The aim of this paper was to investigate the component communities of parasites in Chaetobranchopsis orbicularis from a tributary of the Amazon River system, in Northern Brazil. In 32 fish examined, 902,551 parasites were collected, including Ichthyophthirius multifiliis, Piscinoodinium pillulare, Sciadicleithrum geophagi, Posthodiplostomum sp., Clinostomum marginatum, Echinorhynchus paranensis, Neoechinorhynchus pterodoridis, and Dolops longicauda. I. multifiliis was the dominant and abundant parasite species. The ectoparasites presented aggregate dispersion, but the endoparasites showed random dispersion pattern. Mean species richness was 4.0 ± 1.5 parasites, mean Brillouin diversity (HB) was 0.33 ± 0.28, mean evenness was 0.15 ± 0.13, and Berger-Parker dominance (d) was 0.85 ± 0.17. The species richness of parasites and HB were positively correlated with the length of hosts. There was positive correlation between the abundance of P. pillulare and length and weight, between the abundance of I. multifiliis and weight, as well as between the abundance of E. paranensis and N. pterodoridis and the length of hosts. Body condition of the hosts was not affected by moderate parasitism. The low diversity of endoparasites indicates that C. orbicularis is a host with low position in the food web. This is the first record of all these parasites for C. orbicularis.

  6. Ectoparasites and endoparasites community ofAgeneiosus ucayalensis(Siluriformes: Auchenipteridae), catfish from Amazon River system in northern Brazil.

    Science.gov (United States)

    de Oliveira Ferreira, Drielly; Tavares-Dias, Marcos

    2017-09-01

    This study investigated the community of ectoparasites and endoparasites in Ageneiosus ucayalensis (Auchenipteridae) of a tributary from the Amazon River system, in Northern Brazil. Of 34 fish examined, 100% were parasitized by Ichthyophthirius multifiliis , Cosmetocleithrum bulbocirrus , Demidospermus sp., metacercariae of Genarchella genarchella , Clinostomum marginatum and Herpetodiplostomum sp., Procamallanus ( Spirocamallanus ) belenensis , Cucullanus ageneiosus and larvae of Contracaecum sp. digeneans C. marginatum and Herpetodiplostomum sp. were dominant parasite species, while I. multifiliis was the parasite with higher infection level. Such parasite species showed an aggregated dispersion, except P. ( S. ) belenensis , which showed a random dispersion. The Brillouin diversity (0.53 ± 0.29) was high, while evenness (0.28 ± 0.16) and species richness of parasites (3.7 ± 1.1) were low. The size of the hosts did not influence diversity, species richness and abundance of parasites. The ectoparasites were characterized by high prevalence and abundance, while endoparasites community presented low prevalence and abundance. The main factors responsible for structuring the parasite community in A. ucayalensis were mainly the behavior of this host and the availability of endoparasites infective stages in the environment. This was the first report of I. multifiliis , C. bulbocirus , Demidospermus sp., Contracaecum sp., C. marginatum , Herpetodiplostomum sp. and G. genarchella for A. ucayalensis . The presence of endohelminth larvae suggests that A. ucayalensis is part of the diet of other fish at the top of the food web in the Amazonian ecosystem studied.

  7. Infection by Neospora caninum in dairy cattle belonging to family farmers in the northern region of Brazil

    Directory of Open Access Journals (Sweden)

    Ricardo Vilas Boas

    Full Text Available Neosporosis is considered a major cause of abortion among cattle worldwide. The aim of this study was to investigate the prevalence of anti-Neospora caninum antibodies in dairy cattle and correlate them with possible risk factors on 63 small farms (family farms in the municipality of Ji-Paraná, the main milk-producing region of the state of Rondônia, northern Brazil. For this purpose, 621 serum samples were collected from cows and were evaluated by means of the indirect fluorescence antibody test (IFAT. The overall herd prevalence of N. caninum antibodies among the farms (38/63; 60.31% showed that N. caninum are widespread among the dairy herds in this region, despite only infecting a small proportion of animals (66/621, 10.62%. Occurrences of abortion and birth of weak calves were the only variables that showed as risk factors for the presence of N. caninum. The result from the spatial lag model strongly indicated that birth of weak calves and presence of N. caninum are occurring on farms that are located close to each other, indicating aggregation of disease occurrence.

  8. Temporal variation in the abundance of waterbird species in a coastal lagoon in the northern Rio de Janeiro, southeastern Brazil

    Directory of Open Access Journals (Sweden)

    Davi Castro Tavares

    2014-03-01

    Full Text Available This study evaluated the influence of different rainfall regimes on numerical fluctuations of waterbird species in Ribeira Lagoon, Quissamã, northern Rio de Janeiro state, Brazil. Bird counts were conducted on a monthly basis between August 2008 and July 2009, totaling 12 visits. Rainfall data were obtained at the nearest meteorological automatic station. A total of 50 species were classified into 6 functional groups. Bird richness and abundance were greater during the dry season (May/August. Spearman’s coefficient between bird abundance and monthly rainfall was -0.77 (P = 0.003. Similarly, there was a significant negative correlation between rainfall values and the abundance of dabbling, diving, and gleaning bird groups. The exponential prediction model was the most appropriate to the dataset (R² = 0.53, with a correlation coefficient between predicted and observed abundance values of 0.76 (P = 0.006. The model obtained predicts a significant decline in the total number of birds in months with rainfall over 100 mm in Ribeira Lagoon.

  9. Population dynamics of Libyostrongylus dentatus and L. douglassii of ostriches raised in the Northern Rio de Janeiro State, Brazil.

    Science.gov (United States)

    Lelis, Rosane Teixeira; de Andrade, Josiana Gomes; Vieira, Ricardo Augusto Mendonça; DaMatta, Renato Augusto; Santos, Clóvis de Paula

    2014-02-24

    Libyostrongylus genus contains three species of gastrointestinal nematodes that infect ostriches. Of these, only Libyostrongylus douglassii has been implicated in diseases and lower productivity. A morphological diagnosis method allowing the discrimination of infective larvae of L. douglassii and Libyostrongylus dentatus and the evaluation of eggs per gram of feces (EPG) was used to determine the population dynamics of both species from two ostrich farms located in the northern region of the state of Rio de Janeiro, Brazil. The presence of these nematodes was monitored every 15 days for two years. The average EPG was 4631 and 587 on farms 1 and 2, respectively. Overall, the highest values of EPG were associated with the rainy season on both farms. However, only on farm 1 the rainy season correlated statistically with EPG. Both species of Libyostrongylus occurred on both farms with a higher predominance (86%) of L. douglassii on farm 1, whereas the distribution of infection on farm 2 was more heterogeneous with a slight predominance of L. douglassii. The infection and the prevalence of these species may vary considerably according to the farm facilities, management adopted, and season. Copyright © 2013 Elsevier B.V. All rights reserved.

  10. A high 87Sr 86Sr mantle source for low alkali tholeiite, northern Great Basin

    Science.gov (United States)

    Mark, R.K.; Lee, Hu C.; Bowman, H.R.; Asaro, F.; McKee, E.H.; Coats, R.R.

    1975-01-01

    Olivine tholeiites, the youngest Tertiary units (about 8-11 m.y. old) at five widely spaced localities in northeastern Nevada, are geologically related to the basalts of the Snake River Plain, Idaho, to the north and are similar in major element and alkali chemistry to mid-ocean ridge basalts (MORB) and island arc tholeiites. The measured K (1250-3350 ppm), Rb (1??9-6??2 ppm) and Sr (140-240 ppm) concentrations overlap the range reported for MORB. Three of the five samples have low, unfractionated rare earth element (REE) patterns, the other two show moderate light-REE enrichment. Barium concentration is high and variable (100-780 ppm) and does not correlate with the other LIL elements. The rocks have 87Sr/86Sr = 0??7052-0??7076, considerably higher than MORB (~0??702-0??703). These samples are chemically distinct (i.e. less alkalic) from the olivine tholeiites from the adjacent Snake River Plain, but their Sr isotopic compositions are similar. They contain Sr that is distinctly more radiogenic than the basalts from the adjacent Great Basin. About 10 b.y. would be required for the mean measured Rb/Sr (~ 0??02) of these samples to generate, in a closed system, the radiogenic Sr they contain. The low alkali content of these basalts makes crustal contamination an unlikely mechanism. If the magma is uncontaminated, the time-averaged Rb/Sr of the source material must have been ~0??04. A significant decrease in Rb/Sr of the source material (a factor 2??) thus most probably occurred in the relatively recent (1??09 yr) past. Such a decrease of Rb/Sr in the mantle could accompany alkali depletion produced by an episode of partial melting and magma extraction. In contrast, low 87Sr 86Sr ratios indicate that the source material of the mid-ocean ridge basalts may have been depleted early in the Earth's history. ?? 1975.

  11. The Aquatic Environment as a Reservoir of Vibrio cholerae O1 in Hydrographic Basins of the State of Pernambuco, Brazil

    Science.gov (United States)

    Mendes-Marques, Carina Lucena; Silveira Filho, Vladimir da Mota; da Costa, Ana Paula Rocha; Nunes, Mariana de Lira; da Silva Filho, Sandoval Vieira; Figueirôa, Ângela Cristina Torres de Araújo; Hofer, Ernesto; de Almeida, Alzira Maria Paiva; Leal, Nilma Cintra

    2013-01-01

    After the worldwide cholera epidemic in 1993, permanent environmental monitoring of hydrographic basins was established in Pernambuco, Brazil, where cholera is endemic. After a quiescent period, 4 rfbN (serogroup O1) positive water samples that were culture negative were detected by multiplex single-tube nested PCR (MSTNPCR); 2 of these were also ctxA (cholera toxin) positive. From May to June 2012, 30 V. cholerae O1 isolates were obtained by culturing samples. These isolates were analyzed for the presence of virulence genes by PCR, intergenic spacer region 16S-23S PCR (ISR-PCR), and pulsed field gel electrophoresis (PFGE). The isolates were positive for the rfbN gene and negative for the assessed pathogenic genes and were classified into 2 groups by ISR and the same profile by PFGE. Close genetic similarity was observed between them (2012) and environmental strains from 2004 to 2005, indicating the permanence of endemic V. cholerae O1 in the region. PMID:23533357

  12. Cd, Cu, and Mn from Uruguay River Basin in Uruguaiana, RS, Brazil, and their toxicological potential for human leukocyte

    Directory of Open Access Journals (Sweden)

    Gislaine Rezer Costa

    2016-12-01

    Full Text Available This study assessed the limnology from the Medium Uruguay River Basin in Uruguaiana, Brazil, with a focus on the concentration of heavy metals (Cd, Cu, and Mn, to assess the toxicological potential (cytotoxicity and genotoxicity for humans using as biological matrix of study human leukocyte cells. The conductivity, resistivity, and dissolved O2 levels exceeded the limits recommended by the National Environmental Council (Conselho Nacional do Meio Ambiente - CONAMA. The percentage of non-viable human leukocyte cells exposed to water samples was approximately 20% higher than that of the negative control (<3%, but similar to the positive control. The DNA damage index was high for all heavy metal concentrations assayed when compared to the negative control 12±2.96, p < 0.0001, with a range of 155.66±23.89 to 194.33±23.23, but similar to the positive control (210.62±27.48. Moreover, the leukocyte degeneration index was higher in all samples containing heavy metals than in the negative control (4%, which demonstrates to be due the presence of Cu (11.8-12.5%, Cd (13-15.6%, and Mn (15.6-22.5%. Taken together, our results show that the quality from water samples analyzed is below than recommended by CONAMA and offers risk of contamination by heavy metals for the general population.

  13. Irradiation of quartz grains - a new method of sedimentological analysis applied to Permian - Carboniferous arenites in the Maranhao Basin - Brazil

    International Nuclear Information System (INIS)

    Carmo Faria Junior, L.E. do

    1980-01-01

    The quartz grains of sediments and sedimentary rocks change their colour in variable intensity to smoky-quartz by X-ray irradiation, Co 60 or in reactors, dependent on their temperature of cristallization. The quantity of quartz grains which were stained and which were not stained after being irradiated are related to rock types from the source areas. This method was applied for selected sandstones of different stratigraphical levels of the Permian-Carboniferous in the Maranhao Basin of Brazil. Studeis on heavy minerals of these sandstones have been done before. The heavy mineral associations of the Permian Pedra de Fogo Formation corroborate the results of the analysis of quartz grains which indicate a predominance of the metamorphic rocks in the source area. However, the heavy mineral parageneses of the Carboniferous Piaui Formation are different. This may be because the frequency of those heavy minerals depend directly on the stage of the weathering of the sandstones. It should be mentioned that heavy minerals occur in paleozoic sediments only in a small quantity, sometimes below 1% of the rock constitution. The irradiation analysis, which is applied for the predominant mineral in sandstones, appears to be most reliable. It is used here as the basis for the interpretations presented. (Author) [pt

  14. Changes in Bottom Water Physical Properties Above the Mid-Atlantic Ridge Flank in the Brazil Basin

    Science.gov (United States)

    Zhao, Jian; Thurnherr, Andreas M.

    2018-01-01

    Warming of abyssal waters in recent decades has been widely documented around the global ocean. Here repeat hydrographic data collected in 1997 and 2014 near a deep fracture zone canyon in the eastern Brazil Basin are used to quantify the long-term change. Significant changes are found in the Antarctic Bottom Water (AABW) within the canyon. The AABW in 2014 was warmer (0.08 ± 0.06°C), saltier (0.01 ± 0.005), and less dense (0.005 ± 0.004 kg m-3) than in 1997. In contrast, the change in the North Atlantic Deep Water has complicated spatial structure and is almost indistinguishable from zero at 95% confidence. The resulting divergence in vertical displacement of the isopycnals modifies the local density stratification. At its peak, the local squared buoyancy frequency (N2) near the canyon is reduced by about 20% from 1997 to 2014. Similar reduction is found in the basinwide averaged profiles over the Mid-Atlantic Ridge flank along 25°W in years 1989, 2005, and 2014. The observed changes in density stratification have important implications for internal tide generation and dissipation.

  15. Late Aptian (Cretaceous) paleoceanography of the South Atlantic Ocean inferred from dinocyst communities of the Sergipe Basin, Brazil

    Science.gov (United States)

    Carvalho, Marcelo de A.; Bengtson, Peter; Lana, Cecília C.

    2016-01-01

    The late Aptian (Early Cretaceous) is a crucial time interval for understanding the paleoceanographic changes in the Southern Hemisphere. Oceanographic changes in the emerging South Atlantic Ocean during this interval are reflected in the stratigraphic distribution of dinoflagellate communities recorded in the Muribeca and Riachuelo formations of the Sergipe Basin in northeastern Brazil. The Subtilisphaera community, in the lower and middle parts of the section, appears to be related to the Subtilisphaera Ecozone and suggests the onset of Tethyan influence in the central South Atlantic, in a restricted to inner-neritic environment. The succeeding Spiniferites community, in the middle part of the section, represents the first significant transgression, probably of eustatic origin. The Cyclonephelium-Exochosphaeridium community, in the upper part of the section, appears to be related to an oceanic event characterized by intermittent dysoxic-anoxic conditions. The uppermost part of the section is dominated by the Spiniferites community, related to a progressive regional transgression and culminating in an open-marine, fully Tethyan environment in the central part of the widening South Atlantic.

  16. Biochronostratigraphy and paleoenvironment analysis of Neogene deposits from the Pelotas Basin (well 2-TG-96-RS), Southernmost Brazil.

    Science.gov (United States)

    Silva, Wagner G; Zerfass, Geise S A; Souza, Paulo A; Helenes, Javier

    2015-09-01

    This paper presents the integration of micropaleontological (palynology and foraminifera) and isotopic (87Sr/86Sr) analysis of a selected interval from the well 2-TG-96-RS, drilled on the onshore portion of the Pelotas Basin, Rio Grande do Sul, Brazil. A total of eight samples of the section between 140.20 and 73.50 m in depth was selected for palynological analysis, revealing diversified and abundant palynomorph associations. Species of spores, pollen grains and dinoflagellate cysts are the most common palynomorphs found. Planktic and benthic calcareous foraminifera were recovered from the lowest two levels of the section (140.20 and 134.30 m). Based on the stratigraphic range of the species of dinoflagellate cysts and sporomorphs, a span age from Late Miocene to Early Pliocene is assigned. The relative age obtained from the 87Sr/86Sr ratio in shells of calcareous foraminifers indicates a Late Miocene (Messinian) correspondence, corroborating the biostratigraphic positioning performed with palynomorphs. Paleoenvironmental interpretations based on the quantitative distribution of organic components (palynomorphs, phytoclasts and amorphous organic matter) throughout the section and on foraminiferal associations indicate a shallow marine depositional environment for the section. Two palynologicals intervals were recognized based on palynofacies analysis, related to middle to outer shelf (140.20 to 128.90 m) and inner shelf (115.75 to 73.50 m) conditions.

  17. The role of gravitational collapse in controlling the evolution of crestal fault systems (Espirito Santo Basin, SE Brazil) - Discussion

    Science.gov (United States)

    Jackson, Christopher A.-L.; Rotevatn, Atle; Tvedt, Anette B. M.; Bell, Rebecca E.

    2017-05-01

    Ze and Alves (2016) use 3D seismic reflection data to describe the geometry and throw characteristics of a salt-related normal fault population in the Espirito Santo Basin, offshore SE Brazil. As part of their analysis they test two competing fault growth models; (i) the isolated model, which states that faults grow via a sympathetic increase in their displacement and length, an inference seemingly consistent with displacement-length (D-L) scaling relationships (e.g. Watterson, 1986; Walsh and Watterson, 1988; Dawers et al., 1993; Cartwright et al., 1995; Dawers and Anders, 1995); and (ii) the constant-length model, which states that faults grow via establishment of their near-final length relatively early in their slip history, prior to the accumulation of significant displacement (Fig. 1) (e.g. Morewood and Roberts (1999); Morley, 2002; Walsh et al., 2002, 2003; Childs et al., 2003; Nicol et al., 2005; Schlagenhauf et al., 2008; Giba et al., 2012; Jackson and Rotevatn, 2013). Because they make very different predictions regarding the tectono-stratigraphic evolution and earthquake hazard potential of rifts, critically testing these models is important for structural geologists, geomorphologists and stratigraphers, amongst many others. However, in our view, such critical testing has rarely been undertaken, thus the study of Ze and Alves (2016) is most welcome.

  18. Integrated spatiotemporal trends using TRMM 3B42 data for the Upper São Francisco River basin, Brazil.

    Science.gov (United States)

    Santos, Celso Augusto Guimarães; Brasil Neto, Reginaldo Moura; da Silva, Richarde Marques; Passos, Jacqueline Sobral de Araújo

    2018-02-26

    Trend analysis is an important issue for the decision-making processes. Thus, trends of rainfall, consecutive dry days (CDD), and consecutive wet days (CWD) in the Upper São Francisco River basin, Brazil, using daily rainfall data from the Tropical Rainfall Measuring Mission (TRMM) for recent 18 years, were analyzed. Instead of analyzing the trend of one average time series for one specific confidence level, a spatiotemporal analysis over the entire area with 169 continuous time series is done by applying the nonparametric Mann-Kendall and Sen tests for simultaneously 13 confidence levels and a new integrated confidence classification is proposed. The results show that the rainfall has increased during the less rainy periods (from June to October) and has decreased in the rainy periods (from November to May), with the highest and lowest confidence levels, respectively. An analysis of CDD and CWD shows that the number of CDD has decreased, while the number of CWD has increased, which revealed that the dry periods are more frequently interrupted for the period studied.

  19. The aquatic environment as a reservoir of Vibrio cholerae O1 in hydrographic basins of the state of Pernambuco, Brazil.

    Science.gov (United States)

    Mendes-Marques, Carina Lucena; Silveira Filho, Vladimir da Mota; da Costa, Ana Paula Rocha; Nunes, Mariana de Lira; da Silva Filho, Sandoval Vieira; Figueirôa, Ângela Cristina Torres de Araújo; Hofer, Ernesto; de Almeida, Alzira Maria Paiva; Leal, Nilma Cintra

    2013-01-01

    After the worldwide cholera epidemic in 1993, permanent environmental monitoring of hydrographic basins was established in Pernambuco, Brazil, where cholera is endemic. After a quiescent period, 4 rfbN (serogroup O1) positive water samples that were culture negative were detected by multiplex single-tube nested PCR (MSTNPCR); 2 of these were also ctxA (cholera toxin) positive. From May to June 2012, 30 V. cholerae O1 isolates were obtained by culturing samples. These isolates were analyzed for the presence of virulence genes by PCR, intergenic spacer region 16S-23S PCR (ISR-PCR), and pulsed field gel electrophoresis (PFGE). The isolates were positive for the rfbN gene and negative for the assessed pathogenic genes and were classified into 2 groups by ISR and the same profile by PFGE. Close genetic similarity was observed between them (2012) and environmental strains from 2004 to 2005, indicating the permanence of endemic V. cholerae O1 in the region.

  20. The Aquatic Environment as a Reservoir of Vibrio cholerae O1 in Hydrographic Basins of the State of Pernambuco, Brazil

    Directory of Open Access Journals (Sweden)

    Carina Lucena Mendes-Marques

    2013-01-01

    Full Text Available After the worldwide cholera epidemic in 1993, permanent environmental monitoring of hydrographic basins was established in Pernambuco, Brazil, where cholera is endemic. After a quiescent period, 4 rfbN (serogroup O1 positive water samples that were culture negative were detected by multiplex single-tube nested PCR (MSTNPCR; 2 of these were also ctxA (cholera toxin positive. From May to June 2012, 30 V. cholerae O1 isolates were obtained by culturing samples. These isolates were analyzed for the presence of virulence genes by PCR, intergenic spacer region 16S-23S PCR (ISR-PCR, and pulsed field gel electrophoresis (PFGE. The isolates were positive for the rfbN gene and negative for the assessed pathogenic genes and were classified into 2 groups by ISR and the same profile by PFGE. Close genetic similarity was observed between them (2012 and environmental strains from 2004 to 2005, indicating the permanence of endemic V. cholerae O1 in the region.

  1. Development of cataclastic foliation in deformation bands in feldspar-rich conglomerates of the Rio do Peixe Basin, NE Brazil

    Science.gov (United States)

    Nicchio, Matheus A.; Nogueira, Francisco C. C.; Balsamo, Fabrizio; Souza, Jorge A. B.; Carvalho, Bruno R. B. M.; Bezerra, Francisco H. R.

    2018-02-01

    In this work we describe the deformation mechanisms and processes that occurred during the evolution of cataclastic deformation bands developed in the feldspar-rich conglomerates of the Rio do Peixe Basin, NE Brazil. We studied bands with different deformation intensities, ranging from single cm-thick tabular bands to more evolved clustering zones. The chemical identification of cataclastic material within deformation bands was performed using compositional mapping in SEM images, EDX and XRD analyses. Deformation processes were identified by microstructural analysis and by the quantification of comminution intensity, performed using digital image processing. The deformation bands are internally non homogeneous and developed during five evolutionary stages: (1) moderate grain size reduction, grain rotation and grain border comminution; (2) intense grain size reduction with preferential feldspar fragmentation; (3) formation of subparallel C-type slip zones; (4) formation of S-type structures, generating S-C-like fabric; and (5) formation of C‧-type slip zones, generating well-developed foliation that resembles S-C-C‧-type structures in a ductile environment. Such deformation fabric is mostly imparted by the preferential alignment of intensely comminuted feldspar fragments along thin slip zones developed within deformation bands. These processes were purely mechanical (i.e., grain crushing and reorientation). No clays or fluids were involved in such processes.

  2. Stratigraphic and sedimentary evidences for development of Aptian intrashelf basin in the structural Zagros zone, northern Fars Platform

    Directory of Open Access Journals (Sweden)

    Neda Khoshfam

    2016-12-01

    Therefore despite previous visions, the Fars platform was not a monolith shallow platform. In addition, except Kazhdumi intrashelf basin, there were other deep and local intrashelf basins which were developed within the Fars platform.

  3. Determining the source and genetic fingerprint of natural gases using noble gas geochemistry: a northern Appalachian Basin case study

    Science.gov (United States)

    Hunt, Andrew G.; Darrah, Thomas H.; Poreda, Robert J.

    2012-01-01

    Silurian and Devonian natural gas reservoirs present within New York state represent an example of unconventional gas accumulations within the northern Appalachian Basin. These unconventional energy resources, previously thought to be noneconomically viable, have come into play following advances in drilling (i.e., horizontal drilling) and extraction (i.e., hydraulic fracturing) capabilities. Therefore, efforts to understand these and other domestic and global natural gas reserves have recently increased. The suspicion of fugitive mass migration issues within current Appalachian production fields has catalyzed the need to develop a greater understanding of the genetic grouping (source) and migrational history of natural gases in this area. We introduce new noble gas data in the context of published hydrocarbon carbon (C1,C2+) (13C) data to explore the genesis of thermogenic gases in the Appalachian Basin. This study includes natural gases from two distinct genetic groups: group 1, Upper Devonian (Marcellus shale and Canadaway Group) gases generated in situ, characterized by early mature (13C[C1  C2][13C113C2]: –9), isotopically light methane, with low (4He) (average, 1  103 cc/cc) elevated 4He/40Ar and 21Ne/40Ar (where the asterisk denotes excess radiogenic or nucleogenic production beyond the atmospheric ratio), and a variable, atmospherically (air-saturated–water) derived noble gas component; and group 2, a migratory natural gas that emanated from Lower Ordovician source rocks (i.e., most likely, Middle Ordovician Trenton or Black River group) that is currently hosted primarily in Lower Silurian sands (i.e., Medina or Clinton group) characterized by isotopically heavy, mature methane (13C[C1 – C2] [13C113C2]: 3), with high (4He) (average, 1.85  103 cc/cc) 4He/40Ar and 21Ne/40Ar near crustal production levels and elevated crustal noble gas content (enriched 4He,21Ne, 40Ar). Because the release of each crustal noble gas (i.e., He, Ne, Ar

  4. Growth Normal Faulting at the Western Edge of the Metropolitan Taipei Basin since the Last Glacial Maximum, Northern Taiwan

    Directory of Open Access Journals (Sweden)

    Chih-Tung Chen

    2010-01-01

    Full Text Available Growth strata analysis is an useful tool in understanding kinematics and the evolution of active faults as well as the close relationship between sedimentation and tectonics. Here we present the Shanchiao Fault as a case study which is an active normal fault responsible for the formation of the 700-m-thick late Quaternary deposits in Taipei Basin at the northern tip of the Taiwan mountain belt. We compiled a sedimentary record, particularly the depositional facies and their dated ages, at three boreholes (SCF-1, SCF-2 and WK-1, from west to east along the Wuku Profile that traverses the Shanchiao Fault at its central segment. By incorporating the global sea level change curve, we find that thickness changes of sediments and changes of depositional environments in the Wuku area are in a good agreement with a rapid sea level rise since the Last Glacial Maximum (LGM of about 23 ka. Combining depositional facies changes and their ages with their thickness, we are able to introduce a simple back-stripping method to reconstruct the evolution of growing strata across the Shanchiao Fault since the LGM. We then estimate the vertical tectonic slip rate since 23 ka, which exhibits 2.2 mm yr-1 between SCF-2 and WK-1 and 1.1 mm yr-1 between SCF-1 and SCF-2. We also obtain the Holocene tectonic subsidence rate of 2.3 mm yr-1 at WK-1 and 0.9 mm yr-1 at SCF-2 since 8.4 ka. We thus conclude that the fault zone consists of a high-angle main fault to the east between SCF-2 and WK-1 and a western lower-angle branch fault between SCF-1 and SCF-2, resembling a tulip structure developed under sinistral transtensional tectonism. We find that a short period of 600-yr time span in 9 - 8.4 ka shows important tectonic subsidence of 7.4 and 3.3 m for the main and branch fault, respectively, consistent with possible earthquake events proposed by previous studies during that time. A correlation between geomorphology and subsurface geology in the Shanchiao Fault zone shows

  5. Miocene fern spores and pollen grains from the Solimões Basin, Amazon Region, Brazil

    Directory of Open Access Journals (Sweden)

    Natália de Paula Sá

    Full Text Available ABSTRACT This work documents fern spores and pollen grains (miospores recovered from rocks of the Solimões Formation (Solimões Basin, their botanical affinities, ecology and distribution in the Miocene of the Amazon Region. The assemblage of miospores is well preserved and diverse. They are identified, illustrated and assigned to the ten families of ferns and 22 families of spermatophytes. All miospores were identified to the taxonomic level of species except for two taxa (Perinomonoletes and Podocarpidites. The families Pteridaceae and Arecaceae were most representative of ferns and spermatophytes, respectively. This work contributes to the knowledge of the paleoflora and will aid in paleoenvironmental, paleoecological and biostratigraphic interpretations of the Miocene of the Amazon Region.

  6. Microlepidogaster discus, a new species of Hypoptopomatinae (Siluriformes: Loricariidae) from the rio Jequitinhonha basin, southeastern Brazil.

    Science.gov (United States)

    Martins, Fernanda O; Rosa, Alaina C; Langeani, Francisco

    2014-10-20

    A new Hypoptopomatinae is described from the upper rio Jequitinhonha basin. The new species is distinguished from all congeners by having the ventral laminar expansions of cleithrum and coracoid bearing only 1-30 odontodes, restricted to the area near the pectoral-fin insertion; the anterior plates of mid-ventral lateral series reduced, not ventrally elongated, the first or the second markedly round; pectoral-fin unbranched ray distinctly divided distally, with 7-15 ossified segments, reaching almost half of its length; and accessory process on first epibranchial present. Microlepidogaster discus is further distinguished from its congeners by several other osteological features. The problems concerning the taxonomy of Microlepidogaster, as well as the pattern of distribution of the genus, are discussed.

  7. Spectroscopic Analysis of a Theropod Dinosaur (Reptilia, Archosauria from the Ipubi Formation, Araripe Basin, Northeastern Brazil

    Directory of Open Access Journals (Sweden)

    João Hermínio da Silva

    2013-01-01

    Full Text Available The Araripe Sedimentary Basin is known by the excellence of its fossils, regarding the preservation, diversity, and quantity. Here, we present a spectroscopic analysis using several experimental techniques (X-ray energy dispersion spectroscopy, Fourier-transform infrared spectroscopy as well as X-ray diffraction and thermogravimetric analysis applied in small fragments of bones from the posterior members of a theropod dinosaur. The results agree regarding the different composition of the stone matrix and the fossilized bone, indicating a partial substitution of the material by elements present in the depositional environment. However, differently from what is believed to occur, there is evidence that pyritization is not the only mechanism of fossilization for a specimen of Ipubi formation, but calcification, additionally, plays an important role in the fossil production of this Formation.

  8. Genetic variability of populations of Nyssomyia neivai in the Northern State of Paraná, Brazil

    Directory of Open Access Journals (Sweden)

    Jaqueline de Carvalho Gasparotto

    Full Text Available ABSTRACT The genetic study of sandfly populations needs to be further explored given the importance of these insects for public health. Were sequenced the NDH4 mitochondrial gene from populations of Nyssomyia neivai from Doutor Camargo, Lobato, Japira, and Porto Rico, municipalities in the State of Paraná, Brazil, to understand the genetic structure and gene flow. Eighty specimens of Ny. Neivai were sequenced, 20 from each municipality, and 269 base pairs were obtained. A total of 27 haplotypes and 28 polymorphic sites were found, along with a haplotypic diversity of 0.80696 and a nucleotide diversity of 0.00567. Haplotype H5, with 33 specimens, was the most common among the four populations. Only haplotypes H5 and H7 were present in all four populations. The population from Doutor Camargo showed the highest genetic diversity, and only this population shared haplotypes with those from the other municipalities. The highest number of haplotypes was sheared with Lobato which also had the highest number of unique haplotypes. This probably occurred because of constant anthropic changes that happened in the environment during the first half of the twentieth century, mainly after 1998. There was no significant correlation between genetic and geographical distances regarding these populations. However, the highest genetic and geographical distances, and the lowest gene flow were observed between Japira and Porto Rico. Geographical distance is a possible barrier between these municipalities through the blocking of haplotype sharing.

  9. Flora and phytosociology of an area of Restinga along the northern Coast of Bahia, Brazil

    Directory of Open Access Journals (Sweden)

    Christiano Marcelino Menezes

    2012-03-01

    Full Text Available Areas of restinga are geologically recent environments. The species that inhabit this type of ecosystem are typical of adjacent areas, such as rain forest, tabuleiro forest and caatinga, and form a diverse community of trees, shrubs and erect and prostrate herbs. The goal of this work was to evaluate the vegetation in an area of restinga located along Praia do Forte, in the state of Bahia, Brazil. Four 200m transects where made within five plots of 100m2 each, and 1,640 individuals within 68 species were collected. High species diversity was found in transects 1 and 2 (H´ = 3.882 and 3 and 4 (H´ = 3.835. The most representative families were Myrtaceae, Rubiaceae and Malpighiaceae. Based on the species composition, a significant difference (p < 0.001 was found between the sampled areas, and the findings show that there are two distinct plant communities in this region, Mata deRestinga and Restinga em Moitas.

  10. Associated factors of overweight in adolescents from public schools in Northern Minas Gerais State, Brazil.

    Science.gov (United States)

    de Pinho, Lucinéia; Botelho, Ana Cristina de C; Caldeira, Antônio Prates

    2014-06-01

    In order to support plans and actions that combat the local increasing overweight and obesity prevalence in adolescents, the factors associated to weight excess in public school students from Montes Claros, MG, Southeast Brazil, were studied. Cross-sectional study with a sample of adolescents from the public schools of the city. The nutritional status was evaluated and an inquiry was carried out in the schools to determine food consumption and practice of physical activities. Factors associated to weight excess were assessed by bivariate analysis followed by logistic regression. Weight excess prevalence was detected in 18.5% of the 535 adolescents evaluated. The factors associated to weight excess were: per capita income above half minimum wage (OR 1.99; 95%CI 1.01-3.93), candy consumption above two daily portions (OR 1.94; 95%CI 1.13-3.32) and absence of sport activity during leisure time (OR 2.54; 95%CI 1.15-5.59). The proportion of weight excess in adolescents from public schools is relevant and associated with socioeconomic condition of the family, bad eating habits and sedentary life.

  11. Two new endangered species of Anomaloglossus (Anura: Aromobatidae) from Roraima State, northern Brazil.

    Science.gov (United States)

    Fouquet, Antoine; Souza, Sergio Marques; Nunes, Pedro M Sales; Kok, Philippe J R; Curcio, Felipe Franco; De Carvalho, Celso Morato; Grant, Taran; Rodrigues, Miguel Trefaut

    2015-03-05

    We describe two new species of Anomaloglossus from Roraima State, Brazil, that are likely endemic to single mountains currently isolated among lowland forest and savanna ecosystems. The first species, Anomaloglossus tepequem sp. nov. was collected in 1986 and 1992 along a single stream at >500 m elevation on a tepui-like mountain named Tepequém, but was not detected during recent investigations. It is mainly diagnosed from other Anomaloglossus species by its well developed foot webbing, immaculate cream abdomen colouration and small body size (males: 18.2-20.1 mm, females: 21.7-24.5). The second species, Anomaloglossus apiau sp. nov. was found along several streams between 500 and 1400 m elevation on Serra do Apiaú, and is mainly diagnosed from congeners by its weakly webbed feet, males with swollen third finger and ventrolateral stripe formed by white dots, and its advertisement call; a long trill (up to almost 40 s) consisting of pairs of very short pulses. The discovery of these two apparently microendemic species suggests that additional Anomaloglossus species remain to be described in the Guiana Shield. Both species should be considered critically endangered given their seemingly reduced range size, association with highland habitat, and the anthropogenic pressure they currently face.

  12. Sedimentary provenance in the southern sector of the São Francisco Basin, SE Brazil

    Directory of Open Access Journals (Sweden)

    Gustavo Macedo de Paula-Santos

    Full Text Available ABSTRACT: We present new Sm-Nd, U-Pb and Hf isotope geochronological data for the siliciclastic rocks in the southern sector of the São Francisco Basin. An abrupt change in the Sm-Nd data is observed from the Carrancas Formation’s oligomitic conglomerates (TDM ages between 2.7 and 3.3 Ga; εNd(550 Ma values between -25.09 and -17.98, its finer facies, and the finer facies of the the Moema Laminite (TDM ages from 1.4 to 2.1 Ga; εNd(550 Ma values between -9.46 and -5.59. No further significant changes in the Sm-Nd data occur farther upwards in the Bambuí Group (Sm-Nd TDM ages within the 1.3-2.0 Ga interval; εNd(550 Ma values from -9.53 to -4.09, showing a lack of reorganization in the source areas throughout the deposition of the basin. This is yet another argument to dismiss an unconformity within the Bambuí Group. The presence of the index fossil Cloudina sp. in the lower Sete Lagoas Formation makes the glaciation probably Late Ediacaran in age. U-Pb ages for detrital zircons of the Bambuí Group range from the Archean to the early Ediacaran, but the current data is insufficient to distinguish between the contribution from sources in the Brasília and Araçuaí belts.

  13. Viruses Surveillance Under Different Season Scenarios of the Negro River Basin, Amazonia, Brazil.

    Science.gov (United States)

    Vieira, Carmen Baur; de Abreu Corrêa, Adriana; de Jesus, Michele Silva; Luz, Sérgio Luiz Bessa; Wyn-Jones, Peter; Kay, David; Vargha, Marta; Miagostovich, Marize Pereira

    2016-03-01

    The Negro River is located in the Amazon basin, the largest hydrological catchment in the world. Its water is used for drinking, domestic activities, recreation and transportation and water quality is significantly affected by anthropogenic impacts. The goals of this study were to determine the presence and concentrations of the main viral etiological agents of acute gastroenteritis, such as group A rotavirus (RVA) and genogroup II norovirus (NoV GII), and to assess the use of human adenovirus (HAdV) and JC polyomavirus (JCPyV) as viral indicators of human faecal contamination in the aquatic environment of Manaus under different hydrological scenarios. Water samples were collected along Negro River and in small streams known as igarapés. Viruses were concentrated by an organic flocculation method and detected by quantitative PCR. From 272 samples analysed, HAdV was detected in 91.9%, followed by JCPyV (69.5%), RVA (23.9%) and NoV GII (7.4%). Viral concentrations ranged from 10(2) to 10(6) GC L(-1) and viruses were more likely to be detected during the flood season, with the exception of NoV GII, which was detected only during the dry season. Statistically significant differences on virus concentrations between dry and flood seasons were observed only for RVA. The HAdV data provides a useful complement to faecal indicator bacteria in the monitoring of aquatic environments. Overall results demonstrated that the hydrological cycle of the Negro River in the Amazon Basin affects the dynamics of viruses in aquatic environments and, consequently, the exposure of citizens to these waterborne pathogens.

  14. Water isotopic characterization of hypersaline formation of a petroleum field Reconcavo basin, Brazil

    International Nuclear Information System (INIS)

    Teles, Danilo Ribeiro de Sa; Azevedo, Antonio Expedito Gomes de

    2010-01-01

    Formation water is the water present in reservoir rock pores, produced together with petroleum. Usually it is hyper saline with concentrations that can be higher than 250 g/l of dissolved solids. The concentration of the dissolved elements and the isotopic composition of the water and of some of the dissolved elements can be excellent tracers to study the dynamic of underground fluid flux, the mixing of distinct sources and the origin of salinization of these waters. This work reports the isotopic composition (δ 2 H , δ 18 O) and electrical conductivity (EC) of formation waters from 10 wells of a petroleum field of the Reconcavo Basin, looking for their evolution, interaction with the minerals and rocks and reservoir interconnection. The samples have electric conductivity ranging from 84 to 137 mS/cm, with conductivity increasing with depth of production zone. It is observed an enrichment of deuterium and oxygen-18 with the depth of production zone, probably due to water-rock interactions that were probably increased by higher temperatures of the deeper levels and longer residence times. The samples from the production zone between 1450 to 1520 m, drained by 7 of the 10 wells sampled, show a small range in isotopic composition and in electric conductivity, indicating homogeneity in this level of the reservoir. In the shallow level of 450 m the values of δ 2 H , δ 18 O and EC are lower, with isotopic composition similar to the oceanic water, possibly representing the original water that entered the reservoir during the sedimentation of the basin. (author)

  15. 210Pb and compositional data of sediments from Rondonian lakes, Madeira River basin, Brazil

    International Nuclear Information System (INIS)

    Bonotto, Daniel Marcos; Vergotti, Marcelo

    2015-01-01

    Gold exploration has been intensive in Brazilian Amazon over the last 40 years, where the use of mercury as an amalgam has caused abnormal Hg concentrations in water bodies. Special attention has been directed to Madeira River due to fact it is a major tributary of Amazon River and that since 1986, gold exploration has been officially permitted along a 350 km sector of the river. The 210 Pb method has been used to date sediments taken from nine lakes situated in Madeira River basin, Rondônia State, and to verify where anthropogenic Hg might exist due to gold exploitation in Madeira River. Activity profiles of excess 210 Pb determined in the sediment cores provided a means to evaluate the sedimentation rates using a Constant Flux: Constant Sedimentation (CF:CS) and Constant Rate of Supply (CRS) of unsupported/excess 210 Pb models. A significant relationship was found between the CF:CS sedimentation rates and the mean values of the CRS sedimentation rates (Pearson correlation coefficient r=0.59). Chemical data were also determined in the sediments for identifying possible relationships with Hg occurring in the area. Significant values were found in statistical correlation tests realized among the Hg, major oxides and Total Organic Carbon (TOC) content in the sediments. The TOC increased in the sediment cores accompanied by a loss on ignition (LOI) increment, whereas silica decreased following a specific surface area raising associated to the TOC increase. The CRS model always provided ages within the permitted range of the 210 Pb-method in the studied lakes, whereas the CF:CS model predicted two values above 140 years. - Highlights: • Gold mining activities. • Madeira River basin at Amazon area. • Pb-210 chronological method. • Models for evaluating sedimentation rates

  16. Concentrations and isotope ratios of mercury in sediments from shelf and continental slope at Campos Basin near Rio de Janeiro, Brazil.

    Science.gov (United States)

    Araujo, Beatriz Ferreira; Hintelmann, Holger; Dimock, Brian; Almeida, Marcelo Gomes; Rezende, Carlos Eduardo

    2017-07-01

    Mercury (Hg) may originate from both anthropogenic and natural sources. The measurement of spatial and temporal variations of Hg isotope ratios in sediments may enable source identification and tracking of environmental processes. In this study we establish the distribution of mercury concentrations and mercury isotope ratios in surface sediments of three transects along the continental shelf and slope in Campos Basin-RJ-Brazil. The shelf showed on average lower total Hg concentrations (9.2 ± 5.3 ng g -1 ) than the slope (24.6 ± 8.8 ng g -1 ). MMHg average concentrations of shelf 0.15 ± 0.12 ng g -1 and slope 0.13 ± 0.06 ng g -1 were not significantly different. Distinct differences in Hg isotope ratio signatures were observed, suggesting that the two regions were impacted by different sources of Hg. The shelf showed more negative δ 202 Hg and Δ 199 Hg values ranging from -0.59 to -2.19‰ and from -0.76 to 0.08‰, respectively. In contrast, the slope exhibited δ 202 Hg values from -0.29 to -1.82‰ and Δ 199 Hg values from -0.23 to 0.09‰. Mercury found on the shelf, especially along the "D" and "I" transects, is depleted in heavy isotopes resulting in more negative δ 202 Hg compared to the slope. Isotope ratios observed in the "D" and "I" shelf region are similar to Hg ratios commonly associated with plants and vegetation and very comparable to those detected in the estuary and adjoining mangrove forest, which suggests that Hg exported from rivers may be the dominating source of Hg in near coastal regions along the northern part of the shelf. Copyright © 2017 Elsevier Ltd. All rights reserved.

  17. A Late-Glacial sedimentary sequence at KIlkeel, Northern Ireland: implications for the glaciation of the Irish Sea Basin

    Science.gov (United States)

    Merritt, Jon; Roberson, Sam; Cooper, Mark

    2017-04-01

    This paper re-evaluates the nature and timing of a Late-Glacial ice sheet re-advance in the north western sector of the Irish Sea basin. The sedimentary archive in the region records the collapse of the Irish Sea Ice Stream, a major outlet glacier of the British-Irish Ice Sheet. The region documents the interplay between southerly flowing Scottish ice, ice flowing southeast from Lough Neagh and locally sourced Mournes ice. We present the results of sedimentological analysis of a glacigenic sequence exposed in a modern cliff section 3 km long between Derryoge and Kilkeel, Co. Down, Northern Ireland. The interaction between an advancing ice-sheet outlet lobe and rapidly changing sea levels are examined using facies analysis and micromorphology. The section is composed of four lithofacies associations (LAs). These are, from the base, a laminated, fossiliferous and deformed silt (LA1) at least 4.5 m thick that contains lenses of diamicton and discontinuous rafts of sandy gravel. Marine shells form the axis of a fold hinge, part of a lightly tectonised channel fill within the raft. LA1 is overlain by a sandy diamict (LA2) up to 14 m thick containing mainly local clasts with some of northern provenance. Within LA2 are wide channel structures infilled by laminated clayey silts (LA2b). These form deposits up to 14 m thick and contain small-scale folds, discrete shear zones and ball-and-pillow structures. LA2b forms a lithofacies association with LA2, consisting of a lower subfacies of sheared and deformed silts, overlain by sandy diamicton, capped by a striated boulder pavement. These are interpreted to represent retreat/advance cycles of a marine terminating ice margin. Up to five such cycles are identified. LA2 is widely punctuated by fissures and conduits infilled by loose sands and gravels. These are inferred to be emplaced by subglacial meltwater during the final stages of ice sheet advance. Covering both LA2 and LA2b, LA3 is a unit of glaciofluvial outwash, composed

  18. Genetic Types and Source of the Upper Paleozoic Tight Gas in the Hangjinqi Area, Northern Ordos Basin, China

    Directory of Open Access Journals (Sweden)

    Xiaoqi Wu

    2017-01-01

    Full Text Available The molecular and stable isotopic compositions of the Upper Paleozoic tight gas in the Hangjinqi area in northern Ordos Basin were investigated to study the geochemical characteristics. The tight gas is mainly wet with the dryness coefficient (C1/C1–5 of 0.853–0.951, and δ13C1 and δ2H-C1 values are ranging from -36.2‰ to -32.0‰ and from -199‰ to -174‰, respectively, with generally positive carbon and hydrogen isotopic series. Identification of gas origin indicates that tight gas is mainly coal-type gas, and it has been affected by mixing of oil-type gas in the wells from the Shilijiahan and Gongkahan zones adjacent to the Wulanjilinmiao and Borjianghaizi faults. Gas-source correlation indicates that coal-type gas in the Shiguhao zone displays distal-source accumulation. It was mainly derived from the coal-measure source rocks in the Upper Carboniferous Taiyuan Formation (C3t and Lower Permian Shanxi Formation (P1s, probably with a minor contribution from P1s coal measures from in situ Shiguhao zone. Natural gas in the Shilijiahan and Gongkahan zones mainly displays near-source accumulation. The coal-type gas component was derived from in situ C3t-P1s source rocks, whereas the oil-type gas component might be derived from the carbonate rocks in the Lower Ordovician Majiagou Formation (O1m.

  19. Paleoshoreline patterns in the transgressive-regressive sequences of Pennsylvanian rocks in the northern Appalachian Basin, U.S.A.

    Science.gov (United States)

    Carlson, Ernest H.

    1994-11-01

    Sheets of sponge spicule flint of Pennsylvanian age (Bashkirian, Moscovian, Kasimovian) that are present in the northern Appalachian Basin of Ohio and adjacent parts of Kentucky, Pennsylvania and West Virginia, are important indicators of paleoshorelines. This flint typically occurs with or occupies the position normally held by shallow-water limestone and contains a normal marine fauna. The flint was deposited above coal or underclay, representing the detritus-starved marine portion of a transgressive-regressive sequence and marking the eastern limit of transgression across a westward-spreading alluvial plain. Flint occurs at several stratigraphic positions in the upper Pottsville-lower Conemaugh interval. The most important are: Boggs, Upper Mercer and Kanawha flints of the upper Pottsville Group; Kilgore-Flint Ridge, Zaleski and Vanport flints of the lower Allegheny Group; and Brush Creek flint of the lower Conemaugh Group. Lithofacies maps of these beds were constructed to show the distribution of the flint. Limestone-hosted flint occurs in long discontinuous chains of sheetlike bodies, whereas shale-hosted flint occurs in single sheets with restricted geographic distribution. Chains of limestone-hosted flint attain maximum dimensions of a few meters in thickness, a few kilometers in width and several hundreds of kilometers in length. The Upper Mercer, Vanport and Brush Creek flints are particularly extensive, forming arcuate shoreline patterns that parallel the fronts of large delta systems. Beds of clay ironstone and/or coal above flint indicate that the lagoonal environment in which flint was deposited was followed closely by a change to stagnant waters. Cementation of flint with silica likely occurred under the lower pH conditions existing at that time and when depths of burial were shallow.

  20. Occurrence and distribution characteristics of fluids in tight sandstone reservoirs in the Shilijiahan zone, northern Ordos Basin

    Directory of Open Access Journals (Sweden)

    Gongqiang Li

    2017-05-01

    Full Text Available High-yield gas layers, low-yield gas layers and (gas bearing water layers of Upper Paleozoic coexist in the Shilijiahan zone in the northern Ordos Basin, but gas–water distribution characteristics, laws and influence factors are not understood well, so the exploration and development of natural gas in this zone are restricted. In this paper, statistical analysis was carried out on the data of Upper Paleozoic formation water in this zone, e.g. salinity, pH value and ion concentration. It is shown that the formation water in this zone is of CaCl2 type. Then, the origin, types, controlling factors and spatial distribution characteristics of formation water were figured out by using core, mud logging, well logging and testing data, combined with the classification and evaluation results of geochemical characteristics of formation water. Besides, the logging identification chart of gas, water and dry layers in this zone was established. Finally, the occurrence and distribution laws of reservoir fluids were defined. The formation water of CaCl2 type indicates a good sealing capacity in this zone, which is favorable for natural gas accumulation. It is indicated that the reservoir fluids in this zone exist in the state of free water, capillary water and irreducible water. Free water is mainly distributed in the west of this zone, irreducible water in the east, and capillary water in the whole zone. The logging identification chart has been applied in many wells in this zone like Well Jin 86. The identification result is basically accordant with the gas testing result. It is verified that gas and water layers can be identified effectively based on this logging identification chart.

  1. Scenarios for shale gas development and their related land use impacts in the Baltic Basin, Northern Poland

    International Nuclear Information System (INIS)

    Baranzelli, Claudia; Vandecasteele, Ine; Ribeiro Barranco, Ricardo; Mari i Rivero, Ines; Pelletier, Nathan; Batelaan, Okke; Lavalle, Carlo

    2015-01-01

    Scenarios for potential shale gas development were modelled for the Baltic Basin in Northern Poland for the period 2015–2030 using the land allocation model EUCS100. The main aims were to assess the associated land use requirements, conflicts with existing land use, and the influence of legislation on the environmental impact. The factors involved in estimating the suitability for placement of shale gas well pads were analysed, as well as the potential land and water requirements to define 2 technology-based scenarios, representing the highest and lowest potential environmental impact. 2 different legislative frameworks (current and restrictive) were also assessed, to give 4 combined scenarios altogether. Land consumption and allocation patterns of well pads varied substantially according to the modelled scenario. Potential landscape fragmentation and conflicts with other land users depended mainly on development rate, well pad density, existing land-use patterns, and geology. Highly complex landscapes presented numerous barriers to drilling activities, restricting the potential development patterns. The land used for shale gas development could represent a significant percentage of overall land take within the shale play. The adoption of appropriate legislation, especially the protection of natural areas and water resources, is therefore essential to minimise the related environmental impact. -- Highlights: •A range of scenarios for shale gas development in Poland were modelled. •The impact in terms of land take and competition for land was assessed. •Of land used for industrial purposes, 7–12% was attributed to shale gas extraction. •If unregulated, 24% of well pads were developed within protected areas. •The legislative framework can have a major influence on overall environmental impact

  2. PERFORMANCE OF ‘TUXPAN VALENCIA’ SWEET ORANGE GRAFTED ONTO 14 ROOTSTOCKS IN NORTHERN BAHIA, BRAZIL

    Directory of Open Access Journals (Sweden)

    NATIANA DE OLIVEIRA FRANÇA

    Full Text Available ABSTRACT In the State of Bahia, Brazil, the citrus industry is located on the north coast with the prevalence of the combination ‘Pera’ sweet orange on ‘Rangpur’ lime. Scion-rootstock diversification may contribute to the increase of yield and the extension of harvest season, as long as to decrease the risk associated to abiotic and biotic stresses. Therefore, the performance of ‘Tuxpan Valencia’ sweet orange grafted onto 14 rootstocks was evaluated in Rio Real – BA. Planting was performed in 2006 under rainfed cultivation on cohesive ultisol and tree spacing of 6.0 m x 4.0 m. Tree size, yield and fruit quality were evaluated in the period of 2010-2014, in addition to tree survival at nine years old and drought tolerance in the field based on leaf wilting. In the evaluated conditions, ‘Sunki Tropical’ and ‘Sunki Maravilha’ mandarins led to the highest scion canopy volume. The highest accumulated yield in five harvests was recorded on ‘Santa Cruz Rangpur’ lime, ‘Volkamer’ lemon, ‘Riverside’ and ‘Indio’ citrandarins, ‘Sunki Tropical’ mandarin and the hybrid TSKC x (LCR x TR – 001. ‘Riverside’ and TSKFL x CTSW – 049 induced higher yield efficiency on the canopy. The rootstocks did not influence the tree survival nine years after planting except for lower survival of TSKFL x CTSW – 049. Drought tolerance was not affected either. Regarding to the fruit quality of ‘Tuxpan Valencia’, the rootstocks influenced the juice content, soluble solids and technological index with the citrandarins, ‘Santa Cruz Rangpur’ lime, ‘Volkamer’ lemon and ‘Sunki Tropical’ mandarin presenting higher performance in general.

  3. Nesting habits of Centris (Hemisiella) dichrootricha (Hymenoptera: Apidae) in the Northern Cerrado of Brazil.

    Science.gov (United States)

    Carvalho, Gracy C A; Carreira, Léa M M; Rêgo, Márcia M C; Albuquerque, Patricia M C

    2016-09-01

    The Neotropical bee Centris (Hemisiella) dichrootricha is a solitary bee that nests in pre-existing cavities that occur in the rain forest. This study describes the nesting biology of C. dichrootricha and its preference for nesting in Cerrado and gallery forest habitats. The study was conducted from January 2012 and December 2013, in Mirador State Park in the municipality of Formosa da Serra Negra, Maranhão State, Brazil. For this, wooden trap-nests of 6, 8, 10, 12, 14 and 16 mm in diameter were used; a total of 300 trap-nests were placed in the gallery forest and Cerrado areas, respectively. Traps were monitored monthly and all completed nests were collected and replaced with empty ones. The nests were then taken to the laboratory to analyze bee development and emergence, nests characteristics and parasites presence. The species used 29 of the trap-nests, which had diameters of 8, 10, 12 and 14 mm. A total of 87 C. dichrootricha specimens emerged. The nests were parasitized by two bee species, Mesocheira bicolor (Apinae) and Coelioxys sp. (Megachilinae), and one fly species, Antrax sp. (Diptera). The highest nesting incidence of 72.4 % was observed in the gallery forest, whereas only 27.6 % in the Cerrado; this difference in habitat use was significant (χ² = 5.56; p Byrsonima crassifolia, B. rotunda, B. spicata and Heteropterys sp.). C. dichrootricha showed a preference for nesting in cavities of various diameters in gallery forest sites. The present study provides a novel description of the nesting habits and biology of C. dichrootricha in habitats of Central/Southern Maranhão. C. dichrootricha primarily used resources from the Cerrado, including soil to build their nests, pollen and floral oils; we concluded that gallery forest and Cerrado areas are intrinsically related to the maintenance of local populations of this species.

  4. Innovative Methodology for Detection of Fracture-Controlled Sweet Spots in the Northern Appalachian Basin

    Energy Technology Data Exchange (ETDEWEB)

    Robert Jacobi; John Fountain; Stuart Loewenstein; Edward DeRidder; Bruce Hart

    2007-03-31

    For two consecutive years, 2004 and 2005, the largest natural gas well (in terms of gas flow/day) drilled onshore USA targeted the Ordovician Trenton/Black River (T/BR) play in the Appalachian Basin of New York State (NYS). Yet, little data were available concerning the characteristics of the play, or how to recognize and track T/BR prospects across the region. Traditional exploration techniques for entry into a hot play were of limited use here, since existing deep well logs and public domain seismic were almost non-existent. To help mitigate this problem, this research project was conceived with two objectives: (1) to demonstrate that integrative traditional and innovative techniques could be used as a cost-effective reconnaissance exploration methodology in this, and other, areas where existing data in targeted fracture-play horizons are almost non-existent, and (2) determine critical characteristics of the T/BR fields. The research region between Seneca and Cayuga lakes (in the Finger Lakes of NYS) is on strike and east of the discovery fields, and the southern boundary of the field area is about 8 km north of more recently discovered T/BR fields. Phase I, completed in 2004, consisted of integrating detailed outcrop fracture analyses with detailed soil gas analyses, lineaments, stratigraphy, seismic reflection data, well log data, and aeromagnetics. In the Seneca Lake region, Landsat lineaments (EarthSat, 1997) were coincident with fracture intensification domains (FIDs) and minor faults observed in outcrop and inferred from stratigraphy. Soil gas anomalies corresponded to ENE-trending lineaments and FIDs. N- and ENE-trending lineaments were parallel to aeromagnetic anomalies, whereas E-trending lineaments crossed aeromagnetic trends. 2-D seismic reflection data confirmed that the E-trending lineaments and FIDs occur where shallow level Alleghanian salt-cored thrust-faulted anticlines occur. In contrast, the ENE-trending FIDs and lineaments occur where Iapetan

  5. Preliminary Measurements Of N2O Partial Pressures In Rivers of Amazon Basin, Brazil

    Science.gov (United States)

    Oliveira, C. B.; Rasera, M. F.; Krusche, A. V.; Victoria, R. L.; Richey, J. E.; Cunha, H. B.; Gomes, B. M.

    2006-12-01

    The concentrations of nitrous oxide (N2O), an important component of the greenhouse effect and with a long residence time in the atmosphere, have significantly increased in this century. The reasons for this atmospheric increase in N2O are still partially unexplained. This uncertainty is worse in relation to aquatic environments. Here we report on preliminary measurements of N2O partial pressures in rivers of the Amazon basin. The study areas are in the state of Rondonia (rivers Ji Parana, Urupa, Comemoracao and Pimenta Bueno) and Amazonas (rivers Solimoes and Negro). The rivers were sampled from October 2005 to April 2006, using with immersion pumps, lowered in the middle of the channel to 60% of total depth. Water was pumped directly into a 1 l plastic bottle, which was overflown three times before closing. Using syringes, 60 ml of N2 were injected into the bottle, simultaenously to the withdrawn of 60 ml of sample. N2O was extracted into these 60 ml of N2 by shaking vigorously for 2 minutes. With the same syringes, the gas was taken from the bottles and injected into sealed evacuated 25 ml vials. Atmospheric samples were taken from one meter above the water column and stored the same way. N2O partial pressures were determined on a Shimadzu GC-14 Green House Gas Analyzer. All rivers showed little variations in N2O partial pressures. Average values in the rivers of Rondonia were around 0.41 ± 0.07 μ atm (n=46), whereas the Solimoes and Negro rivers, in the state of Amazonas, showed values around 0.43 ± 0.08 μ atm (n=131). Atmospheric averages were approximately 0.34 ± 0.04 μ atm (n=58) and 0.32 ± 0.03 μ atm (n=134) in the states of Rondonia and Amazonas, respectively. This means that, although these waters are supersatured in CO2, making evasive fluxes of this gas an important component of the C cycle in this basin, the same does not occur in the N cycle. Small differences in partial pressures of N2O between water and air will result in small fluxes of

  6. Neogene vegetation development in the Amazon Basin: evidence from marine well-2, Foz do Amazonas (Brazil)

    Science.gov (United States)

    Bogota-Angel, Raul; Chemale Junior, Farid; Davila, Roberto; Soares, Emilson; Pinto, Ricardo; Do Carmo, Dermeval; Hoorn, Carina

    2014-05-01

    Origen and development of the highly diverse Amazon tropical forest has mostly been inferred from continental sites. However, sediment records in the marine Foz do Amazonas Basin can provide important information to better understand the influence of the Andes uplift and climate change on its plant biomes evolution since the Neogene. Sediment analyses of samples from BP-Petrobras well 1 and 2, drilled in the Amazon Fan, allowed to infer the onset of the transcontinental Amazon river and the fan phase during the middle to late Miocene (c. 10.5 Ma). As part of the CLIMAMAZON research programme we performed pollen analysis on the 10.5 to 0.4 Ma time interval. 76 ditch cutting samples of the upper 4165 m sediments of well 2 permitted us to infer changes in floral composition in the Amazon Basin. The palynological spectra across this interval (nannofossil based age model) include pollen, fern spores, dinocysts and foram lignings. When possible pollen and fern spores were grouped in four vegetation types: estuarine, tropical, mountain forest and high mountain open treeless vegetation. Pollen is generally corroded and reflects the effects of sediment transportation while reworked material is also common. Good pollen producers such as Poaceae, Asteraceae and Cyperaceae are common and reflect indistinctive vegetation types particularly those associated to riverine systems. Rhizophora/Zonocostites spp. indicate "close-distance" mangrove development. Tropical forest biomes are represented by pollen that resemble Moraceae-Urticaceae, Melastomataceae-Combretaceae, Sapotaceae, Alchornea, Euphorbiaceae, Rubiaceae, Bignoniaceae, Mauritia and Arecaceae. Myrica, and particularly sporadic occurrences of fossil fern spores like Lophosoria, and Cyathea suggest the development of a moist Andean forest in areas above 1000 m. First indicators of high altitudes appear in the last part of late Miocene with taxa associated to current Valeriana and particularly Polylepis, a neotropical taxon

  7. Selenium and aflatoxin levels in raw Brazil nuts from the Amazon basin.

    Science.gov (United States)

    Pacheco, Ariane M; Scussel, Vildes M

    2007-12-26

    Whereas selenium (Se) is an important antioxidant in human metabolism to prevent cancer, aflatoxins are highly carcinogenic. Brazil nuts from Eastern and Western Amazon regions were evaluated to find any relationship between Se and aflatoxins levels. A total of 80 (in-shell and shelled) nuts samples were collected directly from different forest sites and analyzed for Se by atomic emission spectrometry and aflatoxins by liquid chromatography tandem mass spectrometry. The limit of quantitation (LOQ) for Se was 2.0 mg/kg, and LOQ for total aflatoxins was 0.390 microg/kg. Nut Se levels from the Eastern region were higher than the Western, in addition to the aflatoxins. The moisture content (mc) and water activity (aw) of the raw nuts from the two regions did not present a significant difference, for either in-shell or shelled. The mc was 24.5% (minimum of 20.1% and maximum of 30.4%) and 22.1% (minimum of 14.6% and maximum of 28.9%) and a w of 0.85 for both regions. Further studies need to be carried out to discover the role of Se on fungi growth stress and aflatoxin production mechanisms.

  8. A New Species of Tiger Pleco Panaqolus (Siluriformes: Loricariidae from the Xingu Basin, Brazil.

    Directory of Open Access Journals (Sweden)

    Christian Andreas Cramer

    Full Text Available Panaqolus tankei is described from the Xingu River, Brazil. The new species is diagnosed from P. albomaculatus, P. dentex, P. nix, P. nocturnus, and P. koko by its color pattern consisting of dark and light diagonal bars on the body and bands on the fins (vs. body and fins without bars or bands; from P. albivermis, P. maccus, and P. purusiensis by the width of the dark bars being more or less the same of the light bars (vs. dark bars at least two or three times wider than light bars and from P. changae by the absence of vermiculation on the head (vs. vermiculation present on head. The new species differs from P. gnomus by the orientation of the bars from posterodorsal to anteroventral direction (vs. anterodorsal to posteroventral direction, and from P. claustellifer by the orientation of the bands in the dorsal fin that are not parallel to the margin (vs. parallel to the margin. The barcoding region (COI was sequenced for the new species, sequences were deposited in GenBank and were compared with congeners from other drainages. With regard to the current construction of a hydroelectric power plant (a so-called mega dam in the Xingu River, herewith we increase knowledge of the river Xingu's ichthyofauna and, thus improve the assessment of the impacts of that construction on the river.

  9. Hydro-Economic Modeling with Minimum Data Requirements: An Application to the São Francisco River Basin, Brazil

    Science.gov (United States)

    Torres, M.; Maneta, M.; Vosti, S.; Wallender, W.; Howitt, R.

    2008-12-01

    Policymakers have been charged with the efficient, equitable, and sustainable use of water resources of the São Francisco River Basin (SFRB), Brazil, and also with the promotion of economic growth and the reduction of poverty within the basin. To date, policymakers lack scientific evidence on the potential consequences for growth, poverty alleviation or environmental sustainability of alternative uses of water resources. To address these key knowledge gaps, we have linked a hydrologic and an economic model of agriculture to investigate how economic decisions affect available water, and vice versa. More specifically, the models are used to predict the effects of the application of Brazilian federal surface water use policies on farmer's net revenues and on the hydrologic system. The Economic Model of Agriculture. A spatially explicit, farm-level model capable of accommodating a broad array of farm sizes and farm/farmer characteristics is developed and used to predict the effects of alternative water policies and neighbors' water use patterns on crop mix choice. A production function comprised of seven categories of non-water-related inputs used in agriculture (land, fertilizers, pesticides, seeds, hired labor, family labor and machinery) and four water-related inputs used in agriculture (applied water, irrigation labor, irrigation capital and energy) is estimated. The parameters emerging from this estimated production function are then introduced into a non-linear, net revenue maximization positive mathematical programming algorithm that is used for simulations. The Hydrological Model. MIKE Basin, a semi-distributed hydrology model, is used to calculate water budgets for the SFRB. MIKE Basin calculates discharge at selected nodes by accumulating runoff down the river network; it simulates reservoirs using stage-area-storage and downstream release rule curves. The data used to run the model are discharge to calculate local runoff, precipitation, reference ET, crop

  10. REPTILE SPECIES COMPOSITION IN THE MIDDLE GURGUÉIA AND COMPARISON WITH INVENTORIES IN THE EASTERN PARNAÍBA RIVER BASIN, STATE OF PIAUÍ, BRAZIL

    Directory of Open Access Journals (Sweden)

    CLÁUDIA RENATA MADELLA-AURICCHIO

    Full Text Available ABSTRACT The reptile diversity of the Middle Gurguéia River Basin in southern Piauí, Brazil, is little known. The rapid expansion of agriculture in the region is converting the Cerrado and Caatinga into large farming areas, which threatens biodiversity and hastens its loss. In this study, 68 specimens of reptiles from a university collection were examined, comprising 29 species: ten lizards, one amphisbaenian, 15 snakes, two turtles and one crocodilian. They were collected from five locations in the Middle Gurguéia Basin, a region not previously evaluated for reptiles. The most abundant species is a member of Tropidurus. Comparison with eight other areas in the eastern Parnaíba Basin indicated that the diversity of reptiles in the Middle Gurguéia is similar to that in other Caatinga-Cerrado ecotone areas. The reptile assemblage in the eastern Parnaíba Basin comprises 100 species of reptiles: 39 lizards, five amphisbaenians, 50 snakes, four chelonians and two crocodilians. This study expanded the known distributions of some reptiles and recorded the first occurrence of Helicops leopardinus (Schlegel, 1837 for Piauí. A cluster analysis showed that the reptile composition concords with the habitat where species were found, i.e. Cerrado, Caatinga or ecotone. Studies that associate habitat structure with each species are essential to propose efficient strategies for reptile management and conservation for the entire Parnaíba River Basin, mostly in areas that are not yet protected.

  11. China's first intermediate resolution multi-channel seismic survey in the northern Victoria Land Basin and Terror Rift, Ross Sea, Antarctica

    Science.gov (United States)

    Shen, Zhongyan; Gao, Jinyao; Zhang, Tao; Wang, Wei; Ding, Weifeng; Zhang, Sheng

    2017-04-01

    The West Antarctic Rift System (WARS) represents one of the largest active continental rift systems on Earth and is less well known than other rift systems because it is largely covered by thick ice. The Terror Rift (TR), superimposing on the Victoria Land Basin (VLB) in the western Ross Sea, is identified as the most recent deformational zone of the WARS, thus will provide knowledge of the active deformation process of the WARS. The structure and kinematics of the TR is under debate. Originally, the TR was thought to consist of two parts: the Discovery Graben and the magmatically-intruded Lee Arch. New denser seismic grid in the middle and southern segments of the TR revealed a different structure of the Lee Arch while the northern segment of the TR is not well studied. The glacial history of the VLB/TR region is another attractive issue to the geologists since this area records the behavior information of EAIS and WAIS. In the southern part of the VLB, especially in the McMurdo Sound, the framework of the glacial history is well established after several deep cores which recovery the whole stratigraphic sequences since the onset of the glaciation. However, the glacial history of the northern part of the VLB/TR is less well studied and here we emphasize its importance because the northern part of the VLB/TR is a link between the well-studied southern VLB and the sediment-well-preserved Northern Basin. During the 32nd Chinese National Antarctic Research Expedition, on the board of the RV XueLong, we collected intermediate resolution multi-channel seismic reflection data in the northern VLB/TR. These data will establish new constraints on the timing of deformation, structure and kinematics of the TR, and the history of the EAIS and WAIS.

  12. Measurement and modeling of wind waves at the northern coast of Santa Catarina, Brazil

    Directory of Open Access Journals (Sweden)

    José Henrique G. M. Alves

    2001-01-01

    Full Text Available Directional measurements of wind-wave spectra made during the year of 1996 are used in a preliminary investigation of the wind-wave climate and its transformation at the São Francisco do Sul island, northern coast of the Santa Catarina state. Four major sea states and associated meteorological conditions are identified through analyses of joint distributions of observed wave parameters. Transformations of these main sea-state patterns due to refraction and shoaling are investigated through a numerical modeling approach that allows the reconstruction of the wave field within extensive coastal areas, using single point measurements of the wave spectrum in shallow waters. Cross-validation of measured and reconstructed spectra at the study site yield consistent results, suggesting that the proposed methodology works well for the São Francisco do Sul coast.Medições do espectro direcional de ondas geradas pelo vento realizadas em 1996 são utilizadas em uma investigação preliminar do clima de ondas no litoral norte de Santa Catarina, Brasil. Quatro estados de mar predominantes são identificados, em conjunto com os padrões meteorológicos associados a sua ocorrência, através de análises estatísticas. As transformações desses quatro estados de mar devido a refraçâo e empinamento são investigadas através de modelos numéricos, que permitem obter estimativas do campo de ondas em áreas extensas a partir de medições pontuais feitas em águas rasas. Comparações entre espectros medidos e modelados produzem resultados consistentes, sugerindo que a metodologia proposta é válida para a costa de São Francisco do Sul.

  13. Temporal dynamics of soil CO2 efflux in the Northern Pantanal of Mato Grosso, Brazil

    Science.gov (United States)

    Pinto-Jr, O. B.; Brandão, A. A.; Lathuilliere, M. J.; Dalmagro, H. J.; Arruda, P. H.; Couto, E. G.; Johnson, M. S.

    2013-12-01

    To answer questions about the role of different ecosystems, especially wetlands, the carbon cycle, it is necessary to monitor the vertical fluxes of CO2, soil respiration, and all other parameters that can be correlated with them, so to quantify them and relate them. In this context we measured the soil CO2 efflux of a tree island (locally known as a cordilheira) in the Northern Pantanal, near Poconé, Mato Grosso and verified the influence of environmental parameters on the measurements. We also modeled values of Q10 (parameter used to characterize the dependence of the efflux of CO2 from the soil with the soil temperature) as a function of soil temperature and ground CO2 efflux a); as a comparison to our CO2 efflux measurements. The average soil CO2 efflux was 3.98×1.69 μmolm-2s-1. Soil temperature and O2 content significantly influenced CO2 efflux during inundation periods, high water and ebb, while soil moisture and soil CO2 concentration significantly influenced the CO2 efflux during periods of ebb and drought. The matric potential at 10 cm depth significantly influenced the CO2 efflux throughout the measurement period. The average value of the Q10 was 2.16, and did not differ statistically from the modeled Q10. The average value of the soil CO2 efflux estimated was 4.07×0.84 μmolm-2s-1, and was statistically similar to the average value measured.

  14. Identifying key climate and environmental factors affecting rates of post-fire big sagebrush (Artemisia tridentata) recovery in the northern Columbia Basin, USA

    Science.gov (United States)

    Shinneman, Douglas; McIlroy, Susan

    2016-01-01

    Sagebrush steppe of North America is considered highly imperilled, in part owing to increased fire frequency. Sagebrush ecosystems support numerous species, and it is important to understand those factors that affect rates of post-fire sagebrush recovery. We explored recovery of Wyoming big sagebrush (Artemisia tridentata ssp.wyomingensis) and basin big sagebrush (A. tridentata ssp. tridentata) communities following fire in the northern Columbia Basin (Washington, USA). We sampled plots across 16 fires that burned in big sagebrush communities from 5 to 28 years ago, and also sampled nearby unburned locations. Mixed-effects models demonstrated that density of large–mature big sagebrush plants and percentage cover of big sagebrush were higher with time since fire and in plots with more precipitation during the winter immediately following fire, but were lower when precipitation the next winter was higher than average, especially on soils with higher available water supply, and with greater post-fire mortality of mature big sagebrush plants. Bunchgrass cover 5 to 28 years after fire was predicted to be lower with higher cover of both shrubs and non-native herbaceous species, and only slightly higher with time. Post-fire recovery of big sagebrush in the northern Columbia Basin is a slow process that may require several decades on average, but faster recovery rates may occur under specific site and climate conditions.

  15. First record of Annonaceae wood for the Neogene of South America, Amazon Basin, Brazil

    Directory of Open Access Journals (Sweden)

    Emilio Alberto Amaral Soares

    Full Text Available ABSTRACT: The relief of the regions of Manaus and Itacoatiara, Central Amazon, is supported by Neogene siliciclastic rocks, bounded at the base and top by lateritic paleosols and covered by quaternary sedimentary deposits from the Solimões-Amazon river system. This unit is informally assigned to the Novo Remanso Formation, consists of usually reddish and ferruginized sandstones, conglomerates and pelites, with few identified fossil records, a fact that has hindered its stratigraphic position, and the paleoenvironmental reconstruction of the last phase of the Amazon Basin settling. This study describes, for the first time, the occurrence of fossil wood in outcroppings of the left bank of the Amazon River, where anatomical and morphological data has enabled its characterization to the species level. Thus, the data marks the record of the Annonaceae in South America, as well as the depositional processes related to incorporation of organic material in the sandy layer and the fossilization processes that allowed its preservation. In an unprecedented way, this study has described Duguetiaxylon amazonicum nov. gen and sp. and provided information on the anatomical and systematic character, as well as data on plant-insect interaction, and a better understanding of the family.

  16. Endocrine disruptors in water filters used in the Rio dos Sinos Basin region, Southern Brazil

    Directory of Open Access Journals (Sweden)

    CM Furtado

    Full Text Available The activated carbon filter is used in residences as another step in the treatment of drinking water, based on a physical-chemical process to absorb pollutants that are not removed in conventional treatment. Endocrine disruptors (EDCs are exogenous substances or mixtures of substances that acts on the endocrine system similarly to the endogenously produced hormones, triggering malfunctions and harmful changes to human and animal health. The objective of the present work was to study EDCs through semi-quantitative analysis of residential water filters collected in the region of Rio dos Sinos basin, focusing on two specific classes: hormones and phenols. The solid phase extraction principle was used for the extraction of compounds and gas chromatography coupled with mass spectrometry for the separation and characterization of EDCs. Four samples of residential filters collected from public water distribution and artesian wells, from the cities of Novo Hamburgo and São Leopoldo were analysed. Using the developed methodology, it was possible to detect and comparatively quantify selected EDCs in all studied samples, which indicates the presence of these contaminants in drinking water from different sources.

  17. Endocrine disruptors in water filters used in the Rio dos Sinos Basin region, Southern Brazil.

    Science.gov (United States)

    Furtado, C M; von Mühlen, C

    2015-05-01

    The activated carbon filter is used in residences as another step in the treatment of drinking water, based on a physical-chemical process to absorb pollutants that are not removed in conventional treatment. Endocrine disruptors (EDCs) are exogenous substances or mixtures of substances that acts on the endocrine system similarly to the endogenously produced hormones, triggering malfunctions and harmful changes to human and animal health. The objective of the present work was to study EDCs through semi-quantitative analysis of residential water filters collected in the region of Rio dos Sinos basin, focusing on two specific classes: hormones and phenols. The solid phase extraction principle was used for the extraction of compounds and gas chromatography coupled with mass spectrometry for the separation and characterization of EDCs. Four samples of residential filters collected from public water distribution and artesian wells, from the cities of Novo Hamburgo and São Leopoldo were analysed. Using the developed methodology, it was possible to detect and comparatively quantify selected EDCs in all studied samples, which indicates the presence of these contaminants in drinking water from different sources.

  18. Rescaled range analysis of streamflow records in the São Francisco River Basin, Brazil

    Science.gov (United States)

    Araujo, Marcelo Vitor Oliveira; Celeste, Alcigeimes B.

    2018-01-01

    Hydrological time series are sometimes found to have a distinctive behavior known as long-term persistence, in which subsequent values depend on each other even under very large time scales. This implies multiyear consecutive droughts or floods. Typical models used to generate synthetic hydrological scenarios, widely used in the planning and management of water resources, fail to preserve this kind of persistence in the generated data and therefore may have a major impact on projects whose design lives span for long periods of time. This study deals with the evaluation of long-term persistence in streamflow records by means of the rescaled range analysis proposed by British engineer Harold E. Hurst, who first observed the phenomenon in the mid-twentieth century. In this paper, Hurst's procedure is enhanced by a strategy based on statistical hypothesis testing. The case study comprises the six main hydroelectric power plants located in the São Francisco River Basin, part of the Brazilian National Grid. Historical time series of inflows to the major reservoirs of the system are investigated and 5/6 sites show significant persistence, with values for the so-called Hurst exponent near or greater than 0.7, i.e., around 40% above the value 0.5 that represents a white noise process, suggesting that decision makers should take long-term persistence into consideration when conducting water resources planning and management studies in the region.

  19. Influence of urban area on the water quality of the Campo River basin, Paraná State, Brazil.

    Science.gov (United States)

    Carvalho, K Q; Lima, S B; Passig, F H; Gusmão, L K; Souza, D C; Kreutz, C; Belini, A D; Arantes, E J

    2015-12-01

    The Campo River basin is located on the third plateau of the Paraná State or trap plateau of Paraná, at the middle portion between the rivers Ivaí and Piquiri, southern Brazil, between the coordinates 23° 53 and 24° 10' South Latitude and 52° 15' and 52° 31' West Longitude. The basin has 384 Km² area, being 247 km² in the municipality of Campo Mourão and 137 km² in the municipality of Peabiru, in Paraná State. The Campo River is a left bank tributary of the Mourão River, which flows into the Ivaí River. The objective of this study was to monitor water quality in the Km 119 River and the Campo River, tributaries of the Mourão River, with monthly collection of water samples to determine pH, temperature, turbidity, biochemical oxygen demand, dissolved oxygen, fecal coliforms, total solids, total nitrogen, ammoniacal nitrogen, nitrite, nitrate and total phosphorus. The results obtained were compared with the indices established by the environmental legislation and applied in the determination of the Water Quality Index (WQI) used by the Water Institute of Paraná State, regulating environmental agency. Poor water quality in these rivers presents a worrying scenario for the region, since this river is the main source of water supply for the public system. Results of organic matter, fecal coliforms and total phosphorus were higher than the limits established by Resolution CONAMA 357/2005 to river class 2, specially at downstream of the Km 119 River and the Campo River, due to the significant influence of the urban anthropic activity by the lack of tertiary treatment and also rural by the lack of basic sanitation in this area. Results of WQI of Km 119 River and do Campo River indicated that water quality can be classified as average in 71% and good in 29% of the sites evaluated.

  20. Influence of urban area on the water quality of the Campo River basin, Paraná State, Brazil

    Directory of Open Access Journals (Sweden)

    K. Q. Carvalho

    Full Text Available The Campo River basin is located on the third plateau of the Paraná State or trap plateau of Paraná, at the middle portion between the rivers Ivaí and Piquiri, southern Brazil, between the coordinates 23° 53 and 24° 10’ South Latitude and 52° 15’ and 52° 31’ West Longitude. The basin has 384 Km² area, being 247 km2 in the municipality of Campo Mourão and 137 km2 in the municipality of Peabiru, in Paraná State. The Campo River is a left bank tributary of the Mourão River, which flows into the Ivaí River. The objective of this study was to monitor water quality in the Km 119 River and the Campo River, tributaries of the Mourão River, with monthly collection of water samples to determine pH, temperature, turbidity, biochemical oxygen demand, dissolved oxygen, fecal coliforms, total solids, total nitrogen, ammoniacal nitrogen, nitrite, nitrate and total phosphorus. The results obtained were compared with the indices established by the environmental legislation and applied in the determination of the Water Quality Index (WQI used by the Water Institute of Paraná State, regulating environmental agency. Poor water quality in these rivers presents a worrying scenario for the region, since this river is the main source of water supply for the public system. Results of organic matter, fecal coliforms and total phosphorus were higher than the limits established by Resolution CONAMA 357/2005 to river class 2, specially at downstream of the Km 119 River and the Campo River, due to the significant influence of the urban anthropic activity by the lack of tertiary treatment and also rural by the lack of basic sanitation in this area. Results of WQI of Km 119 River and do Campo River indicated that water quality can be classified as average in 71% and good in 29% of the sites evaluated.

  1. Geochemical behavior and dissolved species control in acid sand pit lakes, Sepetiba sedimentary basin, Rio de Janeiro, SE - Brazil

    Science.gov (United States)

    Marques, Eduardo D.; Sella, Sílvia M.; Bidone, Edison D.; Silva-Filho, Emmanoel V.

    2010-12-01

    This work shows the influence of pluvial waters on dissolved components and mineral equilibrium of four sand pit lakes, located in the Sepetiba sedimentary basin, SE Brazil. The sand mining activities promote sediment oxidation, lowering pH and increasing SO 4 contents. The relatively high acidity of these waters, similar to ore pit lakes environment and associated acid mine drainage, increases weathering rate, especially of silicate minerals, which produces high Al concentrations, the limiting factor for fish aquaculture. During the dry season, basic cations (Ca, Mg, K and Na), SiO 2 and Al show their higher values due to evapoconcentration and pH are buffered. In the beginning of the wet season, the dilution factor by rainwater increases SO 4 and decreases pH values. The aluminum monomeric forms (Al(OH) 2+ and Al(OH) 2+), the most toxic species for aquatic organisms, occur during the dry season, while AlSO 4+ species predominate during the wet season. Gibbsite, allophane, alunite and jurbanite are the reactive mineral phases indicated by PHREEQC modeling. During the dry season, hydroxialuminosilicate allophane is the main phase in equilibrium with the solution, while the sulphate salts alunite and jurbanite predominate in the rainy season due to the increasing of SO 4 values. Gibbsite is also in equilibrium with sand pit lakes waters, pointing out that hydrolysis reaction is a constant process in the system. Comparing to SiO 2, sulphate is the main Al retriever in the pit waters because the most samples (alunite and jurbanite) are in equilibrium with the solution in both seasons. This Al hydrochemical control allied to some precaution, like pH correction and fertilization of these waters, allows the conditions for fishpond culture. Equilibrium of the majority samples with kaolinite (Ca, Mg, Na diagrams) and primary minerals (K diagram) points to moderate weathering rate in sand pit sediments, which cannot be considered for the whole basin due to the anomalous

  2. Late Paleozoic paleofjord in the southernmost Parana Basin (Brazil): Geomorphology and sedimentary fill

    Science.gov (United States)

    Tedesco, Julia; Cagliari, Joice; Coitinho, Julia dos Reis; da Cunha Lopes, Ricardo; Lavina, Ernesto Luiz Correa

    2016-09-01

    In the southernmost part of the Parana Basin, records of the late Paleozoic glaciation occur in a discontinuous form preserved in paleovalley systems excavated in the crystalline basement. This paper addresses one of these paleovalleys, the Mariana Pimentel, which extends over 60 km with NW-SE valley direction and a constant width of 2.5 km. With the objective of demonstrating that the paleovalley worked as a fjord during the glaciation period, its origin as well as sedimentary fill and morphology were analyzed. The paleovalley morphology was obtained through electrical resistivity (electrical sounding and lateral mapping) and mathematical modeling in four transverse sections. The morphology of the paleovalley documented by the U-shape, steady width, and high depth reaching up to 400 m are typical features of modern glacial valleys. The sedimentary facies that fill the base of the paleovalley, such as rhythmites and dropstones with thickness up to 70 m and diamictites with faceted pebbles (up to 5 m thick) are signs of its glacial origin. During the glaciation period, the paleovalley had a connection to the epicontinental sea located to the northwest, extended toward Namibia, and was excavated by glaciers from the highlands of this region. Thus, the evidence attests that the Mariana Pimentel paleovalley was a fjord during the late Paleozoic glaciation. The duration of the late Paleozoic glaciation (which is longer than the Quaternary glaciation), the apatite fission track that suggests erosion up to 4 km thick in the study area, and the lack of preserved hanging valleys in the Mariana Pimentel indicate that the paleovalley once featured a higher dimension. Furthermore, the existence of paleofjords excavated in the border of the basement corroborates the idea of small ice centers controlled by topography during the late Paleozoic glaciation.

  3. Structural aspects and floristic similarity among tropical dry forest fragments with different management histories in northern Minas Gerais, Brazil

    Directory of Open Access Journals (Sweden)

    Daniel Meira Arruda

    2011-02-01

    Full Text Available In order to produce useful knowledge to the initiatives of protection and management of forest fragments, more specifically for tropical dry forests which suffer with frequent anthropic activities, and due to the lack of specific studies, this article aimed describe the structure and the floristic similarity among three areas of dry forest with different management histories. The study was developed in Capitão Enéas municipality, Northern Minas Gerais, Brazil, where three fragments were evaluated, being one in regeneration for 30 years, another submitted to occasional fire and the third with selective cut in small scale. The sampling was developed through the point quarter method considering all the alive phanerophyte individuals with circumference at breast height (CBH > 15 cm. In the three fragments, 512 individuals, distributed in 60 species, 47 genera, and 23 families were sampled. The most representative families were Fabaceae (26, Anacardiaceae (4, Bignoniaceae (3 and Combretaceae (3. However, fourteen families were represented by only one species. Only eight species were common to all fragments - Myracrodruon urundeuva standed out with 26.9% of all sampled individuals - while a great number of species were exclusive of each fragment. The floristic and structural differences between the fragments are possibly related to the history and intensity of management in each area besides the topography variations and the presence or absence of limestone outcrops. These results show the importance of each fragment, indicating that the loss of anyone would cause negative impacts on the regional flora and consequently to the associated biodiversity.

  4. Muscoid Diptera as potential vectors of bacterial agents on dairy farms in the northern region of Paraná, Brazil

    Directory of Open Access Journals (Sweden)

    Josaine Leila Almeida

    2014-12-01

    Full Text Available The aim of this study was to determine the isolation frequency and microbial sensitivity profiles of Escherichia coli, Salmonella spp., and Staphylococcus spp. isolated from synanthropic flies captured in entomological traps placed near the milking parlors of 30 dairy farms located in Northern Paraná, Brazil. In total, 192 flies were captured, and the isolation frequencies of muscids (21/30 = 70% and califorids (27/30 = 90% were significantly higher than that of sarcophagids (7/30 = 23.3%. Bacteriological tests on the internal contents and external surfaces of the flies showed that E. coli was present only in muscids (14.3% and caliphorids (33.3%. Salmonella spp. was isolated from 9.5% of the muscids, 7.4% of the caliphorids, and 14.29% of the sarcophagids. Staphylococcus spp. was isolated from 28.5% of the muscids and 29.6% of the caliphorids. E. coli isolation was more frequent in flies captured on farms at which domestic chickens were housed near the milking parlors (p = 0.031 and which did not use sugarcane for animal feed (p = 0.042. Two out of 27 (7.4% Staphylococcus spp. strains presented a phenotype of coagulase enzyme production. Ceftriaxone, ciprofloxacin, enrofloxacin, and gentamicin were the most effective antibiotics against E. coli and Salmonella spp. Tetracycline was the least effective antibiotic against the isolates. The Staphylococcus spp. strains isolated did not show the phenotype of oxacillin resistance. We conclude that regional flies are potential mechanical vectors of microbial agents able to cause enteritis in goats, mastitis in cows, and contamination of milk products for human consumption.

  5. Risk factors and prevalence of newborn hearing loss in a private health care system of Porto Velho, Northern Brazil

    Science.gov (United States)

    de Oliveira, Juliana Santos; Rodrigues, Liliane Barbosa; Aurélio, Fernanda Soares; da Silva, Virgínia Braz

    2013-01-01

    OBJECTIVE: To determine the prevalence of hearing loss and to analyze the results of newborn hearing screening and audiological diagnosis in private health care systems. METHODS Cross-sectional and retrospective study in a database of newborn hearing screening performed by a private clinic in neonates born in private hospitals of Porto Velho, Rondônia, Northern Brazil. The screening results, the risk for hearing loss, the risk indicators for hearing loss and the diagnosis were descriptively analyzed. Newborns cared in rooming in with their mothers were compared to those admitted to the Intensive Care Unit regarding risk factors for hearing loss. RESULTS: Among 1,146 (100%) enrolled newborns, 1,064 (92.8%) passed and 82 (7.2%) failed the hearing screening. Among all screened neonates, 1,063 (92.8%) were cared in rooming and 83 (7.2%) needed intensive care; 986 (86.0%) were considered at low risk and 160 (14.0%) at high risk for hearing problems. Of the 160 patients identified as having high risk for hearing loss, 83 (37.7%) were admitted to an hospitalized in the Intensive Care Unit, 76 (34.5%) used ototoxic drugs and 38 (17.2%) had a family history of hearing loss in childhood. Hearing loss was diagnosed in two patients (0.2% of the screened sample). CONCLUSIONS: The prevalence of hearing loss in newborns from private hospitals was two cases per 1,000 evaluated patients. The use of ototoxic drugs, admission to Intensive Care Unit and family history of hearing loss were the most common risk factors for hearing loss in the studied population. PMID:24142311

  6. Promoter hypermethylation of CDH1, FHIT, MTAP and PLAGL1 in gastric adenocarcinoma in individuals from Northern Brazil

    Science.gov (United States)

    Leal, Mariana Ferreira; Lima, Eleonidas Moura; Silva, Patrícia Natália Oliveira; Assumpção, Paulo Pimentel; Calcagno, Danielle Queiroz; Payão, Spencer Luiz Marques; Burbano, Rommel Rodríguez; Smith, Marília de Arruda Cardoso

    2007-01-01

    AIM: To evaluate the methylation status of CDH1, FHIT, MTAP and PLAGL1 promoters and the association of these findings with clinico-pathological characteristics. METHODS: Methylation-specific PCR (MSP) assay was performed in 13 nonneoplastic gastric adenocarcinoma, 30 intestinal-type gastric adenocarcinoma and 35 diffuse-type gastric adenocarcinoma samples from individuals in Northern Brazil. Statistical analyses were performed using the chi-square or Fisher's exact test to assess associations between methylation status and clinico-pathological characteristics. RESULTS: Hypermethylation frequencies of CDH1, FHIT, MTAP and PLAGL1 promoter were 98.7%, 53.9%, 23.1% and 29.5%, respectively. Hypermethylation of three or four genes revealed a significant association with diffuse-type gastric cancer compared with nonneoplastic cancer. A higher hypermethylation frequency was significantly associated with H pylori infection in gastric cancers, especially with diffuse-type. Cancer samples without lymph node metastasis showed a higher FHIT hypermethylation frequency. MTAP hypermethylation was associated with H pylori in gastric cancer samples, as well as with diffuse-type compared with intestinal-type. In diffuse-type, MTAP hypermethylation was associated with female gender. CONCLUSION: Our findings show differential gene methylation in tumoral tissue, which allows us to conclude that hypermethylation is associated with gastric carcinogenesis. MTAP promoter hypermethylation can be characterized as a marker of diffuse-type gastric cancer, especially in women and may help in diagnosis, prognosis and therapies. The H pylori infectious agent was present in 44.9% of the samples. This infection may be correlated with the carcinogenic process through the gene promoter hypermethylation, especially the MTAP promoter in diffuse-type. A higher H pylori infection in diffuse-type may be due to greater genetic predisposition. PMID:17552003

  7. Application of the authigenic 10Be/9Be dating method to Late Miocene-Pliocene sequences in the northern Danube Basin (Pannonian Basin System): Confirmation of heterochronous evolution of sedimentary environments

    Science.gov (United States)

    Šujan, Michal; Braucher, Régis; Kováč, Michal; Bourlès, Didier L.; Rybár, Samuel; Guillou, Valéry; Hudáčková, Natália

    2016-02-01

    Authigenic 10Be/9Be dating method was applied to lacustrine, deltaic and alluvial sequences of the northern Danube Basin (Pannonian Basin System), to bridge the insufficiency of geochronological data for the Late Miocene to Pliocene period. The measurements of 51 samples (both lacustrine and floodplain), ranging from 11.6 to 0.95 Ma are consistent with the existing magnetostratigraphic and biostratigraphic data standing mainly on the evolution degree of endemic mollusk fauna, mammals and dinocysts. This agreement confirms our assumption that the incoming beryllium fluxes remained constant over the studied time period and thus that the two initial 10Be/9Be ratios determined in actual Holocene/Late Pleistocene sediments (lacustrine and floodplain) are valid for these environments. The obtained ages indicate gradual progradation of the deltaic depositional systems across the Danube Basin with a clear time-transgressional character, replacing basin floor and shelfal environments. Deltaic sedimentation occurred firstly in the north at foothills of the Western Carpathians from 11.0 Ma, and changed to the alluvial environment after 10.5 Ma. At the same time (~ 10.5 Ma), the paleo-Danube deltaic system draining the Eastern Alps entered the study area from the Vienna Basin situated on the West. Later, the deltaic systems were merged in the central part of the basin and reached its southeastern margin at ~ 9.4 Ma. Regression of the Lake Pannon from the southernmost part of the study area is evidenced after 8.7 Ma. Alluvial deposition of meandering rivers lasting until 6.0-5.0 Ma followed and was interrupted by the early Pliocene basin inversion. Sedimentation of braided streams took place during the late Pliocene and Pleistocene, reflecting uplift of mountains surrounding the basin margins. This study documents the powerful potential of the authigenic 10Be/9Be dating method and its reliability in a basin with complicated tectonic and sedimentary history. It demonstrates that

  8. Transpressive dextral shear in the Italva-Itaperuna section, Northern State of Rio de Janeiro, Brazil

    Directory of Open Access Journals (Sweden)

    Tiago R. Karniol

    2008-09-01

    Full Text Available Structural analysis carried out on a segment of the Neoproterozoic Ribeira Belt, southeastern Brazil, show that it represents part of the transpressive dextral orogen related to the Central Mantiqueira Province. NNE-trending and steeply dipping regional mylonitic belts form anastomosed geometry, and describe a map-scale, S-C-like structure that is characterized by their deflection towards NE near the Além Paraíba Lineament. Lithological and structural control related to deformation partition were responsible for the formation of felsic mylonitic granulites with S-type granites lenses developed in ductile shear zones, alternated with less deformed intermediate to basic granulites associated with charnockites. The dextral shear sense indicators are consistent with transpressive deformation in the region and are common especially at the border of the main shear zones. The presence of S-type leucogranite may lead to variations of linear and planar relationships, which result in local extension zones. These elements are consistent with oblique continental collision considering the São Francisco Craton as a stable block.A análise estrutural efetuada num segmento neoproterozóico do Cinturão Ribeira, Sudeste do Brasil, mostra que ele representa parte do orógeno transpressivo destral, relacionado com a Província Mantiqueira Central. Caracteriza-se regionalmente por um cinturão milonítico de direção NNE e mergulhos subverticais, com geometria anastomosada, descrevendo em escala de mapa estruturas do tipo S-C, que são defletidas para direção NE nas proximidades do Lineamento de Além-Paraíba. O controle estrutural e litológico e a partição da deformação foram responsáveis pela formação de granulitos miloníticos félsicos com lentes de granitos tipo-S, desenvolvidos em zonas de cisalhamento dúcteis, alternados com granulitos básicos a intermediários menos deformados com charnockitos associados. Na região, os indicadores cinem

  9. Environmental risk assessment in five rivers of Parana River basin, Southern Brazil, through biomarkers in Astyanax spp.

    Science.gov (United States)

    Barros, Ivaldete Tijolin; Ceccon, Juliana Parolin; Glinski, Andressa; Liebel, Samuel; Grötzner, Sonia Regina; Randi, Marco Antonio Ferreira; Benedito, Evanilde; Ortolani-Machado, Claudia Feijó; Filipak Neto, Francisco; de Oliveira Ribeiro, Ciro Alberto

    2017-07-01

    In the current study, water quality of five river sites in Parana River basin (Brazil), utilized for public water supply, was assessed through a set of biomarkers in fish Astyanax spp. Population growth and inadequate use of land are challenges to the preservation of biodiversity and resources such as water. Some physicochemical parameters as well as somatic indexes, gills and liver histopathology, genotoxicity, and biochemical biomarkers were evaluated. The highest gonadosomatic index (GSI) and antioxidant parameters (catalase and glutathione S-transferase activities, non-protein thiols), as well as the lowest damage to biomolecules (lipid peroxidation, protein carbonylation, DNA damage) were observed in site 0 (Piava River), which is located at an environmental protected area. Site 1, located in the same river, but downstream site 0 and outside the protection area, presents some level of impact. Fish from site 2 (Antas River), which lack of riparian forest and suffer from silting, presented the highest micronucleus incidence and no melanomacrophages. Differently, individuals from site 3 (Xambrê River) and site 4 (Pinhalzinho River) which receive surface runoff from Umuarama city, urban and industrial sewage, have the highest incidences of liver and gill histopathological alterations, including neoplasia, which indicated the worst health conditions of all sites. In particular, site 4 had high levels of total nitrogen and ammonia, high turbidity, and very low oxygen levels, which indicate important chemical impact. Comparison of the biomarkers in fish allowed classification of the five sites in terms of environmental impact and revealed that sites 3 and 4 had particular poor water quality.

  10. Ichnology applied to sequence stratigraphic analysis of Siluro-Devonian mud-dominated shelf deposits, Paraná Basin, Brazil

    Science.gov (United States)

    Sedorko, Daniel; Netto, Renata G.; Savrda, Charles E.

    2018-04-01

    Previous studies of the Paraná Supersequence (Furnas and Ponta Grossa formations) of the Paraná Basin in southern Brazil have yielded disparate sequence stratigraphic interpretations. An integrated sedimentological, paleontological, and ichnological model was created to establish a refined sequence stratigraphic framework for this succession, focusing on the Ponta Grossa Formation. Twenty-nine ichnotaxa are recognized in the Ponta Grossa Formation, recurring assemblages of which define five trace fossil suites that represent various expressions of the Skolithos, Glossifungites and Cruziana ichnofacies. Physical sedimentologic characteristics and associated softground ichnofacies provide the basis for recognizing seven facies that reflect a passive relationship to bathymetric gradients from shallow marine (shoreface) to offshore deposition. The vertical distribution of facies provides the basis for dividing the Ponta Grossa Formation into three major (3rd-order) depositional sequences- Siluro-Devonian and Devonian I and II-each containing a record of three to seven higher-order relative sea-level cycles. Major sequence boundaries, commonly coinciding with hiatuses recognized from previously published biostratigraphic data, are locally marked by firmground Glossifungites Ichnofacies associated with submarine erosion. Maximum transgressive horizons are prominently marked by unbioturbated or weakly bioturbated black shales. By integrating observations of the Ponta Grossa Formation with those recently made on the underlying marginal- to shallow-marine Furnas Formation, the entire Paraná Supersequence can be divided into four disconformity-bound sequences: a Lower Silurian (Llandovery-Wenlock) sequence, corresponding to lower and middle units of the Furnas; a Siluro-Devonian sequence (?Pridoli-Early Emsian), and Devonian sequences I (Late Emsian-Late Eifelian) and II (Late Eifelian-Early Givetian). Stratigraphic positions of sequence boundaries generally coincide with

  11. Insectivory in Potamotrygon signata (Chondrichthyes: Potamotrygonidae, an endemic freshwater stingray from the Parnaíba River basin, northeastern Brazil

    Directory of Open Access Journals (Sweden)

    G. Moro

    Full Text Available Potamotrygon signata is an endemic freshwater stingray species in the Parnaíba River basin, Brazil. After its original description, only citations in systematic lists were recorded in the literature and the biology of the species remains unknown, including the feeding habits. The aim of this study is to characterize the overall diet of P. signata based on analysing stomach contents and to provide preliminary information on intraspecific diet variability between sexes and maturity stages. The stomach contents of 56 specimens of P. signata were analyzed. The taxonomic identification of food items showed the presence of 13 prey orders, including insects, mollusks, crustaceans and teleost fish. The Index of Relative Importance (IRI% indicated P. signata as an insectivorous species, with a dominance of Diptera larvae (60.64% and Ephemeroptera nymphs (34.68%. Differences in diet were observed between sexes, as well as between mature and immature individuals. The IRI% of females showed a similar occurrence of Diptera and Ephemeroptera (47.12% and 47.86%, respectively, whereas for males, Ephemeroptera was the main item (79.56%. Immature individuals showed a dominance of Diptera (76.20% while mature individuals showed a similar occurrence of Diptera (46.95% and Ephemeroptera (47.23%. The observed sexual and ontogenetic differences in diet may be related to distinct nutritional requirements of males and females, and to the variation of morphological aspects of the oral apparatus and dentition of males and females and of immature individuals and adults. The essentially insectivorous diet of the species is possibly adaptively advantageous in the Caatinga semi-arid environment, where the availability of fish as prey may be subject to strong seasonal variation.