995 resultados para PARAGUAY BELT


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Origin of samples of Cannabis sativa through insect fragments associated with compacted hemp drug in South America. Insects associated with a seizure of Cannabis sativa L. may indicate the origin of the illicit drug. Nevertheless, no work regarding this subject has been previously published for South America. In the present investigation, seven kilograms of vegetal material (C. sativa) were inspected for insect fragments. Three species were identified and used to test the origin of the seizure of cannabis plant material: Euschistus heros (Fabricius, 1794), Thyanta perditor (Fabricius, 1794) (Heteroptera, Pentatomidae), and Cephalotes pusillus (Klug, 1824) (Hymenoptera, Formicidae). These insect species restricted the geographic origin of the drug to the Neotropical region, and their distribution patterns showed an overlap of the State of Mato Grosso (Brazil), Argentina, and Paraguay. Based on this information, two of the three major C. sativa growing areas in South America were excluded: (1) the Colombian territory and (2) northeastern Brazil.

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On the identity of Melipona torrida Friese (Hymenoptera, Apidae). Melipona marginata var. torrida Friese, 1916, described from three workers putatively collected in Costa Rica, never had its identity properly recognized. Since its original description, no additional specimens have ever been collected in Costa Rica. It is argued here that Melipona torrida was based on mislabeled specimens and corresponds to Melipona marginata obscurior Moure, 1971, a form known only from southern Brazil, Argentina and Paraguay. A lectotype is designated for Melipona torrida and notes on the type material of Melipona marginata obscurior are provided. Other known examples of species described from mislabeled specimens in Friese's Zur Bienenfauna von Costa Rica are discussed. It is pointed out that additional names proposed in this work, based on material from Costa Rica, might turn out to correspond to South American taxa. Also, the date of publication of this Friese's paper is discussed.

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Carbon and oxygen isotope studies of the host and gangue carbonates of Mississippi Valley-type zinc-lead deposits in the San Vicente District hosted in the Upper Triassic to Lower Jurassic dolostones of the Pucara basin (central Peru) were used to constrain models of the ore formation. A mixing model between an incoming hot saline slightly acidic radiogenic (Pb, Sr) fluid and the native formation water explains the overall isotopic variation (delta(13)C = - 11.5 to + 2.5 parts per thousand relative to PDB and delta(18)O = + 18.0 to + 24.3 parts per thousand relative to SMOW) of the carbonate generations. The dolomites formed during the main ore stage show a narrower range (delta(13)C = - 0.1 to + 1.7 parts per thousand and delta(18)O = + 18.7 to + 23.4 parts per thousand) which is explained by exchange between the mineralizing fluids and the host carbonates combined with changes in temperature and pressure. This model of fluid-rock interaction explains the pervasive alteration of the host dolomite I and precipitation of sphalerite I. The open-space filling hydrothermal white sparry dolomite and the coexisting sphalerite II formed by prolonged fluid-host dolomite interaction and limited CO2 degassing. Late void-filling dolomite III (or calcite) and the associated sphalerite III formed as the consequence of CO2 degassing and concomitant pH increase of a slightly acidic ore fluid. Widespread brecciation is associated to CO2 outgassing. Consequently, pressure variability plays a major role in the ore precipitation during the late hydrothermal events in San Vicente. The presence of native sulfur associated with extremely carbon-light calcites replacing evaporitic sulfates (e.g., delta(13)C = - 11.5 parts per thousand), altered native organic matter and heavier hydrothermal bitumen (from - 27.0 to - 23.0 parts per thousand delta(13)C) points to thermochemical reduction of sulfate and/or thiosulfate. The delta(13)C- and delta(18)O-values of the altered host dolostone and hydrothermal carbonates, and the carbon isotope composition of the associated organic matter show a strong regional homogeneity. These results coupled with the strong mineralogical and petrographic similarities of the different MVT occurrences perhaps reflects the fact that the mineralizing processes were similar in the whole San Vicente belt, suggesting the existence of a common regional mineralizing hydrothermal system with interconnected plumbing.

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This paper, fundamentally stratigraphic, is based on the vertical distribution of fauna in sediments which constitute the Montgri Massif. The stratigraphic series is composed of two units: one allochtonous (Mesozoic) and a second one autochtonous (Paleogene). The latter crops out in front of the thrust belt and presents the typical facies described by PALLI (1972). The allochtonous part is formed by the following units (from bottom to top): variegated gypsiferous shales of Keuper age; marls, limestones and dolomites from the Lias (Domerian); gray breccia ted dolomites: supraliassic; and Cretaceous limestones with rare interbeds of calcareous marls and nodular shaly marls. In this unit the Neocomian, Barremian (?), Aptian, Albian, Cenomanian, Turonian (?) and Santonian haven been recognized. Structurally, the Montgri Massif is part of a thrust belt which has been divided into three parts of different development ang age. Both parts are affected by ample synclinal folds of NE-SW directions and fractures of NW-SE orientation. The fractures condition the torrential streams as well as the karstic phenomena present in the Massif. These and the eolian actions are the main causes of the present geomorphology of the Montgri

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We present in this work a couple of weapons and objects related to the military equipment of early VIII century from two sites on Girona's province: the castellum of Sant Julià de Ramis (in the municipality of the same name), and the fort of Puig Rom (in Roses). The comparation of these materials has permitted to recompose a quite complete panoply with various types of knives and daggers, shield-handles, axes, spearheads and javelinheads, tips (regatones), arrowheads, belt-buckles and some buckles and horse harness elements

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Two granitic plutons, the Tso Morari gneiss and the Rupshu metagranite, crop out in the Tso Morari area. The Polokongka La granite, classically interpreted as a young intrusion in the Tso Morari gneiss, has been recognized as the undeformed facies of the latter. Conventional isotope dilution U-Pb zircon dating on single-grain and small multi-grain fractions yielded magmatic ages of 479 +/- 2 Ma for the Tso Morari gneiss and the Polokongka La granite, and 482.5 +/- 1 Ma for the Rupshu granite. There is a great difference in zircon morphology between the Tso Morari gneiss (peraluminous type) and the Rupshu granite (alkaline type). This difference is confirmed by whole-rock chemistry. The Tso Morari gneiss is a typical deformed S-type granite, resulting from crustal anatexis. On the other hand, the Rupshu granite is an essentially metaluminous alkali-calcic intrusion derived from a different source material. Data compilation from other Himalayan Cambro-Ordovician granites reveals huge and widespread magmatic activity all along and beyond the northern Indian plate between 570 and 450 Ma, with a peak at 500-480 Ma. A major, continental-scale tectonic event is required to generate such a large magmatic belt; it has been tentatively compared to the Variscan post-orogenic extensional regime of Western Europe, as a late evolution stage of a Pan-African orogenic event.

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Na região de Lavras (MG), foram selecionados perfis de solos com horizonte B textural para a avaliação micropedológica dos processos de alteração e investigação de características de evolução pedológica vinculadas ao material de origem. Os solos com horizonte B textural foram selecionados para tal estudo, dado seu grau de evolução que permite avaliar características herdadas da rocha original. Foram escolhidas classes de solos com B textural, desenvolvidos em relevo ondulado a forte ondulado, a partir de materiais geológicos litoquimicamente distintos: Perfil 1 - Argissolo Vermelho-Amarelo distrófico, originado por alteração de rochas do domínio geológico Granito de Itutinga; Perfil 2 - Argissolo Vermelho eutrófico, desenvolvido a partir de rochas do domínio geológico Diorito do Rosário; e Perfil 3 - Chernossolo Argilúvico férrico, desenvolvido a partir de rochas do domínio geológico Greenstone-belt de Lavras. Ao longo dos perfis de alteração selecionados, realizaram-se análises petrográficas dos fácies rocha fresca e rocha alterada, bem como análises micromorfológicas dos fácies alterito, de transição e sólum. Para avaliar os processos de alteração, observaram-se as reações de alteração e feições texturais, com auxílio da difração de raios-X com vistas em identificar a mineralogia da fração argila, numa discussão envolvendo material de origem versus processos de alteração pedogenética, possibilitando estabelecer a ordem de destruição dos minerais primários. A evolução dos processos de alteração ao longo dos perfis mostrou-se diretamente vinculada à textura, composição química e mineralógica dos materiais originais, refletindo-se nas características micromorfológicas e composição mineralógica dos horizontes que compõem cada perfil, especialmente o horizonte diagnóstico - B textural.

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For the first time, an albite orthogneiss has been recognised and dated within the HP-LT blueschist facies metabasites and metapelites of the Ile de Groix. It is characterised by a peraluminous composition, high LILE, Th and U contents, MORB-like HREE abundances and moderate Nb and Y values. A U-Pb age of 480.8 +/- A 4.8 Ma was obtained by LA-ICP-MS dating of zircon and titanite. It is interpreted as the age of the magmatic emplacement during the Early Ordovician. Morphologically different zircon grains yield late Neoproterozoic ages of 546.6-647.4 Ma. Zircon and titanite U-Pb ages indicate that the felsic magmatism from the Ile de Groix is contemporaneous with the acid, pre-orogenic magmatism widely recognised in the internal zones of the Variscan belt, related to the Cambro-Ordovician continental rifting. The magmatic protolith probably inherited a specific chemical composition from a combination of orogenic, back-arc and anorogenic signatures because of partial melting of the Cadomian basement during magma emplacement. Besides, the late Devonian U-Pb age of 366 +/- A 33 Ma obtained for titanite from a blueschist facies metapelite corresponds to the age of the HP-LT peak metamorphism.

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Na região de Lavras (MG), realizou-se a avaliação das transformações mineralógicas ao longo da alteração pedogenética em perfis de solos, discriminados pela composição geoquímica ácida, intermediária e básica do material de origem. Os solos com horizonte B textural foram selecionados para tal estudo, sendo escolhidas as seguintes classes destes solos: Perfil 1 - Argissolo Vermelho-Amarelo distrófico (PVAd), originado por alteração de rochas do Domínio geológico Granito de Itutinga; Perfil 2 - Argissolo Vermelho eutrófico (PVe), desenvolvido a partir de rochas do Domínio geológico Diorito do Rosário, e Perfil 3 - Chernossolo Argilúvico férrico (MTf), evoluído a partir de rochas do Domínio geológico Greenstone-belt de Lavras. Ao longo de cada perfil, desde a rocha fresca até o sólum, realizaram-se análises microscópicas para avaliar os processos de alteração, mediante evolução das reações de transformação mineralógica, com auxílio da difração de raios-X na identificação da mineralogia da fração argila. O estudo permitiu elaborar a ordem de destruição intempérica dos minerais primários e conseqüente formação da mineralogia do solo, estabelecendo-se reações de transformações mineralógicas e caracterização dos processos atuantes ao longo da evolução da alteração pedogenética, assim como suas relações com o material de origem. As reações de transformação mineralógica esquematizadas indicam que, nos Argissolos estudados, os minerais primários foram alterados para caulinita, gibbsita e sesquióxidos de ferro, acrescentando-se sesquióxidos de titânio e vermiculita com hidróxi entre camadas no caso do PVe. Persistiram como resíduos o quartzo e o feldspato potássico, este último apenas no PVAd. Já no Chernossolo avaliado, as alterações originaram talco, esmectita, caulinita e sesquióxidos de ferro e titânio, não havendo minerais primários residuais.

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Os solos derivados de rochas serpentinizadas ou serpentinitos constituem um grupo especial de solos em toda superfície terrestre. De caráter ultramáfico, ou seja, rochas com mais de 70 % de minerais máficos (ferromagnesianos), os serpentinitos apresentam uma mineralogia pobre em sílica e escassa em Al, sendo, no entanto, muito enriquecida em Mg. São poucos os estudos sobre a morfologia, mineralogia, gênese e classificação dos solos desenvolvidos de tais rochas. Em ambiente tropical úmido no sudoeste de Minas Gerais, na zona do greenstone belt do Morro de Ferro, em superfícies geomórficas jovens, três perfis de solos representativos dessa paisagem sobre rochas serpentinizadas foram caracterizados por meio de descrições macro e micromorfológicas, análises granulométricas, químicas e por mineralogia de raios X das frações argila e silte. Complementarmente, para acompanhamento da alteração geoquímica dos horizontes do solo, foram feitas microanálises das seções delgadas por EDRX. Os solos foram classificados como Chernossolo Háplico Férrico típico, Cambissolo Háplico eutroférrico léptico e Neossolo Regolítico eutrófico típico e, embora situados num clima que favorece o rápido intemperismo, do ponto de vista morfológico e mineralógico, mostraram-se similares aos solos derivados de rochas serpentinizadas das regiões subtropicais e temperada. No processo de formação de solo, a evolução da trama segue a seguinte seqüência: alteração da rocha ® trama frâgmica ® trama porfírica com cavidades ® trama porfírica aberta por coalescência de cavidades. O processo de argiluviação é evidente e se dá em dois estádios distintos: argiluviação primária, que ocorre nas fendas e cavidades que se formam por alteração de rocha, e argiluviação secundária, verificada na porosidade mais aberta e evoluída da coalescência das cavidades. Os solos apresentam mineralogia pouco comum para solos tropicais, com presença de minerais primários de fácil decomposição até mesmo na fração argila, com destaque para o talco, clorita trioctaedral e ocorrência limitada de tremolita, sendo esta última abundante na fração silte. Óxidos de Fe, caulinita e os interestratificados de clorita-esmectita e de clorita-vermiculita completam a assembléia mineralógica. A tendência de evolução é para B textural ou para B nítico com mineralogia 1:1 e alto conteúdo de óxidos de Fe. Nas fases iniciais de alteração, os alteromorfos já apresentam composição química similar aos agregados do solo, com forte perda de Mg, Ca e Si e acúmulo relativo de Al e Fe. Nas três situações estudadas, ocorreu um rejuvenescimento superficial por erosão diferencial, que acumulou material grosseiro e removeu os finos, contribuindo para o incremento da relação textural.

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In the European GLORIA project, 12 summits (treeline to nival belt) were inventoried in three regions of Switzerland: two in the Swiss National Park Graubünden and one in Valais. Vascular plants were recorded in all three regions and bryophytes and lichens were recorded only in Valais. On each summit, vegetation and temperature data were sampled using sampling protocols for the GLORIA project (Global Observation Research Initiative in Alpine environment) on large summit sections and in clusters of four 1x1-m quadrats. We observed a general decrease of species richness for all three systematic groups with increasing elevation in the summit sections, but only for vascular plants in the quadrats. In Valais, there was higher species richness for vascular plants than for bryophytes and lichens on the lower summits, but as the decrease in species richness was less pronounced for cryptogams, the latter were more numerous than vascular plants on the highest summit. Vascular species showed a clear shift of the dominant life form with elevation, with chamaephytes replacing hemicryptophytes. Bryophytes and lichens showed a weak trend among the life forms at the summit section scale, but a stronger shift of the dominant forms was seen in the quadrats, with cushion replacing turf bryophytes and crustaceous replacing fruticose lichens. Altogether, these results sustain the temperature-physiographic hypothesis to explain the species richness decrease along the altitudinal gradient: the harsh climatic conditions of the alpine-nival belts act as a filter for species, but the diminishing diversity of microhabitats is also an important factor. Because cryptogams depend more on humidity than temperature and more on smaller microhabitats than vascular plants, the decrease of species richness is more gradual with elevation for bryophytes and lichens.

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Background and Aims Paleoclimatic data indicate that an abrupt climate change occurred at the Eocene-Oligocene (E-O) boundary affecting the distribution of tropical forests on Earth. The same period has seen the emergence of South-East (SE) Asia, caused by the collision of the Eurasian and Australian plates. How the combination of these climatic and geomorphological factors affected the spatio-temporal history of angiosperms is little known. This topic is investigated by using the worldwide sapindaceous clade as a case study. Methods Analyses of divergence time inference, diversification and biogeography (constrained by paleogeography) are applied to a combined plastid and nuclear DNA sequence data set. Biogeographical and diversification analyses are performed over a set of trees to take phylogenetic and dating uncertainty into account. Results are analysed in the context of past climatic fluctuations. Key Results An increase in the number of dispersal events at the E-O boundary is recorded, which intensified during the Miocene. This pattern is associated with a higher rate in the emergence of new genera. These results are discussed in light of the geomorphological importance of SE Asia, which acted as a tropical bridge allowing multiple contacts between areas and additional speciation across landmasses derived from Laurasia and Gondwana. Conclusions This study demonstrates the importance of the combined effect of geomorphological (the emergence of most islands in SE Asia approx. 30 million years ago) and climatic (the dramatic E-O climate change that shifted the tropical belt and reduced sea levels) factors in shaping species distribution within the sapindaceous clade.

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Ultramafic rocks, mainly serpentinized peridotites of mantle origin, are mostly associated with the ophiolites of Mesozoic age that occur in belts along three of the margins of the Caribbean plate. The most extensive exposures are in Cuba. The ultramafic-mafic association (ophiolites) were formed and emplaced in several different tectonic environments. Mineralogical studies of the ultramafic rocks and the chemistry of the associated mafic rocks indicate that most of the ultramafic-mafic associations in both the northern and southern margins of the plate were formed in arc-related environments. There is little mantle peridotite exposed in the ophiolitic associations of the west coast of Central America, in the south Caribbean in Curacao and in the Andean belts in Colombia. In these occurrences the chemistry and age of the mafic rocks indicates that this association is mainly part of the 89 Ma Caribbean plateau province. The age of the mantle peridotites and associated ophiolites is probably mainly late Jurassic or Early Cretaceous. Emplacement of the ophiolites possibly began in the Early Cretaceous in Hispaniola and Puerto Rico, but most emplacement took place in the Late Cretaceous to Eocene (e.g. Cuba). Along the northern South America plate margin, in the Caribbean mountain belt, emplacement was by major thrusting and probably was not completed until the Oligocene or even the early Miocene. Caribbean mantle peridotites, before serpentinization, were mainly harzburgites, but dunites and lherzolites are also present. In detail, the mineralogical and chemical composition varies even within one ultramafic body, reflecting melting processes and peridotite/melt interaction in the upper mantle. At least for the northern Caribbean, uplift (postemplacement tectonics) exposed the ultramafic massifs as a land surface to effective laterization in the beginning of the Miocene. Tectonic factors, determining the uplift, exposing the peridotites to weathering varied. In the northern Caribbean, in Guatemala, Jamaica, and Hispaniola, uplift occurred as a result of transpresional movement along pre-existing major faults. In Cuba, uplift occurred on a regional scale, determined by isostatic adjustment. In the south Caribbean, uplift of the Cordillera de la Costa and Serrania del Interior exposing the peridotites, also appears to be related to strike-slip movement along the El Pilar fault system. In the Caribbean, Ni-laterite deposits are currently being mined in the central Dominican Republic, eastern Cuba, northern Venezuela and northwest Colombia. Although apparently formed over ultramafic rocks of similar composition and under similar climatic conditions, the composition of the lateritic soils varies. Factors that probably determined these differences in laterite composition are geomorphology, topography, drainage and tectonics. According to the mineralogy of principal ore-bearing phases, Dominican Ni-laterite deposits are classified as the hydrous silicate-type. The main Ni-bearing minerals are hydrated Mg-Ni silicates (serpentine and ¿garnierite¿) occurring deeper in the profile (saprolite horizon). In contrast, in the deposits of eastern Cuba, the Ni and Cooccurs mainly in the limonite zone composed of Fe hydroxides and oxides as the dominant mineralogy in the upper part of the profile, and are classified as the oxide-type.

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In Iowa, hundreds of people die and thousands more are injured on our public roadways each year despite decades of efforts to end this su�ffering. Past safety e�efforts have resulted in Iowans bene�fiting from one of the best state roadway systems in the nation. Due to multi-agency e�efforts, Iowa has achieved 90 percent compliance with the state’s mandatory front seat belt use law, earned the nation’s second-lowest percent of alcohol involvement in fatal crashes and made safety gains in system-wide roadway design and operational improvements. Despite these ongoing e�efforts, the state’s annual average of 445 deaths and thousands of life-changing injuries is a tragic toll and an unacceptable public health epidemic in our state. To save more lives on our roadways, Iowans must be challenged to think �differently about lifesaving measures addressing young drivers, safety belts, and motorcycle helmet use and accept innovative designs such as roundabouts. Iowa must apply evidence-based strategies and create a safety culture that motivates all citizens to travel more responsibly. They must demand a lower level of tolerance for Iowa’s roadway deaths and injuries. The Iowa Comprehensive Highway Safety Plan (CHSP) engages diverse safety stakeholders and charts the course for this state, bringing to bear sound science and the power of shared community values to change the culture and achieve a standard of safer travel for our citizens. How many roadway deaths and injuries are too many? Iowa’s highway safety stakeholders believe that, “One death is one too many” and e�effective culture-changing policy and program strategies must be implemented to help reduce this death toll from an annual average of 445 to 400 by the year 2015.

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The As Pontes basin (12 km2), NW Iberian Peninsula, is bounded by a double restraining bend of a dextral strike-slip fault, which is related to the western onshore end of the Pyrenean belt. Surface and subsurface data obtained from intensive coal exploration and mining in the basin since the 1960s together with additional structural and stratigraphic sequence analysis allowed us to determine the geometric relationships between tectonic structures and stratigraphic markers. The small size of the basin and the large amount of quality data make the As Pontes basin a unique natural laboratory for improving our understanding of the origin and evolution of restraining bends. The double restraining bend is the end stage of the structural evolution of a compressive underlapping stepover, where the basin was formed. During the first stage (stepover stage), which began ca. 30 Ma ago (latest Rupelian) and lasted 3.4 My, two small isolated basins bounded by thrusts and normal faults were formed. For 1.3 My, the strike-slip faults, which defined the stepover, grew towards each other until joining and forming the double restraining bend, which bounds one large As Pontes basin (transition stage). The history of the basin was controlled by the activity of the double restraining bend for a further 3.4 My (restraining bend stage) and ended in mid-Aquitanian times (ca. 22 Ma).