475 research outputs found
Different meanings for cummingtonite-hornblende association in plutonic rocks (Iberian Massif, Portugal)
Cummingtonite-grunerite series is frequently related with metamorphism or volcanic environments but rarely described as belonging to a plutonic assemblage [1]. Recently, in Iberian Massif (Portugal), there have been several references [2,3,4,5] of this Fe-Mg amphibole intimately associated with Ca amphiboles (mainly hornblende) on plutonic rocks. Different textural relations between two amphibole types have been argued to for a primary (igneous) or subsolidus metamorphic origin for Fe-Mg amphibole.
Cummingtonite-grunerite (Cum, hereafter all abbreviation from [6]) from gabbros and diorites Carrascal Massif (Central Iberian Zone) occurs as tiny exsolution lamellae within a dominant hornblende (Hbl) crystal. Their textural occurrence agrees with the subsolidus growth of the Fe-Mg amphibole reflecting the equation Hbl+ Qtz= Cum + An + H2O [7].
Nevertheless, on Hospitais tonalite (Ossa-Morena Zone) Cum occur as euhedral to subhedral cores usually mantled by Hbl. Although seldom described in literature, Cum on Hospitais tonalite was interpreted as an igneous crystallizing early phase. As a consequence of the high water content of calc-alkaline magmas, the Fe-Mg amphibole should reflect the equation Opx+H2O = Cum+Mag+SiO2+H2 [8]. The similarity between Mg # on Cum and Hbl from tonalitic rocks suggests an equilibrium crystallizing assemblage as pointed by Wones and Gilbert [9] for a hypabyssal igneous suite.
Considering that the Cum spectrum analyses from both occurrences exhibited a clear overlap; Carrascal gabbro-dorites (Mg#: 0.49-0.64; Al2O3: 0.7-2.37%; TiO2: 0.01-0.37%) and Hospitais tonalite (Mg#: 0.43-0.53; Al2O3: 1.22-2.44 %; TiO2; 0.05-0.27%), textural relations should be the main (only?) tool to decipher between igneous vs metamorphic growth. More detailed petrographic studies on plutonic rocks from Iberian Massif are needed to ascertain the petrogenetic significance of the association Cum-Hbl
Geochemistry of the Rio Espinharas hybrid complex, northeastern Brazil
The Rio Espinharas pluton, northeastern Brazil, belongs to the shoshonitic series and consists mainly of syenogranite, quartz-monzonite and porphyritic quartz-monzonite, but diorite, quartz-monzodiorite, quartz-syenite and microsyenogranite also occur containing microgranular enclaves, except for the diorite. Most variation diagrams of rocks, amphiboles, biotites and allanites show linear trends, but K, Zr, Sr and Ba of rocks display curved scattered trends. The rocks ranging from diorite to syenogranite define a pseudo-errorchron and have similar REE patterns. Syenogranite and microsyenogranite are derived from two distinct pulses of granite magma with initial 87Sr/86Sr ratio of 0.7083±0.0003 and 0.7104±0.0007, respectively. Modelling of major and trace elements shows that the syenogranite evolved by fractional crystallization of plagioclase, microcline, edenite, biotite and titanite, whereas quartz-monzonite, porphyritic quartz-monzonite, quartz-monzodiorite and quartz-syenite resulted from simple mixing between an upper mantle-derived dioritic magma and the upper crust-derived syenogranite magma. Dioritic enclaves are globules of a mafic magma from the upper mantle.http://www.sciencedirect.com/science/article/B6V6J-46X86NR-5/1/0e5ce1dcc0c8fe91ebd680e6f2ac523
Sensitive areas under radium/uranium mine drainage - the Picoto mine case study, central Portugal
A zona mineira de Picoto está localizada próximo de Vilar Seco (Viseu, Centro de Portugal). Ocorre numa área de declive suave, altitude variando entre 360-380 m, incluída na bacia do rio Cagavaio, com drenagem dominante NE-SW. A mineralização ocorre em veios de quartzo, que intersectam o granito Varisco, porfiróide de duas micas. Os filões de quartzo preenchem falhas N37°-45°E e N50°-70°E, localmente brechificadas. Estes filões contêm meta-torbernite e uranófano, e alguns minerais portadores de U, como clorite e hidróxidos de Fe e Mn. A exploração ocorreu em duas fases, entre 1917 e 1953. Após cessada a exploração, permaneceram as escombreiras resultantes da exploração e a área nunca foi reabilitada. Neste momento, está ocupada por culturas locais, principalmente vinhas e produtos agrícolas. Vinte amostras de águas superficiais e subterrâneas foram colhidas entre 2008 e 2009. Em geral, as águas apresentam valores de pH entre 4.7 a 6.3 e são pouco mineralizadas (CE = 44-190 μS/cm; TDS = 49-137 mg/L). Contudo, algumas águas estão contaminadas em NO2, Fe, Mn, Cu, As e U, e não devem ser utilizadas para consumo humano nem em atividades agrícolas. A contaminação da água está associada principalmente à antiga mina de rádio/urânio e atividades humanas desenvolvidas.The Picoto mine area is located at Vilar Seco village (Viseu, central Portugal), in a soft slope area with altitudes ranging from 360 to 380 m, included in the Cagavaio river catchment, with a dominant NE-SW drainage. The mineralization occurs mainly in quartz veins, which intersect a Variscan porphyritic two-mica granite. The quartz veins fill N37°-45°E and N50°-70°E faults, locally brecciated. The quartz veins contain meta-torbernite and uranophane, and some U-bearing minerals, such as chlorite and Fe- and Mn-hydroxides. The exploitation was carried out in two stages, between 1917 and 1953. Since closure, the area contains mine rejected materials and has never been restored. Therefore, a local cultivated area, mainly for vines and domestic consumption agricultural products, is now deployed. A total of twenty surface and groundwater samples were collected between 2008 and 2009. In general, the waters yield pH values ranging from 4,4 to 6,3 and are poorly mineralized (EC=44-190 µS/cm; TDS= 49-137 mg/L). However, some waters are contaminated with NO₂, Fe, Mn, Cu, As and U and must not be used neither for human consumption nor in agricultural activities. The water contamination is mainly associated with the old radium/uranium mine and subsequent human activities developed in the area.Este trabalho teve suporte financeiro através do ICT e do projeto UID/GEO/04035/2013.info:eu-repo/semantics/publishedVersio
Effect of the Ages of Parasitoid and Host Eggs on Telenomus podisi (Hymenoptera: Platygastridae) Parasitism.
This study investigates the influence of parasitoid age and egg age of the hosts Euschistus heros (Fabricius) and Dichelops melacanthus (Dallas) on parasitism of Telenomus podisi Ashmead. Six separate bioassays were conducted: parasitism on eggs of E. heros (bioassay 1) and D. melacanthus (bioassay 2) by T. podisi females of different age (1, 5, and 10 days old); parasitism by T. podisi on eggs of different age (1, 2, 3, 4, and 5 days of embryonic development) of the hosts E. heros (bioassay 3) and D. melacanthus (bioassay 4); preference of T. podisi females for eggs at different embryonic developmental stages (eggs of 1, 2, 3, 4, and 5 days) of the hosts E. heros (bioassay 5) and D. melacanthus (bioassay 6). The age of T. podisi females and their hosts affected parasitism on both E. heros and D. melacanthus eggs. Overall, the parasitism rate was higher in older than younger parasitoids, independent of the tested host species, and host eggs between 1 and 3 days old were similarly parasitized. Thus, in T. podisi mass rearing facilities, it is recommended to use older adults (5 to 10 days old) as mother wasps to increase parasitism on the offered eggs. In addition, when hosts are completely absent in the field, or climatic conditions are unfavorable for release, mass-reared adults can be kept in the laboratory (25°C) for up to 10 days for later release in the field without any impairment of their subsequent parasitism performance
Utilização do farelo de castanha de caju na terminação de ovinos em confinamento.
O trabalho foi conduzido com o objetivo de avaliar a utilização de concentrados contendo farelo de castanha de caju (FCC) na alimentação de ovinos mantidos em confinamento. Foram testados quatro tipos de concentrados isoprotéicos contendo 0, 12, 24 e 36% de FCC, tendo o concentrado participado com 30% da matéria seca (MS) da dieta total. Foram utilizados 32 ovinos sem raça definida (SRD), machos e fêmeas, em esquema fatorial 4 x 2 (4 níveis de inclusão de FCC e 2 sexos) e quatro repetições. Foram avaliados o ganho de peso e conversão alimentar, bem como os consumos de matéria seca (CMS), proteína bruta (CPB), extrato etéreo (CEE) e fibra em detergente neutro (CFDN). Estas variáveis foram analisadas conforme o consumo em g/animal/dia, % do peso vivo(PV) e g/UTM(PV0,75), tendo sido feito a análise de variância com teste de médias e estudo de regressão. Foram observadas diferenças no CMS , CPB e CEE de animais alimentados com dietas com 0 e 36% de FCC, com tendência de diminuição dos consumos de MS, PB e FDN, a medida que aumentou o FCC na dieta. O consumo de EE elevou com a adição FCC às dietas. O ganho de peso e a conversão alimentar foram semelhantes para as quatro dietas fornecidas. Portanto o FCC deve ser utilizado com um nível de inclusão de 24% do concentrado, não ultrapassando 6% de lipídios na dieta total. LEVELS OF CASHEW NUTS MEAL IN DIETS FOR FEEDLOT SHEEP. ABSTRACT: A study was conducted to evaluate the use of cashew nuts meal (CNM) in diets for sheeps, raised in feedlot. Thirty two crossbred animals received concentrates with the same amount of crude protein, but four differents levels of CNM (0, 12, 24 and 36%). A factorial 4 X 2 was used, with four levels of CNM and 2 sexes, with four repetitions. Daily weight gain and feed conversion as well as intake of dry matter (DM), crude protein (CP), ether extract(EE), neutral detergent fiber(NDF) and ashes were determined by analysis of variance, duncan statistical test and regression analysis. Intake was estimated as g/animal/day, percentage of body weight (%BW) and g/BW0.75. There are differences in intake of DM, CP and EE when animals were fed concentrates with 0 and 36% of CNM. Also, intake of DM, CP and NDF tended to decrease as the levels of CNM increased inthe diet. Intake of EE varied among treatments, given that animals received differents levels of fat. The type of diet did not significantly affect either weight gain or feed conversion. Therefore, cashew nut meal can be included up to 24% in the concentrate, but the total diets should not have more than 6% of fat
Intake, nutrients digestibility and nitrogen balance of elephant grass silages with mango by-product addition.
The objective of this study was to evaluate the nutritive value of elephant grass silages with increasing levels of dried mango by-product (DMB). Five addition levels were studied (0, 4, 8, 12 and 16%) using 20 rams, in a randomized complete design with five treatments (addition levels) and four replications. Dry matter (DM), organic matter (OM), crude protein (CP), neutral detergent fiber (NDF), acid detergent fiber (ADF), ether extract (EE), total carbohydrates (TC), non-fibrous carbohydrates (NFC) intake and digestibility were evaluated, as well as the total digestible nutrients (TDN) and the silage nitrogen balance (NB). Mango by-product addition did not influence the DM, CP and TC intakes, the TDN level or the OM, CT and NFC digestibilities. On the other hand, DMB addition reduced the NDF and the ADF intakes, as well as the DM, CP, NDF and ADF digestibilities, and the NB of the silages. There was also a increasing linear effect of DMB addition on the EE and NFC intakes, and on EE digestibility. The elephant grass silage with DMB by-product may not be used as a single feed to ruminants because it reduces the NDF and the ADF intakes and the DM, CP, NDF and ADF digestibilities, as well as the nitrogen balance
Desempenho de ovinos alimentados com dietas à base de silagem de capim elefante (Pennisetum purpureum, Schum) contendo ou não bagaço de cajú (Anacardium occidentale, L).
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