Lithium isotopic composition of pore fluids and sediments in the Costa Rica subduction zone

Pore fluid and sediment Li concentrations and isotopic ratios provide important insights on the hydrology, sediment contribution to the arc volcanoes and fluid-sediment reactions at the dominantly non-accretionary Costa Rica subduction zone. Ocean Drilling Program Site 1039 in the trench axis provides a reference section of 400 m of the incoming sediments, and Site 1040, situated arcward from the trench, consists of a deformed sedimentary wedge and apron sediments, the décollement, and the partially dewatered underthrust sediment section. At the reference site, pore fluids show important isotopic variations (delta6Li=-21.7 to -37.8 per mil), reflecting the interplay of in situ alteration of volcanic material and ion exchange with clay minerals. In the basal section, a reversal of Li concentration and delta6Li toward seawater values is observed, providing supporting evidence for a lateral seawater flow system in the upper oceanic basement underlying this sediment section. At Site 1040, pore fluid of the lower deformed wedge sediments and within the décollement is enriched in Li and the isotopic compositions are relatively light, suggesting infiltration of a deep-seated fluid. The delta6Li value of -22 per mil of this Li-enriched fluid (261 µM), when compared with the delta6Li value of the subducted sediment section (-11 per mil), suggests that the deep source fluid originates from mineral fluid dehydration and transformation reactions at temperatures of 100 to 150°C, consistent with the temperature range of the up-dip seismogenic zone and of transformation of smectite to illite. The distribution of Li and its isotopes in the underthrust section are similar to those at the reference site, indicating near complete subduction of the incoming sediments and that early dewatering of the underthrust sediments occurs predominantly by lateral flow into the ocean. The hemipelagic clay-rich sediment section of the subducting plate carries most of the Li into this subduction zone, and the pelagic diatomaceous and nannofossil calcareous oozes contain little Li. The Li isotopes of both the clay-rich hemipelagic sediments and of the pelagic oozes are, however, similar, with delta6Li values of -9 to -12 per mil. The observations that (1) the delta6Li values of the underthrust sediments are distinctly lower than that of the mantle, and (2) the lavas of the Costa Rican volcanoes are enriched in Li and 7Li, provide an approximation of the contribution of the subducted sediments to the arc volcanoes. A first order mass balance calculation suggests that approximately half of the Li flux delivered by subducted sediments and altered oceanic crust into the Middle American Trench is recycled to the Costa Rican arc and at most a quarter of sedimentary Li is returned into the ocean through thrust faults, primarily the décollement thrust.

(Table 1) Results of pore water analyses, including boron content and boron isotope ratios

Drilling a transect of holes across the Costa Rica forearc during ODP Leg 170 demonstrated the margin wedge to be of continental, non accretionary origin, which is intersected by permeable thrust faults. Pore waters from four drillholes, two of which penetrated the décollement zone and reached the underthrust lower plate sedimentary sequence of the Cocos Plate, were examined for boron contents and boron isotopic signatures. The combined results show dilution of the uppermost sedimentary cover of the forearc, with boron contents lower than half of the present-day seawater values. Pore fluid "refreshening" suggests that gas hydrate water has been mixed with the sediment interstitial water, without profoundly affecting the d11B values. Fault-related flux of a deeply generated fluid is inferred from high B concentration in the interval beneath the décollement, being released from the underthrust sequence with incipient burial. First-order fluid budget calculations over a cross-section across the Costa Rica forearc indicate that no significant fluid transfer from the lower to the upper plate is inferred from boron fluid profiles, at least within the frontal 40 km studied. Expulsed lower plate pore water, which is estimated to be 0.26-0.44 km3 per km trench, is conducted efficiently along and just beneath the décollement zone, indicating effective shear-enhanced compaction. In the upper plate forearc wedge, dewatering occurs as diffuse transport as well as channelled flow. A volume of approximately 2 km3 per km trench is expulsed due to compaction and, to a lesser extent, lateral shortening. Pore water chemistry is influenced by gas hydrate instability, so that it remains unknown whether deep processes like mineral dehydration or hydrocarbon formation may play a considerable role towards the hinterland.

A discussion of Fashion Victims: Various responses to the report by War on Want, Critical Perspectives on International Business, Vol. 3 Iss: 2, pp.170 - 185

Purpose – The purpose of this paper is to present a selection of responses to the report Fashion Victims, published by War on Want in December 2006. It offers a range of viewpoints presented by members of the Editorial Advisory Board of CPOIB. These are presented in chronological order of submission. There is some cross-reference by contributors to the work of others, but no attempt is made to present a unified argument. Design/methodology/approach – Presents the full contributions of involved participants, without mediation or editorial change. Findings – A number of different perspectives are presented on the central issue that is summarised by the opening heading in War on Want’s report – “How cheap is too cheap?” It is seen that the answer to this question is very much dependent upon the standpoint of the respondent. Originality/value – In presenting this form of commentary, members of the CPOIB Editorial Board seek to stimulate debate about an issue of concern to contemporary society, without resort to the time delay and mediating processes of peer-review normally attached to academic writing. It is hoped that this discussion will provoke further contributions and a widening of the debate. Keywords Corporate social responsibility, Multinational companies, Conditions of employment, Trade unions

Sapientia, 1988, Vol. XLIII, nº 170 (número completo)

Contenido: La realidad del concepto de la trascendentalidad y pridcamentalidad (Cont.) / Octavio Nicolás Derisi – El entender como posesión : la función gnoseológica del verbo mental (Cont.) / J. L. González Alió -- ¿El alma humana “entre intelectual en potencia”, según Tomás de Aquino? / Ricardo Marimón Batlló – Notas y comentarios -- Bibliografía

Diário da Constituinte [gravação de vídeo] : [programa n. 170 A]

Sessão extraordinária da Assembleia Nacional Constituinte (ANC) discutirá a Reforma Agrária, um debate que promete colocar, lado a lado nas galerias, representantes da UDR (União Democrática Ruralista) e dos trabalhadores rurais. O Deputado Gonzaga Patriota (PMDB-PE) explica o posicionamento do PMDB sobre a Reforma Agrária. O Deputado Victor Fontana (PFL-SC) informa ser necessário ter, ao lado das desapropriações de terras improdutivas, uma política agrícola. O Deputado Mário Assad (PFL-MG) considera que há necessidade de se fazer uma reforma agrária sem paixão, que atenda as contingências dos produtores rurais. Imagens de pessoas assinando a emenda popular da Reforma Agrária. José Francisco, Presidente da Confederação Nacional dos Trabalhadores Agrícolas (CONTAG), estima que são mais de quatrocentas mil assinaturas colhidas. Francisco Whitaker, Presidente do Grupo Pró-Participação Popular, declara que se o povo não conseguir tudo o que quer agora, que tenha oportunidade de propor melhorias mais tarde. O Deputado Brandão Monteiro (PDT-RJ) defende plebiscitos para que o povo se manifeste sobre o sistema de governo e sobre o mandato do Presidente Sarney. O Deputado Virgílio Guimarães (PT-MG) propõe plebiscitos para aprovar ou rejeitar o texto final da Constituição e para determinados temas mais importantes. O Deputado José Lourenço (PFL-BA) declara que o mandato que recebeu do povo baiano lhe transfere autoridade para redigir a Constituição e, portanto, é contra plebiscitos. O Deputado Haroldo Lima (PC do B-BA) afirma que é justa a consulta pública. O Deputado Bernardo Cabral (PMDB-AM) questiona que, se a Constituição não for aprovada no plebiscito, então haveria a necessidade de criar outra Constituinte.

Diário da Constituinte [gravação de vídeo] : [programa n. 170]

Donas de casa fazem ato público no Congresso, ao entregar proposta de emenda popular estabelecendo concessão de aposentadoria às mulheres que trabalham no lar. Lúcia Pacífico, representante do Movimento das Donas de Casa de Minas Gerais, declara que a proposta de aposentadoria corrige injustiça social. O Plenário Pró-Participação Popular na Constituinte apresentou 350.000 assinaturas pedindo instrumentos que garantam a participação do povo na elaboração das leis. A Deputada Moema São Thiago (PDT-CE) considera que o que está em jogo é o avanço ou o retrocesso da democracia. O Deputado Geraldo Alckmin (PMDB-SP) informa que a emenda popular é muito forte, ela traz a legitimidade daquilo que o povo deseja e torna mais fidedigna a Constituinte em relação aos anseios da sociedade. Em discurso, O Deputado Ulysses Guimarães (PMDB-SP) prometeu empenho para que as emendas populares se transformem em leis. Em mesa redonda, coordenada pelo Primeiro Secretário da Assembleia Nacional Constituinte (ANC), Deputado Marcelo Cordeiro (PMDB-BA), constituintes analisam a questão econômica. Sessão extraordinária da ANC discutiu ontem: redivisão territorial, fortalecimento dos estados e municípios e a reforma tributária. O Deputado Gastone Righi (PTB-SP) almeja que o país seja dividido administrativamente em União e municípios, com o fim dos governos estaduais na Constituição. O Deputado Siqueira Campos (PDC-GO) defende a divisão do Estado de Goiás para que seja criado o Estado de Tocantins e defende a realização de um plebiscito para definir a questão.

On the nutrition of Polyphemus pediculus (L.). [Translation from: Trudy Instituta Biologii Vnutrennykh Vodnany 12(15) 170-174, 1966.]

Many sides of the biology of Polyphemus pediculus are adequately studied at the present time. Most complicated is the question of its feeding. Dissection does not give an idea of the composition of the food, since Polyphemus strongly grinds its food with its mandibles. For clarification of the composition of the food of Polyphemus pediculus, the authors carried out in July and August 1962 a series of experiments with the application of radio-carbon methods in order to judge the degree of utilization of one or other foods by the quantity of C14, accumulated in the body of the crustacean after feeding. Particular attention in these experiments was given to the question of the possibility of the utilization by polyphemus of plant food - bacteria, algae and detritus.

On the population dynamics of Eudiaptomus gracilis Sars and Heterocope borealis Fischer in the Bodensee-Obersee. Part B. Eudiaptomus gracilis Sars. [Translation from: Trudy Instituta Biologii Vnutrennykh Vodnany 12(15) 170-174, 1966.]

Experimental research was conducted to study the development of eggs of Eudiaptomus gracilis Sars. The egg production was studied as well as the population dynamics. Factors like losses in the lake and through the effluent Rhine at Konstanz were considered.

Spectroscopy of neutron-rich Dy168,170: Yrast band evolution close to the NpNn valence maximum

The yrast sequence of the neutron-rich dysprosium isotope Dy168 has been studied using multinucleon transfer reactions following collisions between a 460-MeV Se82 beam and an Er170 target. The reaction products were identified using the PRISMA magnetic spectrometer and the γ rays detected using the CLARA HPGe-detector array. The 2+ and 4+ members of the previously measured ground-state rotational band of Dy168 have been confirmed and the yrast band extended up to 10+. A tentative candidate for the 4+→2+ transition in Dy170 was also identified. The data on these nuclei and on the lighter even-even dysprosium isotopes are interpreted in terms of total Routhian surface calculations and the evolution of collectivity in the vicinity of the proton-neutron valence product maximum is discussed. © 2010 The American Physical Society.

SULFUR IX TO XIII SPECTRAL MEASURMENTS BETWEEN 170 AND 500Å

This paper reports laboratory measurements of the spectrum of highly ionized sulfur. The spectrum of S Ⅸ–S ⅩⅢ has been observed in the wavelength range 170–500 Å. A total of 54 lines have been measured. Forty-two of them have been classified as 2s22pk–2s2pk+1and 2s2pk–2pk+1 transitions. Twelve other lines have been ascribed to 2s–2p,4p–5s,5p–6s,5d–6p, and 6p–8d transitions. These spectral lines have been identified, among which 22 are new and accurately measured. The analysis of the spectra was based on a comparison with other experimental results and calculated values.