C and H geochemistry of altered oceanic crus of ODP/IODP Hole 1256D

Carbon and hydrogen concentrations and isotopic compositions were measured in 19 samples from altered oceanic crust cored in ODP/IODP Hole 1256D through lavas, dikes down to the gabbroic rocks. Bulk water content varies from 0.32 to 2.14 wt% with dD values from -64per mil to -25per mil. All samples are enriched in water relative to fresh basalts. The dD values are interpreted in terms of mixing between magmatic water and another source that can be either secondary hydrous minerals and/or H contained in organic compounds such as hydrocarbons. Total CO2, extracted by step-heating technique, ranges between 564 and 2823 ppm with d13C values from -14.9per mil to -26.6per mil. As for water, these altered samples are enriched in carbon relative to fresh basalts. The carbon isotope compositions are interpreted in terms of a mixing between two components: (1) a carbonate with d13C = -4.5per mil and (2) an organic compound with d13C = -26.6per mil. A mixing model calculation indicates that, for most samples (17 of 19), more than 75% of the total C occurs as organic compounds while carbonates represent less than 25%. This result is also supported by independent estimates of carbonate content from CO2 yield after H3PO4 attack. A comparison between the carbon concentration in our samples, seawater DIC (Dissolved Inorganic Carbon) and DOC (Dissolved Organic Carbon), and hydrothermal fluids suggests that CO2 degassed from magmatic reservoirs is the main source of organic C addition to the crust during the alteration process. A reduction step of dissolved CO2 is thus required, and can be either biologically mediated or not. Abiotic processes are necessary for the deeper part of the crust (>1000 mbsf) because alteration temperatures are greater than any hyperthermophilic living organism (i.e. T > 110 °C). Even if not required, we cannot rule out the contribution of microbial activity in the low-temperature alteration zones. We propose a two-step model for carbon cycling during crustal alteration: (1) when "fresh" oceanic crust forms at or close to ridge axis, alteration starts with hot hydrothermal fluids enriched in magmatic CO2, leading to the formation of organic compounds during Fischer-Tropsch-type reactions; (2) when the crust moves away from the ridge axis, these interactions with hot hydrothermal fluids decrease and are replaced by seawater interactions with carbonate precipitation in fractures. Taking into account this organic carbon, we estimate C isotope composition of mean altered oceanic crust at ? -4.7per mil, similar to the d13C of the C degassed from the mantle at ridge axis, and discuss the global carbon budget. The total flux of C stored in the altered oceanic crust, as carbonate and organic compound, is 2.9 ± 0.4 * 10**12 molC/yr.

Diário da Constituinte [gravação de vídeo] : [programa n. 312]

Foi aprovada, na Comissão de Sistematização, a emenda do Deputado Carlos Mosconi (PMDB-MG) que proíbe a comercialização de órgãos. Posteriormente, o Congresso deverá votar uma lei que regulamenta a atividade de doação de órgãos. Aprovada, ainda, a emenda do Senador Jarbas Passarinho (PDS-PA) que dá isenção fiscal a entidades de assistência social, caso da Santa Casa da Misericórdia. O Deputado Egídio Ferreira Lima (PMDB-PE) tem emenda aprovada determinando que só uma entidade do governo seja responsável pelos recursos da ciência e tecnologia. Rejeitada a proposta do Deputado Bocayuva Cunha (PDT-RJ) de retirar o dispositivo que transfere ao Ministério da Saúde a prevenção contra acidentes de trabalho. Aprovada a emenda do Deputado Inocêncio de Oliveira (PFL-PE) que retira a exclusividade do governo na importação de equipamentos e insumos para a fabricação de medicamentos. Aprovada a emenda do Deputado Augusto Carvalho (PCB-DF) que concede tratamento igual ao homem e à mulher na condição de dependente, para efeito da previdência social. Sete crianças levam cartazes formando a palavra justiça. Elas pedem um mundo sem fome, sem violência, com justiça social e esperança. Ulysses Guimarães (PMDB-SP), presidente da Assembleia Nacional Constituinte (ANC), recepciona as crianças e declara que gostaria de colocá-las na Tribuna para elas colocarem suas reivindicações, mas o Regimento não permite.

Three Melodies for Solo Vibraphone Recital performed by Cory Bracken, Percussionist Brooklyn College Studio 312 in Roosevelt Hall, Bedford Ave. Brooklyn, NY Authors: Lyon, E. Publication date: 27 Oct 2011

Thursday, October 27 · 7:00pm - 8:00pm
Location
Brooklyn College
Studio 312 in Roosevelt Hall, Bedford Ave.
Brooklyn, NY
Created By
Cory Bracken

[review] Ulrich LEISINGER (ED.), Bach: Messe in h-Moll BWV 232 (Stuttgart: Carus, [2014]), 312 pp + 1 DVD-ROM, ISMN: 9790007142599, €199

This latest edition of J. S. Bach’s B-minor Mass, by Ulrich Leisinger, described by the publisher as a ‘hybrid edition’, aptly addresses the needs of present-day performers and at the same time fulfils the scholarly expectations of new critical editions to conform to the current study environment

HG 312.30-312.40

Grey sediment with clasts ranging from small to medium in size. Edge-to-edge grain crushing is abundant, with some lineations. Minor amounts of rotation structures can also be seen.