Rare earth and trace elements in igneous and metamorphic minerals of oceanic gabbros from the Mid-Atlantic Ridge

SIMS analyses have been carried out on clinopyroxenes, plagioclases and amphiboles of six gabbroic samples from Holes 921-924 of the Ocean Drilling Program Leg 153 sited in the MARK area of the Mid-Atlantic Ridge at the ridge-transform intersection, to investigate the rare earth, trace and volatile element distribution in the lower ocean crust during igneous crystallization and higher grade metamorphic conditions. The metagabbros underwent granulite to subgreenschist facies conditions through three main tectono-metamorphic phases: (1) ductile regime (750 < T < 1000 °C and P = 0.3 GPa); (2) transitional regime (600 < T < 700 °C and P = 0.2 GPa); (3) brittle regime (350 < T < 600 °C and P < 0.2 GPa). Igneous clinopyroxenes show Cl-chondrite normalized patterns depleted in LREE, and nearly flat for HREE. The rare earth and trace element distributions in igneous clinopyroxenes and plagioclases indicate that these minerals act as REE reservoirs, and comprise the main contribution to the overall rock content. The abundances in igneous minerals reflect the degree of fractionation of the parent liquids. In metamorphic clinopyroxenes recrystallized in anhydrous assemblages, the REE and trace elements patterns mimic those of the primary ones. Conversely, clinopyroxerie re-equilibrated in amphibolebearing assemblages shows a significant increase in REE, Ti, Zr, Y and V, a negative Eu anomaly, and slight decreases in Sr and Ba. An overall increase of REE and some trace elements is evident in hydrous assemblages, with preferential partitioning in the amphibole. It shows high Ti (18196-22844 ppm), LREE depleted patterns and LaN/SmN = 0.10-0.33, LaN/YbN = 0.10-0.30. Amphiboles from granoblastic assemblages show homogeneous patterns with no or a positive anomaly for TiN and negative anomalies for SrN and ZrN. Volatiles in amphibole are low, with Cl/F < 1; H2O% is significantly lower than the stoichiometric ratio (1.33-1.53%). The composition of the clinopyroxene and amphibole recrystallized in low-strain domains records evidence of incomplete re-equilibration, and element diffusion and partitioning is in part controlled by the textural site. The possible origins of the fluids involved in the metamorphic recrystallization are discussed: (1) remobilization from igneous amphibole; (2) exsolution from evolved melts; (3) introduction of seawater-derived fluids modified in rock-dominated systems; (4) injection of highly evolved hydrous melts during the metamorphic process.

Fungal Planet description sheets: 128-153

Novel species of microfungi described in the present study include the following from Australia: Catenulostroma corymbiae from Corymbia, Devriesia stirlingiae from Stirlingia, Penidiella carpentariae from Carpentaria, Phaeococcomyces eucalypti from Eucalyptus, Phialophora livistonae from Livistona, Phyllosticta aristolochiicola from Aristolochia, Clitopilus austroprunulus on sclerophyll forest litter of Eucalyptus regnans and Toxicocladosporium posoqueriae from Posoqueria. Several species are also described from South Africa, namely: Ceramothyrium podocarpi from Podocarpus, Cercospora chrysanthemoides from Chrysanthemoides, Devriesia shakazului from Aloe, Penidiella drakensbergensis from Protea, Strelitziana cliviae from Clivia and Zasmidium syzygii from Syzygium. Other species include Bipolaris microstegii from Microstegium and Synchaetomella acerina from Acer (USA), Brunneiapiospora austropalmicola from Rhopalostylis (New Zealand), Calonectria pentaseptata from Eucalyptus and Macadamia (Vietnam), Ceramothyrium melastoma from Melastoma (Indonesia), Collembolispora aristata from stream foam (Czech Republic), Devriesia imbrexigena from glazed decorative tiles (Portugal), Microcyclospora rhoicola from Rhus (Canada), Seiridium phylicae from Phylica (Tristan de Cunha, Inaccessible Island), Passalora lobeliaefistulosis from Lobelia (Brazil) and Zymoseptoria verkleyi from Poa (The Netherlands). Valsalnicola represents a new ascomycete genus from Alnus (Austria) and Parapenidiella a new hyphomycete genus from Eucalyptus (Australia). Morphological and culture characteristics along with ITS DNA barcodes are also provided. © 2012 Nationaal Herbarium Nederland & Centraalbureau voor Schimmelcultures.

Tris(tert-butyl 3-oxobutanoato-kappa O-2(1),O- )-aluminium(III) at 153 K

In the title complex, [Al(C8H13O3)(3)], a potential metal-organic chemical vapour deposition (MOCVD) precursor, three bidentate ligand molecules are bound to the metal atom, forming an octahedral geometry. Two non-planar six-membered chelate rings adopt screw-boat conformations, while the third ring has a conformation that lies about halfway between an envelope and a screw-boat.

Sapientia, 1984, Vol. XXXIX, nº 153 (número completo)

Contenido: Aspectos fundamentales del conocimiento humano. III. Valor trascendente del conocimiento / Octavio N. Derisi -- Del ente participado al Ser imparticipado / Octavio N. Derisi -- Las tesis de C. Fabro / Julio Raúl Méndez -- Exigencias filosóficas para determinar "lo psicológico" en el proceso de aprendizaje / William R. Darós -- Lo inteligible / Alejandro De Paoli -- Notas y comentarios -- Bibliografía

Diário da Constituinte [gravação de vídeo] : [programa n. 153]

O Plenário debate a criação de novos municípios. No anteprojeto do Relator Bernardo Cabral (PMDB-AM) a decisão de emancipação caberia aos próprios moradores, através de plebiscito. A arrecadação municipal deverá atingir cinco milésimos do último exercício. O Deputado Ivo Mainardi (PMDB-RS) propõe que os Estados voltem a ter o direito de legislar sobre emancipações. O Deputado Virgildásio Sena (PMDB-BA) considera que os dispositivos são muito rígidos e deverão ser modificados, pois tornam inviável a emancipação. A Deputada Sandra Cavalcanti (PFL-RJ) acredita que, havendo plebiscito, não haverá necessidade de posterior aprovação municipal. No Brasil acontece um milhão de acidentes de trabalho por ano, uma média que vem se mantendo desde 1980. José Luiz Riani, Secretário de Segurança do Trabalho do Ministério do Trabalho, relata sobre os números de acidentes de trabalho. O Centro de Reabilitação Profissional do INSS, em Brasília, recebe cerca de duzentos acidentados por mês. O Deputado Antônio Carlos Mendes Thame (PFL-SP) diz que a situação é grave, pois não apenas a maquinaria continua perigosa, mas também a contaminação do ar e o nível de vibrações e ruídos são muito altos em grande parte das indústrias brasileiras. O Deputado Carlos Mosconi (PMDB-MG) almeja que a saúde ocupacional faça parte do SUS. O Deputado Antônio Carlos Mendes Thame (PFL-SP) propõe medidas de reparação do dano, como a garantia de emprego, seguro desemprego e aposentadoria especial.