Organic geochemistry of ODP Sites 128-798 and 128-799

Miocene to Quaternary sediments from the Oki Ridge (Site 798) and the Kita-Yamato Trough (Site 799) in the Japan Sea contain organic carbon ranging from about 0.6% in light-colored layers to almost 6% in dark layers. The organic matter consists of a variable mixture of marine and terrigenous contributions, the ratio of which is not correlated to the total organic carbon content. Marine organic particles clearly dominate in the deeper section of Hole 799B. The extractable bitumen is strongly dominated by long-chain alkenones from microalgae in the shallower sediments, whereas bishomohopanoic acid (C32) of eubacterial origin is the single most abundant compound in deeper samples. Normal alkanes and straight-chain carboxylic acids, both of which show a bimodal distribution with odd and even carbon-number predominance, respectively, are two other groups of compounds which are important constituents of the extracts. The deepest samples at Site 799 contain a considerable amount of short-chain components, which probably migrated upward from thermally more altered deeper sediments.

Quaternary planktonic foraminifera of DSDP Hole 72-517

Quaternary sediments were recovered at all four Sites at Leg 72. Planktonic foraminifers were abundant and well preserved, especially in the holes shielded from Antarctic Bottom Water (AABW) influence. The fauna belonged to the subtropical province marked by Globigerinoides ruber and to a lesser extent by Globorotalia inflata. Thirty planktonic foraminiferal species were distinguished, and a detailed study of the Site 517 stratigraphy was made. The Quaternary sequence of the Rio Grande Rise was subdivided slightly differently from the Bolli and Premoli Silva (1973) pattern. Five subzones were identified but some difficulties arose when a precise correlation became necessary in the subzones of the tropical provinces. Correlations could nevertheless be made, particularly with respect to the earliest Quaternary. Quaternary faunal data have been dated by isotopic stratigraphy (Vergnaud Grazzini et al.,1983) and partially contradict results previously published for this part of the Atlantic (Williams and Ledbetter, 1979). By studying the occurrence of planktonic foraminifers, we obtained more information about hydrologic variations during the Quaternary sequence of Hole 517; two broad periods were recognized. Finally, we identified the interaction between the Brazil Current and the subtropical convergence

Whole rock geochemistry and stable isotopes of rocks, fragments and foraminifers from two ODP Leg 166 holes

Total carbon and carbonate contents, quantitative carbonate mineralogy, trace metal concentrations, and stable isotope compositions were determined on a suite of samples from the Miocene sections at Sites 1006 and 1007. The Miocene section at Site 1007, located at the toe-of-slope, contains a relatively high proportion of bank-derived components and becomes fully lithified at a depth of ~300 meters below seafloor (mbsf). By contrast, Miocene sediments at Site 1006, situated in Neogene drift deposits in the Straits of Florida and composed primarily of pelagic carbonates, do not become fully lithified until a depth of ~675 mbsf. Diagenetic and compositional contrasts between Sites 1006 and 1007 are reflected in geochemical data derived from sediment samples from each site.

Nuevos modos de socialización : El rol del cuerpo en el marco de las sociedades de control

Este trabajo reflexiona a nivel teórico sobre el cuerpo en un contexto histórico-global donde las nuevas tecnologías complejizan su lugar tradicional en los espacios de socialización. Los intercambios sociales tradicionales se caracterizaron por un soporte subjetivo en el cuerpo mientras que en la contemporaneidad la virtualidad posibilita la ausencia del mismo en las relaciones. ¿Existen otro tipo de lazos sociales que prescinden del cuerpo? O se trata de estrategias de marketing del self publicitado, por ejemplo en la web, buscando redefinir la subjetividad y los modos de lazo social. ¿La imagen es un discurso o reemplaza a lo corporal? Según Deleuze en las sociedades de control nos encontramos ante cambios culturales donde el avance de la informática genera cambios subjetivos y produce -a la vez- integración y exclusión social. Se modifica la relación entre tiempo/espacio y por lo tanto, inferimos que se reconfiguran los registros perceptivos del otro y de uno mismo en el intercambio social. ¿Cómo se redefine el lugar del cuerpo en este contexto? Este trabajo no pretende desestimar los cambios sociales acontecidos sino entender el modo en el que los mismos se integran en la vida cotidiana y establecen nuevas modos, saberes y espacios de socialización.