(Table 1) Elemental composition, pyrite-Fe and degree of pyritisation in Upper Pliensbachian and Lower Toarcian sediments from the costal section of Yorkshire

Profiles of Mo/total organic carbon (TOC) through the Lower Toarcian black shales of the Cleveland Basin, Yorkshire, United Kingdom, and the Posidonia shale of Germany and Switzerland reveal water mass restriction during the interval from late tenuicostatum Zone times to early bifrons Zone times, times which include that of the putative Early Toarcian oceanic anoxic event. The degree of restriction is revealed by crossplots of Mo and TOC concentrations for the Cleveland Basin, which define two linear arrays with regression slopes (ppm/%) of 0.5 and 17. The slope of 0.5 applies to sediment from the upper semicelatum and exaratum Subzones. This value, which is one tenth of that for modern sediments from the Black Sea (Mo/TOC regression slope 4.5), reveals that water mass restriction during this interval was around 10 times more severe than in the modern Black Sea; the renewal frequency of the water mass was between 4 and 40 ka. The Mo/TOC regression slope of 17 applies to the overlying falciferum and commune subzones: the value shows that restriction in this interval was less severe and that the renewal frequency of the water mass was between 10 and 130 years. The more restricted of the two intervals has been termed the Early Toarcian oceanic anoxic event but is shown to be an event caused by basin restriction local to NW Europe. Crossplots of Re, Os, and Mo against TOC show similar trends of increasing element concentration with increase in TOC but with differing slopes. Together with modeling of 187Os/188Os and d98Mo, the element/TOC trends show that drawdown of Re, Os, and Mo was essentially complete during upper semicelatum and exaratum Subzone times (Mo/TOC regression slope of 0.5). Drawdown sensitized the restricted water mass to isotopic change forced by freshwater mixing so that continental inputs of Re, Os, and Mo, via a low-salinity surface layer, created isotopic excursions of up to 1.3 per mil in d98Mo and up to 0.6 per mil for 187Os/188Os. Restriction thereby compromises attempts to date Toarcian black shales, and possibly all black shales, using Re-Os chronology and introduces a confounding influence in the attempts to use d98Mo and initial 187Os/188Os for palaeo-oceanographic interpretation.

Changes in calcareous nannofossil assemblages across the Paleocene/Eocene transition from the paleo-equatorial Pacific Ocean

Quantitative analyses of selected calcareous nannofossils in deep-sea sections recovered from the paleo-equatorial Pacific (ODP Leg 199) provide new information about biostratigraphy, biochronology and the evolutionary history of calcareous nannofossils across the Paleocene/Eocene transition interval. The sediment cores from ODP Leg 199 represent the first continuous Paleocene/Eocene boundary sections ever to be sampled in the central equatorial Pacific Ocean. Calcareous nannofossil assemblages are studied to document the distribution of biostratigraphically useful taxa such as Ericsonia, Discoaster, Fasciculithus, Rhomboaster and Tribrachiatus. Focus is given to the evolution of the Rhomboaster-Tribrachiatus lineage in the lower Eocene interval at Site 1215, and on the stratigraphic relationship of these taxa relative to species in the genus Fasciculithus. Critical intervals of North Atlantic DSDP Site 550 have also been re-examined. The Tribrachiatus digitalis morphotype was described at Site 550 from an interval affected by down-hole contamination, partly originating from within the Tribrachiatus orthostylus range. The T. digitalis morphotype represents an evolutionary transitional form between T. contortus and T. orthostylus, entering the stratigraphic record within the range of the former species and disappearing within the lower part of the range of the latter species. The subzonal subdivision of Zone NP10 hence collapses. Lithological and colour variability reflecting orbital cyclicity occur in the lower Eocene of Site 1215, permitting a relative astronomical age calibration of the Tribrachiatus taxa. The distinct Rhomboaster spp.-Discoaster araneus association also occurs in the paleo-equatorial Pacific Ocean, together with a marked decrease in diversity of Fasciculithus spp. Site 1220 reveals a short peak abundance of Thoracosphaera spp. just above the P/E boundary interval, which probably reflects a stressed surface water environment.

(Table DR1) Biogenic silica and chert in the Pacific Ocean, DSDP and ODP data

Evidence for the dissolution of biogenic silica at the base of pelagic sections supports the hypothesis that much of the chert formed in the Pacific derives from the dissolution and reprecipitation of this silica by hydrothermal waters. As ocean bottom waters flow into and through the crust, they become warmer. Initially they remain less saturated with respect to dissolved silica than pore water in the overlying sediments. With the diffusion of heat, dissolved ions, and to some extent the advection of water itself, biogenic silica in the basal part of the sedimentary section is dissolved. Upon conductively cooling, these pore waters precipitate chert layers. The most common thickness for the basal silica-free zone (20 m) lies below the most common height of the top of the chert interval above basement (50 m). This mode of chert formation explains the frequent occurrence of chert layers at very shallow subbottom depths in pelagic sections of the Pacific. It is also consistent with the common occurrence of cherts

Age determination and geochemistry of corals from the North Pacific

A depth transect of deep-sea bamboo corals along the California margin provides evidence that coral strontium to calcium ratios (Sr/Ca[coral]) record seawater Sr/Ca ratios (Sr/Ca[sw]). A calibration was constructed utilizing Sr/Ca[coral] ratios and previously published Pacific Sr/Ca[sw] data (R**2 = 0.53, n = 12, p < 0.01): Sr/Ca[coral] (mmol/mol) = 4.62*Sr/Ca[sw] (mmol/mol) - 36.64. Sr/Ca[sw] is ultimately governed by the remineralization of Sr-containing shells of surface water-derived marine organisms (e.g., Acantharia) at intermediate water depths. California margin Sr/Cacoral records from 792 and 1295 m document fluctuations in Sr/Ca[sw] that appear decadal-scale. These results suggest that Sr/Casw may not be as stable as previously assumed and may be influenced by surface productivity on short timescales.

Chert intervals in DSDP and ODP sites (Table 1)

Radiolarian cherts in the Tethyan realm of Jurassic age were recently interpreted as resulting from high biosiliceous productivity along upwelling zones in subequatorial paleolatitudes the locations of which were confirmed by revised paleomagnetic estimates. However, the widespread occurrence of cherts in the Eocene suggests that cherts may not always be reliable proxies of latitude and upwelling zones. In a new survey of the global spatio-temporal distribution of Cenozoic cherts in Deep Sea Drilling Project (DSDP) and Ocean Drilling Program (ODP) sediment cores, we found that cherts occur most frequently in the Paleocene and early Eocene, with a peak in occurrences at ~50 Ma that is coincident with the time of highest bottom water temperatures of the early Eocene climatic optimum (EECO) when the global ocean was presumably characterized by reduced upwelling efficiency and biosiliceous productivity. Cherts occur less commonly during the subsequent Eocene global cooling trend. Primary paleoclimatic factors rather than secondary diagenetic processes seem therefore to control chert formation. This timing of peak Eocene chert occurrence, which is supported by detailed stratigraphic correlations, contradicts currently accepted models that involve an initial loading of large amounts of dissolved silica from enhanced weathering and/or volcanism in a supposedly sluggish ocean of the EECO, followed during the subsequent middle Eocene global cooling by more vigorous oceanic circulation and consequent upwelling that made this silica reservoir available for enhanced biosilicification, with the formation of chert as a result of biosilica transformation during diagenesis. Instead, we suggest that basin-basin fractionation by deep-sea circulation could have raised the concentration of EECO dissolved silica especially in the North Atlantic, where an alternative mode of silica burial involving widespread direct precipitation and/or absorption of silica by clay minerals could have been operative in order to maintain balance between silica input and output during the upwelling-deficient conditions of the EECO. Cherts may therefore not always be proxies of biosiliceous productivity associated with latitudinally focused upwelling zones.

Tensiones y desajustes en los roles actanciales en torno al episodio del asesinato de Lope Díaz de haro según la versión de la Crónica de Sancho IV

Las tensiones políticas que signaron el reinado de Sancho IV (1284-1295) llegan a un punto de inflexión en la entrevista que en 1288 se lleva a cabo en Alfaro, en la cual resulta asesinado el principal enemigo del rey, el conde Lope Díaz de Haro. El episodio se recoge tanto en la Crónica de tres reyes como en la sección conocida como *Historia hasta 1288 dialogada, transmitida en la Estoria del fecho de los godos . La orientación que al hecho se le asigna en ambas versiones es diversa ?entre otras cosas? en el grado de responsabilidad que se le asigna al rey en la decisión de matar al conde. La Crónica de tres reyes tiende a mitigar la injerencia del monarca en los hechos al punto de organizar una serie de situaciones previas que generan las condiciones necesarias para que el asesinato se presente como un hecho inevitable que excede el radio de acción de Sancho.

Traducción e interpretación : problemas presentes en la IV Égloga de Virgilio

Este texto presenta problemas de traducción en algunos versos que merecen ser atentamente examinados para no oscurecer el significado del poema. Es necesario dilucidar la cosmovisión y la concepción del tiempo que el poeta ha querido transmitir para poder traducir con adecuación y la mayor precisión posible el texto y no quebrar su unidad y coherencia. Los textos problemáticos a examinar: v. 5 'ab integro'; v. 8 'puero, quo'; v. 11 'decus hoc aevi'; v. 3436: 'alter', 'altera', 'altera'; v. 60 'risu'; v. 62 'risere parentes / parentem /parenti'.

Compasión y ciudadanía : Un debate normativo en torno al pensamiento de M.Nussbaum

Fil: Lacunza, María Celina. Universidad Nacional de La Plata. Facultad de Humanidades y Ciencias de la Educación; Argentina.

"Acá hay un trabajo político" : Actores y relaciones en la producción del Plan FinEs 2 Secundaria en la Provincia de Buenos Aires

La ponencia retoma los resultados preliminares de un proyecto de investigación en curso en la Universidad Pedagógica de la Provincia de Buenos Aires referido a la implementación del Plan FinEs 2 Secundaria en tres distritos del Conurbano Bonaerense. Se analiza la producción de esta política pública, su desarrollo e institucionalización en el período 2011-2014, concebido como una arena de disputa en la cual los sujetos y organizaciones participantes a nivel local generan "apropiaciones" (Ezpeleta, 2004), que plasman en sentidos, prácticas y dispositivos singulares, producto de una particular trama de relaciones. La hechura del Plan FinEs 2S transita en los intercambios entre actores referenciados en organizaciones y ámbitos gubernamentales diversos, impregnados por racionalidades, intereses y lógicas atribuibles al sistema educativo, a la política social, a la organización popular. Las permanentes interacciones que se tejen entre ellos en la resignificación cotidiana del Plan y las diversas instancias de negociación, cooperación y conflicto que se van hilvanando, lejos de paralizar su despliegue, resultan particularmente potentes. En los clivajes planteados entre "educación"/"política", "escuela"/"programa de inclusión", "burocracia estatal"/"militancia", se tensionan las tradiciones selectivas del nivel secundario, la dimensión relacional de las capacidades estatales (Alonso, 2007) y la formas hegemónicas de la política territorial