Mid-Pleistocene benthic foraminiferal record in the Southwest Pacific

Benthic foraminiferal faunas from three bathyal sequences provide a proxy record of oceanographic changes through the mid-Pleistocene transition (MPT) on either side of the Subtropical Front (STF), east of New Zealand. Canonical correspondence analyses show that factors related to water depth, latitude and climate cycles were more significant than oceanographic factors in determining changes in faunal assemblage composition over the last 1 Ma. Even so, mid-Pleistocene faunal changes are recognizable and can be linked to inferred palaeoceanographic causes. North of the largely stationary STF the faunas were less variable than to the south, perhaps reflecting the less extreme glacial-interglacial fluctuations in the overlying Subtropical Surface Water. Prior to Marine Isotope Stage (MIS) 21 and after MIS 15, the northern faunas had fairly constant composition, but during most of the MPT faunal composition fluctuated in response to climate-related food-supply variations. Faunal changes through the MPT suggest increasing food supply and decreasing dissolved bottom oxygen. South of the STF, beneath Subantarctic Surface Water, mid-Pleistocene faunas exhibited strong glacial-interglacial fluctuations, inferred to be due to higher interglacial nutrient supply and lower oxygen levels. The most dramatic faunal change in the south occurred at the end of the MPT (MIS 17- 12). with an acme of Abditodentrix pseudothalmanni, possibly reflecting higher carbon flux and lower bottom oxygen. This study suggests that the mid-Pleistocene decline and extinction of a group of elongate, cylindrical deep-sea foraminifera may have been related to decreased bottom oxygen concentrations as aresult of slower deep-water currents.

Los textos escondidos de Nicolás Olivari, aportes para redefinir su obra

Una serie de hallazgos en torno a la obra de Nicolás Olivari pone en evidencia diversos problemas (históricos, críticos, filológicos y bibliotécnicos) no abordados por los estudios especializados. Para estudiar estas cuestiones, los textos localizados se agrupan en textos poco conocidos - el volumen de cuentos eróticos Carne al sol (1922)-; textos desconocidos - las novelas eróticas de 1922 y 1923- y textos conocidos - la versión corregida de La musa de la mala pata- .

Horacio : La determinación genérica y la inmortalidad inmanente

El tema de la inmortalidad en el aquende que el poeta obtiene con su poesía y la que confiere a los que canta, rehúye el ámbito estrecho de la musa pedestris y reclama un ritmo y una métrica distinta de la yámbica de los Epodos o del hexámetro coloquial y entrecortado de las Sátiras. Horacio encuentra en la métrica eolia, alcaica y sáfica, la conexión apropiada entre tópico y tipo de metro adecuada a sus Odas.

Los textos escondidos de Nicolás Olivari, aportes para redefinir su obra

Una serie de hallazgos en torno a la obra de Nicolás Olivari pone en evidencia diversos problemas (históricos, críticos, filológicos y bibliotécnicos) no abordados por los estudios especializados. Para estudiar estas cuestiones, los textos localizados se agrupan en textos poco conocidos - el volumen de cuentos eróticos Carne al sol (1922)-; textos desconocidos - las novelas eróticas de 1922 y 1923- y textos conocidos - la versión corregida de La musa de la mala pata- .

Horacio : La determinación genérica y la inmortalidad inmanente

El tema de la inmortalidad en el aquende que el poeta obtiene con su poesía y la que confiere a los que canta, rehúye el ámbito estrecho de la musa pedestris y reclama un ritmo y una métrica distinta de la yámbica de los Epodos o del hexámetro coloquial y entrecortado de las Sátiras. Horacio encuentra en la métrica eolia, alcaica y sáfica, la conexión apropiada entre tópico y tipo de metro adecuada a sus Odas.

Surface sediment analyses, bivalve and gastropod taxa of marine sediments from the Banc d'Arguin, Mauritania

High-nutrient tropical carbonate systems are known to produce sediments that, in terms of skeletal composition, are reminiscent of their extra-tropical counterparts. Such carbonate systems and associated carbonate grain assemblages in the tropics are rare in the present-day world. Nonetheless, it is crucial to gain a better understanding of those ecosystems, including their drivers and players because such settings potentially represent models for ancient depositional systems as well as for predicted future environmental conditions. One of the modern occurrences of eutrophic tropical carbonate systems is the northern Mauritanian Shelf. The marine environment is characterized by an eastern boundary upwelling system that pushes cool and nutrient-rich intermediate waters onto a wide epicontinental platform (Golfe d'Arguin) where the waters warm up to tropical temperatures. The resulting facies is mixed carbonate-siliciclastic with a dominant foramol association grading into bimol and barnamol grain assemblages in the shallowest areas forming the Banc d'Arguin. Besides this cool water-related heterozoan association, the carbonate sediment is characterized by tropical molluskan species, while chlorozoan biota (e.g., corals and algal symbiont-bearing foraminifers) are entirely absent. We here present a first comprehensive facies analysis of this model example of eutrophic tropical carbonates. Furthermore, we reconstruct the loci of carbonate production and provide a conclusive depositional model of the Banc d'Arguin that received little attention to date due to its poorly accessible nature.

Los textos escondidos de Nicolás Olivari, aportes para redefinir su obra

Una serie de hallazgos en torno a la obra de Nicolás Olivari pone en evidencia diversos problemas (históricos, críticos, filológicos y bibliotécnicos) no abordados por los estudios especializados. Para estudiar estas cuestiones, los textos localizados se agrupan en textos poco conocidos - el volumen de cuentos eróticos Carne al sol (1922)-; textos desconocidos - las novelas eróticas de 1922 y 1923- y textos conocidos - la versión corregida de La musa de la mala pata- .

Horacio : La determinación genérica y la inmortalidad inmanente

El tema de la inmortalidad en el aquende que el poeta obtiene con su poesía y la que confiere a los que canta, rehúye el ámbito estrecho de la musa pedestris y reclama un ritmo y una métrica distinta de la yámbica de los Epodos o del hexámetro coloquial y entrecortado de las Sátiras. Horacio encuentra en la métrica eolia, alcaica y sáfica, la conexión apropiada entre tópico y tipo de metro adecuada a sus Odas.

Planktonic assemblages during sapropel S5 deposits in the Urania Basin

A micropaleontological study of planktonic assemblages on the partially laminated sapropel S5 (late Pleistocene, marine isotope stage (MIS) 5e) was performed in two piston cores from Urania Basin area (eastern Mediterranean, west of Crete): UM94PC16 and UM94PC31 recovered during a PALEOFLUX Project Cruise. The abundance of Florisphaera profunda indicates the development of a deep chlorophyll maximum (DCM) before the anoxic condition at bottom were established, whereas patterns of upper photic zone coccoliths suggest extreme oligotrophy in surface water. The short appearance of Globorotalia scitula and the presence of Globigerinoides ruber in the lower part of sapropel testify to a thermal stratification, also recorded by changes in primary producers. During G. scitula occurrence, diatoms, mainly represented by Pseudosolenia calcar-avis, appear and bloom because of their capability in using nutrients from DCM. Scanning electron microscope analyses performed on selected intervals from UM94PC16 show that the sapropel is organized in microlaminae mostly composed by siliceous microfossils. In particular, sapropel S5 could be related to an enhanced nutrient availability in the lower-middle part of the photic zone, stratified conditions, and a higher continental input.

Benthic foraminifera stratigraphy of sediments from ODP Leg 199 sites

Benthic foraminifers from Ocean Drilling Program Leg 199 Holes 1215A, 1220B, and 1221C were examined across the Paleocene/Eocene boundary. Assemblages were studied in 240 samples. The benthic foraminiferal extinction event that correlates with the Paleocene/Eocene epoch boundary was recognized at these sites. Benthic assemblages before the event are characterized by high diversity, but those after the event are low in diversity. An assemblage of agglutinated foraminifers without carbonate cement was recognized at Sites 1220 and 1221. These assemblages were typically found after the event. The discovery of such agglutinated assemblages has never been reported before at this boundary.

Abundance and biomass of the benthic infauna of the North Sea

In 1986 participants of the Benthos Ecology Working Group of ICES conducted a synoptic mapping of the infauna of the southern and central North Sea. Together with a mapping of the infauna of the northern North Sea by Eleftheriou and Basford (1989, doi:10.1017/S0025315400049158) this provides the database for the description of the benthic infauna of the whole North Sea in this paper. Division of the infauna into assemblages by TWINSPAN analysis separated northern assemblages from southern assemblages along the 70 m depth contour. Assemblages were further separated by the 30, 50 m and 100 m depth contour as well as by the sediment type. In addition to widely distributed species, cold water species do not occur further south than the northern edge of the Dogger Bank, which corresponds to the 50 m depth contour. Warm water species were not found north of the 100 m depth contour. Some species occur on all types of sediment but most are restricted to a special sediment and therefore these species are limited in their distribution. The factors structuring species distributions and assemblages seem to be temperature, the influence of different water masses, e.g. Atlantic water, the type of sediment and the food supply to the benthos.