Sedimentology of the Vietnam shelf

On the Vietnam Shelf more than 1000 miles of shallow high-resolution seismics were analyzed to unravel post-glacial evolution in a tropical, siliciclastic environment together with 25 sediment cores from water depths between 21 and 169 m to determine stratigraphy, distribution and style of sedimentation. Fourty-seven samples were dated with the AMS-14C technique. The shelf was grouped into three regions: a southern part, a central part, and a northern part. On the broad Southern Shelf, sedimentation is influenced by the Mekong River, which drains into the SCS in this area. Here, incised valley fills are abundant that were cut into the late Pleistocene land surface by the Paleo-Mekong River during times of sea level lowstand. Those valleys are filled with transgressive deposits. The Holocene sedimentation rate in this low gradient accommodation-dominated depositional system is in the range of 5-10 and 25-40 cm/ky at locations sheltered from currents. The Central Shelf is narrow and the sedimentary strata are conformable. Here, numerous small mountainous rivers reach the SCS and transport large amounts of detrital sediment onto the shelf. Therefore, the Holocene sedimentation rate is high with values of 50-100 cm/ky in this supply-dominated depositional system. The broad Northern Shelf in the vicinity of the Red River Delta shows, as on the Southern Shelf, incised valleys cut into the Pleistocene land surface by paleo river channels. In this accommodation-dominated shelf area, the sedimentation rate is low with values of 5-10 cm/ky. Where applicable, we assigned the sampled deposits to different paleo-facies. The latter are related to certain intervals of water depths at their time of deposition. Comparison with the sea-level curve of (Hanebuth et al., 2000, doi:10.1126/science.288.5468.1033) indicates subsidence on the Central Shelf, which is in agreement with the high sedimentation rates in this area. In contrast, data from the Northern Shelf suggest tectonic uplift that might be related to recent tectonic movements along the Ailao Shan-Red River Fault zone. Data from the Southern Shelf are generally in agreement with the sea-level curve mentioned above.

Bolaño y los clásicos

Esta ponencia intenta dar cuenta del modo en que una memoria astillada se asocia con una temporalidad particular y un modo de narrar que evita los centros (como sucede siempre que el centro es un trauma) para elaborar un relato de gran coherencia y armonía. En particular, se subraya la importancia de ciertos movimientos y motivos de la antigüedad clásica: por un lado, la función de la profecía; por el otro, la de la mitologización; por último, las modalidades de interacción entre la temporalidad cíclica (relato del trauma), y la temporalidad lineal de un relato más "realista"

Physical oceanography and current velocity during Nathaniel B. Palmer cruise NBP97-05

An extensive set of conductivity-temperature-depth (CTD)/lowered acoustic Doppler current profiler (LADCP) data obtained within the northwestern Weddell Sea in August 1997 characterizes the dense water outflow from the Weddell Sea and overflow into the Scotia Sea. Along the outer rim of the Weddell Gyre, there is a stream of relatively low salinity, high oxygen Weddell Sea Deep Water (defined as water between 0° and ?0.7°C), constituting a more ventilated form of this water mass than that found farther within the gyre. Its enhanced ventilation is due to injection of relatively low salinity shelf water found near the northern extreme of Antarctic Peninsula's Weddell Sea shelf, shelf water too buoyant to descend to the deep-sea floor. The more ventilated form of Weddell Sea Deep Water flows northward along the eastern side of the South Orkney Plateau, passing into the Scotia Sea rather than continuing along an eastward path in the northern Weddell Sea. Weddell Sea Bottom Water also exhibits two forms: a low-salinity, better oxygenated component confined to the outer rim of the Weddell Gyre, and a more saline, less oxygenated component observed farther into the gyre. The more saline Weddell Sea Bottom Water is derived from the southwestern Weddell Sea, where high-salinity shelf water is abundant. The less saline Weddell Sea Bottom Water, like the more ventilated Weddell Sea Deep Water, is derived from lower-salinity shelf water at a point farther north along the Antarctic Peninsula. Transports of Weddell Sea Deep and Bottom Water masses crossing 44°W estimated from one LADCP survey are 25 ? 10**6 and 5 ? 10**6 m**3/s, respectively. The low-salinity, better ventilated forms of Weddell Sea Deep and Bottom Water flowing along the outer rim of the Weddell Gyre have the position and depth range that would lead to overflow of the topographic confines of the Weddell Basin, whereas the more saline forms may be forced to recirculate within the Weddell Gyre.

Postglacial deposition of sand in the Eckernfoerder Bay, western Baltic Sea

At the NW-slope of Eckernforder Bay (Western Baltic) between 14 and 21 m water depth 7 sand cores were taken with a vibrocorer. The cores were between 85 and 250 cm long. The sand was analysed for grain size distribution, proportions of organic carbon and carbonate, and contents of microfossils. The radiometric age and stable carbon isotope ratios were determined on organic material from 14 sample. With regard to benthic foraminifera and other microorganisms four different types of depositional conditions could be distinguished: Types 1 and 2: two types of offshore sand areas. Type 3: lagoon and nearshore. Type 4: subaerial or limnic. Using sedimentological and geochemical parameters two formation areas could be distinguished with the aid of a discriminant analysis: offshore (types 1 and 2) and nearshore (types 3 and 4). A juxtaposition of core sections indicated two distinct profiles. Their ages fit into the picture of the assumed postglacial sea-level rise. The lagoon- and nearshore sands are interpreted as the result of sea-level stagnation at 17-18 m below present sea-level. The accumulation rates of the sand in the offshore areas are, with a maximum of 0.15 mm/yr., an order of magnitude smaller than in the mud areas, located several hundred metres away.

Bolaño y los clásicos

Esta ponencia intenta dar cuenta del modo en que una memoria astillada se asocia con una temporalidad particular y un modo de narrar que evita los centros (como sucede siempre que el centro es un trauma) para elaborar un relato de gran coherencia y armonía. En particular, se subraya la importancia de ciertos movimientos y motivos de la antigüedad clásica: por un lado, la función de la profecía; por el otro, la de la mitologización; por último, las modalidades de interacción entre la temporalidad cíclica (relato del trauma), y la temporalidad lineal de un relato más "realista"

Bolaño y los clásicos

Esta ponencia intenta dar cuenta del modo en que una memoria astillada se asocia con una temporalidad particular y un modo de narrar que evita los centros (como sucede siempre que el centro es un trauma) para elaborar un relato de gran coherencia y armonía. En particular, se subraya la importancia de ciertos movimientos y motivos de la antigüedad clásica: por un lado, la función de la profecía; por el otro, la de la mitologización; por último, las modalidades de interacción entre la temporalidad cíclica (relato del trauma), y la temporalidad lineal de un relato más "realista"

Time lapse sea-bed photos (benthos) with associated current meter data from ROBIO lander deployments during Discovery cruise D297

A baited imaging lander was deployed six times in the Nazare Canyon at depths from 909 to 4361 m during August 2005 to investigate the demersal scavenging fishes. Species observed and lander-derived abundance estimates were similar to previous data from the Porcupine Seabight and abyssal plain, north-east Atlantic Ocean.

X-ray fotos of 10 sediment cores from the Baltic Sea

Various types of trace fossils have been studied on radiographs of sediment cores from the Western Baltic since the early nineteen sixties. lnvestigations on the endo- und epifauna including their habitats and population densities carried out independently by biologists helped to identify the processes of their formation and classify the structures. Biogenic traces are ubiquitous in both sandy and muddy sediments of the Great Belt, where the bottom waters are weil oxygenated through inflows from the North Sea (through Kattegat-Skagerrak). Almost all types of bioturbation structures encountered in the Kiel Bay are also observed in a variety of shapes and forms, and can be considered as representative for the Western Baltic area. Polychaetes, bivalves and echinoderms were recorded at the sediment surface of the cores, and also in living positions in the sediment. The different types of burrows having distint outlines ('trace fossis'), and those having indistinct outlines ('biodeformational strctures'), and their varying abundance encountered in the area have been linked, wherever possible, to the sediment type, and to the macro-benthos.