Hydrocarbons in surface layer bottom sediments from the North Dvina Riverand the southern part of the Dvina Bay, White Sea

Analysis of molecular composition of alkanes in bottom sediments of the southern part of Dvina Bay (White Sea) in October 2001 revealed the following main peculiarities of hydrocarbon behavior in the estuary: dominating of high molecular C23-C45 compounds and irregular distribution of hydrocarbons in bottom sediments as a result of high sedimentation rate and active hydrodynamics in the studied area.

Isotopic composition of bottom and interstitial waters in the area of gas plumes, Sea of Okhotsk

Data on isotopic composition of interstitial and bottom waters collected in an area of gas hydrate occurrence in the Sea of Okhotsk are presented. Investigations indicate that heavy isotopes of oxygen and hydrogen are used in generation of gas hydrate, so that isotopic composition of its water of constitution is: d18O = +1.9 per mil, d2H = +23 per mil (relative to SMOW). Production of authigenic carbonates results in isotopic exchange with interstitial water, which in turn alters its isotopic composition by an increase in d18O. Bottom waters are isotopically light relative to the SMOW standard and to the average isotopic composition of interstitial waters in the area of gas hydrate occurrence in study.

Intersubjetividad en Luhmann : Consideraciones preliminares en torno a la triple contingencia en la TGSS

El presente trabajo releva, reconstruye y analiza el concepto de intersubjetividad resultante del "giro comunicativo" y del desplazamiento del umbral de irreductibilidad social postulados por la teoría general de sistemas sociales (TGSS) de Niklas Luhmann. El trabajo asume la perspectiva de los jóvenes críticos luhmannianos, desde cuyo punto de vista es renovado el interés por el estatuto sociológico del concepto de intersubjetividad, ya que una vez reformulado comunicativamente, éste se vuelve problemático a la luz de las ambivalencias de su forma: consenso/disenso. Nuestra hipótesis de trabajo afirma que la intersubjetividad es emergente con respecto a la recursividad de las comunicaciones a la vez que es irreductible a la diferenciación estructural de expectativas. Se indagan de manera complementaria los vínculos con el concepto de selección de información y la diferencia entre aportes y temas, y se examinan los resultados obtenidos a la luz del concepto de triple contingencia

Perón y la Triple A : ¿Una relación necesaria?

Este trabajo se plantea como un aporte al debate, actualmente vigente, sobre la responsabilidad de Juan Domingo Perón en la creación y sostenimiento de la Alianza Anticomunista Argentina. En la primera parte del trabajo se detallan, en base a la reciente aparición de nuevas fuentes y testimonios, la relación personal y directa de Perón con los principales integrantes de la Triple A. Luego, se analizan las principales medidas represivas tomadas por Perón durante su tercera presidencia para finalmente confrontar la información examinada con las explicaciones de la historiografía especializada en torno a su responsabilidad e intenciones

Intersubjetividad en Luhmann : Consideraciones preliminares en torno a la triple contingencia en la TGSS

El presente trabajo releva, reconstruye y analiza el concepto de intersubjetividad resultante del "giro comunicativo" y del desplazamiento del umbral de irreductibilidad social postulados por la teoría general de sistemas sociales (TGSS) de Niklas Luhmann. El trabajo asume la perspectiva de los jóvenes críticos luhmannianos, desde cuyo punto de vista es renovado el interés por el estatuto sociológico del concepto de intersubjetividad, ya que una vez reformulado comunicativamente, éste se vuelve problemático a la luz de las ambivalencias de su forma: consenso/disenso. Nuestra hipótesis de trabajo afirma que la intersubjetividad es emergente con respecto a la recursividad de las comunicaciones a la vez que es irreductible a la diferenciación estructural de expectativas. Se indagan de manera complementaria los vínculos con el concepto de selección de información y la diferencia entre aportes y temas, y se examinan los resultados obtenidos a la luz del concepto de triple contingencia

Geochemical parameters of bottom sediments from the Stromboli Canyon

In recent sediments of the Stromboli Canyon sides features of mineral and grain size compositions, redox conditions, behavior of Fe, Mn, organic carbon, Mo, and W in an environment of active input of pyroclastic material are considered. Differences in conditions of sedimentation and early diagenesis in the east and west sides of the canyon depending on position of the prevailing direction of drift and steepness of the slopes, as well as types of differentiation of detrital material in sediments under conditions of permanent vibrations are specified.

Composition of bottom sediments from the Gulf of California

Abundances of globules, micronodules and their aggregates composed of iron sulfides from bottom sediments of the Gulf of California have been determined together with studies of chemical composition of these sediments.

Bitumoids and methane in bottom sediments of the northeast Black Sea

Complex investigations of recent and ancient Black Sea sediments from the outer shelf, continental slope, and deep-water basin of the Russian Black Sea sector have been carried out. Samples were collected during Cruise 100 of R/V Professor Shtokman organized by the P.P. Shirshov Institute of Oceanology (March 2009) and expedition of UZHMORGEO (summer 2006). Rates of the main anaerobic processes during diagenesis (sulfate reduction, dark CO2 assimilation, methanogenesis, and methane oxidation) were studied for the first time in sediment cores of the studied area. Two peaks in the rate of microbial processes and two sources of these processes were identified: the upper peak near the water-sediment contact is related to solar energy (OM substrate of the water column) and the lower peak at the base of ancient Black Sea sediments with high(>1 mmol) methane concentration related to energy of anaerobic methane oxidation. New labile OM formed during this process is utilized by other groups of microorganisms. According to experimental data, daily rate of anaerobic methane oxidation is many times higher than that of methanogenesis, which unambiguously indicates migration nature of the main part of methane.

Concentrations of organic compounds in suspended matter from surface waters and surface layer bottom sediments of the Obskay Guba (Ob River estuary) and the Kara Sea

Data are presented on concentrations of aliphatic and polycyclic aromatic hydrocarbons (AHC and PAH) in interstitial waters and bottom sediments of the Kara Sea compared to distribution of particulate matter and organic carbon. It was found that AHC concentrations within the water mass (aver. 16 µg/l) are mainly formed by natural processes. Distribution of AHC represents variability of hydrological and sedimentation processes in different regions of the sea. The widest ranges of the concentrations occurred in the Obskaya Guba - Kara Sea section: in water (10-310 µg/l for AHC and 0.4-7.2 ng/l for PAH) and in the surface layer of the bottom sediments (8-42 µg/l for AHC and 9-94 ng/g for PAH). Differentiation of hydrocarbons (HC) in different media follows regularities typical for marginal filters; therefore no oil and pyrogenic compounds are supplied to the open sea. In sediments contents of HC depend on variations in redox conditions in sediments and on their composition.

Chemical and mineral compositions of bottom sediments from the East Pacific Rise near 13°N

During underwater photography and sampling of the rift valley bottom in the axial part of the East Pacific Rise, where water transparency is reduced due to hydrothermal input, ore manifestations have been found. The bottom is covered by them as by a jacket on both sides from the EPR axial zone. However, exposed pillow-lavas and clumpy blocks in rift ledges are covered by a thin metal-bearing film. It is supposed that sedimentation results mainly from hydrothermal input of dissolved chemical elements in seawater, their transformation on the geochemical barrier, and subsequent deposition as particulates. Contents of ore components in metalliferous sediments have been measured by atomic-absorption and X-ray radiometry methods. Sediment age has been determined as Middle Pleistocene - Holocene. Maximal hydrothermal activity was at the beginning of Early Holocene, about 10 Ka. A smoker has been found on the western slope of the rift valley.

Composition of bottom sediments from the Isfjord, Western Svalbard

Lithology, heavy mineral associations, and chemical composition of bottom sediments studied in two gravity cores from Isfjord, Western Spitsbergen (Svalbard) accompanied by high-frequency seismic records, provide a new insight on provenance and glaciomarine sedimentation in the fjord from the last deglaciation through Holocene.

Composition of organic matter from water, suspended matter, and bottom sediments of Nha Trang Bay, South China Sea

This research has been carried out in the Nha Trang Bay (Southern Vietnam, South China Sea) at a section from the estuary of the Cai River to the marine part of the bay, as well as in the area of coral reefs. River- and sea waters, suspended matter, and bottom sediments are studies. Data on dissolved organic carbon and total nitrogen in water are obtained. Organic carbon concentration is estimated in suspended matter; organic carbon and molecular and group compositions of n-alkanes are determined in bottom sediments. Molecular and group compositions of n-alkanes in bottom sediments of the landfill made it possible to identify three types of organic matter (OM): marine, mixed, and mainly of terrigenous origin. All these types of OM are closely related to specificity of sedimentation and hydrodynamics of waters in this area.