Notas sobre la vida cultural en Argentina : Radiografía de la pampa y otros escritos de Ezequiel Martínez Estrada

La compleja vida cultural en la década del '30, más concretamente la que precede y se trasunta en el ensayo publicado en 1933, Radiografía de la pampa de Ezequiel Martínez Estrada, encuentra asidero en la reconstrucción de la zigzagueante tanto como problemática ubicación del escritor argentino en la escala social de producción. Aludir a las redes intelectuales que se tejieron y a las políticas culturales que se llevaron a cabo en relación con el proceso de profesionalización creciente, pero vivido como agónico por las figuras de la inteligencia en el país, implica un minucioso trabajo exploratorio, cuyo cauce confluye en las diferencias cualitativas inherentes a las relaciones que entablaron entre sí los intelectuales, visibles, en particular, a través de las cartas y relatos que sobre estos vínculos se publicaron. Nos referimos a la articulación posible entre el discurso del mencionado ensayo con el de El hermano Quiroga, que incluye las cartas enviadas por Quiroga a Martínez Estrada, al ensayo Leopoldo Lugones, retrato sin retocar , así como a las cartas de Martínez Estrada a Samuel Glusberg, editor de numerosas de sus obras bajo el sello Babel. La presente propuesta de investigación se orienta sobre la premisa, expresada por la crítica, de que las conexiones entre los textos y las circunstancias político-culturales a las que refieren resultan desacompasadas y asimétricas, así como su construcción implica una deliberada invención que no excluye la ficcionalización. Con estos supuestos se abordará la lectura de un posicionamiento: el de Martínez Estrada en el marco de la cultura nacional.

Chemical composition of surficial bottom sediments from the Chukchi Sea and adjacent part of the Arctic Ocean

This paper presents data on chemical composition of bottom sediments from the Chukchi Sea and the adjacent Arctic Ocean. Multivariate statistical techniques were used for analysis of the data set and revealed that grain size fractionation of the original terrigenous component during sedimentation was the major factor of clustering of the samples in study. Secondary factors include accumulation of biogenic siliceous and carbonate material and chemogenic or biochemical accumulation of iron, manganese, and some trace elements. The latter factor was significant in areas of tectonic activity within the graben-rift system of the Chukchi Sea.

Chemical composition of rocks and minerals from the Karymsky volcanic center, Eastern Kamchatka

The powerful eruption in the Akademii Nauk caldera on January 2, 1996 marked a new activity phase of the Karymsky volcano and became a noticeable event in the history of modern volcanism in Kamchatka. The paper reports data obtained by studying more than 200 glassy melt inclusions in phenocrysts of olivine (Fo82-72), plagioclase (An92-73), and clinopyroxene (Mg# 83-70) in basalts of the 1996 eruption. The data were used to estimate composition of the parental melt and physicochemical parameters of the magma evolution. According to our data, the parental melt corresponded to low magnesium, high aluminum basalt (SiO2 = 50.2%, MgO = 5.6%, Al2O3 = 17%) of the mildly potassium type (K2O = 0.56%) and contained much dissolved volatile components (H2O = 2.8%, S = 0.17%, and Cl = 0.11%). Melt inclusions in the minerals are similar in chemical composition, a fact testifying that the minerals crystallized simultaneously with one another. Their crystallization started at pressure ~1.5 kbar, proceeded within a narrow temperature range of 1040+/-20°C, and continued until near-surface pressure ~100 bar was reached. Degree of crystallization of the parental melt during its eruption was close to 55%. Massive crystallization was triggered by H2O degassing under pressure <1 kbar. Magma degassing in an open system resulted in escape of 82% H2O, 93% S, and 24% Cl (of their initial contents in the parental melt) to the fluid phase. Release of volatile compounds to the atmosphere during the eruption that lasted for 18 h was estimated as 1.7x10**6 t H2O, 1.4x10**5 t S, and 1.5x10**4 t Cl. Concentrations of most incompatible trace elements in the melt inclusions are close to those in the rocks and to the expected fractional differentiation trend. Melt inclusions in plagioclase were found to be selectively enriched in Li. The Li-enriched plagioclase with melt inclusions thought to originate from cumulate layers in the feeding system beneath Karymsky volcano, in which plagioclase interacted with Li-rich melts/brines and was subsequently entrapped and entrained by the magma during the 1996 eruption.

Simulated transition to agropastoralism in the Indus valley 7500-3000 BC

The Indus Valley Civilization (IVC) was one of the first great civilizations in prehistory. This bronze age civilization flourished from the end of the fourth millennium BC. It disintegrated during the second millennium BC; despite much research effort, this decline is not well understood. Less research has been devoted to the emergence of the IVC, which shows continuous cultural precursors since at least the seventh millennium BC. To understand the decline, we believe it is necessary to investigate the rise of the IVC, i.e., the establishment of agriculture and livestock, dense populations and technological developments 7000-3000 BC. Although much archaeologically typed information is available, our capability to investigate the system is hindered by poorly resolved chronology, and by a lack of field work in the intermediate areas between the Indus valley and Mesopotamia. We thus employ a complementary numerical simulation to develop a consistent picture of technology, agropastoralism and population developments in the IVC domain. Results from this Global Land Use and technological Evolution Simulator show that there is (1) fair agreement between the simulated timing of the agricultural transition and radiocarbon dates from early agricultural sites, but the transition is simulated first in India then Pakistan; (2) an independent agropas- toralism developing on the Indian subcontinent; and (3) a positive relationship between archeological artifact richness and simulated population density which remains to be quantified.