Tensiones en torno a la cultura originaria y la cultura otra : Juan Bautista Pomar / Fray Toribio de Benavente (Motolinía)

Las crónicas del México colonial son textos que, lejos de manifestar un proceso armónico de adquisición de una cultura distinta o la cómoda integración de sus componentes, evidencian una imposición y presentan elementos que relevan las tensiones internas. Entre la apropiación y el rechazo de esa cultura otra, los autores de los discursos coloniales reflejan diversos procesos de resistencia a la aculturación. Para esto, proponemos un recorrido por Relación de Texcoco (1582), del cronista mestizo Juan Bautista Pomar e Historia de los indios de la Nueva España (1541), del fraile franciscano Toribio de Benavente, apodado Motolinía, que presentan características estilísticas, ejes temáticos y puntos de vista indudablemente semejantes. En sus textos, estos autores omiten la descripción y valoración del período de conquista que, usualmente, se presenta como centro de las crónicas de Indias. La relación entre ambos cronistas nos concierne, también, por ser Juan Bautista Pomar representante del ideario y las condiciones que, pocos años antes, fray Toribio de Motolinía expresaba e idealizaba en su Historia de los indios de la Nueva España. Por todo esto, analizaremos los componentes multiculturales y polifónicos que dan cuenta de la presencia de dos culturas distintas pero, a la vez, íntimamente relacionadas.

Territorio y gobernabilidad ambiental : Análisis y reflexiones para el turismo de sol y playa en el litoral marítimo de la provincia de Buenos Aires

El impacto del turismo de sol y playa en el litoral marítimo de la Provincia de Buenos Aires; Argentina, necesita una caracterización y análisis en relación con la construcción del territorio y las transformaciones en el paisaje y en el ambiente ocurridas en sus costas. El objetivo principal de este trabajo será establecer una aproximación teórica y epistemológica para el estudio de la evolución histórica, el estado de sus playas, el riesgo de erosión marina, el avance del medio construido en el frente costero y las políticas de gestión territorial para el ambiente costero. Así se permitirá denotar la articulación entre la actividad turística con la gobernabilidad ambiental y las capacidades de generar herramientas participativas.

(Table 1) Primary production and chlorophyll a concentration in the Northeastern Tropical Atlantic

Results of simultaneous determinations of chlorophyll "a" concentrations and primary production in the northeastern part of the Tropical Atlantic in spring 1977 are discussed. Primary production was low (250-350 mg C/m**2/day in the open parts of the ocean and high (600-1500 mg C/m**2/day) mainly in zones of current divergences and coastal region of the West Africa. Chlorophyll "a" concentration throughout the euphotic zone varied from 6 to 36 mg/m**3 and in the surface layer from 0.05 to 0.60 mg/m**3. Uneven distribution of primary production is due to physiological condition of phytoplankton.

Geochemistry of last glacial sediments of Isla de los Estados, southeastern Tierra del Fuego

The island of Isla de los Estados is situated at 54.5°S, 64°W, east of Argentinian Tierra del Fuego, and is located in a sensitive geographic position in relation to the zonal circulation between Antarctica and South America. Its terrestrial records of the last deglaciation, recording atmospheric conditions but within an oceanic setting, can help to clarify changes of regional circulation patterns, both atmospheric and marine. Here, we present geochemical analyses from 16-10 ka cal BP of a peat core from Lago Galvarne Bog at the northern coast of the island, and a lake sediment core from Laguna Cascada 3 km further south. The data comprise TC, TN, loss on ignition analyses and continuous XRF scanning on both cores as well as age-depth modeling based on AMS-14C dating. Deglaciation and onset of peat formation in the coastal areas began before 16 ka cal BP followed by a rapid glacial retreat and the start of lacustrine sedimentation further inland. Data suggest initially windy conditions with permafrost succeeded by gradually warmer and wetter conditions until ca 14.5 ka cal BP. The warming trend slows down until ca 13.5 ka cal BP, followed by arid conditions culminating around 12.8 ka cal BP. Our data suggest fairly warm conditions and the establishment of denser peat and forest vegetation ca 10.6 ka cal BP, contemporaneous with the onset of the Antarctic thermal optimum. This indicates large-scale shifts in the placement of zonal flow and the Westerlies at the beginning of the Holocene.

Description and geochemical composition of manganese nodules retrieved from Lake Ontario, Canada

A large deposit of ferromanganese oxide coated sands and scattered manganese nodules occurs in the northern portion of Lake Ontario. The Mn and Fe contents of the concretions are similar to those in concretions from other environments, while their Ni, Cu, and Co contents are lower than in deep-sea nodules, but higher than in most previously described lacustrine concretions. Pb and Zn are high in the coatings and exceed the concentrations found in many previously analyzed Mn deposits. Within the deposit, Mn, Ni, Co, and Zn contents are correlated, and they vary inversely with Fe. Mn, Fe, Ni, Cu, and Pb are present in the interstitial waters of the sediments underlying the deposit in higher concentrations than in the overlying lake waters, thus providing a potential source of metals for concretion formation.The origin and compositional variations in the deposit possibly can be explained in terms of the fractionation and precipitation of Fe and Mn as a result of redox variations in the lake sediments. Eh increases from south to north across the deposit in such a way that iron may be selectively oxidized and precipitated in the south and manganese, in the north. The upward diffusion of Mn, Fe, and associated elements from the underlying sediments probably provides the principal source of the metals in the south of the deposit, while metal-enriched bottom waters are probably the principal source in the north.

Age of samples from the sedimentary cover of the Primorye continental slope and from the submarine Bogorov Rise

Results of a complex study of the sedimentary cover (continuous seismic profiling and diatom analysis) in the northeastern Sea of Japan including the Bogorov Rise an adjacent part of the Japan Basin and the continental slope, are presented. Two varied-age complexes were distinguished in the sedimentary cover of the continental slope of Primorye: Middle Miocene and Late Miocene - Pleistocene. These complexes formed in a stable tectonic setting with no significant vertical movements. A depression in the acoustic basement is located along the continental slope and it is divided from the Japan Basin by a group of volcanic structures, the most uplifted part of which forms the Bogorov Rise. The depression probably formed before Middle Miocene. In Middle Miocene the Bogorov Rise was already at depths close to modern ones. In the sedimentary cover near the Bogorov Rise buried zones were found. Probably they were channels for gas transportation in pre-Pleistocene. Deformations of sediments that occurred in the beginning of Pleistocene are established in the basin.