Heavy mineral content of ODP Leg 107 holes

Analyses of rock clasts and of heavy minerals in upper Miocene coarse detrital units drilled along the East Sardinia passive-type continental margin (Sites 654, 653, 652, and 656) reveal that the stretched basement contains quite complex rock suites. Taking also into account previous sampling data, in moving from west to east across the margin, the nature of the basement changes drastically. To the west there are mostly Hercynian basement rocks with their cover, referable to the alpine foreland of the Corsica-Sardinia block. To the east, along the lower margin, where crustal thinning is quite severe, the basement contains rock suites referable to a pre-upper Tortonian orogenized zone with units constituting parts of the Alpine and Apenninic chains (presumably with thickened continental crust prior to stretching). Largest thinning and ocean forming occurred then, in a rather short time, mostly at the expense of unstable crust just thickened by orogenetic/tectogenetic processes.

Simbolismo, Ritual y Performance. En: Avá, nº 11

El libro se presenta como el resultado del trabajo de un grupo de investigadores que pretende abordar la dimensión simbólica en los estudios antropológicos, recuperando la producción renovada del campo del simbolismo y el ritual, haciendo intervenir el concepto de performance como variable dinámica.

El espacio metaperformativo en Odisea, 11

Este trabajo pretende lograr una interpretación de Odisea a partir del Canto 11, su centro arquitectónico y frontera formal, considerando especialmente la categoría «espacio ¼. A través del análisis de la estructura que despliega el Canto, de relato dentro del relato, intentaremos demostrar que el Canto 11 resulta un espacio épico ineludible que reformula el código ético-heroico mediante una performance interactiva.

El espacio metaperformativo en Odisea, 11

Este trabajo pretende lograr una interpretación de Odisea a partir del Canto 11, su centro arquitectónico y frontera formal, considerando especialmente la categoría «espacio ¼. A través del análisis de la estructura que despliega el Canto, de relato dentro del relato, intentaremos demostrar que el Canto 11 resulta un espacio épico ineludible que reformula el código ético-heroico mediante una performance interactiva.

Messinian and pre-Messinian sediments of ODP Holes 107-652A and 107-654A

Sedimentology, mineralogy, and petrology of the pre-Pliocene sediments drilled at ODP Sites 652 and 654 in the Tyrrhenian Sea (Leg 107) have been studied with emphasis on the lower Messinian to pre-Messinian intervals. Messinian at Site 652 is essentially turbiditic and basinal in character; it was deposited during the syn-rift phase in a strongly subsiding half-graben and is correlatable with emerged coeval sequences; in part with the Laga Formation of the foredeep of Apennines, and in part with the filling of grabens dissecting that chain in the Tyrrhenian portion of Tuscany. The sequence found in Site 654 indicates an upper Tortonian to Messinian transgression accompanying crustal stretching in the western Tyrrhenian Sea and is perfectly correlatable with the so-called "Sahelian cycle" and with "postorogenic" cycles recognized in peninsular Italy and in Sicily.

El espacio metaperformativo en Odisea, 11

Este trabajo pretende lograr una interpretación de Odisea a partir del Canto 11, su centro arquitectónico y frontera formal, considerando especialmente la categoría «espacio ¼. A través del análisis de la estructura que despliega el Canto, de relato dentro del relato, intentaremos demostrar que el Canto 11 resulta un espacio épico ineludible que reformula el código ético-heroico mediante una performance interactiva.

Stable carbon and oxygen isotopes of foraminifera fand carbon content of ODP Leg 107 holes

High-resolution bio- and chemostratigraphy of an earliest Pliocene section from ODP Site 652 indicates that postflood paleoceanographic conditions in the Tyrrhenian Sea can be sub-divided into two discrete intervals. The first is manifested by an acme of Sphaeroidinellopsis spp., increasing carbonate contents, and a progressive decrease upsection in both the d13C and dl8O values of the planktonic foraminifera. The lower part of the acme interval contains unusual surface-to-bottom water isotope gradients suggesting a stratification of two water masses. Normal gradients in the upper part of the acme interval suggest a well-mixed water body. Between the end of the acme interval and the MP11/MP12 boundary, denoted by the first occurrence (F.O.) of Globorotalia margaritae, a migrational first appearance, there was a catastrophic collapse of the gradient marking an onset of the second post-flood interval. The disintegration of habitable conditions is suggested by a sharp decrease in carbonate content and the disappearance of the benthonic assemblage, which is subsequently replaced predominantly by Uvigerinapygmea, indicative of cold, low-oxygenated bottom waters. The introduction of benthonic species denoting well-oxygenated bottom conditions occurs within the lower MP12 zone. Superimposed on these overall trends are shorter term, warm-cold cycles, which are interpreted as orbitally induced, climatic fluctuations. Correlative studies of the less complete earliest Pliocene sections from ODP Holes 653B and 654A confirm these interpretations. A scenario derived from an integration of all the stratigraphic data indicates that normal paleoceanographic conditions were operating in the Tyrrhenian Sea only approximately 250,000 yr after the cessation of Messinian evaporative conditions at the Miocene/Pliocene boundary. The post-flood interval is marked by an initial period of gradual infilling, the Sphaeroidinellopsis spp. acme interval, followed by a disintegration of oceanographic conditions and a second recovery period. A sudden influx of cold, deep Atlantic waters into the Tyrrhenian Sea, resulting from a major tectonic break in the Gibraltar sill, may have caused this catastrophic reversal in the orderly recovery of normal paleoceanographic conditions in the post-flood period.