Éditeur(s) : HAL CCSD Elsevier
Résumé : International audience
In this study, we report new U-Pb zircon ages and amphibole and biotite 40Ar-39Ar cooling ages for igneous and metaigneous rocks from the eastern portion of the Borborema Province (NE Brazil). We combine these results with preliminary thermobarometric estimates and existing data to place constraints on the timing and duration of the Brasiliano-Pan-African Orogeny in northeastern Brazil and on the subsequent late- to post-orogenic history. The Alcantil orthogneiss contains a complex zircon population, but the youngest concordant analyses yielded an age of 632 ± 17 Ma (2σ). These grains have low Th/U ratios (<0.1), and the age of 632 Ma is therefore interpreted as dating the metamorphic event responsible for the acquisition of the gneissic fabric. In the Caruaru biotite amphibole orthogneiss, concordant analyses provided an age of 618 ± 4 Ma (2σ), which we relate to emplacement of the protolith of the Caruaru orthogneiss. Together with available U-Pb data from the literature, the 632-600 Ma age range is regarded as dating development of a regional flat-lying foliation coeval with high-grade metamorphism (upper amphibolite facies conditions). The 586 ± 3 Ma age (2σ) of the Panelas pluton is similar to those of other granitic plutons associated with a voluminous plutonism of high-K calc-alkaline to shoshonitic nature that occurred at 590-580 Ma. This plutonism slightly predated or was synchronous with development of large strike-slip shear zones. Amphibole grains yielded 40Ar-39Ar ages ranging from 584 ± 4 Ma to about 530 Ma, suggesting that regional temperatures remained near the closing temperature of this mineral (≈500 °C) for a long time. Most 40Ar-39Ar biotite ages range from 552 to 533 Ma, but two samples yielded plateau ages of 519 ± 5 Ma and 509 ± 5 Ma. The inferred rather slow cooling of the studied region possibly reflects low rates of unroofing, allowing persistence of a protracted thermal anomaly caused by the massive injection of magmas at the end of the Neoproterozoic.
ISSN: 0895-9811

hal-00745698
https://hal.archives-ouvertes.fr/hal-00745698
DOI : 10.1016/j.jsames.2012.06.003

Éditeur(s) : Université des Antilles Études caribéennes
Résumé : L’écrivain africain-américain John Edgar Wideman publie en 2003 un récit de voyage commandité par la National Geographic Society. L’écrivain choisit pour destination la Martinique. Etranger dans cette île de la Caraïbe francophone, mais lui-même héritier d’une Histoire coloniale transatlantique douloureuse, il retranscrit son expérience sensible d’un espace insulaire revisité, guidant ses lecteurs dans un périple touristique et scriptural qui se transforme en un questionnement sur soi et son rapport à l’Autre. Notre analyse de l’écriture viatique de Wideman vise à interroger le regard que l’auteur porte sur l’île, dans sa dimension touristique, historique et culturelle.
The African American writer John Edgar Wideman published in 2003 a travel memoir commissioned by the National Geographic Society. As an heir to a painful transatlantic History of colonialism, the writer chooses Martinique as his destination. Unfamiliar with this French-speaking Caribbean Island, Wideman transcribes his intimate experience of Martinique and guides his readers through a touristic and literary journey that becomes a reflection on the self in relation to others. Our analysis of Wideman’s travel writing aims to explore the author’s perception of the island as a touristic, historical, and cultural site.
Martinique

Droits : info:eu-repo/semantics/openAccess
urn:doi:10.4000/etudescaribeennes.6898
http://journals.openedition.org/etudescaribeennes/6898