Éditeur(s) : HAL CCSD Wiley-Blackwell
Résumé : International audience
This paper aims to decipher the thermal evolution of the Montagne Noire Axial Zone (MNAZ,southern French Massif Central) gneiss core and its metasedimentary cover through determination ofP–T paths and temperature gradients. Migmatitic gneiss from the core of the dome record a clock-wise evolution culminating at 725 25 °C and 0.8 0.1 GPa with partial melting, followed by adecompression path with only minor cooling to 690 25° C and 0.4 0.1 GPa. Field structuralanalyses as well as detailed petrological observations interpreted in a petrogenetic grid indicate thatthe cover sequence experienced LP-HT metamorphism at <0.4 GPa. Apparent thermal gradientswithin the cover were determined with garnet–biotite thermometry and Raman Spectroscopy on Car-bonaceous Matter. High-temperature apparent gradients (e.g. 530 °C km1 along one transect) areexplained by late brittle–ductile extensional shearing evidenced by phyllonites that post-date peakmetamorphism. In areas where normal faults are less abundant and closely spaced, gradients of 20to 50 °C km1 are calculated. These gradients can be accounted for by a combination of domeemplacement and ductile shearing (collapse of isotherms), without additional heat input. Finally, thethermal evolution of the MNAZ is typical for many gneiss domes worldwide as well as with otherLP-HT terranes in the Variscides.
ISSN: 0263-4929

Droits : http://creativecommons.org/licenses/by-nc-nd/
insu-01290388
https://hal-insu.archives-ouvertes.fr/insu-01290388
https://hal-insu.archives-ouvertes.fr/insu-01290388/document
https://hal-insu.archives-ouvertes.fr/insu-01290388/file/jmg12188.pdf
DOI : 10.1111/jmg.12188

Éditeur(s) : Université des Antilles Études caribéennes
Résumé : Les zones franches sont des espaces de dérogations législative et sociale. Elles sont spécialisées dans des activités manufacturières où dominent majoritairement l’assemblage textile et minoritairement l’électronique et les services. Elles se développent dans la région Caraïbe, au cours des décennies 1980 et 1990, dans un contexte économique favorable. Dans cet article nous nous interrogeons sur les causes économiques de leur émergence. Ces espaces industriels sont difficiles à définir tant les activités présentes sont diverses et évolutives dans le temps. C’est pour cette raison que dans la première partie nous traitons de la complexité de cette notion. Ensuite, nous verrons les causes économiques de leur émergence. Le semi-échec des politiques d’industrialisation par substitution des importations oriente l’industrialisation vers l’extraversion. Les principes libéraux appliqués à Puerto-Rico servent à encadrer les industries exportatrices. Les plans d’ajustement du FMI pour réguler le problème de l’endettement ont servi de catalyseur aux exportations des biens manufacturés. Parallèlement, les accords commerciaux du Caribbean Basin Initiative (CBI) avec la puissance étasunienne ont encadré leur essor. Enfin, nous montrerons les modalités de leur implantation dans la Caraïbe, modalités qui induisent des différences géographiques entre des îles entièrement franches et celles où les zones franches sont des enclaves économiques. L’étude de ces dernières en République dominicaine permet de mettre en exergue leur expansion spatiale.
The free zones are spaces of social and legislative exemptions. They are specialized in manufacturing activities dominated mainly by the textile assembly. They develop in the Caribbean during decades 1980s and 1990s, in a favourable economic environment. In this article we question the economic causes of their emergence. These industrial areas are difficult to define as these activities are diverse and evolving over time. For this reason in the first part we deal with the complexity of the concept. Then we will see the economic causes of their emergence. The semi-failed policies of industrialization by import substitution industrialization oriented toward the extrovert. The IMF adjustment plans to regulate the problem of indebtedness has been a catalyst for exports of manufactured goods. Meanwhile, the trade agreements of the Caribbean Basin Initiative (CBI) with the U.S.A. supervised their development. Finally, we show how their presence in the Caribbean, conditions that lead to geographical differences between completely free zone islands and those where the free zones are economic enclaves. The recent study in the Dominican Republic will highlight their spatial expansion.
Caraïbes

Droits : info:eu-repo/semantics/openAccess
urn:doi:10.4000/etudescaribeennes.4100
http://journals.openedition.org/etudescaribeennes/4100

Éditeur(s) : HAL CCSD Springer Verlag
Résumé : International audience
The chemical and isotopic compositions of clay minerals such as illite and chlorite are commonly used to quantify diagenetic and low-grade metamorphic conditions, an approach that is also used in the present study of the Monte Perdido thrust fault from the South Pyrenean fold-and-thrust belt. The Monte Perdido thrust fault is a shallow thrust juxtaposing upper Cretaceous-Paleocene platform carbonates and Lower Eocene marls and turbidites from the Jaca basin. The core zone of the fault, about 6 m thick, consists of intensely deformed clay-bearing rocks bounded by major shear surfaces. Illite and chlorite are the main hydrous minerals in the fault zone. Illite is oriented along cleavage planes while chlorite formed along shear veins (<50 μm in thickness). Authigenic chlorite provides essential information about the origin of fluids and their temperature. δ18O and δD values of newly formed chlorite support equilibration with sedimentary interstitial water, directly derived from the local hanging wall and footwall during deformation. Given the absence of large-scale fluid flow, the mineralization observed in the thrust faults records the P-T conditions of thrust activity. Temperatures of chlorite formation of about 240°C are obtained via two independent methods: chlorite compositional thermometers and oxygen isotope fractionation between cogenetic chlorite and quartz. Burial depth conditions of 7 km are determined for the Monte Perdido thrust reactivation, coupling calculated temperature and fluid inclusion isochores. The present study demonstrates that both isotopic and thermodynamic methods applied to clay minerals formed in thrust fault are useful to help constrain diagenetic and low-grade metamorphic conditions.
ISSN: 0010-7999

hal-00757736
https://hal.archives-ouvertes.fr/hal-00757736
DOI : 10.1007/s00410-011-0718-0

Éditeur(s) : HAL CCSD Maison de la géographie
Résumé : International audience
The location and history of theCaribbean Basin have undoubtedly favouredthe development of these spaces founded onthe principle of permanent exemption. Firsttolerated and then given legal status, theyplay a dual role : they are comparatively“unregulated”, but at the same time contri-bute to the regulation of the world system.But can this double game last in a preca-rious and instable international context?
La situación geográfica y la his-toria del Caribe favorecieron el desarrollo deespacios particulares, cimentados a partir delprincipio de la derogación permanente.Tolerados y luego legalizados, todos desem-peñan un doble papel, en distintos niveles : sonzonas en las cuales no se respeta el derecho yal mismo tiempo participan de la regulacióndel sistema-mundo. ¿Se puede seguir jugandocon dos barajas en un contexto internacionaltrastornado e inestable ?
La situation et l’histoire duBassin caraïbe ont incontestablement favo-risé le développement d’espaces fondés surle principe de la dérogation permanente.Tolérés puis légalisés, ils jouent un doublerôle : ils sont des zones de non-droit etcependant ils participent à la régulation dusystème monde. Ce double jeu peut-il néan-moins perdurer dans un monde ébranlé etinstable ?
ISSN: 1769-7298

hal-01172647
https://hal.archives-ouvertes.fr/hal-01172647