Le paléolithique inférieur et moyen en Midi toulousain : nouvelles données et perspectives de l’archéologie préventive

Depuis quelques années, les opérations d’archéologie préventive menées en Midi toulousain ont permis de réactualiser certaines données relatives à la géomorphologie des sites paléolithiques inférieur et moyen. Ainsi, plusieurs contextes peuvent être considérés comme plus favorables que d’autres pour la conservation du matériel. Par ailleurs, les résultats préliminaires d’études typo-technologiques des industries mises au jour récemment, offrent de nouvelles perspectives de recherche pour la constitution d’un cadre chrono-culturel plus précis.In the last years, preventive archeology projects conducted in the Midi toulousain Region (southern France) allowed to update data concerning the geomorphology of Early and Middle Palaeolithic sites. It became apparent that certain contexts can be considered as more favorable to vestige conservation than others. Besides, preliminary results of typo-technological studies of recently discovered artifacts offer new research perspectives for the definition of a more precise chrono-cultural frame

Le paléolithique inférieur et moyen en Midi toulousain : nouvelles données et perspectives de l’archéologie préventive

Depuis quelques années, les opérations d’archéologie préventive menées en Midi toulousain ont permis de réactualiser certaines données relatives à la géomorphologie des sites paléolithiques inférieur et moyen. Ainsi, plusieurs contextes peuvent être considérés comme plus favorables que d’autres pour la conservation du matériel. Par ailleurs, les résultats préliminaires d’études typo-technologiques des industries mises au jour récemment, offrent de nouvelles perspectives de recherche pour la constitution d’un cadre chrono-culturel plus précis.In the last years, preventive archeology projects conducted in the Midi toulousain Region (southern France) allowed to update data concerning the geomorphology of Early and Middle Palaeolithic sites. It became apparent that certain contexts can be considered as more favorable to vestige conservation than others. Besides, preliminary results of typo-technological studies of recently discovered artifacts offer new research perspectives for the definition of a more precise chrono-cultural frame

Du Paléolithique ancien au Paléolithique moyen ancien dans le piémont pyrénéen occidental : relations entre les chaînes opératoires, continuités et ruptures

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L'Univers matériel. Premier récit. Les Traditions, par le baron Alfred d'Espiard-Colonge. Première livraison

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Artillerie pratique employée sous les règnes et dans les guerres de Louis XIV et Louis XV, par le Bon Espiard de Colonge,... ouvrage inédit, mis au jour par son petit-neveu le Bon Alfred d'Espiard de Colonge,...

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Structure and evolution of an active resurgent dome evidenced by geophysical investigations: The Yenkahe dome-Yasur volcano system (Siwi caldera, Vanuatu)

International audienceIn this contribution, we focus on one of the most active resurgences on Earth, that of the Yenkahe dome in the Siwi caldera (Tanna Island, Vanuatu), which is associated with the persistently active Yasur volcano. Gravity and magnetic surveys have been carried out over the past few years in the area, as well as electrical methods including electrical resistivity tomography (ERT), time domain electro-magnetics (TDEM) and self-potential (SP). These investigations were completed by thermometry, CO2 soil gas measurements, field observations and sampling. This multi-method approach allows geological structures within the caldera to be identified, as well as associated hydrothermal features. The global structure of the caldera is deduced from gravity data, which shows the caldera rim as a high density structure. Large lava fields, emplaced before and after the onset of resurgence, are evidenced by combined gravity, magnetic and resistivity signals. In the middle of the caldera, the Yenkahe dome apparently results from a combination of volcanic and tectonic events, showing that lava extrusion and resurgence have been operating simultaneously or alternately during the Siwi caldera post-collapse history. There is a clear distinction between the western and eastern parts of the dome. The western part is older and records the growth of an initial volcanic cone and the formation of a small caldera. This small caldera (paleo-Yasur caldera), partially filled with lava flows, is the present-day focus of volcanic activity and associated fluid circulation and alteration. The eastern part of the dome is presumably younger, and is characterized by intense, extensive hydrothermal alteration and activity. Its northern part is covered by lava flow piles and exhibits a shallow hydrothermal zone in ERT. The southern part has hydrothermal alteration and activity extending at least down to the base of the resurgent dome. This part of the dome is built up of low cohesion rock and is thus potentially prone to gravitational landslides. Lastly, while self-potential and temperature data suggest that widespread hydrothermal circulation occurs throughout almost all of the caldera, and possibly beyond, the most active parts of this hydrothermal system are associated with the dome. The presence of this active hydrothermal system is the clearest indicator that these methods can provide of a potential shallow magmatic body underneath the dome

Structure and evolution of an active resurgent dome evidenced by geophysical investigations: The Yenkahe dome-Yasur volcano system (Siwi caldera, Vanuatu)

Brothelande, E. et. al.In this contribution, we focus on one of the most active resurgences on Earth, that of the Yenkahe dome in the Siwi caldera (Tanna Island, Vanuatu), which is associated with the persistently active Yasur volcano. Gravity and magnetic surveys have been carried out over the past few years in the area, as well as electrical methods including electrical resistivity tomography (ERT), time domain electro-magnetics (TDEM) and self-potential (SP). These investigations were completed by thermometry, CO2 soil gas measurements, field observations and sampling. This multi-method approach allows geological structures within the caldera to be identified, as well as associated hydrothermal features. The global structure of the caldera is deduced from gravity data, which shows the caldera rim as a high density structure. Large lava fields, emplaced before and after the onset of resurgence, are evidenced by combined gravity, magnetic and resistivity signals. In the middle of the caldera, the Yenkahe dome apparently results from a combination of volcanic and tectonic events, showing that lava extrusion and resurgence have been operating simultaneously or alternately during the Siwi caldera post-collapse history. There is a clear distinction between the western and eastern parts of the dome. The western part is older and records the growth of an initial volcanic cone and the formation of a small caldera. This small caldera (paleo-Yasur caldera), partially filled with lava flows, is the present-day focus of volcanic activity and associated fluid circulation and alteration. The eastern part of the dome is presumably younger, and is characterized by intense, extensive hydrothermal alteration and activity. Its northern part is covered by lava flow piles and exhibits a shallow hydrothermal zone in ERT. The southern part has hydrothermal alteration and activity extending at least down to the base of the resurgent dome. This part of the dome is built up of low cohesion rock and is thus potentially prone to gravitational landslides. Lastly, while self-potential and temperature data suggest that widespread hydrothermal circulation occurs throughout almost all of the caldera, and possibly beyond, the most active parts of this hydrothermal system are associated with the dome. The presence of this active hydrothermal system is the clearest indicator that these methods can provide of a potential shallow magmatic body underneath the domeThis research was co-financed by the French Government “ANR ARC-Vanuatu: Programme Catastrophes Telluriques et Tsunamis” (ANR-06-CATT-02) and Laboratory of Excellence initiative n°ANR-10-LABX-0006, the Laboratoire Magmas et Volcans (LMV), the Laboratoire GéoSciences Réunion, the Région Auvergne and the European Regional Development Fund. Datasets are available at LMV. In addition, gravimetric data are available at International Gravimetric Bureau. This is Laboratory of Excellence ClerVolc contribution number 171 and IPGP contribution number 3654.Peer reviewe