Syntectonic mobility of supergene nickel ores of New Caledonia (Southwest Pacific). Evidence from faulted regolith and garnierite veins.

International audienceSupergene nickel deposits of New Caledonia that have been formed in the Neogene by weathering of obducted ultramafic rocks are tightly controlled by fracture development. The relationship of tropical weathering and tectonic structures, faults and tension gashes, have been investigated in order to determine whether fractures have play a passive role only, as previously thought; or alternatively, if brittle tectonics was acting together with alteration. From the observation of time-relationship, textures, and mineralogy of various fracture fills and fault gouges, it may be unambiguously established that active faulting has play a prominent role not only in facilitating drainage and providing room for synkinematic crystallisation of supergene nickel silicate, but also in mobilising already formed sparse nickel ore, giving birth to the very high grade ore nicknamed "green gold"

Réflexion sur les notions de territorialité et d'environnement en Méditerranée orientale : le cas de la vallée du Jourdain

Le processus de paix entre Israéliens et Palestiniens, qui a débuté depuis 1993, est plus synonyme jusqu'alors de séparation que de coopération. Dans ce contexte, il existe une forte territorialité. L'objet de cette publication, est de mener une réflexion, d'un point de vue extérieur, sur les relations qui peuvent exister entre environnement, territorialité et développement agricole dans la vallée du Jourdain (Cisjordanie et Jordanie) en fonction des différentes populations (jordanienne, israélienne, palestinienne).The peace process between Israelis and Palestinians, since 1993, is more a separation process than a cooperation process, until now. In this context, the phenomenon of territoriality is very important. The aim of this paper is to lead a reflexion, from an external point of view, about relations existing between environment, territoriality and agricultural development in the Jordan valley (west and east banks) in relation to the different populations (Jordanian, Israelian, Palestinian)

Development and installation of control system for a test rig interconnecting a micro Gas Turbine, a Heat Pump and a PCM Storage system

The need to enhance flexibility on current power plant is linked to the strong penetration of non-dispatchable sources in the current energy network, which causes a dramatic need for ancillary services to sustain the grid operability. A framework including a micro Gas Turbine (mGT), a Heat Pump (HP) and a PCM Storage is considered to enhance plant flexibility while facing grid and price fluctuations during day operations. The system so composed is devoted to electrical energy production only. A proper use of the HP allows, for instance, to heat up the compressor intake temperature whilst the system is operating at minimum load. The system can then produce a lower amount of energy in order to be more competitive in the infra-day energy market. At the same time, the cold storage is charged and the stored energy can be later used to power up the system during the peak hours by cooling the compressor intake. This work presents then the installation of the control system devoted to the management and the control of such complex system. The test-bed is defined to test different operating conditions and to validate the operating framework of the whole compound

Quelques remarques sur la genèse du gisement de minerai de fer de Segré (Maine-et-Loire)

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Quelques remarques sur la genèse du minerai de fer de Chaze-Henry déduites de l'étude minéralogique

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Les minerais de fer d'âge primaire de Normandie et de l'Anjou

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Etude minéralogique de diverses "glauconies"actuelles. Nouvelle contribution à la genèse des minerais de fer sédimentaires

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