Carte ; Géographie physique ; Manuel ; Monde ; Volcan ; Volcanisme
Manuel d'assez larges diffusion qui présente les grands volcans du monde selon un plan régional fondé sur les ensembles structuraux et les océans. Nombreuses cartes et photos en noir et en couleur. L'index recense plus de 1 600 volcans. (FC).
Evolution quaternaire du volcan Nisyros dans la mer Egée: croissance d'un strato-volcan dans lequel une caldeira se développe, dômes péléens, petits cônes vulcaniens et solfatares.
Physics and chemistry of arc magma| arc volcanism in time and space| geothermal and energetic aspects of arc volcanism| prediction, hazards and environmental aspects of volcanic activities. Fifteen selected papers.
Douze édifices volcaniques ont été inventoriés dans la région du dôme des Tharsis. Alba Patera (1 400 km de diamètre) n'a pas d'équivalent sur terre. Olympus Mons et les trois Tharsis sont des volcans géants qui culminent tous les quatre à 27 km
. L'existence de ces volcans géants s'explique par l'absence sur Mars d'une tectonique des plaques et la fixité des points chauds. Ils possèdent des caractères propres, que l'on peut attribuer au gigantisme des chambres à magma. 7 volcans de plus petite taille
Soil variation with altitude on Volcan Barva, Costa Rica
Altitude ; Barva volcan ; Costa Rica ; Géographie physique ; Montagne ; Propriété du sol ; Pédologie ; Sol ; Zonation altitudinale ; Zone intertropicale
The AA. examine the hypothesis that soil chemical properties other than nitrogen supply partly explain the altitudinal changes in the rain forest. They also compare the soils on Volcan Barva with those on several other tropical mountains to see
Geomorphology of South Atlantic Volcanic Islands. Part I: the Tristan da Cunha group
Atlantique ; Atlantique, sud ; Côte volcanique ; Géographie physique ; Géomorphologie ; Géomorphologie littorale ; Ile ; Ile volcanique ; Littoral ; Tristan da Cunha ; Volcan ; Volcanisme
Volcanoes of the Tristan Group have varied physiography resulting from the interplay of repeated volcanic eruptions, coastal erosion and fluvial erosion. The geomorphic histories of the islands are more complicated than was described in earlier
Comparative geochemistry of volcanics from rift valleys, transform faults and aseismic ridges
It is suggested that transform faults have, by faulting, exposed more fractioned types of basaltic rocks (may be as intrusives) than the rift valley volcanics. While aseismic ridges have undergone a greater degree of differentiation than both
Riftward younging of volcanic units in the Addis Ababa region, Ethiopian rift valley
A general riftward younging of surficial volcanic units is a feature of the Addis Ababa sector of the Ethiopian rift valley. The narrowing of the volcanic zone with time in due to crustal necking and topographical control.
Age of volcanism and rifting in southwestern Ethiopia
Field data and K-Ar isotopic ages from southwestern Ethiopia indicate that volcanism in this area began earlier than previously suspected, and that Quaternary volcanism was not restricted to the axial zone. That major rifting in this region did
Consideration of the structure and morphology of the study area as a whole, as well as that of a small constructional volcanic hill suggests that it evolved in two phases. The principal phase of development involved a period of crustal extension
and volcanic activity at a spreading centre, and the second phase involved a period of off-axis volcanic and tectonic activity.
Pogrebennye i podvodnye vulkany Kuril'skoj glubokovodnoj kotloviny Ohotskogo morja Volcans fossiles et sous-marins de la cuvette abyssale des Kouriles dans la mer d'Okhotsk
A volcanic ash generated by explosions where ignimbrite entered the sea
A remarkably widely dispersed and crystal-rich volcanic ash-fall deposit is described, which resulted from immense explosions generated in the littoral zone in New Zealand where a major rhyolitic ignimbrite flowed into the sea. This partially
Estimation of allophane and halloysite in three sequences of volcanic soils, New Zealand in Volcanic soils. Weathering and landscape relationships of soils on tephra and basalt.
Ce volcan sous-marin puis émergé a été formé par une seule éruption continue depuis 886 ap. J.-C. A une première phase sont dues des séries sédimentaires variées, dont certaines en profil dunaire inversé. Au cours d'une deuxième phase s'est formé un
Obsidian hydration dating of volcanic events had been compared with ages of the same events determined by the C and K-Ar methods at several localities ranging in age from 1200 to over 1million yr. In most cases the agreement is quite good. A number
of factors including volcanic glass composition and exposure-temperature history must be known in order to relate hydration thickness to age. The effect of composition can be determined from chemical analysis or the refractive index of the glass. Exposure