L'HISTOIRE PHANEROZOIQUE EST AINSI REVUE: LE CRATON NORD-CHINOIS ET LE CRATON NORD-AMERICAIN ONT ETE ASSOCIES AU PRECAMBRIEN, LE CRATON NORD-CHINOIS ET LA CORDILLERE NORD-AMERICAINE SE SONT DETACHES AU PALEZOIQUE ET SE SONT ACCOLES AU CRATON
SIBERIEN, LA CORDILLERE NORD-AMERICAINE S'EST SEPAREE DE L'ASIE ORIENTALE DURANT LE MESOZOIQUE ET S'EST RATTACHE AU CRATON NORD-AMERICAIN DURANT LE CENOZOIQUE. CES MOUVEMENTS SONT ETUDIES A LA LUMIERE DU MODELE DE CONVECTION TETRAHEDRIQUE INSTABLE (UNSTABLE
Geomorphological development of the eastern margin of the Australian Craton
In this paper, the development of several major uplands located at or near the eastern margin of the Australian Craton is considered. It is not intended that each and every range and plateau be discussed; rather, the AA. will consider regions
Multistage landform development, with particular reference to a cratonic bornhardt
the Cainozoic. The geomorphological evolution of landforms of the shield lands and cratons extends over vast ages and cannot be regarded as a geologically recent phenomenon.
Geomorphic analysis of the rifted cratonic margins of Western Australia
Synthèse sur l'évolution géomorphologique de la partie interne et des bordures W et S du craton. L'accent est mis sur les effets respectifs de la technique des plaques et de l'expansion des fonds océaniques, des variations mondiales du niveau marin
3,360-Myr old gneisses from the South Indian Craton
We report here preliminary Rb-Sr whole rock data for Archaean gneisses from the Gorur-Hassan area, South Indian Craton which yield the oldest age yet reported from the Indian subcontinent (3,35866Myr) with a very unradiogenic initial Sr/Sr ratio
Cyclical patterns of exposure, weathering and burial of cratonic surfaces, with some examples from North America and Australia
Amérique du Nord ; Australie ; Craton ; Cycle d'érosion ; Géographie physique ; Géomorphogenèse ; Météorisation ; Paléoclimat ; Paléogéographie ; Paléosol ; Pénéplaine ; Tectonique des plaques
The continental cratons are the most long-lived, almost permanent megafeatures of the Planet Earth, and thus preserve veneers of ancient duricrusted paleosols and shallow marine transgressions, thus, an alternation between thalassocratic
Oldlands are complex surfaces of low relief preserved on Precambrian shields and cratons and Paleozoic massifs. Interpretation of their character and age is difficult, but as a consequence of its particular location and of conceptual developments
, much of the Australian Craton is now susceptible to analysis in terms of exhumation, etching, and multistage development. Exhumed surfaces of many ages are recorded.
An extensive zone of mylonites, up to 10km thick, on the coastal margin of the West African Craton is a suture developed during the late Archaean at the site of collision of two granitic continental masses, now preserved in a partially reworked
state as the Guyana Shield and the West African Craton... it supports the opinion that primitive plate tectonic mechanisms were active in the Archaean. (Extraits de l'A.).
Ultimate and proximate origins : tests based in the geomorphic evolution of the southeastern Gawler Craton and the Stuart and Spencer Shelves, South Australia
The interpretation of various features and forms found on the Gawler Craton, and the adjacent Stuart and Spencer shelves, is considered and evaluated. It is concluded that evidence, and the inferences drawn from it, need to be definite, narrow
In the Gourma and Iforas regions (Mali) rifting occured around 800-850 Myr ago along the eastern margin of the West African craton with a triple point in Mali, the Gourma being interpreted as an aulacogen-Oceanic closure around 600Myr led
to a collision between the passive continental margin of the West African craton and an active continental margin to the east displaying island arc and marginal trough volcano-clastic assemblages bordering a deformed continental mass intruded by a high-level
batholith. The suture is marked by a string of positive gravity anomalies corresponding to the emplacement of ultrabasic and basic rocks including perhaps ophiolites. East-West shortening was accompanied by the translation onto the West African craton
Asthénosphère ; Craton ; Géographie physique ; Géosynclinal ; Orogenèse ; Phase d'expansion ; Phase de compression ; Pulsation terrestre ; Rift ; Tectonique de plaques ; Tectonique globale ; Zone de rift
Le concept de tectonique des plaques s'accorde mal avec l'immense durée d'évolution des plus grandes structures cratoniques et avec l'absence ou le faible développement de l'asthénosphère sous les cratons jusqu'à la profondeur de 400-600km. La
Situé à l'Ouest du fossé crétacé de Gao, le Gourma oriental appartient à la chaîne pan-africaine du Mali. Il correspond à de grandes nappes pelliculaires mises en place vers l'W-SW à la bordure du craton ouest africain. Les nappes internes portent
passive du craton ouest-africain. Des intrusions mantelliques basiques-ultrabasiques datées à 800m.a. jalonnent la suture dans la zone Timetrine-Amalaoulaou.
Cet article traite les sujets suivants: 1) Préparation des échantillons et conditions de mesure. 2) Le craton de l'Antarctique oriental. 3) L'unité allochtone (Mount Wegener Nappe).
The historical approach to geomorphology seems to be useful in the study of bedrock geomorphology on the Fennoscandian craton. A field meeting on the theme preglacial weathering and landform evolution was held in southern Sweden, May 16-20, 1988