Earth and Atmospheric Sciences, Department of
Date of this Version
1989
Abstract
Resume - Le Leg 120 du programme international de forages oceaniques (Ocean Drilling Project) a permis de determiner la nature et l'age du plateau de Kerguelen et de decrire son evolution depuis Ie Cretace. Le socle, fore aux sites 747, 749 ct 750, est compose de coulees basaltiqucs qui correspondent a des tholeiites transitionnelles saturees en silice. Ces basaltes se sont mis en place dans des conditions aeriennes ou sub-aeriennes avant Ie Cenomanien sur une surface quasiment horizontalc. Les premiers sediments, d'age Cenomanien, se sont deposes en milieu fluviatile. Au Campanien et a la fin du Maestrichtien Ie plateau a subside rapidement et a ete affecte par une phase tectonique extensive majeure entre 75 et 68 M.a. Ces deux evenernents marquent sans doute la separation du domaine sud du plateau de Kerguelen et de I'ensemble Broken Ridge-Diamantina Zone.
Abstract - Leg 120 of the Ocean Drilling Program was devoted to studying the nature and evolution of the Central and Southern Kerguelen Plateau. The basement drilled at sites 747, 749 and 750 is composed of basaltic flows which are silica-saturated transitional tholeiites. These basalts were erupted prior to the Cenomanian under subaerial or shallow marine conditions and were emplaced on a near horizontal surface. The early sedimentation during the Cenomanian denotes fluvial conditions. During the Campanian and late Maestrichtian the plateau subsided rapidly and a major tectonic episode occurred between 75 and 68 M.a. These events are possibly related to the breakup between the Southern Kerguelen Plateau and Broken Ridge-Diamantina Zone.
Comments
Published in C. R. Acad. Sci. Paris, t. 308, Serie II, p. 1597-1603, 1989. Copyright 1989. Used by permission.