La dorsale medio-atlantique et le renouvellement des fonds océaniques

There is an important gap between marine studies based upon geophysics and field geology, which fundamentally remains at a descriptive level. If we want to reach a general understanding of the earth history, we must consider all the informations from land and oceanic areas. This short paper is an attempt to draw the attention of geologists upon the data acquired in oceanic areas. From the example of the mid-ocean atlantic ridge (studied through geophysical and geological methods), the theories of sea floor spreading and plate tectonics are exposed. Considering these theories, a model for the origin of the Atlantic ocean can be established. Obviously, the atlantic origin depends on compression, distension and shear strength phenomena, that have had an important effect on continental area. The geologist task consists of testing and trying the oceanic movement implications from the models of geophysics, in the field of this researclies. Today marine and land geologists cannot work separately, and the only purpose of the present paper is to point out the interest of oceanographic researches, as a basis of exchange and close collaboration, to the geologist. [NOT CONTROLLED OCR]