SYMMETRY OF THE SEA FLOOR AS THE KEY TO THE MID-ATLANTIC RIDGE RIFT ZONE MORPHOSTRUCTURE GENESIS

Abstract

Quantitative analysis of the transform displacements in Mid-Atlantic rift zone has been carried out. In general, sinistral displacements predominate. Consequently the west drift of American lithospheric plate predominates too, but nevertheless the seafl oor symmetry is well preserved. It means that centre of spreading migrates to the side of removing plate. Migration takes place by the spreading centre jumping. That is how segmentation of the rift zone occurs. In other words constant reproduction of the symmetry exerts primary control over the formation of the sea fl oor morphostructure. The line of spreading centre migrates along the ridge from a segment of one age to a segment of different age on the model of relay race. This suggests a conclusion that submeridional breakup in the place of modern Atlantic has been existent since the Pangea breakup and has been evenly developing through time.