Behavior of Martim Vaz Fracture Zone, from Mid Atlantic Ridge to Brazilian Coast

Martim Vaz Fracture Zone (MVFZ), located at 20°10'S in the Mid-Atlantic Ridge (MAR), was defined by seismic register, gravity and magnetic isochrones. Today, this FZ show a second-order discontinuity, with offset 15 km corresponding to 1 My. However, in both sides of MAR, the MVFZ, two fossils FZ can be observed. If these fossils FZs were part of MVFZ, then MV was a double FZ during 5-20 My, and triple FZ between 20-80 My, with a width of 130km. Prior this time the tectonic network seemed to be more complex. The MVFZ was tectonic active, observed in seismic data set, with reactivations of old faults, strikeslip tectonics which has up lift the sedimentary column (Medium Oligocene), and beyond structure related the lithospheric flexure. All of these observation attested by a rich fractured oceanic crust and the overlaying sedimentation, with alternations of comprehensive and distensile stress associated with volcanism and normal faulting. Geological and geophysical studies, in addition earthquake epicenters, suggest that the continuation of ZFMV is related to the Cabo Frio High and to the tectonic and volcanic activity, which is express by the Poços de Caldas / Cabo Frio / Montes Submarinos Almirante Saldanha e São Tomé Alkalic Magmatic Seismic Lineament. All these observation let us to believe that MVFZ acts as a path way for the magma generated in the Tristão da Cunha Mantle Plume.