Were the Mascarene and Laxmi Basins (western Indian Ocean) formed at the same spreading centre?

Although the Mascarene-Seychelles area represents a fundamental zone for th e Cretaceous Indian Ocean kinematics, its northern part remains almost unkn own. Bathymetric, seismic, magnetic and altimetry data interpretation allow us to propose a structural scheme of the whole region. Two major opening p hases are identified (83-68 Ma; 68-59 Ma). The first one is composed of two different spreading rate periods (low and intermediate). The second one (f ast spreading rate) is characterized by the progressive southward extinctio n of the ridge, that requires a synchroneous opening eastward Seychelles, i n the Laxmi Basin, between 67 and 59 Ma. (C) 2000 Academie des sciences / E ditions scientifiques et medicales Elsevier SAS.