THŁ OPENING OF THE EQUATORIAL ATLANTIC AND IT'S RELATIONSHIP TO CONTINENTAL TECTONIC DEFORMATION

Colour maps showing the free air gravity field of the Atlantic Ocean, generated from Haxby's 5'x5' gridded GEOSAT data, provide greater resolution of oceanic tectonic fabrics than Haxby's SEASAT dataset. The history of the opening of the Equatorial Atlantic will be shown to be distinctly different from that of the Central and South Atlantic. This paper will review models of' previous workers and discuss their implications for the equatorial region, suggesting that they do not adequately explain features revealed from GEOSAT Observations. It is proposed that the Equatorial Atlantic be treated as a discrete area for at least part of it's history and that it's development is related to the differential opening history of the Central and South Atlantic. This differential opening has not been restricted to the oceanic parts of the Equatorial Atlantic but has, in part, been taken up by the development of strike-slip and extensional basins within adjacent continents.