This is a project to map a section of the Mid-Atlantic Ridge in the South Atlantic and is designed to answer fundamental questions and to test hypothese central to understanding of a slow to intermediate spreading rate ridge system in the South Atlantic. The questions to be addreses include: 1) What is the segmentation geometry of the Mid-Atlantic Ridge in the South Atlantic and what is the relative abundance of first and second order discontinuities? 2) How does the segmentation geometry observed along a representative length of ridge compare with the early segmentation character of the South Atlantic in terms of the distribution of first and second order discontinuities? 3) What are the structual and kinematic characteristics associated with a change in plate boundary geometry and the creation of a second-order discontinuity? 4) What are the strutural and morphologic characteristics associated with the trnsfromation of a first-order discontinuity to a second-order discontinuity and what is the age of the offset when the boundary no longer behaves rigily? 5) What are the morphotectonic characteristics associated with evolution of a second-order discontinuity to a third-order discontinuity? 6) What is the distribution of rifted and non- rifted ridge segments along the MAR between 22S and 34S?