This work will provide a coherent data set consisting of bathymetry, geophysics, petrology, and hydrothermal activity for a substantial length of the Mid-Atlantic Ridge affected by the Azores hotspot. The overall aim to find the links among the diverse types of data in order to contribute to maore comprehensive models of ocean crust formation. Petrologic sampling of a diversity of segment types will reveal the scale of petrological segmentation of the Mid-Atlantic Ridge, the relationships between petrological variations and segment type, and provide data to test geophysical models of the organization and mechanism of melt segreation and supply to the crust. Also sufficient sampling to define the fractionation trends for individual segments and to investigate the relationship between major and trace element variations should reveal far more about the nature of the Azores hotspot. Hydrothermal studies are designed to inventory as completely as possible the amount of geothermal mass and heat stored over this redge section, and to establish the number and location of any hydrothermally active areas on this section of the ridge.