| The St. Paul Fracture Zone (FZ) in the equatorial Atlantic is interrupted by three intratransform ridge (ITR) spreading centers. A detailed magnetic survey, corrected for the diurnal variations using a moored magnetic station, six submersible dives, and three bottom-towed video camera tracks provide data on the most eastern ITR (0degrees37'N, 25degrees27'W). Visual observations and submersible sampling displayed a high ultramafic/volcanic ratio, supporting the assumption that the ITR is in a magmatically starved state. Volcanics were mainly found on the rift valley floor from 4700 to 4000 m and as a thin cap (<160 m) on the top of the eastern rift crest (2700 m). Most of the rift walls consist essentially of serpentinized peridotites and gabbros. The... |
