9415989 Sinton This work is the combined effort of three investigators to analyze rocks collected during a dive program that was conducted on the East Pacific Rise between 17 and 19 degrees S in December 1993. The rocks are from the ridge axis, from an abandoned ridge a few kilometers from the active ridge and from nearby seamounts. The purpose in analyzing the rocks is to determine the frequency and chemical variability on this very fast spreading ridge. They will also review dive tapes and photographs to estimate the volumes of eruptions. The techniques to be used are electron microprobe of basalt glass, XRF of whole rocks, and U-Th-Ra geochronology. ***