Location map for western Pacific marginal basins. Thin lines are fracture zones, thick lines are spreading centers, and triangled lines are convergent plate edges. Transects of methane and dissolved Mn along the central spreading axis in the North Fiji Basin. Note that the data base is not identical for each tracer. Triangle shows location of known venting sites.
Insets show geographic location of profiles.
The distributions suggest other venting sites north and south of the triple junction at 17 S. Fig. 15. Triangle shows location of known venting sites. Location map for the northern Mid-Atlantic Ridge and Reykjanes Ridge. Known and suspected hydrothermal sites identified in Figure 19. Thin dashed line on each plot marks the regional background value of Mn and CH 4 .