This is a project to clarify the importance of small scale ridge offsets with regard to magmatic segmentation. The field program will use transponder navigated, closely spaced dredging, together with SeaBeam, and camera tows to study the area from 12 to 12 30' N along the East Pacific Rise where preliminary data shows the existence of magmatic segmentation. The new field data will be integrated with existing SeaMARC I data to get fine scale resolution of along-axis variations in chemistry to determine the scale of magmatic segmentation. The project will also involve off-axis dredges that, coupled with side scan and camera data, will help resolve temporal variations as well. %%% Suggested scales of volcanic centers on the East Pacific Rise range from a few kilometers to a few hundred kilometers. Thus the appropriate scale on which to consider the magmatic organization of the East Pacific Rise is uncertain. This project will take an important step in clarifying the scale of magmatic segmentation and its relation to small ridge offsets. This is a problem of first order importance in marine basalt petrogenesis.
