This is a project to carry out a study of modal phase proportions, crystal size distribution, and major and trace element compositions of mid-ocean ridge basalts and spatially associated gabbros from the Juan Ridge (10-12 N), and the Mid- Atlantic Ridge (45 N, 36 N, and 23-26 N), and Mid-Cayman RIse and Southwest Indian Ridge. This is a baseline study not before attempted on a regional scale. The objectives are to relate model proportions, crystal size distributions, major and trace element compositions to spreading rate, ridge segmentation, cooling history, and other factors. %%% This work represents a major effort to relate petrographic signature as seen in modal phase proportions, crystal size, etc. to petrological processes on a regional scale at ocean ridge crests. This is a time consuming, basic effort in petrology of first order importance. Dr. Bryan has been a leader in the study of ocean floor basalts for many years. Dr. Meyer is a young associate who is very adapt at applying modern techniques to petrologic problems. This work should lead to important knew knowledge regarding magmatic processes at ocean ridge crests.
