The relationship between depth and chemistry is one of the most-studied aspects of mid-ocean ridge basalt genesis, because such a relationship provides evidence of the connection between physical processes in the mantle and the chemical composition of the ocean crust. The mid-Atlantic ridge between the Kane and Hayes fracture zones (24 - 33 N) has a change of 1500 meters in regional depth, yet is erupting almost exclusively "normal MORB." Currently at Lamont more than forty on and off-axis dredges from this regions exist, including twenty-nine collected by the PI in January 1987 in a NSF funded project. Preliminary microprobe data show that there are clearly defined, systematic variations in major elements that are consistent with the global correlations between depth and chemistry is shown by the PI and has associates. This region is ideal for exploring the detailed systematic of depth/ chemistry relationships for normal MORB in terms of major elements, trace elements and isotopes. It is proposed to carry out precise analytical studies of major elements trace elements, highly incompatible trace elements and isotopes from basalt glasses and whole rocks this region to understand the complex problem of petrogensis of Mid Ocean Ridge basalts.
