Pressure of origin of primary mid-ocean ridge basaltsEvidence bearing on the pressure of origin of primary mid-ocean ridge basalts (MORBs) is reviewed. Consideration is given to the constraints derived from pseudoliquidus phase diagrams, the importance of silica contents in primitive MORB glasses, and the mineral compositions in the residual mantle. It is noted that the least depleted abyssal periodotite orthopyroxenes show the dominance of melting and primary MORB genesis at pressures of about 20-25 kbar, a value substantially greater than that (10 kbar) predicted by high-pressure phase equilibrium studies of MORBs.
Document ID
19900046166
Acquisition Source
Legacy CDMS
Document Type
Conference Proceedings
Authors
Elthon, Don (Lunar and Planetary Institute; Houston, University TX, United States)