9220603 Cooper Flexural creep and attenuation experiments on glass-ceramics and synthetic (Co-Mg) olivine-basalt partial-melt aggregates indicate three-to-four distinct anelastic loss (attenuation) mechanisms. These losses interact to produce an attenuation "band" in space. The nature of these losses, if understood, could form an unequivocal foundation for recognizing the attenuation effects(s) uniquely associated with partial melting. Therefore, an experimental investigation of the effects of quasiequilibrated partial melting on the attenuation behavior of polycrystalline silicates will be done. Seismic-to-subseismic frequency experiments will be performed in both shear (reciprocating torsion) and Young's modulus (reciprocating flexure) formats in order to isolate the effects of a steady-state melt morphology on S- and P- wave attenuation. The experiments will be applied to synthetic aggregates of olivine, olivine-plus-(olivine-saturated) tholeiite basalt and aluminosilicate glass-ceramics. ***