The partial molar volume of carbon dioxide in peridotite partial melt at high pressure

The partial molar volume of CO2 ((V) over bar (CO2)) in silicate melt was determined for a komatiite composition using high pressure sink/float experiments in a multi-anvil press. The density of the experimental melt at pressure was determined by observing sinking and floating of pure forsterite (Fo100) and forsterite (Fo90) buoyancy markers. Values for (V) over bar (CO2) were bracketed at 4.3 GPa (23.71 cm(3)/mol) and at 5.5 GPa (22.06 cm(3)/mol), normalized to 2123 K. Combining the current data with previous work we now more accurately constrain the compression curve of (V) over bar (CO2), over the pressure range of 1.0 x 10(-4) to 20 GPa. These data allow the calculation of density at pressure of carbonated silicate melts, such as kimberlite and silica undersaturated alkali basalts, and the determination of their buoyancy and eruptibility. (C) 2011 Elsevier B.V. All rights reserved.