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

• Published in: Earth and planetary science letters Vol. 312; no. 3; pp. 429 - 436
• Main Authors: Duncan, Megan S., Agee, Carl B.
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 15.12.2011
• Subjects: Buoyancy; Carbon dioxide; Density; Forsterite; kimberlite; Komatiites; Melts; Molar volume; peridotite partial melt; Silicates; sink/float; carbon dioxide; molar volume; kimberlite; sink/float; peridotite partial melt
• ISSN: 0012-821X; 1385-013X
• DOI: 10.1016/j.epsl.2011.10.021

The partial molar volume of CO 2 ( V ¯ C O 2 ) 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 ¯ C O 2 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 ¯ C O 2 over the pressure range of 1.0 × 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. ► We determined the partial molar volume of CO 2 in peridotite partial melt. ► Values were bracketed at 4.3 GPa (23.71 cm 3/mol) and 5.5 GPa (22.06 cm 3/mol), at 2123 K. ► Data were combined with previous work to constrain the V ¯ C O 2 compression curve to 20 GPa. ► With these data density of carbonated silicate melts can be calculated at pressure.