The effect of H2O on olivine crystallization in MORB: Experimental calibration at 200 MPa

✍ Scribed by Almeev, R. R.; Holtz, F.; Koepke, J.; Parat, F.; Botcharnikov, R. E.

• Book ID: 118213310
• Publisher: Mineralogical Society of America
• Year: 2007
• Tongue: English
• Weight: 217 KB
• Volume: 92
• Category: Article
• ISSN: 0003-004X
• DOI: 10.2138/am.2007.2484

✦ Synopsis

Crystallization experiments were conducted at 200 MPa and water-undersaturated conditions to quantify the effect of small amounts of H 2 O on the crystallization temperature of olivine in basaltic melts (e.g., Mid-Oceanic Ridge Basalts, MORB).The H 2 O concentrations in the quenched glasses, determined by infrared spectroscopy and Karl-Fischer-Titration, ranged between 0.25 and 4.2 wt% H 2 O. The dry liquidus temperature was estimated from experiments at 0.1 MPa (H 2 O-free) and from the known pressure dependence of olivine crystallization temperature. The liquidus temperature depression can be predicted by the empirical equation (T DRY -T WET ) = 39.69•C H 2 O 0.73 (wt%). The comparison of the experimental results with available crystallization models and empirical methods shows that most of the predicted liquidus temperature depressions differ signiÞ cantly from that observed in this study.