 |
| Titel |
Si and O self-diffusion coefficient of forsterite as a function of water content |
| VerfasserIn |
Tomoo Katsura, Hongzhan Fei, Michael Wiedenbeck, Daisuke Yamazaki |
| Konferenz |
EGU General Assembly 2013
|
| Medientyp |
Artikel
|
| Sprache |
Englisch
|
| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 15 (2013) |
| Datensatznummer |
250073698
|
|
|
|
|
|
| Zusammenfassung |
| It has been considered that small amount of water should decrease mantle viscosity significantly from results of deformation experiments. However, difficulty of such experiments could lead to overestimation of the water effect. As mineral creep is controlled by diffusion of the slow species, we measured Si and O self-diffusion coefficient (D_Si and D_O) in forsterite single crystal at 8 GPa, 1600-1800 K, with water content (C_H2O) ranging from < 1 up to ~800 ppm, showing that D_Si and D_O are proportional to (C_H2O)^(0.32+-0.03) and (C_H2O)^(0.06+-0.14), respectively. The small water content exponents suggests that the role of water on the upper mantle rheology is insignificant. The softening of the oceanic lithosphere cannot be caused by hydration. |
|
|
|
|
|
|