Skip to Main content Skip to Navigation
Journal articles

Viscosity of mafic magmas at high pressures

Abstract : While it is accepted that silica-rich melts behave anomalously with a decrease of their viscosity at increased pressures (P), the viscosity of silica-poor melts is much less constrained. However, modeling of mantle melts dynamics throughout Earth's history, including the magma ocean era, requires precise knowledge of the viscous properties of silica-poor magmas. We extend here our previous measurements on fayalite melt to natural end-members pyroxenite melts (MgSiO 3 and CaSiO 3) using in situ X-ray radiography up to 8 GPa. For all compositions, viscosity decreases with P, rapidly below 5 GPa and slowly above. The magnitude of the viscosity decrease is larger for pyroxene melts than for fayalite melt and larger for the Ca end-member within pyroxene melts. The anomalous viscosity decrease appears to be a universal behavior for magmas up to 13 GPa, while the P dependence of viscosity beyond this remains to be measured. These results imply that mantle melts are very pervasive at depth.
Document type :
Journal articles
Complete list of metadatas

Cited literature [47 references]  Display  Hide  Download

https://hal.sorbonne-universite.fr/hal-01452772
Contributor : Gestionnaire Hal-Upmc <>
Submitted on : Thursday, February 2, 2017 - 11:18:49 AM
Last modification on : Tuesday, October 20, 2020 - 5:02:01 PM
Long-term archiving on: : Friday, May 5, 2017 - 11:43:02 AM

File

grl55442.pdf
Publisher files allowed on an open archive

Identifiers

Citation

C Cochain, Chrystèle Sanloup, C Leroy, Y Kono. Viscosity of mafic magmas at high pressures. Geophysical Research Letters, American Geophysical Union, 2017, 44 (2), pp.818-826 ⟨10.1002/2016GL071600⟩. ⟨hal-01452772⟩

Share

Metrics

Record views

1051

Files downloads

425