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Stability of carbonated magmas at the base of the Earth's upper mantle
Author(s) -
Ghosh Sujoy,
Ohtani Eiji,
Litasov Konstantin,
Suzuki Akio,
Sakamaki Tatsuya
Publication year - 2007
Publication title -
geophysical research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.007
H-Index - 273
eISSN - 1944-8007
pISSN - 0094-8276
DOI - 10.1029/2007gl031349
Subject(s) - mantle (geology) , diamond , basalt , geology , isothermal process , mineralogy , geochemistry , thermodynamics , materials science , metallurgy , physics
We measured the density of carbonated basaltic melt containing 5.0 wt.% CO 2 at 2573 K and in the pressure range from 16.0 to 20.0 GPa by using the sink/float method with single crystal diamond as a density marker. We observed sinking of diamond at 19.0 GPa and flotation of diamond at 20.0 GPa and 2573 K. Using the third order Birch‐Murnaghan equation of state, the calculated isothermal bulk modulus ( K T ) of the carbonated basaltic melt (5.0 wt.% CO 2 ) and its pressure derivative ( K ′) are 16.0 ± 1.0 GPa and 5.2 ± 0.2, respectively. Our result implies that magmas can contain up to 3.0–4.0 wt.% CO 2 to be denser than the surrounding mantle at the top of the 410 km discontinuity.