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Shock‐induced melting of MgSiO 3 perovskite and implications for melts in Earth's lowermost mantle
Author(s) -
Akins Joseph A.,
Luo ShengNian,
Asimow Paul D.,
Ahrens Thomas J.
Publication year - 2004
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 - 10.1029/2004gl020237
Subject(s) - enstatite , post perovskite , geology , mantle (geology) , partial melting , silicate , geophysics , equation of state , melting curve analysis , mineralogy , silicate perovskite , thermodynamics , meteorite , chondrite , astrobiology , physics , chemistry , polymerase chain reaction , biochemistry , astronomy , gene
New shock wave equation of state (EOS) data for enstatite and MgSiO 3 glass constrain the density change upon melting of Mg‐silicate perovskite up to 200 GPa. The melt becomes denser than perovskite near the base of Earth's lower mantle. This inference is confirmed by shock temperature data suggesting a negative pressure‐temperature slope along the melting curve at high pressure. Although melting of Earth's mantle involves multiple phases and chemical components, this implies that the partial melts invoked to explain anomalous seismic velocities in the lowermost mantle may be dynamically stable.