TY - JOUR
T1 - Density of high-Ti basalt magma at high pressure and origin of heterogeneities in the lunar mantle
AU - Sakamaki, Tatsuya
AU - Ohtani, Eiji
AU - Urakawa, Satoru
AU - Suzuki, Akio
AU - Katayama, Yoshinori
AU - Zhao, Dapeng
N1 - Funding Information:
We thank H. Terasaki and T. Sakai of Tohoku University for useful discussions on the manuscript. This work was supported by a Grant-in-Aid for Scientific Research to EO (no. 16340164 ) and SU ( 13440163 , 16340170 and 20103003 ) from the Ministry of Education, Culture, Sports, Science, and Technology of the Japanese Government . This work was also partially supported by the Global Center of Excellence program of Earth and Planetary Science, Tohoku University, Japan . TS was supported by a Research Fellowship of the Japan Society for the Promotion of Science for Young Scientists . The synchrotron radiation experiments were performed at the BL22XU line of the Japan Atomic Energy Agency (JAEA) SPring-8 facility under the Common-Use Facility Program of JAEA (proposal no. 2009B-E13).
PY - 2010/11/1
Y1 - 2010/11/1
N2 - The density of the Apollo 14 black glass melt, which has the highest TiO2 content of pristine mare glasses, was measured to 4.8GPa and 2100K using an X-ray absorption method. A fit of the pressure-density-temperature data to the high-temperature Birch-Murnaghan equation of state yielded the isothermal bulk modulus KT0=9.0±1.2GPa, its pressure derivative K0'=16.0±3.4, and the temperature derivative of the bulk modulus (∂KT/∂T)P=-0.0030±0.0008GPa/K at 1700K. The high-Ti basalt magma is less dense than the lunar mantle below about 1.0GPa. Therefore, the high-Ti basalt magma produced in the hybridized source (100-200km) can ascend to the lunar surface. The basalt formed at the higher pressure could not ascend but move downwards, and solidify in the lunar mantle. The solidified high-Ti basalt components can create chemical heterogeneities in the lunar mantle and can cause the low-velocity anomalies observed seismologically.
AB - The density of the Apollo 14 black glass melt, which has the highest TiO2 content of pristine mare glasses, was measured to 4.8GPa and 2100K using an X-ray absorption method. A fit of the pressure-density-temperature data to the high-temperature Birch-Murnaghan equation of state yielded the isothermal bulk modulus KT0=9.0±1.2GPa, its pressure derivative K0'=16.0±3.4, and the temperature derivative of the bulk modulus (∂KT/∂T)P=-0.0030±0.0008GPa/K at 1700K. The high-Ti basalt magma is less dense than the lunar mantle below about 1.0GPa. Therefore, the high-Ti basalt magma produced in the hybridized source (100-200km) can ascend to the lunar surface. The basalt formed at the higher pressure could not ascend but move downwards, and solidify in the lunar mantle. The solidified high-Ti basalt components can create chemical heterogeneities in the lunar mantle and can cause the low-velocity anomalies observed seismologically.
KW - Density
KW - Equation of state
KW - High pressure
KW - High-Ti basalt
KW - X-ray absorption method
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U2 - 10.1016/j.epsl.2010.09.007
DO - 10.1016/j.epsl.2010.09.007
M3 - Article
AN - SCOPUS:78049290298
SN - 0012-821X
VL - 299
SP - 285
EP - 289
JO - Earth and Planetary Sciences Letters
JF - Earth and Planetary Sciences Letters
IS - 3-4
ER -